"use strict"

// TODO: optional rule - force marches

// TODO: 6.2 - In Sieges, the attacker /may/ retreat or stay on siege.
// TODO: new combat deployment in round 2/3 if defenders are wiped out and reserves are coming?
//		see https://boardgamegeek.com/thread/423599/article/3731006
// TODO: sea move into attacked fortified port as defender responder? -- not besieged yet

exports.scenarios = [
	"Standard"
]

exports.roles = [
	"Franks",
	"Saracens",
]

const { CARDS, BLOCKS, TOWNS, PORTS, ROADS, SHIELDS, block_index, town_index } = require('./data')

const FRANKS = "Franks"
const SARACENS = "Saracens"
const OBSERVER = "Observer"
const BOTH = "Both"

const NOWHERE = 0
const DEAD = 1
const F_POOL = 2
const S_POOL = 3
const SEA = 4

const ENGLAND = 5
const FRANCE = 6
const GERMANIA = 7

const first_town = 5 // TODO: exclude staging areas? include sea?
const last_town = TOWNS.length - 1
const last_block = BLOCKS.length - 2 // assassins are not a real block

const ALEPPO = town_index["Aleppo"]
const ANTIOCH = town_index["Antioch"]
const DAMASCUS = town_index["Damascus"]
const MASYAF = town_index["Masyaf"]
const ST_SIMEON = town_index["St. Simeon"]
const TRIPOLI = town_index["Tripoli"]
const TYRE = town_index["Tyre"]

const NOBODY = -1
const ASSASSINS = block_index["Assassins"]
const RICHARD = block_index["Richard"]
const ROBERT = block_index["Robert"]
const CROSSBOWS = block_index["Crossbows"]
const SALADIN = block_index["Saladin"]
const AL_ADIL = block_index["Al Adil"]
const AL_AZIZ = block_index["Al Aziz"]
const AL_AFDAL = block_index["Al Afdal"]
const AL_ZAHIR = block_index["Al Zahir"]

const ENGLISH_CRUSADERS = [ RICHARD, ROBERT, CROSSBOWS ]
const GERMAN_CRUSADERS = [ "Barbarossa", "Frederik", "Leopold" ].map(name => block_index[name])
const FRENCH_CRUSADERS = [ "Philippe", "Hugues", "Fileps" ].map(name => block_index[name])
const SALADIN_FAMILY = [ SALADIN, AL_ADIL, AL_AZIZ, AL_AFDAL, AL_ZAHIR ]

const INTRIGUE = 3
const WINTER_CAMPAIGN = 6

const GERMAN_ROADS = [ ST_SIMEON, ANTIOCH, ALEPPO ]

const KINGDOMS = {
	Syria: SARACENS,
	Antioch: FRANKS,
	Tripoli: FRANKS,
	Jerusalem: FRANKS,
	Egypt: SARACENS,
}

const VICTORY_TOWNS = [
	town_index["Aleppo"],
	town_index["Damascus"],
	town_index["Egypt"],
	town_index["Antioch"],
	town_index["Tripoli"],
	town_index["Acre"],
	town_index["Jerusalem"]
]

// serif cirled numbers
const DIE_HIT = [ 0, '\u2776', '\u2777', '\u2778', '\u2779', '\u277A', '\u277B' ]
const DIE_MISS = [ 0, '\u2460', '\u2461', '\u2462', '\u2463', '\u2464', '\u2465' ]
const DIE_SELF = '\u2716'

const ATTACK_MARK = "*"
const RESERVE_MARK_1 = "\u2020"
const RESERVE_MARK_2 = "\u2021"

const block_seats = []
const block_seat_names = []
const block_seat_names_or = []

function list_seats(who) {
	if (block_type(who) === 'nomads')
		return [ block_home(who) ]
	let list = []
	for (let town = first_town; town <= last_town; ++town)
		if (set_has(SHIELDS[town], who))
			list.push(town)
	return list
}

for (let b = 0; b <= last_block; ++b) {
	block_seats[b] = list_seats(b)
	let names = block_seats[b].map(town_name)
	block_seat_names[b] = names.join(", ")
	block_seat_names_or[b] = join(names, "or")
}

let states = {}

let game = null

function random(n) {
	if (game.rng === 1)
		return Math.floor(((game.seed = game.seed * 48271 % 0x7fffffff) / 0x7fffffff) * n)
	return (game.seed = game.seed * 200105 % 34359738337) % n
}

function log(s) {
	game.log.push(s)
}

function logi(s) {
	game.log.push(">" + s)
}

function active_adjective() {
	return (game.active === FRANKS ? "Frank" : "Saracen")
}

function join(list, conj = "or") {
	if (list.length === 0) return ""
	if (list.length === 1) return list[0]
	if (list.length === 2) return `${list[0]} ${conj} ${list[1]}`
	return `${list.slice(0,-1).join(", ")}, ${conj} ${list[list.length-1]}`
}

function log_move_start(from) {
	game.move_buf = [ from ]
}

function log_move_continue(to, mark) {
	if (mark)
		game.move_buf.push("#" + to + mark)
	else
		game.move_buf.push(to)
}

function log_move_end() {
	if (game.move_buf && game.move_buf.length > 1)
		game.summary.push(game.move_buf)
	delete game.move_buf
}

function print_summary(text, skip_if_empty = false) {
	if (skip_if_empty && game.summary.length === 0) {
		delete game.summary
		return
	}

	let lines = game.summary.map(function (move) {
		let s = ""
		for (let i = 0; i < move.length; ++i) {
			let x = move[i]
			if (i > 0)
				s += " \u2192 "
			if (typeof x === 'number')
				s += "#" + x
			else
				s += x
		}
		return s
	}).sort()
	delete game.summary

	log(text)

	let last = lines[0]
	let n = 0
	for (let entry of lines) {
		if (entry !== last) {
			logi(n + " " + last)
			n = 0
		}
		++n
		last = entry
	}
	if (n > 0)
		logi(n + " " + last)
	else
		logi("nothing.")
}

const id_player = [ null, FRANKS, SARACENS ]

function player_id(p) {
	if (p === FRANKS) return 1
	if (p === SARACENS) return 2
	return 0
}

function enemy(p) {
	if (p === FRANKS) return SARACENS
	if (p === SARACENS) return FRANKS
	return null
}

function is_inactive_player(current) {
	return current === OBSERVER || (game.active !== current && game.active !== BOTH)
}

function is_winter() {
	return game.turn === 6
}

function remove_from_array(array, item) {
	let i = array.indexOf(item)
	if (i >= 0)
		array.splice(i, 1)
}

function gen_action_undo(view) {
	if (!view.actions)
		view.actions = {}
	if (game.undo && game.undo.length > 0)
		view.actions.undo = 1
	else
		view.actions.undo = 0
}

function gen_action(view, action, argument) {
	if (!view.actions)
		view.actions = {}
	if (argument !== undefined) {
		if (!(action in view.actions)) {
			view.actions[action] = [ argument ]
		} else {
			if (!view.actions[action].includes(argument))
				view.actions[action].push(argument)
		}
	} else {
		view.actions[action] = 1
	}
}

function roll_d6() {
	return random(6) + 1
}

function shuffle_deck() {
	let deck = []
	for (let c = 1; c <= 27; ++c)
		deck.push(c)
	return deck
}

function deal_cards(deck, n) {
	let hand = []
	for (let i = 0; i < n; ++i) {
		let k = random(deck.length)
		hand.push(deck[k])
		deck.splice(k, 1)
	}
	return hand
}

function select_random_block(where) {
	let list = []
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where)
			list.push(b)
	if (list.length === 0)
		return NOBODY
	return list[random(list.length)]
}

function select_random_enemy_block(where) {
	let list = []
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && block_owner(b) === enemy(game.active))
			list.push(b)
	if (list.length === 0)
		return NOBODY
	return list[random(list.length)]
}

function town_name(where) {
	return TOWNS[where].name
}

function block_name(who) {
	return BLOCKS[who].name
}

function block_type(who) {
	return BLOCKS[who].type
}

function block_home(who) {
	return BLOCKS[who].home
}

function is_home_seat(where, who) {
	if (block_type(who) === 'nomads')
		return where === block_home(who)
	if (set_has(SHIELDS[where], who))
		return true
	return false
}

function block_pool(who) {
	if (BLOCKS[who].owner === FRANKS)
		return F_POOL
	return S_POOL
}

function block_owner(who) {
	return BLOCKS[who].owner
}

function block_initiative(who) {
	return BLOCKS[who].initiative
}

function block_fire_power(who) {
	return BLOCKS[who].fire_power
}

function block_move(who) {
	return BLOCKS[who].move
}

function block_max_steps(who) {
	return BLOCKS[who].steps
}

function is_saladin_family(who) {
	return who === SALADIN || who === AL_ADIL || who === AL_AZIZ || who === AL_AFDAL || who === AL_ZAHIR
}

function is_english_crusader(who) {
	return who === RICHARD || who === ROBERT || who === CROSSBOWS
}

function are_crusaders_not_in_pool(crusaders) {
	for (let b of crusaders)
		if (game.location[b] === F_POOL)
			return false
	return true
}

function is_block_on_map(who) {
	let location = game.location[who]
	return location && location !== DEAD && location !== F_POOL && location !== S_POOL
}

function is_block_on_land(who) {
	let location = game.location[who]
	return location && location !== DEAD && location !== F_POOL && location !== S_POOL &&
		location !== ENGLAND && location !== FRANCE && location !== GERMANIA
}

function road_id(a, b) {
	return (a < b) ? a * 100 + b : b * 100 + a
}

function road_was_last_used_by_enemy(from, to) {
	return map_get(game.last_used, road_id(from, to)) === player_id(enemy(game.active))
}

function road_was_last_used_by_friendly(from, to) {
	return map_get(game.last_used, road_id(from, to)) === player_id(game.active)
}

function road_type(a, b) {
	return ROADS[road_id(a,b)]
}

function road_limit(a, b) {
	return map_get(game.road_limit, road_id(a,b), 0)
}

function set_road_limit(a, b, n) {
	map_set(game.road_limit, road_id(a,b), n)
}

function reset_road_limits() {
	game.road_limit.length = 0
}

function count_player(p, where) {
	let count = 0
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && block_owner(b) === p)
			++count
	return count
}

function count_friendly(where) {
	let p = game.active
	let count = 0
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && block_owner(b) === p)
			++count
	return count
}

function count_enemy(where) {
	let p = enemy(game.active)
	let count = 0
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && block_owner(b) === p)
			++count
	return count
}

function count_friendly_in_field(where) {
	let p = game.active
	let count = 0
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && block_owner(b) === p)
			if (!is_block_in_castle(b))
				++count
	return count
}

function count_enemy_in_field(where) {
	let p = enemy(game.active)
	let count = 0
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && block_owner(b) === p)
			if (!is_block_in_castle(b))
				++count
	return count
}

function count_friendly_in_field_excluding_reserves(where) {
	let p = game.active
	let count = 0
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && block_owner(b) === p)
			if (!is_block_in_castle(b) && !is_reserve(b))
				++count
	return count
}

function count_enemy_in_field_excluding_reserves(where) {
	let p = enemy(game.active)
	let count = 0
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && block_owner(b) === p)
			if (!is_block_in_castle(b) && !is_reserve(b))
				++count
	return count
}

function count_blocks_in_castle(where) {
	let n = 0
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && set_has(game.castle, b))
			++n
	return n
}

function count_enemy_in_field_and_reserve(where) {
	let n = 0
	for (let b = 0; b <= last_block; ++b)
		if (block_owner(b) !== game.active)
			if (game.location[b] === where && !set_has(game.castle, b))
				++n
	return n
}

function count_reserves(where) {
	let n = 0
	for (let b = 0; b <= last_block; ++b)
		if (block_owner(b) === game.active)
			if (game.location[b] === where && is_reserve(b))
				++n
	return n
}

function is_player_kingdom(p, where) {
	return KINGDOMS[TOWNS[where].region] === p
}

function is_friendly_kingdom(where) {
	return KINGDOMS[TOWNS[where].region] === game.active
}

function is_enemy_kingdom(where) {
	return KINGDOMS[TOWNS[where].region] !== game.active
}

/* Town queries include castle and field. */
function is_friendly_town(where) {
	return (count_enemy(where) === 0) && (count_friendly(where) > 0 || is_friendly_kingdom(where))
}
function is_enemy_town(where) {
	return (count_friendly(where) === 0) && (count_enemy(where) > 0 || is_enemy_kingdom(where))
}
function is_vacant_town(where) {
	return count_friendly(where) === 0 && count_enemy(where) === 0
}
function is_contested_town(where) {
	return count_friendly(where) > 0 && count_enemy(where) > 0
}
function is_enemy_occupied_town(where) {
	return count_enemy(where) > 0
}

/* Field queries exclude castles. */
function is_friendly_field(where) {
	return (count_enemy_in_field(where) === 0) && (count_friendly_in_field(where) > 0 || is_friendly_kingdom(where))
}
function is_enemy_field(where) {
	return (count_friendly_in_field(where) === 0) && (count_enemy_in_field(where) > 0 || is_enemy_kingdom(where))
}
function is_contested_field(where) {
	return count_friendly_in_field(where) > 0 && count_enemy_in_field(where) > 0
}
function is_friendly_or_vacant_field(where) {
	return is_friendly_field(where) || is_vacant_town(where)
}
function is_enemy_or_contested_field(where) {
	return (count_enemy_in_field(where) > 0 || is_enemy_kingdom(where))
}

/* Battle field queries exclude castles and reserves. */
function is_contested_battle_field() {
	let f = count_friendly_in_field_excluding_reserves(game.where)
	let e = count_enemy_in_field_excluding_reserves(game.where)
	return f > 0 && e > 0
}
function is_friendly_battle_field() {
	return count_enemy_in_field_excluding_reserves(game.where) === 0
}
function is_enemy_battle_field() {
	return count_friendly_in_field_excluding_reserves(game.where) === 0
}

function is_reserve(who) {
	return set_has(game.reserves1, who) || set_has(game.reserves2, who)
}

function is_field_attacker(who) {
	if (game.location[who] === game.where && block_owner(who) === game.attacker[game.where])
		return !is_reserve(who) && !is_block_in_castle(who)
	return false
}

function is_field_defender(who) {
	if (game.location[who] === game.where && block_owner(who) !== game.attacker[game.where])
		return !is_reserve(who) && !is_block_in_castle(who)
	return false
}

function is_field_combatant(who) {
	if (game.location[who] === game.where)
		return !is_reserve(who) && !is_block_in_castle(who)
	return false
}

function is_block_in_field(who) {
	return !is_reserve(who) && !is_block_in_castle(who)
}

function is_siege_attacker(who) {
	return set_has(game.storming, who)
}

function is_siege_defender(who) {
	return is_block_in_castle_in(who, game.where)
}

function is_siege_combatant(who) {
	return set_has(game.storming, who) || is_block_in_castle_in(who, game.where)
}

function castle_limit(where) {
	return TOWNS[where].rating
}

function is_more_room_in_castle(where) {
	return count_blocks_in_castle(where) < castle_limit(where)
}

function is_within_castle_limit(where) {
	return count_friendly(where) <= Math.max(1, castle_limit(where))
}

function is_castle_town(where) {
	return castle_limit(where) > 0
}

function is_under_siege(where) {
	return count_blocks_in_castle(where) > 0
}

function is_block_in_castle(b) {
	return set_has(game.castle, b)
}

function is_block_in_castle_in(b, town) {
	return game.location[b] === town && set_has(game.castle, b)
}

function besieged_player(where) {
	for (let b = 0; b <= last_block; ++b)
		if (is_block_in_castle_in(b, where))
			return block_owner(b)
	return null
}

function besieging_player(where) {
	return enemy(besieged_player(where))
}

function is_port(where) {
	return TOWNS[where].port
}

function is_friendly_port(where) {
	return TOWNS[where].port && is_friendly_field(where)
}

function can_activate(who) {
	return block_owner(who) === game.active &&
		is_block_on_map(who) &&
		!is_block_in_castle(who) &&
		!set_has(game.moved, who)
}

function can_activate_for_sea_move(who) {
	return block_owner(who) === game.active &&
		is_block_on_map(who) &&
		!set_has(game.moved, who)
}

function count_pinning(where) {
	return count_enemy_in_field_excluding_reserves(where)
}

function count_pinned(where) {
	let count = 0
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === where && block_owner(b) === game.active)
			if (!is_reserve(b))
				++count
	return count
}

function is_pinned(who, from) {
	if (game.active === game.p2) {
		if (count_pinned(from) <= count_pinning(from))
			return true
	}
	return false
}

function can_block_use_road(from, to) {
	if (game.active === game.guide) {
		switch (road_type(from, to)) {
		case 'iron-bridge':
			// https://boardgamegeek.com/thread/744750/20-rules-iron-bridge-question
			// fallthrough
		case 'major':
			return road_limit(from, to) < 8
		case 'minor':
			return road_limit(from, to) < 4
		}
	} else {
		switch (road_type(from, to)) {
		case 'iron-bridge':
			if (game.iron_bridge)
				return road_limit(from, to) < 3
			else
				return road_limit(from, to) < 4
		case 'major':
			return road_limit(from, to) < 4
		case 'minor':
			return road_limit(from, to) < 2
		}
	}
	return false
}

function can_block_land_move_to(who, from, to) {
	if (can_block_use_road(from, to)) {
		if (count_pinning(from) > 0)
			if (road_was_last_used_by_enemy(from, to))
				return false

		// cannot start or reinforce battles in winter
		if (is_winter() && is_enemy_occupied_town(to)) {
			// but can move through friendly sieges
			if (!is_friendly_field(to))
				return false
			if (game.distance + 1 >= block_move(who))
				return false
		}

		return true
	}
	return false
}

function can_germans_move(who) {
	let from = game.location[who]
	if (from === GERMANIA) {
		if (can_activate(who)) {
			for (let to of GERMAN_ROADS)
				if (can_germans_move_to(who, to))
					return true
		}
	}
	return false
}

function can_germans_move_to(who, to) {
	if (are_crusaders_not_in_pool(GERMAN_CRUSADERS)) {
		if (is_winter() && is_enemy_occupied_town(to))
			return false
		if (to === ALEPPO)
			return true
		if (to === ANTIOCH)
			return true
		if (to === ST_SIMEON)
			return road_limit(GERMANIA, ST_SIMEON) < 2
	}
	return false
}

function can_block_land_move(who) {
	if (can_activate(who)) {
		let from = game.location[who]
		if (from) {
			if (is_pinned(who, from))
				return false
			for (let to of TOWNS[from].exits)
				if (can_block_land_move_to(who, from, to))
					return true
		}
	}
	return false
}

function can_use_richards_sea_legs(who, to) {
	// English Crusaders may attack by sea.
	// If combined with another attack, the English must be the Main Attacker.
	if (is_english_crusader(who)) {
		if (is_enemy_or_contested_field(to)) {
			if (!game.attacker[to])
				return true
			if (game.attacker[to] === FRANKS)
				return (get_main_road(to) === ENGLAND)
		}
	}
	return false
}

function can_enter_besieged_port(where) {
	// Tripoli and Tyre are friendly to besieged defender!
	if (where === TRIPOLI || where === TYRE)
		if (besieged_player(where) === game.active)
			return count_blocks_in_castle(where) < castle_limit(where)
	return false
}

function can_leave_besieged_port(where) {
	// Tripoli and Tyre are friendly to besieged defender!
	if (where === TRIPOLI || where === TYRE)
		if (besieged_player(where) === game.active)
			return true
	return false
}

function can_block_sea_move_to(who, to) {
	if (is_port(to)) {
		// cannot start or reinforce battles in winter
		if (!is_winter()) {
			if (can_use_richards_sea_legs(who, to))
				return true
			if (can_enter_besieged_port(to))
				return true
		}
		return is_friendly_port(to)
	}
	return false
}

function can_block_sea_move_from(who, from) {
	if (is_friendly_port(from))
		return true
	if (can_leave_besieged_port(from))
		return true
	if (from === ENGLAND)
		return are_crusaders_not_in_pool(ENGLISH_CRUSADERS)
	if (from === FRANCE)
		return are_crusaders_not_in_pool(FRENCH_CRUSADERS)
	return false
}

function can_block_sea_move(who) {
	if (can_activate_for_sea_move(who)) {
		let from = game.location[who]
		if (can_block_sea_move_from(who, from)) {
			for (let to of PORTS)
				if (to !== from && can_block_sea_move_to(who, to))
					return true
		}
	}
	return false
}

function can_block_continue(who, from, to) {
	if (is_contested_field(to))
		return false
	if (game.distance >= block_move(who))
		return false
	return true
}

function can_block_retreat_to(who, to) {
	let from = game.location[who]
	if (block_owner(who) === game.attacker[from]) {
		if (!road_was_last_used_by_friendly(from, to))
			return false
	}
	if (is_friendly_field(to) || is_vacant_town(to)) {
		if (can_block_use_road(from, to)) {
			if (road_was_last_used_by_enemy(from, to))
				return false
			return true
		}
	}
	return false
}

function can_block_retreat(who) {
	if (block_owner(who) === game.active) {
		let from = game.location[who]
		for (let to of TOWNS[from].exits)
			if (can_block_retreat_to(who, to))
				return true
	}
	return false
}

function can_block_regroup_to(who, to) {
	// regroup during winter campaign
	if (is_winter() && is_enemy_occupied_town(to))
		return false
	if (is_friendly_field(to) || is_vacant_town(to)) {
		let from = game.location[who]
		if (can_block_use_road(from, to))
			return true
	}
	return false
}

function can_block_regroup(who) {
	if (block_owner(who) === game.active) {
		let from = game.location[who]
		for (let to of TOWNS[from].exits)
			if (can_block_regroup_to(who, to))
				return true
	}
	return false
}

function can_block_use_road_to_muster(from, to) {
	return can_block_use_road(from, to) && is_friendly_or_vacant_field(to)
}

function can_block_muster_with_3_moves(n0, muster) {
	for (let n1 of TOWNS[n0].exits) {
		if (can_block_use_road_to_muster(n0, n1)) {
			if (n1 === muster)
				return true
			for (let n2 of TOWNS[n1].exits) {
				if (n2 === n0) continue // don't backtrack!
				if (can_block_use_road_to_muster(n1, n2)) {
					if (n2 === muster)
						return true
					if (set_has(TOWNS[n2].exits, muster))
						if (can_block_use_road_to_muster(n2, muster))
							return true
				}
			}
		}
	}
	return false
}

function can_block_muster_with_2_moves(n0, muster, avoid) {
	for (let n1 of TOWNS[n0].exits) {
		if (n1 === avoid)
			continue
		if (can_block_use_road_to_muster(n0, n1)) {
			if (n1 === muster)
				return true
			if (set_has(TOWNS[n1].exits, muster))
				if (can_block_use_road_to_muster(n1, muster))
					return true
		}
	}
	return false
}

function can_block_muster_with_1_move(n0, muster) {
	if (set_has(TOWNS[n0].exits, muster))
		return can_block_use_road_to_muster(n0, muster)
	return false
}

function can_block_muster(who, muster) {
	let from = game.location[who]
	if (from === muster)
		return false
	if (can_activate(who)) {
		if (is_pinned(who, from))
			return false
		if (block_move(who) === 3)
			return can_block_muster_with_3_moves(from, muster)
		else
			return can_block_muster_with_2_moves(from, muster, NOWHERE)
	}
	return false
}

function can_muster_to(muster) {
	for (let b = 0; b <= last_block; ++b)
		if (can_block_muster(b, muster))
			return true
	return false
}

function can_muster_anywhere() {
	for (let where = first_town; where <= last_town; ++where)
		if (is_friendly_field(where))
			if (can_muster_to(where))
				return true
	return false
}

function lift_siege(where) {
	if (is_under_siege(where) && !is_contested_town(where)) {
		log("Siege lifted at #" + where + ".")
		for (let b = 0; b <= last_block; ++b)
			if (is_block_in_castle_in(b, where))
				set_delete(game.castle, b)
	}
}

function lift_all_sieges() {
	for (let town = first_town; town <= last_town; ++town)
		lift_siege(town)
}

function reset_blocks() {
	for (let b = 0; b <= last_block; ++b) {
		game.location[b] = NOWHERE
		game.steps[b] = block_max_steps(b)
	}
}

function deploy(who, where) {
	game.location[who] = where
	game.steps[who] = block_max_steps(who)
}

function disband(who) {
	game.summary.push([game.location[who]])
	if (is_saladin_family(who) || block_type(who) === 'crusaders' || block_type(who) === 'military_orders')
		game.location[who] = NOWHERE // permanently eliminated
	else
		game.location[who] = DEAD // into to the pool next year
	game.steps[who] = block_max_steps(who)
}

function eliminate_block(who) {
	set_delete(game.castle, who)
	if (game.sallying) set_delete(game.sallying, who)
	if (game.storming) set_delete(game.storming, who)
	log(block_name(who) + " was eliminated.")
	if (is_saladin_family(who) || block_type(who) === 'crusaders' || block_type(who) === 'military_orders')
		game.location[who] = NOWHERE // permanently eliminated
	else
		game.location[who] = DEAD // into to the pool next year
	game.steps[who] = block_max_steps(who)
}

function reduce_block(who) {
	if (game.steps[who] === 1) {
		eliminate_block(who)
	} else {
		--game.steps[who]
	}
}

// DEPLOYMENT

function is_valid_frank_deployment() {
	let errors = []
	for (let town = first_town; town <= last_town; ++town)
		if (!is_within_castle_limit(town))
			errors.push(TOWNS[town].name)
	return errors
}

function goto_frank_deployment() {
	game.active = FRANKS
	game.state = 'frank_deployment'
}

states.frank_deployment = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Deployment: Waiting for " + game.active + "."
		gen_action_undo(view)
		let errors = is_valid_frank_deployment()
		if (errors.length === 0)
			gen_action(view, 'next')
		for (let b = 0; b <= last_block; ++b) {
			if (block_owner(b) === game.active && is_block_on_land(b))
				if (block_seats[b].length > 1)
					gen_action(view, 'block', b)
		}
		if (errors.length > 0)
			view.prompt = "Deployment: Too many blocks in " + join(errors, "and") + "."
		else
			view.prompt = "Deployment: You may make seat adjustments."
	},
	block: function (who) {
		push_undo()
		game.who = who
		game.state = 'frank_deployment_to'
	},
	next: function () {
		clear_undo()
		goto_saracen_deployment()
	},
	undo: pop_undo
}

states.frank_deployment_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Deployment: Waiting for " + game.active + "."
		view.prompt = "Deployment: Move " + block_name(game.who) + " to " + block_seat_names_or[game.who] + "."
		gen_action_undo(view)
		gen_action(view, 'block', game.who)
		let from = game.location[game.who]
		for (let town of block_seats[game.who])
			if (town !== from)
				gen_action(view, 'town', town)
	},
	town: function (where) {
		game.location[game.who] = where
		game.who = NOBODY
		game.state = 'frank_deployment'
	},
	block: pop_undo,
	undo: pop_undo
}

function goto_saracen_deployment() {
	for (let i = 0; i < 4; ++i) {
		let nomad = select_random_block(S_POOL)
		log(BLOCKS[nomad].name + " arrived in #" + block_home(nomad) + ".")
		deploy(nomad, block_home(nomad))
	}
	game.active = SARACENS
	game.state = 'saracen_deployment'
	game.who = SALADIN
}

states.saracen_deployment = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Deployment: Waiting for " + game.active + "."
		view.prompt = "Deployment: You may swap places with Saladin and any other block of his family."
		gen_action(view, 'next')
		gen_action_undo(view)
		if (game.location[SALADIN] === DAMASCUS) {
			for (let b of SALADIN_FAMILY)
				if (b !== SALADIN && game.location[b] !== game.location[SALADIN])
					gen_action(view, 'block', b)
		}
	},
	block: function (who) {
		push_undo()
		let saladin = game.location[SALADIN]
		game.location[SALADIN] = game.location[who]
		game.location[who] = saladin
		game.who = NOBODY
	},
	next: function () {
		clear_undo()
		game.who = NOBODY
		start_year()
	},
	undo: pop_undo
}

// GAME TURN

function is_friendly_town_for_player(p, where) {
	return (count_player(enemy(p), where) === 0) && (count_player(p, where) > 0 || is_player_kingdom(p, where))
}

function is_friendly_town_for_vp(p, town) {
	if (is_friendly_town_for_player(p, town))
		return true
	if (is_under_siege(town))
		return besieged_player(town) === p
	return false
}

function count_victory_points(p) {
	let vp = 0
	for (let town of VICTORY_TOWNS)
		if (is_friendly_town_for_vp(p, town))
			++ vp
	return vp
}

function check_sudden_death() {
	if (count_victory_points(FRANKS) === 7) {
		game.state = 'game_over'
		game.result = FRANKS
		game.victory = "Franks controlled all seven victory cities."
		log("")
		log(game.victory)
		return true
	}
	if (count_victory_points(SARACENS) === 7) {
		game.state = 'game_over'
		game.result = SARACENS
		game.victory = "Saracens controlled all seven victory cities."
		log("")
		log(game.victory)
		return true
	}
}

function start_year() {
	log("")
	log(".h1 Year " + game.year)

	game.turn = 1

	let deck = shuffle_deck()
	game.f_hand = deal_cards(deck, 6)
	game.s_hand = deal_cards(deck, 6)
	game.prior_f_card = 0
	game.prior_s_card = 0

	start_game_turn()
}

function start_game_turn() {
	log("")
	log(".h1 Turn " + game.turn + " of Year " + game.year)

	game.guide = null
	game.jihad = null

	// Reset movement and attack tracking state
	reset_road_limits()
	game.last_used = []
	game.attacker = {}
	set_clear(game.reserves1)
	set_clear(game.reserves2)
	set_clear(game.moved)

	goto_card_phase()
}

// CARD PHASE

function goto_card_phase() {
	game.f_card = 0
	game.s_card = 0
	game.show_cards = false
	game.state = 'play_card'
	game.active = BOTH
}

function resume_play_card() {
	if (game.s_card && game.f_card)
		reveal_cards()
	else if (game.f_card)
		game.active = SARACENS
	else if (game.s_card)
		game.active = FRANKS
	else
		game.active = BOTH
}

states.play_card = {
	prompt: function (view, current) {
		if (current === OBSERVER) {
			view.prior_s_card = game.prior_s_card
			view.prior_f_card = game.prior_f_card
			return view.prompt = "Card Phase: Waiting for players to play a card."
		}
		if (current === FRANKS) {
			view.prior_s_card = game.prior_s_card
			if (game.f_card) {
				view.prompt = "Card Phase: Waiting for Saracens to play a card."
			} else {
				view.prior_f_card = game.prior_f_card
				view.prompt = "Card Phase: Play a card."
				for (let c of game.f_hand)
					if (game.turn > 1 || c !== INTRIGUE)
						gen_action(view, 'play', c)
			}
		}
		if (current === SARACENS) {
			view.prior_f_card = game.prior_f_card
			if (game.s_card) {
				view.prompt = "Card Phase: Waiting for Franks to play a card."
			} else {
				view.prior_s_card = game.prior_s_card
				view.prompt = "Card Phase: Play a card."
				for (let c of game.s_hand)
					if (game.turn > 1 || c !== INTRIGUE)
						gen_action(view, 'play', c)
			}
		}
	},
	play: function (card, current) {
		if (current === FRANKS) {
			remove_from_array(game.f_hand, card)
			game.f_card = card
		}
		if (current === SARACENS) {
			remove_from_array(game.s_hand, card)
			game.s_card = card
		}
		resume_play_card()
	},
	undo: function (_, current) {
		if (current === FRANKS) {
			game.f_hand.push(game.f_card)
			game.f_card = 0
		}
		if (current === SARACENS) {
			game.s_hand.push(game.s_card)
			game.s_card = 0
		}
		resume_play_card()
	}
}

function reveal_cards() {
	log("")
	log("Franks played " + CARDS[game.f_card].name + ".")
	log("Saracens played " + CARDS[game.s_card].name + ".")
	game.show_cards = true

	if (CARDS[game.f_card].event && CARDS[game.s_card].event) {
		log("Game Turn cancelled.")
		game.prior_f_card = game.f_card
		game.prior_s_card = game.s_card
		end_game_turn()
		return
	}

	if (game.f_card === INTRIGUE) {
		game.f_card = game.prior_s_card
		log("Intrigue copied " + CARDS[game.f_card].name + ".")
	}
	if (game.s_card === INTRIGUE) {
		game.s_card = game.prior_f_card
		log("Intrigue copied " + CARDS[game.s_card].name + ".")
	}

	delete game.winter_campaign
	if (is_winter()) {
		if (game.f_card === WINTER_CAMPAIGN)
			game.winter_campaign = FRANKS
		if (game.s_card === WINTER_CAMPAIGN)
			game.winter_campaign = SARACENS
	}

	game.prior_f_card = game.f_card
	game.prior_s_card = game.s_card

	let fp = CARDS[game.f_card].event ? 10 : CARDS[game.f_card].moves
	let sp = CARDS[game.s_card].event ? 10 : CARDS[game.s_card].moves

	if (fp === sp) {
		let die = roll_d6()
		log("Random first player.")
		if (die > 3)
			++fp
		else
			++sp
	}

	if (fp > sp) {
		game.p1 = FRANKS
		game.p2 = SARACENS
	} else {
		game.p1 = SARACENS
		game.p2 = FRANKS
	}

	game.active = game.p1
	start_player_turn()
}

function start_player_turn() {
	log("")
	log(".h2 " + game.active)
	reset_road_limits()
	game.main_road = []
	let card = CARDS[game.active === FRANKS ? game.f_card : game.s_card]
	if (card.event)
		goto_event_card(card.event)
	else
		goto_move_phase(card.moves)
}

function end_player_turn() {
	game.moves = 0
	game.main_road = null

	if (game.active === game.p2) {
		goto_combat_phase()
	} else {
		game.active = game.p2
		start_player_turn()
	}
}

// EVENTS

function goto_event_card(event) {
	switch (event) {
	case 'assassins': goto_assassins(); break
	case 'guide': goto_guide(); break
	case 'jihad': goto_jihad(); break
	case 'manna': goto_manna(); break
	}
}

function goto_assassins() {
	game.state = 'assassins'
	game.who = ASSASSINS
	game.assassins = 1
}

states.assassins = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Assassins: Waiting for " + game.active + "."
		view.prompt = "Assassins: Choose one enemy block."
		for (let b = 0; b <= last_block; ++b) {
			if (is_block_on_land(b) && block_owner(b) === enemy(game.active))
				gen_action(view, 'block', b)
		}
	},
	block: function (who) {
		game.where = game.location[who]
		game.who = select_random_enemy_block(game.where)
		game.location[ASSASSINS] = game.where
		game.state = 'assassins_show_1'
	},
}

states.assassins_show_1 = {
	prompt: function (view, current) {
		view.assassinate = game.who
		view.who = ASSASSINS
		if (is_inactive_player(current))
			return view.prompt = "Assassins: Waiting for " + game.active + "."
		view.prompt = "Assassins: The assassins target " + block_name(game.who) + " in " + town_name(game.where) + "."
		gen_action(view, 'next')
		gen_action(view, 'block', game.who)
		gen_action(view, 'block', ASSASSINS)
	},
	next: assassins_next_1,
	block: assassins_next_1,
}

function assassins_next_1() {
	assassinate(game.who, game.where)
	game.state = 'assassins_show_2'
}

states.assassins_show_2 = {
	prompt: function (view, current) {
		view.assassinate = game.who
		view.who = ASSASSINS
		if (is_inactive_player(current))
			return view.prompt = "Assassins: Waiting for " + game.active + "."
		view.prompt = "Assassins: The assassins hit " + block_name(game.who) + " in " + town_name(game.where) + "."
		gen_action(view, 'next')
		gen_action(view, 'block', ASSASSINS)
		gen_action(view, 'town', MASYAF)
	},
	next: assassins_next_2,
	block: assassins_next_2,
	town: assassins_next_2,
}

function assassins_next_2() {
	game.location[ASSASSINS] = MASYAF
	game.who = NOBODY
	if (count_friendly(game.where) > 0 && count_enemy(game.where) === 0) {
		goto_regroup()
	} else {
		delete game.assassins
		game.where = NOWHERE
		end_player_turn()
	}
}

function assassinate(who, where) {
	let hits = 0
	let rolls = []
	for (let i = 0; i < 3; ++i) {
		let die = roll_d6()
		if (die <= 3) {
			rolls.push(DIE_HIT[die])
			++hits
		} else {
			rolls.push(DIE_MISS[die])
		}
	}
	hits = Math.min(hits, game.steps[who])
	log("Assassins hit " + block_name(who) + " at #" + where + ": " + rolls.join("") + ".")
	for (let i = 0; i < hits; ++i)
		reduce_block(who)
}

function goto_guide() {
	game.guide = game.active
	game.state = 'move_phase_event'
	game.summary = []
}

function goto_jihad() {
	game.jihad = game.active
	game.state = 'move_phase_event'
	game.summary = []
}

function goto_select_jihad() {
	game.jihad_list = []
	for (let where = first_town; where <= last_town; ++where)
		if (is_contested_field(where) || besieging_player(where) === game.active)
			game.jihad_list.push(where)
	if (game.jihad_list.length === 0) {
		delete game.jihad_list
		return end_player_turn()
	}
	if (game.jihad_list.length === 1) {
		game.jihad = game.jihad_list[0]
		log("Jihad in #" + game.jihad + ".")
		delete game.jihad_list
		return end_player_turn()
	}
	game.state = 'select_jihad'
}

states.select_jihad = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Jihad: Waiting for " + game.active + "."
		view.prompt = "Jihad: Select battle for Jihad."
		for (let town of game.jihad_list)
			gen_action(view, 'town', town)
	},
	town: function (where) {
		game.jihad = where
		log("Jihad in #" + game.jihad + ".")
		delete game.jihad_list
		end_player_turn()
	},
}

function goto_manna() {
	game.state = 'manna'
	game.moves = 3
	set_clear(game.moved)
	game.summary = []
}

states.manna = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Manna: Waiting for " + game.active + "."
		view.prompt = "Manna: Add one step to three different friendly blocks \u2014 " + game.moves + " left."
		gen_action_undo(view)
		gen_action(view, 'next')
		if (game.moves > 0) {
			for (let b = 0; b <= last_block; ++b) {
				if (is_block_on_land(b) && block_owner(b) === game.active && !set_has(game.moved, b))
					if (game.steps[b] < block_max_steps(b))
						gen_action(view, 'block', b)
			}
		}
	},
	block: function (who) {
		push_undo()
		game.summary.push([game.location[who]])
		++game.steps[who]
		--game.moves
		set_add(game.moved, who)
	},
	next: function () {
		clear_undo()
		print_summary(game.active + " used Manna:")
		set_clear(game.moved)
		end_player_turn()
	},
	undo: pop_undo
}

// MOVE PHASE

function queue_attack(who, round) {
	if (round === 1)
		return ATTACK_MARK
	if (round === 2) {
		set_add(game.reserves1, who)
		return RESERVE_MARK_1
	}
	if (round === 3) {
		set_add(game.reserves2, who)
		return RESERVE_MARK_2
	}
}

function get_main_road(to) {
	return map_get(game.main_road, to, NOWHERE)
}

function set_main_road(to, x) {
	map_set(game.main_road, to, x)
}

function move_block(who, from, to) {
	game.location[who] = to
	set_road_limit(from, to, road_limit(from, to) + 1)
	game.distance ++
	if (is_contested_field(to)) {
		map_set(game.last_used, road_id(from, to), player_id(game.active))

		// 6.56 Main Attack relief force by Player 2 arrives one round later than normal
		let relief_delay = 0
		if (game.active === game.p2 && besieged_player(to) === game.p2) {
			relief_delay = 1
		}

		if (!game.attacker[to]) {
			game.attacker[to] = game.active
			set_main_road(to, from)
			return queue_attack(who, 1 + relief_delay)
		} else {
			// Attacker main attack or reinforcements
			if (game.attacker[to] === game.active) {
				if (get_main_road(to) !== from)
					return queue_attack(who, 2 + relief_delay)
				return queue_attack(who, 1 + relief_delay)
			}

			// Defender reinforcements
			if (!get_main_road(to))
				set_main_road(to, from)

			if (get_main_road(to) === from) {
				return queue_attack(who, 2)
			} else {
				return queue_attack(who, 3)
			}
		}
	}
	return false
}

function goto_move_phase(moves) {
	game.state = 'move_phase'
	game.moves = moves
}

function end_move_phase() {
	if (game.moves > 0) {
		push_undo()
		game.state = 'confirm_end_move_phase'
		return
	}

	clear_undo()
	game.who = NOBODY
	game.where = NOWHERE
	game.moves = 0

	// declined to use winter campaign
	if (game.winter_campaign === game.active)
		delete game.winter_campaign

	if (game.active === game.jihad)
		goto_select_jihad()
	else
		end_player_turn()
}

states.confirm_end_move_phase = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		if (game.moves > 1)
			view.prompt = "Move Phase: You have " + game.moves + " moves left"
		else
			view.prompt = "Move Phase: You have 1 move left"
		view.prompt += " \u2014 are you sure you want to end the move phase?"
		gen_action_undo(view)
		gen_action(view, 'end_move_phase')
	},
	end_move_phase: function () {
		if (game.moves === 1)
			log(game.active + " did nothing with " + game.moves + " move.")
		else
			log(game.active + " did nothing with " + game.moves + " moves.")
		game.moves = 0
		end_move_phase()
	},
	undo: pop_undo
}

states.move_phase = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		if (game.moves === 0)
			view.prompt = "Move Phase: No moves left."
		else if (game.moves === 1)
			view.prompt = "Move Phase: 1 move left."
		else
			view.prompt = "Move Phase: " + game.moves + " moves left."
		gen_action_undo(view)
		gen_action(view, 'end_move_phase')
		if (game.moves > 0) {
			for (let b = 0; b <= last_block; ++b) {
				if (can_block_land_move(b))
					gen_action(view, 'block', b)
				if (can_block_sea_move(b))
					gen_action(view, 'block', b)
				if (can_germans_move(b))
					gen_action(view, 'block', b)
			}
			if (can_muster_anywhere())
				gen_action(view, 'muster')
			if (game.winter_campaign === game.active)
				gen_action(view, 'winter_campaign')
		}
	},
	winter_campaign: function () {
		push_undo()
		--game.moves
		game.state = 'winter_campaign'
	},
	muster: function () {
		push_undo()
		--game.moves
		game.state = 'muster'
	},
	block: function (who) {
		push_undo()
		game.summary = []
		game.who = who
		game.where = game.location[who]
		if (game.where === GERMANIA) {
			game.state = 'german_move_to'
		} else if (game.where === FRANCE || game.where === ENGLAND) {
			game.state = 'sea_move_to'
		} else {
			game.state = 'move_phase_to'
		}
	},
	end_move_phase: end_move_phase,
	undo: pop_undo
}

states.move_phase_event = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = group_move_name(1) + "Waiting for " + game.active + "."
		view.prompt = group_move_name(0) + "Choose a block to group move."
		gen_action_undo(view)
		gen_action(view, 'end_move_phase')
		// TODO: can_germans_move!
		for (let b = 0; b <= last_block; ++b)
			if (can_block_land_move(b))
				gen_action(view, 'block', b)
	},
	block: function (who) {
		push_undo()
		game.where = game.location[who]
		game.who = who
		game.distance = 0
		game.last_from = NOWHERE
		game.state = 'group_move_to'
	},
	end_move_phase: end_move_phase,
	undo: pop_undo
}

// Start new group move or sea move.
states.move_phase_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		view.prompt = "Move Phase: Move " + block_name(game.who)
		gen_action_undo(view)
		gen_action(view, 'block', game.who)
		let from = game.location[game.who]
		let can_group_move = false
		let can_sea_move = false
		if (can_block_land_move(game.who)) {
			for (let to of TOWNS[from].exits) {
				if (can_block_land_move_to(game.who, from, to)) {
					gen_action(view, 'town', to)
					can_group_move = true
				}
			}
		}
		if (can_block_sea_move(game.who)) {
			gen_action(view, 'town', SEA)
			can_sea_move = true
		}
		if (can_group_move && can_sea_move)
			view.prompt += " by road or by sea."
		else if (can_sea_move)
			view.prompt += " by sea."
		else
			view.prompt += " by road."
	},
	town: function (to) {
		set_add(game.moved, game.who)
		let from = game.location[game.who]
		if (to === SEA) {
			log_move_start(from)
			log_move_continue(to)
			game.location[game.who] = SEA
			game.state = 'sea_move_to'
			return
		}
		-- game.moves
		game.distance = 0
		log_move_start(from)
		let mark = move_block(game.who, from, to)
		if (mark)
			log_move_continue(to, mark)
		else
			log_move_continue(to)
		lift_siege(from)
		game.last_from = from
		if (!can_block_continue(game.who, from, to))
			end_move()
		else {
			game.state = 'group_move_to'
		}
	},
	block: pop_undo,
	undo: pop_undo
}

// GROUP MOVE

function group_move_name() {
	if (game.active === game.jihad) return "Jihad: "
	if (game.active === game.guide) return "Guide: "
	return "Group Move: "
}

function can_group_move_more() {
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === game.where)
			if (can_block_land_move(b))
				return true
	return false
}

states.group_move_who = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = group_move_name(1) + "Waiting for " + game.active + "."
		view.prompt = group_move_name(0) + "Move blocks from " + town_name(game.where) + "."
		gen_action_undo(view)
		if (game.active === game.guide || game.active === game.jihad)
			gen_action(view, 'end_move_phase')
		else
			gen_action(view, 'end_group_move')
		for (let b = 0; b <= last_block; ++b)
			if (game.location[b] === game.where)
				if (can_block_land_move(b))
					gen_action(view, 'block', b)
	},
	block: function (who) {
		push_undo()
		game.who = who
		game.distance = 0
		game.last_from = NOWHERE
		game.state = 'group_move_to'
	},
	end_move_phase: function () {
		end_group_move()
		end_move_phase()
	},
	end_group_move: end_group_move,
	undo: pop_undo
}

states.group_move_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = group_move_name(1) + "Waiting for " + game.active + "."
		view.prompt = group_move_name(0) + "Move " + block_name(game.who) + "."
		gen_action_undo(view)
		if (game.distance === 0)
			gen_action(view, 'block', game.who)
		let from = game.location[game.who]
		if (game.distance > 0) {
			// cannot start or reinforce battles in winter
			if (!(is_winter() && is_enemy_occupied_town(from)))
				gen_action(view, 'town', from)
		}
		for (let to of TOWNS[from].exits) {
			if (to !== game.last_from && can_block_land_move_to(game.who, from, to)) {
				gen_action(view, 'town', to)
			}
		}
	},
	town: function (to) {
		set_add(game.moved, game.who)
		let from = game.location[game.who]
		if (to === from) {
			end_move()
			return
		}
		if (game.distance === 0)
			log_move_start(from)
		let mark = move_block(game.who, from, to)
		if (mark)
			log_move_continue(to, mark)
		else
			log_move_continue(to)
		lift_siege(from)
		game.last_from = from
		if (!can_block_continue(game.who, from, to))
			end_move()
	},
	block: pop_undo,
	undo: pop_undo
}

function end_move() {
	log_move_end()
	game.who = NOBODY
	game.distance = 0
	if (can_group_move_more())
		game.state = 'group_move_who'
	else
		end_group_move()
}

function end_group_move() {
	print_summary(game.active + " activated #" + game.where + ":")
	game.state = 'move_phase'
}

// SEA MOVE

states.german_move_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		view.prompt = "Move Phase: Move " + block_name(game.who) + " to Aleppo, Antioch, or St. Simeon."
		gen_action_undo(view)
		gen_action(view, 'block', game.who)
		for (let to of GERMAN_ROADS)
			if (can_germans_move_to(game.who, to))
				gen_action(view, 'town', to)
	},
	town: function (to) {
		--game.moves
		let from = GERMANIA
		game.location[game.who] = to
		set_add(game.moved, game.who)
		game.distance = 0
		let mark = move_block(game.who, from, to)
		if (mark)
			log(game.active + " moved:\n Germania \u2192 #" + to + mark + ".")
		else
			log(game.active + " moved:\n Germania \u2192 #" + to + ".")
		game.who = NOBODY
		game.state = 'move_phase'
	},
	block: pop_undo,
	undo: pop_undo,
}

states.sea_move_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		if (is_english_crusader(game.who))
			view.prompt = "Sea Move: Move " + block_name(game.who) + " to a port."
		else
			view.prompt = "Sea Move: Move " + block_name(game.who) + " to a friendly port."
		gen_action_undo(view)
		gen_action(view, 'block', game.who)
		let from = game.location[game.who]
		if (from === GERMANIA) {
			for (let to of GERMAN_ROADS)
				if (can_germans_move_to(game.who, to))
					gen_action(view, 'town', to)
		} else {
			for (let to of PORTS)
				if (to !== game.where && can_block_sea_move_to(game.who, to))
					gen_action(view, 'town', to)
		}
	},
	town: function (to) {
		--game.moves

		let from = game.where
		game.location[game.who] = to
		set_add(game.moved, game.who)

		lift_siege(from)

		set_delete(game.castle, game.who)

		if ((to === TYRE || to === TRIPOLI) && besieged_player(to) === game.active && is_more_room_in_castle(to)) {
			// Move into besieged fortified port
			set_add(game.castle, game.who)
			log(game.active + " sea moved:")
			logi("#" + from + " \u2192 #" + to + " castle.")

		} else if (!is_friendly_port(to)) {
			// English Crusaders attack!
			game.attacker[to] = FRANKS
			set_main_road(to, ENGLAND)
			log(game.active + " sea moved:")
			logi("#" + from + " \u2192 #" + to + ATTACK_MARK + ".")

		} else {
			// Normal move.
			log(game.active + " sea moved:")
			logi("#" + from + " \u2192 #" + to + ".")
		}

		game.who = NOBODY
		game.state = 'move_phase'
	},
	block: pop_undo,
	undo: pop_undo,
}

// MUSTER

states.muster = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		view.prompt = "Muster: Choose a friendly muster town."
		gen_action_undo(view)
		for (let where = first_town; where <= last_town; ++where) {
			// cannot start or reinforce battles in winter
			if (is_winter()) {
				if (is_friendly_town(where))
					if (can_muster_to(where))
						gen_action(view, 'town', where)
			} else {
				if (is_friendly_field(where))
					if (can_muster_to(where))
						gen_action(view, 'town', where)
			}
		}
	},
	town: function (where) {
		push_undo()
		game.where = where
		game.state = 'muster_who'
		game.summary = []
	},
	undo: pop_undo,
}

states.muster_who = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		view.prompt = "Muster: Move blocks to " + town_name(game.where) + "."
		view.muster = game.where
		gen_action_undo(view)
		gen_action(view, 'end_muster')
		for (let b = 0; b <= last_block; ++b)
			if (can_block_muster(b, game.where))
				gen_action(view, 'block', b)
	},
	block: function (who) {
		push_undo()
		game.who = who
		game.state = 'muster_move_1'
	},
	end_muster: function () {
		print_summary(game.active + " mustered to #" + game.where + ":")
		game.where = NOWHERE
		game.state = 'move_phase'
	},
	undo: pop_undo,
}

states.muster_move_1 = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		view.prompt = "Muster: Move " + block_name(game.who) + " to " + town_name(game.where) + "."
		view.muster = game.where
		gen_action_undo(view)
		gen_action(view, 'block', game.who)
		let from = game.location[game.who]
		let muster = game.where
		if (block_move(game.who) === 3) {
			for (let to of TOWNS[from].exits) {
				if (can_block_use_road_to_muster(from, to)) {
					if (to === muster || can_block_muster_with_2_moves(to, muster, from))
						gen_action(view, 'town', to)
				}
			}
		} else {
			for (let to of TOWNS[from].exits) {
				if (can_block_use_road_to_muster(from, to)) {
					if (to === muster || can_block_muster_with_1_move(to, muster))
						gen_action(view, 'town', to)
				}
			}
		}
	},
	town: function (to) {
		let from = game.location[game.who]
		set_add(game.moved, game.who)
		log_move_start(from)
		log_move_continue(to)
		move_block(game.who, from, to)
		lift_siege(from)
		if (to === game.where) {
			end_muster_move()
		} else {
			game.state = 'muster_move_2'
		}
	},
	block: pop_undo,
	undo: pop_undo,
}

states.muster_move_2 = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		view.prompt = "Muster: Move " + block_name(game.who) + " to " + town_name(game.where) + "."
		view.muster = game.where
		gen_action_undo(view)
		let from = game.location[game.who]
		let muster = game.where
		if (block_move(game.who) === 3) {
			for (let to of TOWNS[from].exits) {
				if (can_block_use_road_to_muster(from, to)) {
					if (to === muster || can_block_muster_with_1_move(to, muster))
						gen_action(view, 'town', to)
				}
			}
		} else {
			for (let to of TOWNS[from].exits) {
				if (can_block_use_road_to_muster(from, to)) {
					if (to === muster)
						gen_action(view, 'town', to)
				}
			}
		}
	},
	town: function (to) {
		let from = game.location[game.who]
		log_move_continue(to)
		move_block(game.who, from, to)
		if (to === game.where) {
			end_muster_move()
		} else {
			game.state = 'muster_move_3'
		}
	},
	undo: pop_undo,
}

states.muster_move_3 = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		view.prompt = "Muster: Move " + block_name(game.who) + " to " + town_name(game.where) + "."
		view.muster = game.where
		gen_action_undo(view)
		let from = game.location[game.who]
		let muster = game.where
		for (let to of TOWNS[from].exits) {
			if (can_block_use_road_to_muster(from, to)) {
				if (to === muster)
					gen_action(view, 'town', to)
			}
		}
	},
	town: function (to) {
		let from = game.location[game.who]
		log_move_continue(to)
		move_block(game.who, from, to)
		end_muster_move()
	},
	undo: pop_undo,
}

function end_muster_move() {
	log_move_end()
	game.who = NOBODY
	game.state = 'muster_who'
}

// WINTER CAMPAIGN

states.winter_campaign = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Move Phase: Waiting for " + game.active + "."
		view.prompt = "Winter Campaign: Select a siege to maintain over the winter."
		gen_action_undo(view)
		for (let town = first_town; town <= last_town; ++town)
			if (is_friendly_field(town) && is_under_siege(town))
				gen_action(view, 'town', town)
	},
	town: function (where) {
		log(game.active + " winter campaigned at #" + where + ".")
		game.winter_campaign = where
		game.state = 'move_phase'
	},
	undo: pop_undo
}

// COMBAT PHASE

function goto_combat_phase() {
	if (is_winter()) {
		set_clear(game.moved)
		return end_game_turn()
	}

	game.combat_list = []
	for (let where = first_town; where <= last_town; ++where)
		if (is_contested_town(where))
			set_add(game.combat_list, where)
	resume_combat_phase()
}

function resume_combat_phase() {
	reset_road_limits()
	reset_moved_for_combat()

	if (game.combat_list.length > 0) {
		game.active = game.p1
		game.state = 'combat_phase'
	} else {
		goto_draw_phase()
	}
}

states.combat_phase = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Battle Phase: Waiting for " + game.active + "."
		view.prompt = "Battle Phase: Choose the next battle or siege!"
		for (let where of game.combat_list)
			gen_action(view, 'town', where)
	},
	town: function (where) {
		set_delete(game.combat_list, where)
		game.where = where
		start_combat()
	},
}

function start_combat() {
	game.flash = ""
	log("")
	log(".h3 Battle at #" + game.where)
	game.combat_round = 0
	game.halfhit = NOBODY
	game.storming = []
	game.sallying = []
	game.hits = 0

	game.show_castle = 0
	game.show_field = 0

	if (is_castle_town(game.where)) {
		if (!is_under_siege(game.where)) {
			log(".h4 Combat Deployment")
			game.castle_owner = enemy(game.attacker[game.where])
			game.active = game.castle_owner
			game.state = 'combat_deployment'
			game.is_existing_siege = 0
		} else {
			game.castle_owner = besieged_player(game.where)
			if (!game.attacker[game.where])
				game.attacker[game.where] = enemy(game.castle_owner)
			log("Existing siege continued.")
			game.is_existing_siege = 1
			next_combat_round()
		}
	} else {
		game.castle_owner = null
		next_combat_round()
	}
}

function end_combat() {
	lift_siege(game.where)

	if (game.jihad === game.where)
		game.jihad = null

	delete game.is_existing_siege
	delete game.castle_owner
	delete game.storming
	delete game.sallying
	delete game.show_castle
	delete game.show_field
	game.where = NOWHERE
	game.flash = ""
	game.combat_round = 0

	resume_combat_phase()
}

// COMBAT DEPLOYMENT

states.combat_deployment = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Battle: Waiting for " + game.active + "."
		view.prompt = "Battle: Deploy blocks on the field and in the castle."
		let max = castle_limit(game.where)
		let n = count_blocks_in_castle(game.where)
		let have_options = false
		if (n < max) {
			for (let b = 0; b <= last_block; ++b) {
				if (block_owner(b) === game.active && !is_reserve(b)) {
					if (game.location[b] === game.where && !set_has(game.castle, b)) {
						gen_action(view, 'withdraw', b)
						gen_action(view, 'block', b)
						have_options = true
					}
				}
			}
		}
		if (!have_options)
			view.flash_next = "Click Next when you're done."
		gen_action_undo(view)
		gen_action(view, 'next')
	},
	withdraw: function (who) {
		push_undo()
		set_add(game.castle, who)
	},
	block: function (who) {
		push_undo()
		set_add(game.castle, who)
	},
	next: function () {
		clear_undo()
		let n = count_blocks_in_castle(game.where)
		if (n === 1)
			log(game.active + " withdrew 1 block.")
		else
			log(game.active + " withdrew " + n + " blocks.")
		game.active = game.attacker[game.where]
		if (count_enemy_in_field_and_reserve(game.where) === 0) {
			return goto_regroup()
		}
		next_combat_round()
	},
	undo: pop_undo
}

// REGROUP AFTER FIELD BATTLE/SIEGE VICTORY

function print_retreat_summary() {
	if (game.summary && game.summary.length > 0)
		print_summary("Retreated from #" + game.where + ":")
}

function goto_regroup() {
	lift_siege(game.where)
	if (!is_under_siege(game.where))
		clear_reserves() // no siege battle, reserves arrive before regroup
	reset_road_limits()
	reset_moved_for_combat()
	game.state = 'regroup'
	game.summary = []
}

states.regroup = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Regroup: Waiting for " + game.active + "."
		view.prompt = "Regroup: Choose a block to move."
		gen_action_undo(view)
		gen_action(view, 'end_regroup')
		for (let b = 0; b <= last_block; ++b) {
			if (game.location[b] === game.where) {
				if (can_block_regroup(b))
					gen_action(view, 'block', b)
			}
		}
	},
	block: function (who) {
		push_undo()
		game.who = who
		game.state = 'regroup_to'
	},
	end_regroup: function () {
		clear_undo()
		reset_road_limits()
		print_summary(game.active + " regrouped:", true)
		if (game.assassins) {
			delete game.assassins
			game.where = NOWHERE
			end_player_turn()
		}
		else if (is_winter())
			goto_winter_2()
		else if (is_contested_town(game.where))
			next_combat_round()
		else
			end_combat()
	},
	undo: pop_undo
}

states.regroup_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Regroup: Waiting for " + game.active + "."
		view.prompt = "Regroup: Move the block to a friendly or vacant town."
		gen_action_undo(view)
		gen_action(view, 'block', game.who)
		for (let to of TOWNS[game.where].exits)
			if (can_block_regroup_to(game.who, to))
				gen_action(view, 'town', to)
	},
	town: function (to) {
		// We can regroup while reserves are still on the way...
		set_delete(game.reserves1, game.who)
		set_delete(game.reserves2, game.who)

		let from = game.where
		game.summary.push([from, to])
		move_block(game.who, game.where, to)
		game.who = NOBODY
		game.state = 'regroup'
	},
	block: pop_undo,
	undo: pop_undo
}

// COMBAT ROUND

function next_combat_round() {
	print_retreat_summary()
	if (game.jihad === game.where && game.combat_round === 1)
		game.jihad = null
	switch (game.combat_round) {
	case 0: return goto_combat_round(1)
	case 1: return goto_combat_round(2)
	case 2: return goto_combat_round(3)
	case 3: return goto_retreat_after_combat()
	}
}

function bring_on_reserves(reserves) {
	let f = 0
	let s = 0
	for (let b = 0; b <= last_block; ++b) {
		if (game.location[b] === game.where) {
			if (set_has(reserves, b)) {
				if (block_owner(b) === FRANKS)
					++f
				else
					++s
				set_delete(reserves, b)
			}
		}
	}
	if (f > 0)
		log(f + " Frank " + (f === 1 ? "reserve arrived." : "reserves arrived."))
	if (s > 0)
		log(s + " Saracen " + (s === 1 ? "reserve arrived." : "reserves arrived."))
}

function clear_reserves(where) {
	for (let b = 0; b <= last_block; ++b) {
		if (game.location[b] === where) {
			set_delete(game.reserves1, b)
			set_delete(game.reserves2, b)
		}
	}
}

function reset_moved_for_combat() {
	set_clear(game.moved)
	for (let b of game.reserves1) set_add(game.moved, b)
	for (let b of game.reserves2) set_add(game.moved, b)
}

function goto_combat_round(new_combat_round) {
	game.combat_round = new_combat_round
	game.summary = []

	let was_contested = is_contested_battle_field()

	// If the main attack regroups away from a new siege while reinforcements
	// are on the way, we need to skip the first combat round.
	if (game.combat_round === 1 && is_under_siege(game.where)) {
		game.active = besieging_player(game.where)
		if (count_friendly_in_field_excluding_reserves(game.where) === 0) {
			log("Combat round skipped because main attack regrouped away.")
			game.combat_round = 2
		}
	}

	log(".h4 Combat Round " + game.combat_round)

	if (game.combat_round === 2)
		bring_on_reserves(game.reserves1)
	if (game.combat_round === 3)
		bring_on_reserves(game.reserves2)

	reset_moved_for_combat()

	if (is_contested_battle_field()) {
		if (is_under_siege(game.where)) {
			if (!was_contested) {
				log("Relief forces arrived!")
				if (game.storming.length > 0) {
					log("Storming canceled by arriving relief force.")
					game.halfhit = NOBODY
					game.storming.length = 0
				}
				let old_attacker = game.attacker[game.where]
				game.attacker[game.where] = besieged_player(game.where)
				if (old_attacker !== game.attacker[game.where]) {
					log(game.attacker[game.where] + " are now the attacker.")
				}
			}
			// No sally first round after combat deployment.
			if (game.combat_round > 1 || game.is_existing_siege)
				return goto_declare_sally()
		}
		return goto_field_battle()
	}

	goto_declare_storm()
}

// DECLARE STORM

function goto_declare_storm() {
	game.active = besieging_player(game.where)
	// Castle is full.
	if (game.storming.length === castle_limit(game.where))
		return goto_siege_battle()
	// Field is empty.
	if (count_friendly(game.where) - game.storming.length === 0)
		return goto_siege_battle()
	game.state = 'declare_storm'
}

states.declare_storm = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Siege Declaration: Waiting for " + game.active + " to declare storm."
		view.prompt = "Siege Declaration: Declare which blocks should storm the castle."
		let have_options = false
		if (game.storming.length < castle_limit(game.where)) {
			for (let b = 0; b <= last_block; ++b) {
				if (block_owner(b) === game.active && !is_reserve(b)) {
					if (game.location[b] === game.where && !set_has(game.storming, b)) {
						gen_action(view, 'storm', b)
						gen_action(view, 'block', b)
						have_options = true
					}
				}
			}
		}
		if (!have_options)
			view.flash_next = "Click Next when you're done."
		gen_action_undo(view)
		gen_action(view, 'next')
	},
	storm: storm_with_block,
	block: storm_with_block,
	next: function () {
		clear_undo()
		let n = game.storming.length
		if (n === 0) {
			game.flash = game.active + " declined to storm."
			if (game.jihad === game.where)
				game.jihad = null
			log(game.active + " declined to storm.")
			goto_declare_sally()
		} else {
			goto_siege_battle()
		}
	},
	undo: pop_undo
}

function storm_with_block(who) {
	push_undo()
	set_add(game.storming, who)
	if (game.storming.length > 1)
		game.flash = game.active + " stormed with " + game.storming.length + " blocks."
	else
		game.flash = game.active + " stormed with 1 block."
	log(game.active[0] + ": " + block_name(who) + " stormed.")
}

// DECLARE SALLY

function goto_declare_sally() {
	game.active = besieged_player(game.where)
	game.state = 'declare_sally'
	game.was_contested = is_contested_battle_field()
}

states.declare_sally = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Siege Declaration: Waiting for " + game.active + " to declare sally."
		view.prompt = "Siege Declaration: Declare which blocks should sally onto the field."
		let have_options = false
		for (let b = 0; b <= last_block; ++b) {
			if (block_owner(b) === game.active && !is_reserve(b) && is_block_in_castle(b)) {
				if (game.location[b] === game.where && !set_has(game.sallying, b)) {
					gen_action(view, 'sally', b)
					gen_action(view, 'block', b)
					have_options = true
				}
			}
		}
		if (!have_options)
			view.flash_next = "Click Next when you're done."
		gen_action_undo(view)
		gen_action(view, 'next')
	},
	sally: sally_with_block,
	block: sally_with_block,
	next: function () {
		clear_undo()
		let n = game.sallying.length
		if (n === 0) {
			game.flash = game.active + " declined to sally."
			log(game.active + " declined to sally.")
		}
		if (is_contested_battle_field()) {
			if (!game.was_contested) {
				log(game.active + " are now the attacker.")
				game.attacker[game.where] = game.active
			}
			goto_field_battle()
		} else if (count_reserves(game.where) > 0) {
			next_combat_round()
		} else {
			goto_siege_attrition()
		}
	},
	undo: pop_undo
}

function sally_with_block(who) {
	push_undo()
	set_delete(game.castle, who)
	set_add(game.sallying, who)
	if (game.sallying.length > 1)
		game.flash = game.active + " sallied with " + game.sallying.length + " blocks."
	else
		game.flash = game.active + " sallied with 1 block."
	log(game.active[0] + ": " + block_name(who) + " sallied.")
}

// RETREAT AFTER COMBAT

function goto_retreat_after_combat() {
	reset_moved_for_combat()

	// withdraw all sallying blocks to castle.
	for (let b of game.sallying)
		set_add(game.castle, b)
	game.sallying.length = 0

	// TODO: 6.2 - In Sieges, the attacker /may/ retreat or stay on siege.

	// withdraw all storming blocks to the field.
	game.halfhit = NOBODY
	game.storming.length = 0

	if (is_contested_field(game.where)) {
		log(".h4 Retreat")
		game.active = game.attacker[game.where]
		game.state = 'retreat'
		game.summary = []
	} else if (is_under_siege(game.where)) {
		goto_siege_attrition()
	} else {
		end_combat()
	}
}

states.retreat = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Retreat: Waiting for " + game.active + "."
		view.prompt = "Retreat: Choose a block to move."
		gen_action_undo(view)
		let can_retreat = false
		for (let b = 0; b <= last_block; ++b) {
			if (game.location[b] === game.where && !is_block_in_castle(b) && can_block_retreat(b)) {
				gen_action(view, 'block', b)
				can_retreat = true
			}
		}
		if (!is_contested_field(game.where) || !can_retreat)
			gen_action(view, 'end_retreat')
	},
	end_retreat: function () {
		clear_undo()
		for (let b = 0; b <= last_block; ++b)
			if (game.location[b] === game.where && !is_block_in_castle(b) && block_owner(b) === game.active)
				eliminate_block(b)
		print_summary(game.active + " retreated:")
		game.active = enemy(game.active)
		goto_regroup()
	},
	block: function (who) {
		push_undo()
		game.who = who
		game.state = 'retreat_to'
	},
	undo: pop_undo
}

states.retreat_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Retreat: Waiting for " + game.active + "."
		view.prompt = "Retreat: Move the block to a friendly or neutral town."
		gen_action_undo(view)
		gen_action(view, 'block', game.who)
		let can_retreat = false
		for (let to of TOWNS[game.where].exits) {
			if (can_block_retreat_to(game.who, to)) {
				gen_action(view, 'town', to)
				can_retreat = true
			}
		}
		if (!can_retreat)
			gen_action(view, 'eliminate')
	},
	town: function (to) {
		let from = game.where
		game.summary.push([from, to])
		move_block(game.who, game.where, to)
		game.who = NOBODY
		game.state = 'retreat'
	},
	eliminate: function () {
		eliminate_block(game.who)
		game.who = NOBODY
		game.state = 'retreat'
	},
	block: pop_undo,
	undo: pop_undo
}

// SIEGE ATTRITION

function goto_siege_attrition() {
	log(".h4 Siege Attrition")
	game.active = besieged_player(game.where)
	game.state = 'siege_attrition'
	game.attrition_list = []
	for (let b = 0; b <= last_block; ++b)
		if (is_block_in_castle_in(b, game.where))
			set_add(game.attrition_list, b)
}

function resume_siege_attrition() {
	if (game.attrition_list.length === 0) {
		delete game.attrition_list
		if (!is_under_siege(game.where)) {
			game.active = enemy(game.active)
			log("#" + game.where + " fell to siege attrition.")
			goto_regroup()
		} else {
			log("Siege continued.")
			end_combat()
		}
	}
}

states.siege_attrition = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Siege Attrition: Waiting for " + game.active + "."
		view.prompt = "Siege Attrition: Roll for siege attrition in " + town_name(game.where) + "."
		for (let b of game.attrition_list)
			gen_action(view, 'block', b)
	},
	block: function (who) {
		let target = (game.where === TYRE || game.where === TRIPOLI) ? 1 : 3
		let die = roll_d6()
		if (die <= target) {
			log("Attrition roll " + DIE_HIT[die] + ".")
			reduce_block(who)
		} else {
			log("Attrition roll " + DIE_MISS[die] + ".")
		}
		set_delete(game.attrition_list, who)
		resume_siege_attrition()
	}
}

// FIELD AND SIEGE BATTLE HELPERS

function count_enemy_hp_in_field() {
	let hp = 0
	for (let b = 0; b <= last_block; ++b)
		if (block_owner(b) !== game.active && is_field_combatant(b))
			hp += game.steps[b]
	return hp
}

function count_enemy_hp_in_siege() {
	let hp = 0
	for (let b = 0; b <= last_block; ++b)
		if (block_owner(b) !== game.active && is_siege_combatant(b))
			if (is_block_in_castle(b))
				hp += game.steps[b] * 2
			else
				hp += game.steps[b]
	if (game.halfhit !== NOBODY && block_owner(game.halfhit) !== game.active)
		hp -= 1
	return hp
}

function must_apply_field_hits() {
	if (game.immediate)
		return game.hits > 0
	return game.hits >= count_enemy_hp_in_field()
}

function must_apply_siege_hits() {
	if (game.immediate)
		return game.hits > 0
	return game.hits >= count_enemy_hp_in_siege()
}

function filter_battle_blocks(ci, is_candidate) {
	let output = null
	for (let b = 0; b <= last_block; ++b) {
		if (is_candidate(b) && !set_has(game.moved, b)) {
			if (block_initiative(b) === ci) {
				if (!output)
					output = []
				output.push(b)
			}
		}
	}
	return output
}

function battle_step(active, initiative, candidate) {
	game.battle_list = filter_battle_blocks(initiative, candidate)
	if (game.battle_list) {
		if (game.active !== active) {
			game.active = active
			if (game.hits > 0) {
				goto_battle_hits()
			}
		}
		return true
	}
	return false
}

function goto_battle_hits() {
	if (game.state === 'field_battle')
		goto_field_battle_hits()
	else if (game.state === 'siege_battle')
		goto_siege_battle_hits()
	else
		throw new Error("invalid battle state")
}

function pump_battle_step(is_candidate_attacker, is_candidate_defender) {
	let attacker = game.attacker[game.where]
	let defender = enemy(attacker)

	if (game.jihad === game.where && game.combat_round === 1) {
		if (battle_step(attacker, 'A', is_candidate_attacker)) return
		if (battle_step(attacker, 'B', is_candidate_attacker)) return
		if (battle_step(attacker, 'C', is_candidate_attacker)) return
		if (battle_step(defender, 'A', is_candidate_defender)) return
		if (battle_step(defender, 'B', is_candidate_defender)) return
		if (battle_step(defender, 'C', is_candidate_defender)) return
	} else {
		if (battle_step(defender, 'A', is_candidate_defender)) return
		if (battle_step(attacker, 'A', is_candidate_attacker)) return
		if (battle_step(defender, 'B', is_candidate_defender)) return
		if (battle_step(attacker, 'B', is_candidate_attacker)) return
		if (battle_step(defender, 'C', is_candidate_defender)) return
		if (battle_step(attacker, 'C', is_candidate_attacker)) return
	}

	if (game.hits > 0) {
		game.active = enemy(game.active)
		return goto_battle_hits()
	}

	next_combat_round()
}

// FIELD BATTLE

function goto_field_battle() {
	resume_field_battle()
}

function resume_field_battle() {
	// we have a queued up harry action
	if (game.harry) {
		game.active = game.harry
		game.state = 'harry'
		delete game.harry
		return
	}

	let save_active = game.active
	game.active = game.attacker[game.where]

	if (is_friendly_field(game.where)) {
		if (game.hits > 0) {
			game.active = enemy(save_active)
			return goto_field_battle_hits()
		}
		print_retreat_summary()
		log("Field battle won by " + game.active + ".")
		game.show_field = 0
		return goto_regroup()
	}

	if (is_enemy_field(game.where)) {
		if (game.hits > 0) {
			game.active = enemy(save_active)
			return goto_field_battle_hits()
		}
		game.active = enemy(game.active)
		print_retreat_summary()
		log("Field battle won by " + game.active + ".")
		game.show_field = 0
		return goto_regroup()
	}

	if (is_enemy_battle_field()) {
		if (game.hits > 0) {
			game.active = enemy(save_active)
			return goto_field_battle_hits()
		}
		print_retreat_summary()
		log("Attacking main force was eliminated.")
		return next_combat_round()
	}

	if (is_friendly_battle_field()) {
		if (game.hits > 0) {
			game.active = enemy(save_active)
			return goto_field_battle_hits()
		}
		print_retreat_summary()
		log("Defending main force was eliminated.")
		log("Battlefield control changed.")
		game.attacker[game.where] = enemy(game.active)
		// The new defender takes control of the empty castle
		if (!is_under_siege(game.where))
			game.castle_owner = game.active
		return next_combat_round()
	}

	game.active = save_active
	game.state = 'field_battle'
	game.show_field = 1
	pump_battle_step(is_field_attacker, is_field_defender)
}

states.field_battle = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Field Battle: Waiting for " + game.active + "."
		view.prompt = "Field Battle: Choose a combat action."
		for (let b of game.battle_list) {
			gen_action(view, 'block', b) // take default action
			gen_action(view, 'fire', b)
			if (set_has(game.sallying, b)) {
				// Only sallying forces may withdraw into the castle
				gen_action(view, 'withdraw', b)
			} else {
				if (can_block_retreat(b)) {
					gen_action(view, 'retreat', b)
					// Turcopoles and Nomads can Harry (fire and retreat)
					if (block_type(b) === 'turcopoles' || block_type(b) === 'nomads')
						gen_action(view, 'harry', b)
				}

				// Defender can withdraw into castle if friendly and there is room.
				if (game.active !== game.attacker[game.where] && game.active === game.castle_owner) {
					// TODO: allow swapping place of sallying block, leaving it to die if it cannot withdraw?
					if (game.sallying.length + count_blocks_in_castle(game.where) < castle_limit(game.where))
						gen_action(view, 'withdraw', b)
				}
			}
			// All Frank B blocks are knights who can Charge
			if (block_owner(b) === FRANKS && block_initiative(b) === 'B')
				gen_action(view, 'charge', b)
		}
		if (game.hits > 0)
			gen_action(view, 'assign')
	},
	assign: function () {
		game.active = enemy(game.active)
		if (game.hits === 1)
			game.flash = `Inflicted 1 hit.`
		else
			game.flash = `Inflicted ${game.hits} hits.`
		goto_field_battle_hits()
	},
	block: field_fire_with_block,
	fire: field_fire_with_block,
	withdraw: field_withdraw_with_block,
	charge: charge_with_block,
	harry: harry_with_block,
	retreat: retreat_with_block,
}

// SIEGE BATTLE

function goto_siege_battle() {
	game.attacker[game.where] = besieging_player(game.where)
	game.show_castle = 1
	resume_siege_battle()
}

function resume_siege_battle() {
	let save_active = game.active
	game.active = game.attacker[game.where]

	if (is_friendly_town(game.where)) {
		log("Siege battle won by " + game.active + ".")
		return goto_regroup()
	}

	if (is_enemy_town(game.where)) {
		game.active = enemy(game.active)
		game.halfhit = NOBODY
		log("Siege battle won by " + game.active + ".")
		return goto_regroup()
	}

	if (count_blocks_in_castle(game.where) === 0) {
		log("Defending main force was eliminated.")
		log(game.active + " are now the defender.")
		game.attacker[game.where] = enemy(game.active)
		// The new defender takes control of the empty castle
		game.castle_owner = game.active
		game.storming.length = 0
		return next_combat_round()
	}

	if (game.storming.length === 0) {
		game.halfhit = NOBODY
		log("Storming repulsed.")
		return next_combat_round()
	}

	game.active = save_active
	game.state = 'siege_battle'
	pump_battle_step(is_siege_attacker, is_siege_defender)
}

states.siege_battle = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Siege Battle: Waiting for " + game.active + "."
		view.prompt = "Siege Battle: Choose a combat action."
		for (let b of game.battle_list) {
			gen_action(view, 'block', b) // take default action
			gen_action(view, 'fire', b)
			if (set_has(game.storming, b))
				gen_action(view, 'retreat', b)
		}
		if (game.hits > 0)
			gen_action(view, 'assign')
	},
	assign: function () {
		game.active = enemy(game.active)
		if (game.hits === 1)
			game.flash = `Inflicted 1 hit.`
		else
			game.flash = `Inflicted ${game.hits} hits.`
		goto_siege_battle_hits()
	},
	block: siege_fire_with_block,
	fire: siege_fire_with_block,
	retreat: siege_withdraw_with_block,
}

// FIELD BATTLE HITS

function goto_field_battle_hits() {
	game.battle_list = list_field_victims()
	if (game.battle_list.length === 0) {
		game.hits = 0
		resume_field_battle()
	} else {
		game.state = 'field_battle_hits'
	}
}

function list_field_victims() {
	let max = 0
	for (let b = 0; b <= last_block; ++b)
		if (block_owner(b) === game.active && is_field_combatant(b) && game.steps[b] > max)
			max = game.steps[b]
	let list = []
	for (let b = 0; b <= last_block; ++b)
		if (block_owner(b) === game.active && is_field_combatant(b) && game.steps[b] === max)
			list.push(b)
	return list
}

states.field_battle_hits = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Field Battle: Waiting for " + game.active + " to assign hits."
		view.prompt = "Field Battle: Assign " + game.hits + (game.hits !== 1 ? " hits" : " hit") + " to your armies."
		for (let b of game.battle_list) {
			gen_action(view, 'hit', b)
			gen_action(view, 'block', b)
		}
	},
	hit: apply_field_battle_hit,
	block: apply_field_battle_hit,
}

function apply_field_battle_hit_to(who, flash) {
	let msg
	msg = block_name(who) + " took a hit."
	log(game.active[0] + ": " + msg)
	if (flash)
		game.flash = msg
	reduce_block(who)
	game.hits--
}

function apply_field_battle_hit(who) {
	apply_field_battle_hit_to(who, true)
	if (game.hits === 0)
		resume_field_battle()
	else {
		game.battle_list = list_field_victims()
		if (game.battle_list.length === 0) {
			game.hits = 0
			resume_field_battle()
		} else {
			game.flash += " " + game.hits + (game.hits === 1 ? " hit left." : " hits left.")
		}
	}
}

// SIEGE BATTLE HITS

function goto_siege_battle_hits() {
	game.battle_list = list_siege_victims()
	if (game.battle_list.length === 0) {
		game.hits = 0
		resume_siege_battle()
	} else {
		game.state = 'siege_battle_hits'
	}
}

function list_siege_victims() {
	if (game.halfhit !== NOBODY && block_owner(game.halfhit) === game.active)
		return [ game.halfhit ]
	let max = 0
	for (let b = 0; b <= last_block; ++b)
		if (block_owner(b) === game.active && is_siege_combatant(b) && game.steps[b] > max)
			max = game.steps[b]
	let list = []
	for (let b = 0; b <= last_block; ++b)
		if (block_owner(b) === game.active && is_siege_combatant(b) && game.steps[b] === max)
			list.push(b)
	return list
}

states.siege_battle_hits = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Siege Battle: Waiting for " + game.active + " to assign hits."
		view.prompt = "Siege Battle: Assign " + game.hits + (game.hits !== 1 ? " hits" : " hit") + " to your armies."
		for (let b of game.battle_list) {
			gen_action(view, 'hit', b)
			gen_action(view, 'block', b)
		}
	},
	hit: apply_siege_battle_hit,
	block: apply_siege_battle_hit,
}

function apply_siege_battle_hit_to(who, flash) {
	let msg = block_name(who) + " took a "
	if (game.halfhit === who) {
		msg += "hit."
		log(game.active[0] + ": " + msg)
		reduce_block(who)
		game.halfhit = NOBODY
	} else {
		if (is_block_in_castle(who)) {
			msg += "half-hit."
			log(game.active[0] + ": " + msg)
			game.halfhit = who
		} else {
			msg += "hit."
			log(game.active[0] + ": " + msg)
			reduce_block(who)
		}
	}
	if (flash)
		game.flash = msg
	game.hits--
}

function apply_siege_battle_hit(who) {
	apply_siege_battle_hit_to(who, true)
	if (game.hits === 0) {
		resume_siege_battle()
	} else {
		game.battle_list = list_siege_victims()
		if (game.battle_list.length === 0) {
			game.hits = 0
			resume_siege_battle()
		} else {
			game.flash += " " + game.hits + (game.hits === 1 ? " hit left." : " hits left.")
		}
	}
}

// BATTLE ACTIONS

function roll_attack(active, b, verb, is_charge) {
	let fire = block_fire_power(b, game.where) + is_charge
	let steps = game.steps[b]
	let name = block_name(b) + " " + BLOCKS[b].initiative + BLOCKS[b].fire_power

	let rolls = []
	let hits = 0
	let self = 0
	for (let i = 0; i < steps; ++i) {
		let die = roll_d6()
		if (die <= fire) {
			rolls.push(DIE_HIT[die])
			++hits
		} else {
			if (is_charge && die === 6) {
				rolls.push(DIE_SELF)
				++self
			} else {
				rolls.push(DIE_MISS[die])
			}
		}
	}
	game.hits += hits

	log(active[0] + ": " + name + " " + verb + " " + rolls.join("") + ".")

	if (game.immediate) {
		game.flash = name + " " + verb + " " + rolls.join(" ") + " "
		if (game.hits === 0)
			game.flash += "and missed."
		else if (game.hits === 1)
			game.flash += "and scored 1 hit."
		else
			game.flash += "and scored " + game.hits + " hits."
	} else {
		game.flash = name + " " + verb + " " + rolls.join(" ")
		if (game.hits === 0)
			game.flash += "."
		else if (game.hits === 1)
			game.flash += " for a total of 1 hit."
		else
			game.flash += " for a total of " + game.hits + " hits."
	}

	if (self > 0) {
		if (self === 1)
			game.flash += " " + self + " self hit."
		else
			game.flash += " " + self + " self hits."
		self = Math.min(self, game.steps[b])
		while (self-- > 0)
			reduce_block(b)
	}
}

function field_fire_with_block(b) {
	set_add(game.moved, b)
	roll_attack(game.active, b, "fired", 0)
	if (must_apply_field_hits()) {
		game.active = enemy(game.active)
		goto_field_battle_hits()
	} else {
		resume_field_battle()
	}
}

function siege_fire_with_block(b) {
	set_add(game.moved, b)
	roll_attack(game.active, b, "fired", 0)
	if (must_apply_siege_hits()) {
		game.active = enemy(game.active)
		goto_siege_battle_hits()
	} else {
		resume_siege_battle()
	}
}

function charge_with_block(b) {
	set_add(game.moved, b)
	roll_attack(game.active, b, "charged", 1)
	if (must_apply_field_hits()) {
		game.active = enemy(game.active)
		goto_field_battle_hits()
	} else {
		resume_field_battle()
	}
}

function field_withdraw_with_block(b) {
	game.flash = block_name(b) + " withdrew."
	log(game.active[0] + ": " + game.flash)
	set_add(game.moved, b)
	set_delete(game.sallying, b)
	set_add(game.castle, b)
	resume_field_battle()
}

function siege_withdraw_with_block(b) {
	game.flash = block_name(b) + " withdrew."
	log(game.active[0] + ": " + game.flash)
	set_add(game.moved, b)
	set_delete(game.storming, b)
	resume_siege_battle()
}

function harry_with_block(b) {
	game.harry = game.active // remember to retreat after hits have been applied
	game.who = b
	roll_attack(game.active, b, "harried", 0)
	if (must_apply_field_hits()) {
		game.active = enemy(game.active)
		goto_field_battle_hits()
	} else {
		resume_field_battle()
	}
}

states.harry = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Field Battle: Waiting for " + game.active + " to retreat the harrying block."
		view.prompt = "Field Battle: Retreat the harrying block to a friendly or vacant town."
		for (let to of TOWNS[game.where].exits)
			if (can_block_retreat_to(game.who, to))
				gen_action(view, 'town', to)
	},
	town: function (to) {
		game.flash += " " + block_name(game.who) + " retreated."
		game.summary.push([game.active, to])
		game.location[game.who] = to
		move_block(game.who, game.where, to)
		game.who = NOBODY
		resume_field_battle()
	},
}

function retreat_with_block(b) {
	game.who = b
	game.state = 'retreat_in_battle'
}

states.retreat_in_battle = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Field Battle: Waiting for " + game.active + " to retreat."
		gen_action(view, 'undo')
		gen_action(view, 'block', game.who)
		view.prompt = "Field Battle: Retreat the block to a friendly or vacant town."
		for (let to of TOWNS[game.where].exits)
			if (can_block_retreat_to(game.who, to))
				gen_action(view, 'town', to)
	},
	town: function (to) {
		game.flash = block_name(game.who) + " retreated."
		log(game.active[0] + ": " + game.flash)
		game.summary.push([game.active, to])
		game.location[game.who] = to
		move_block(game.who, game.where, to)
		game.who = NOBODY
		resume_field_battle()
	},
	block: function () {
		game.who = NOBODY
		resume_field_battle()
	},
	undo: function () {
		game.who = NOBODY
		resume_field_battle()
	}
}

// DRAW PHASE

function goto_draw_phase() {
	delete game.combat_list
	if (game.year > 1187 && !is_winter()) {
		game.active = game.p1
		log("")
		start_draw_phase()
	} else {
		end_game_turn()
	}
}

function start_draw_phase() {
	game.state = 'draw_phase'
	if (game.active === FRANKS) {
		game.who = select_random_block(F_POOL)
		if (game.who === NOBODY)
			end_draw_phase()
	} else {
		game.who = select_random_block(S_POOL)
		if (game.who === NOBODY)
			end_draw_phase()
	}
}

states.draw_phase = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Draw Phase: Waiting for " + game.active + "."
		let can_place = false
		switch (block_type(game.who)) {
		case 'crusaders':
			view.prompt = "Draw Phase: Place " + block_name(game.who) + " in the staging area."
			gen_action(view, 'town', block_home(game.who))
			can_place = true
			break
		case 'pilgrims':
			view.prompt = "Draw Phase: Place " + block_name(game.who) + " in a friendly port."
			for (let town = first_town; town <= last_town; ++town) {
				if (is_friendly_port(town) || can_enter_besieged_port(town)) {
					gen_action(view, 'town', town)
					can_place = true
				}
			}
			break
		case 'turcopoles':
		case 'outremers':
		case 'emirs':
		case 'nomads':
			view.prompt = "Draw Phase: Place " + block_name(game.who) + " at full strength in "
				+ block_seat_names[game.who] + " or at strength 1 in any friendly town."
			for (let town = first_town; town <= last_town; ++town) {
				if (town === ENGLAND || town === FRANCE || town === GERMANIA)
					continue
				if (is_friendly_town(town)) {
					if (set_has(block_seats[game.who], town))
						gen_action(view, 'town', town)
					else
						gen_action(view, 'townb', town)
					can_place = true
				}
			}
			break
		}
		if (!can_place)
			gen_action(view, 'next')
	},
	townb: function (where) {
		this.town(where)
	},
	town: function (where) {
		let type = block_type(game.who)

		log(game.active + " deployed at #" + where + ".")

		game.location[game.who] = where
		if (type === 'turcopoles' || type === 'outremers' || type === 'emirs' || type === 'nomads') {
			if (is_home_seat(where, game.who))
				game.steps[game.who] = block_max_steps(game.who)
			else
				game.steps[game.who] = 1
		} else {
			game.steps[game.who] = block_max_steps(game.who)
			if (can_enter_besieged_port(where))
				set_add(game.castle, game.who)
		}

		game.who = NOBODY
		end_draw_phase()
	},
	next: function () {
		end_draw_phase()
	},
}

function end_draw_phase() {
	if (game.active === game.p1) {
		game.active = game.p2
		start_draw_phase()
	} else {
		end_game_turn()
	}
}

function end_game_turn() {
	if (is_winter()) {
		goto_winter_1()
	} else {
		if (check_sudden_death())
			return
		game.turn ++
		start_game_turn()
	}
}

// WINTER CAMPAIGN & SUPPLY

function goto_winter_1() {
	log("")
	log(".h1 Winter of " + game.year)
	log("")
	if (game.winter_campaign)
		goto_winter_siege_attrition()
	else
		goto_winter_2()
}

function goto_winter_siege_attrition() {
	log(game.active + " winter campaigned at #" + game.winter_campaign + ".")
	game.where = game.winter_campaign

	game.active = besieged_player(game.where)
	game.state = 'winter_siege_attrition'
	game.attrition_list = []
	for (let b = 0; b <= last_block; ++b)
		if (is_block_in_castle_in(b, game.where))
			set_add(game.attrition_list, b)
}

function resume_winter_siege_attrition() {
	if (game.attrition_list.length === 0) {
		delete game.attrition_list
		if (!is_under_siege(game.where)) {
			game.active = enemy(game.active)
			log("#" + game.where + " fell to siege attrition.")
			goto_regroup()
		} else {
			log("Siege continued.")
			goto_winter_2()
		}
	}
}

states.winter_siege_attrition = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Winter Siege Attrition: Waiting for " + game.active + "."
		view.prompt = "Winter Siege Attrition: Roll for siege attrition in " + town_name(game.where) + "."
		for (let b of game.attrition_list)
			gen_action(view, 'block', b)
	},
	block: function (who) {
		let target = (game.where === TYRE || game.where === TRIPOLI) ? 2 : 4
		let die = roll_d6()
		if (die <= target) {
			log("Attrition roll " + DIE_HIT[die] + ".")
			reduce_block(who)
		} else {
			log("Attrition roll " + DIE_MISS[die] + ".")
		}
		set_delete(game.attrition_list, who)
		resume_winter_siege_attrition()
	}
}

function goto_winter_2() {
	game.where = NOWHERE
	eliminate_besieging_blocks(FRANKS)
	eliminate_besieging_blocks(SARACENS)
	lift_all_sieges()
	if (check_sudden_death())
		return
	if (game.year === 1192)
		return goto_year_end()
	goto_winter_supply()
}

function eliminate_besieging_blocks(owner) {
	game.summary = []
	for (let b = 0; b <= last_block; ++b) {
		if (block_owner(b) === owner) {
			let where = game.location[b]
			if (where === game.winter_campaign)
				continue
			if (is_block_on_land(b) && is_under_siege(where))
				if (block_owner(b) === besieging_player(where))
					disband(b)
		}
	}
	if (game.summary.length > 0)
		print_summary(owner + " disbanded sieges:")
	else
		game.summary = null
}

function need_winter_supply_check() {
	for (let town = first_town; town <= last_town; ++town) {
		if (town === game.winter_campaign)
			continue
		if (is_friendly_town(town) && !is_within_castle_limit(town))
			return true
	}
	return false
}

function goto_winter_supply() {
	game.active = FRANKS
	if (need_winter_supply_check()) {
		game.state = 'winter_supply'
		game.summary = []
	} else {
		game.active = SARACENS
		if (need_winter_supply_check()) {
			game.state = 'winter_supply'
			game.summary = []
		} else {
			game.active = FRANKS
			goto_winter_replacements()
		}
	}
}

states.winter_supply = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Winter Supply: Waiting for " + game.active + "."
		gen_action_undo(view)
		let okay_to_end = true
		for (let b = 0; b <= last_block; ++b) {
			if (block_owner(b) === game.active) {
				if (is_block_on_land(b)) {
					let where = game.location[b]
					if (where === game.winter_campaign)
						continue
					if (!is_within_castle_limit(where)) {
						gen_action(view, 'block', b)
						okay_to_end = false
					}
				}
			}
		}
		if (okay_to_end) {
			view.prompt = "Winter Supply: Disband excess blocks \u2014 done."
			gen_action(view, 'next')
		} else {
			view.prompt = "Winter Supply: Disband excess blocks."
		}
	},
	block: function (who) {
		push_undo()
		disband(who)
	},
	next: function () {
		clear_undo()
		if (game.summary.length > 0)
			print_summary(game.active + " disbanded:")
		if (game.active === FRANKS) {
			game.active = SARACENS
			game.summary = []
		} else {
			game.active = FRANKS
			goto_winter_replacements()
		}
	},
	undo: pop_undo
}

// WINTER REPLACEMENTS

function goto_winter_replacements() {
	game.rp = {}

	for (let town = first_town; town <= last_town; ++town)
		if (is_under_siege(town))
			game.rp[town] = 0
		else
			game.rp[town] = castle_limit(town)

	game.summary = []
	game.state = 'winter_replacements'
}

function replacement_cost(where) {
	let region = TOWNS[where].region
	if (KINGDOMS[region] === game.active)
		return 1
	return 2
}

states.winter_replacements = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Winter Replacements: Waiting for " + game.active + "."
		view.prompt = "Winter Replacements: Distribute replacement points."
		gen_action_undo(view)
		let okay_to_end = true
		for (let b = 0; b <= last_block; ++b) {
			if (block_owner(b) === game.active && is_block_on_land(b)) {
				let where = game.location[b]
				let cost = replacement_cost(where)
				if (is_friendly_town(where) && game.rp[where] >= cost) {
					if (game.steps[b] < block_max_steps(b)) {
						gen_action(view, 'block', b)
						okay_to_end = false
					}
				}
			}
		}
		if (okay_to_end) {
			view.prompt = "Winter Replacements: Distribute replacement points \u2014 done."
			gen_action(view, 'next')
		} else {
			view.prompt = "Winter Replacements: Distribute replacement points."
		}
	},
	block: function (who) {
		push_undo()
		let where = game.location[who]
		let cost = replacement_cost(where)
		game.summary.push([where])
		game.steps[who] ++
		game.rp[where] -= cost
	},
	next: function () {
		clear_undo()
		end_winter_replacements()
	},
	undo: pop_undo
}

function end_winter_replacements() {
	print_summary(active_adjective() + " replacements:")
	if (game.active === FRANKS) {
		game.active = SARACENS
		game.summary = []
	} else {
		goto_year_end()
	}
}

function goto_year_end() {
	if (game.year === 1192) {
		game.state = 'game_over'
		let f_vp = count_victory_points(FRANKS)
		let s_vp = count_victory_points(SARACENS)
		if (f_vp > s_vp) {
			game.result = FRANKS
			game.victory = "Franks won!"
		} else if (f_vp < s_vp) {
			game.victory = "Saracens won!"
			game.result = SARACENS
		} else {
			game.victory = "The game ended in a draw."
			game.result = "None"
		}
		log("")
		log(game.victory)
		return
	}

	// Return eliminated blocks to pool.
	for (let b = 0; b <= last_block; ++b)
		if (game.location[b] === DEAD)
			game.location[b] = block_pool(b)

	game.year ++
	start_year()
}

// GAME OVER

states.game_over = {
	prompt: function (view) {
		view.prompt = game.victory
	}
}

// SETUP

function setup_game() {
	reset_blocks()
	game.year = 1187
	game.turn = 0
	for (let b = 0; b <= last_block; ++b) {
		if (block_owner(b) === FRANKS) {
			switch (block_type(b)) {
			case 'pilgrims':
				deploy(b, block_pool(b))
				break
			case 'crusaders':
				deploy(b, block_pool(b))
				break
			default:
				deploy(b, block_home(b))
				break
			}
		}
		if (block_owner(b) === SARACENS) {
			if (block_type(b) === 'emirs')
				deploy(b, block_home(b))
			if (block_type(b) === 'nomads')
				deploy(b, block_pool(b))
		}
	}
	deploy(ASSASSINS, MASYAF)
	goto_frank_deployment()
}

// VIEW

function make_battle_view() {
	let battle = {
		FR: [], FC: [], FF: [],
		SR: [], SC: [], SF: [],
		FCS: (game.castle_owner === FRANKS) ? castle_limit(game.where) : 0,
		SCS: (game.castle_owner === SARACENS) ? castle_limit(game.where) : 0,
		storming: game.storming,
		sallying: game.sallying,
		halfhit: game.halfhit,
		flash: game.flash,
		round: game.combat_round,
		show_castle: game.show_castle,
		show_field: game.show_field,
		town: game.where,
	}

	if (is_under_siege(game.where) && !is_contested_battle_field(game.where))
		battle.title = enemy(game.castle_owner) + " besiege " + town_name(game.where)
	else
		battle.title = game.attacker[game.where] + " attack " + town_name(game.where)
	if (game.combat_round === 0)
		battle.title += " \u2014 Combat Deployment"
	else
		battle.title += " \u2014 Round " + game.combat_round + " of 3"
	if (game.where === game.jihad)
		battle.title += " \u2014 Jihad!"

	function fill_cell(cell, owner, fn) {
		for (let b = 0; b <= last_block; ++b)
			if (game.location[b] === game.where & block_owner(b) === owner && fn(b))
				cell.push(b)
	}

	fill_cell(battle.FR, FRANKS, b => is_reserve(b))
	fill_cell(battle.FC, FRANKS, b => is_block_in_castle(b))
	fill_cell(battle.FF, FRANKS, b => is_block_in_field(b) && !set_has(game.storming, b))
	fill_cell(battle.FF, SARACENS, b => is_block_in_field(b) && set_has(game.storming, b))
	fill_cell(battle.SF, FRANKS, b => is_block_in_field(b) && set_has(game.storming, b))
	fill_cell(battle.SF, SARACENS, b => is_block_in_field(b) && !set_has(game.storming, b))
	fill_cell(battle.SC, SARACENS, b => is_block_in_castle(b))
	fill_cell(battle.SR, SARACENS, b => is_reserve(b))

	return battle
}

exports.setup = function (seed, scenario, options) {
	game = {
		seed: seed,
		log: [],
		undo: [],

		active: null,
		moves: 0,
		who: NOBODY,
		where: NOWHERE,

		show_cards: false,
		s_hand: [],
		f_hand: [],
		s_card: 0,
		f_card: 0,

		location: [],
		steps: [],

		attacker: {},
		road_limit: [],
		last_used: [],

		castle: [],
		main_road: [],
		moved: [],
		reserves1: [],
		reserves2: [],
	}

	// Old RNG for ancient replays
	if (options.rng)
		game.rng = options.rng

	log(".h1 Crusader Rex")
	log("")

	if (options && options.iron_bridge) {
		game.iron_bridge = 1
		log("Iron Bridge:\nThe road between Antioch and Harim has a move limit of 3.")
		log("")
	}

	if (options && options.immediate)
		game.immediate = 1

	setup_game()
	return game
}

exports.action = function (state, current, action, arg) {
	game = state
	let S = states[game.state]
	if (action in S)
		S[action](arg, current)
	else
		throw new Error("Invalid action: " + action)
	return game
}

function make_siege_view() {
	let list = {}
	for (let town = first_town; town <= last_town; ++town)
		if (is_under_siege(town))
			list[town] = besieging_player(town)
	return list
}

function observer_hand() {
	let hand = []
	hand.length = Math.max(game.s_hand.length, game.f_hand.length)
	hand.fill(0)
	return hand
}

exports.is_checkpoint = (a, b) => a.turn !== b.turn

exports.view = function(state, current) {
	game = state

	let view = {
		log: game.log,
		year: game.year,
		turn: game.turn,
		active: game.active,
		p1: game.p1,
		f_vp: count_victory_points(FRANKS),
		s_vp: count_victory_points(SARACENS),
		f_card: (game.show_cards || current === FRANKS) ? game.f_card : 0,
		s_card: (game.show_cards || current === SARACENS) ? game.s_card : 0,
		hand: (current === FRANKS) ? game.f_hand : (current === SARACENS) ? game.s_hand : observer_hand(),
		who: (game.active === current) ? game.who : NOBODY,
		location: game.location,
		castle: game.castle,
		steps: game.steps,
		moved: game.moved,
		sieges: make_siege_view(),
		last_used: game.last_used,
		road_limit: game.road_limit,
		battle: null,
		prompt: null,
	}

	if (game.jihad && game.jihad !== game.p1)
		view.jihad = game.jihad
	if (game.winter_campaign && game.winter_campaign !== game.p1 && game.winter_campaign !== game.p2)
		view.winter_campaign = game.winter_campaign

	if (game.main_road && game.main_road.length > 0) {
		view.main_road = []
		for (let i = 0; i < game.main_road.length; i += 2)
			if (game.main_road[i+1] !== ENGLAND)
				set_add(view.main_road, road_id(game.main_road[i+0], game.main_road[i+1]))
	}

	states[game.state].prompt(view, current)

	if (states[game.state].show_battle)
		view.battle = make_battle_view()

	return view
}


// === COMMON LIBRARY ===

// remove item at index (faster than splice)
function array_remove(array, index) {
	let n = array.length
	for (let i = index + 1; i < n; ++i)
		array[i - 1] = array[i]
	array.length = n - 1
	return array
}

// insert item at index (faster than splice)
function array_insert(array, index, item) {
	for (let i = array.length; i > index; --i)
		array[i] = array[i - 1]
	array[index] = item
	return array
}

function array_insert_pair(array, index, key, value) {
	for (let i = array.length; i > index; i -= 2) {
		array[i] = array[i-2]
		array[i+1] = array[i-1]
	}
	array[index] = key
	array[index+1] = value
}

function set_clear(set) {
	set.length = 0
}

function set_has(set, item) {
	let a = 0
	let b = set.length - 1
	while (a <= b) {
		let m = (a + b) >> 1
		let x = set[m]
		if (item < x)
			b = m - 1
		else if (item > x)
			a = m + 1
		else
			return true
	}
	return false
}

function set_add(set, item) {
	let a = 0
	let b = set.length - 1
	while (a <= b) {
		let m = (a + b) >> 1
		let x = set[m]
		if (item < x)
			b = m - 1
		else if (item > x)
			a = m + 1
		else
			return set
	}
	return array_insert(set, a, item)
}

function set_delete(set, item) {
	let a = 0
	let b = set.length - 1
	while (a <= b) {
		let m = (a + b) >> 1
		let x = set[m]
		if (item < x)
			b = m - 1
		else if (item > x)
			a = m + 1
		else
			return array_remove(set, m)
	}
	return set
}

function set_toggle(set, item) {
	let a = 0
	let b = set.length - 1
	while (a <= b) {
		let m = (a + b) >> 1
		let x = set[m]
		if (item < x)
			b = m - 1
		else if (item > x)
			a = m + 1
		else
			return array_remove(set, m)
	}
	return array_insert(set, a, item)
}

function map_get(map, key, missing) {
	let a = 0
	let b = (map.length >> 1) - 1
	while (a <= b) {
		let m = (a + b) >> 1
		let x = map[m<<1]
		if (key < x)
			b = m - 1
		else if (key > x)
			a = m + 1
		else
			return map[(m<<1)+1]
	}
	return missing
}

function map_set(map, key, value) {
	let a = 0
	let b = (map.length >> 1) - 1
	while (a <= b) {
		let m = (a + b) >> 1
		let x = map[m<<1]
		if (key < x)
			b = m - 1
		else if (key > x)
			a = m + 1
		else {
			map[(m<<1)+1] = value
			return
		}
	}
	array_insert_pair(map, a<<1, key, value)
}

// Fast deep copy for objects without cycles
function object_copy(original) {
	if (Array.isArray(original)) {
		let n = original.length
		let copy = new Array(n)
		for (let i = 0; i < n; ++i) {
			let v = original[i]
			if (typeof v === "object" && v !== null)
				copy[i] = object_copy(v)
			else
				copy[i] = v
		}
		return copy
	} else {
		let copy = {}
		for (let i in original) {
			let v = original[i]
			if (typeof v === "object" && v !== null)
				copy[i] = object_copy(v)
			else
				copy[i] = v
		}
		return copy
	}
}

function clear_undo() {
	if (game.undo.length > 0)
		game.undo = []
}

function push_undo() {
	let copy = {}
	for (let k in game) {
		let v = game[k]
		if (k === "undo")
			continue
		else if (k === "log")
			v = v.length
		else if (typeof v === "object" && v !== null)
			v = object_copy(v)
		copy[k] = v
	}
	game.undo.push(copy)
}

function pop_undo() {
	let save_log = game.log
	let save_undo = game.undo
	game = save_undo.pop()
	save_log.length = game.log
	game.log = save_log
	game.undo = save_undo
}