"use strict"

exports.scenarios = [
	"Historical",
	"Free Deployment",
	// TODO: Avalon Digital scenarios?
]

exports.roles = [
	"Caesar",
	"Pompeius",
]

const { CARDS, SPACES, EDGES, BLOCKS } = require('./data')

function find_block(name) {
	return BLOCKS.findIndex(b => b.name === name)
}

function find_space(name) {
	return SPACES.findIndex(s => s.name === name)
}

const block_count = BLOCKS.length
const space_count = SPACES.length
const first_map_space = 2

const APOLLO = 1
const JUPITER = 2
const MARS = 3
const MERCURY = 4
const NEPTUNE = 5
const PLUTO = 6
const VULCAN = 7

const OBSERVER = "Observer"
const BOTH = "Both"
const CAESAR = "Caesar"
const POMPEIUS = "Pompeius"

const B_CAESAR = find_block("Caesar")
const B_POMPEIUS = find_block("Pompeius")
const B_CLEOPATRA = find_block("Cleopatra")
const B_OCTAVIAN = find_block("Octavian")
const B_BRUTUS = find_block("Brutus")
const B_ANTONIUS = find_block("Antonius")
const B_SCIPIO = find_block("Scipio")

const ALEXANDRIA = find_space("Alexandria")
const ROMA = find_space("Roma")
const DEAD = find_space("Dead")
const LEVY = find_space("Levy")

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

const ATTACK_MARK = "*"
const RESERVE_MARK = ""

let game = null

function random(n) {
	// Largest MLCG that will fit its state in a double.
	// Uses BigInt for arithmetic, so is an order of magnitude slower.
	// https://www.ams.org/journals/mcom/1999-68-225/S0025-5718-99-00996-5/S0025-5718-99-00996-5.pdf
	// m = 2**53 - 111
	return (game.seed = Number(BigInt(game.seed) * 5667072534355537n % 9007199254740881n)) % n
}

function logbr() {
	if (game.log.length > 0 && game.log[game.log.length-1] !== "")
		game.log.push("")
}

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

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

function log_battle(s) {
	game.log.push(game.active[0] + ": " + s)
}

function logp(s) {
	game.log.push(game.active + " " + s)
}

function log_move_start(from, to, mark = false) {
	if (mark)
		game.turn_buf = [ from, to, mark ]
	else
		game.turn_buf = [ from, to ]
}

function log_move_continue(to, mark = false) {
	if (mark)
		game.turn_buf.push(to, mark)
	else
		game.turn_buf.push(to)
}

function log_move_end() {
	if (game.turn_buf) {
		game.turn_log.push(game.turn_buf)
		delete game.turn_buf
	}
}

function log_levy(where) {
	game.turn_log.push([where])
}

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

	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.")
}

function print_turn_log(verb) {
	print_turn_log_no_active(game.active + " " + verb + ":")
}

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

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_pass(view, text) {
	if (!view.actions)
		view.actions = {}
	view.actions['pass'] = text
}

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

function gen_action_battle(view, action, b) {
	gen_action(view, action, b)
}

function gen_action_block(view, b) {
	gen_action(view, 'block', b)
}

function gen_action_space(view, s) {
	gen_action(view, 'space', s)
}

function edge_id(A, B) {
	if (A > B)
		return B * 100 + A
	return A * 100 + B
}

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

function reset_deck() {
	let deck = []
	for (let c = 1; c <= 27; ++c)
		if (!game.removed || !game.removed.includes(c))
			deck.push(c)
	return deck
}

function deal_cards(deck, n) {
	let hand = []
	let events = 0
	let max_events = (game.max_2_events ? 2 : n)
	while (hand.length < n) {
		let c = random(deck.length)
		if (events < max_events || deck[c] > 7) {
			if (deck[c] <= 7)
				++events
			set_add(hand, deck[c])
			deck.splice(c, 1)
		}
	}
	return hand
}

function reset_road_limits() {
	game.sea_moved = []
	game.sea_retreated = false
	game.limits = []
}

function road_limit(e) {
	return map_get(game.limits, e, 0)
}

function set_attacker(where, side) {
	if (side === CAESAR) {
		set_add(game.c_attacker, where)
		set_delete(game.p_attacker, where)
	} else {
		set_add(game.p_attacker, where)
		set_delete(game.c_attacker, where)
	}
}

function get_attacker(where) {
	if (set_has(game.c_attacker, where))
		return CAESAR
	if (set_has(game.p_attacker, where))
		return POMPEIUS
	return null
}

function move_to(who, from, to) {
	let e = edge_id(from, to)
	game.location[who] = to
	game.last_from = from
	map_set(game.limits, e, road_limit(e) + 1)
	if (is_contested_space(to)) {
		if (game.active === CAESAR) {
			set_add(game.c_last_used, e)
			set_delete(game.p_last_used, e)
		} else {
			set_add(game.p_last_used, e)
			set_delete(game.c_last_used, e)
		}
	}
}

function block_original_owner(who) {
	if (who >= B_CLEOPATRA)
		return POMPEIUS
	return CAESAR
}

function block_owner(who) {
	if (set_has(game.traitor, who))
		return enemy(block_original_owner(who))
	return block_original_owner(who)
}

function space_name(where) {
	return SPACES[where].name
}

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

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

function block_initiative(who) {
	if (block_type(who) === 'ballista')
		return is_defender(who) ? 'B' : 'D'
	return BLOCKS[who].initiative
}

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

function block_strength(who) {
	if (block_type(who) === 'elephant')
		return game.steps[who] * 2
	return game.steps[who]
}

function is_dead(b) {
	return game.location[b] === DEAD
}

function eliminate_block(who) {
	if (who === B_CLEOPATRA) {
		set_toggle(game.traitor, who)
		game.flash = "Cleopatra was captured."
		log("Cleopatra joined " + block_owner(who) + "!")
	} else {
		game.flash = block_name(who) + " was eliminated."
		log(block_name(who) + " was eliminated.")
		game.location[who] = DEAD
		game.steps[who] = BLOCKS[who].steps
		set_delete(game.traitor, who)
	}
}

function disband_block(who) {
	game.location[who] = LEVY
	game.steps[who] = BLOCKS[who].steps
	set_delete(game.traitor, who)
}

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

/* Game state queries */

function enemy(p) {
	return p === CAESAR ? POMPEIUS : CAESAR
}

function enemy_player() {
	return enemy(game.active)
}

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

function has_friendly(where) {
	let p = game.active
	for (let b = 0; b < block_count; ++b)
		if (game.location[b] === where && block_owner(b) === p)
			return true
	return false
}

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

function has_enemy(where) {
	let p = enemy_player()
	for (let b = 0; b < block_count; ++b)
		if (game.location[b] === where && block_owner(b) === p)
			return true
	return false
}

function count_pinning(where) {
	let count = 0
	if (game.active === game.p2) {
		let p = enemy_player()
		for (let b = 0; b < block_count; ++b) {
			if (game.location[b] === where && block_owner(b) === p)
				if (!game.reserves.includes(b))
					++count
		}
	}
	return count
}

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

function is_pinned(who) {
	if (game.active === game.p2) {
		let where = game.location[who]
		if (count_pinned(where) <= count_pinning(where))
			return true
	}
	return false
}

function is_city(where) {
	let t = SPACES[where].type
	return t === 'city' || t === 'major-port' || t === 'port'
}

function is_port(where) {
	let t = SPACES[where].type
	return t === 'major-port' || t === 'port'
}

function is_sea(where) {
	return SPACES[where].type === 'sea'
}

function is_map_space(where) {
	return where >= first_map_space
}

function is_navis(b) {
	return BLOCKS[b].type === 'navis'
}

function is_friendly_space(where) { return has_friendly(where) && count_enemy(where) === 0 }
function is_enemy_space(where) { return count_friendly(where) === 0 && has_enemy(where) }
function is_vacant_space(where) { return count_friendly(where) === 0 && count_enemy(where) === 0 }
function is_contested_space(where) { return has_friendly(where) && has_enemy(where) }

function is_friendly_city(where) { return is_city(where) && is_friendly_space(where) }
function is_enemy_city(where) { return is_city(where) && is_enemy_space(where) }
function is_contested_city(where) { return is_city(where) && is_contested_space(where) }

function is_friendly_sea(where) { return is_sea(where) && is_friendly_space(where) }
function is_vacant_sea(where) { return is_sea(where) && is_vacant_space(where) }
function is_contested_sea(where) { return is_sea(where) && is_contested_space(where) }

function have_contested_spaces() {
	for (let s = first_map_space; s < space_count; ++s)
		if (is_contested_space(s))
			return true
	return false
}

function supply_limit(where) {
	if (SPACES[where].type === 'sea')
		return 0
	return 3 + SPACES[where].value
}

function is_over_supply_limit(where) {
	let count = 0
	for (let b = 0; b < block_count; ++b) {
		if (game.location[b] === where)
			++count
	}
	return count > supply_limit(where)
}

function count_vp() {
	let old_active = game.active
	game.active = CAESAR
	game.c_vp = 0
	game.p_vp = 0
	game.active = CAESAR
	for (let s = first_map_space; s < space_count; ++s) {
		if (is_friendly_city(s))
			game.c_vp += SPACES[s].value
		if (is_enemy_city(s))
			game.p_vp += SPACES[s].value
	}
	if (is_dead(B_POMPEIUS)) game.c_vp += 1
	if (is_dead(B_SCIPIO)) game.c_vp += 1
	if (is_dead(B_BRUTUS)) game.c_vp += 1
	if (is_dead(B_CAESAR)) game.p_vp += 1
	if (is_dead(B_ANTONIUS)) game.p_vp += 1
	if (is_dead(B_OCTAVIAN)) game.p_vp += 1
	game.active = old_active
}

/* Game ability queries */

function can_amphibious_move_to(b, from, to) {
	let e = edge_id(from, to)
	if (EDGES[e] === 'sea') {
		if (is_city(to)) {
			if (is_friendly_space(to) || is_vacant_space(to)) {
				return true
			}
		} else {
			if (is_friendly_space(to)) {
				return true
			}
		}
	}
}

function can_amphibious_move(b) {
	if (block_owner(b) === game.active && !set_has(game.moved, b)) {
		if (BLOCKS[b].type === 'navis')
			return false
		if (is_pinned(b))
			return false
		let from = game.location[b]
		for (let to of SPACES[from].exits)
			if (can_amphibious_move_to(b, from, to))
				return true
	}
	return false
}

function can_regroup_to(b, from, to) {
	if (is_vacant_space(to) || is_friendly_space(to)) {
		let e = edge_id(from, to)
		let b_type = BLOCKS[b].type
		let e_type = EDGES[e]
		if (b_type === 'navis')
			return e_type === 'sea'
		if (e_type === 'major')
			return road_limit(e) < 4
		if (e_type === 'minor')
			return road_limit(e) < 2
		if (e_type === 'strait')
			return road_limit(e) < 2
	}
	return false
}

function can_block_use_road(b, from, to) {
	let e = edge_id(from, to)
	let b_type = BLOCKS[b].type
	let e_type = EDGES[e]

	if (b_type === 'navis') {
		if (game.mars === game.active)
			return false
		if (game.mercury === game.active)
			return false
		if (game.pluto === game.active)
			return false
		return e_type === 'sea'
	} else {
		if (game.neptune === game.active)
			return false
	}

	if (game.pluto === game.active) {
		if (is_enemy_space(to) || is_contested_space(to)) {
			if (e_type === 'major')
				return road_limit(e) < 6
			if (e_type === 'minor')
				return road_limit(e) < 3
			if (e_type === 'strait')
				return road_limit(e) < 2
		}
	}

	if (e_type === 'major')
		return road_limit(e) < 4
	if (e_type === 'minor')
		return road_limit(e) < 2
	if (e_type === 'strait') {
		if (is_enemy_space(to) || is_contested_space(to))
			return road_limit(e) < 1
		else
			return road_limit(e) < 2
	}
	return false
}

function can_block_use_road_to_retreat(b, from, to) {
	let e = edge_id(from, to)
	let b_type = BLOCKS[b].type
	let e_type = EDGES[e]
	if (b_type === 'navis')
		return e_type === 'sea'
	if (e_type === 'major')
		return road_limit(e) < 4
	if (e_type === 'minor')
		return road_limit(e) < 2
	if (e_type === 'strait')
		return road_limit(e) < 1
	return false
}

function did_active_last_use(e) {
	if (game.active === CAESAR)
		return set_has(game.c_last_used, e)
	return set_has(game.p_last_used, e)
}

function did_enemy_last_use(e) {
	if (game.active === CAESAR)
		return set_has(game.p_last_used, e)
	return set_has(game.c_last_used, e)
}

function can_block_move_to(b, to) {
	let from = game.location[b]
	if (can_block_use_road(b, from, to)) {
		if (count_pinning(from) > 0) {
			let e = edge_id(from, to)
			if (did_enemy_last_use(e))
				return false
		}
		return true
	}
	return false
}

function can_block_continue_to(b, to) {
	let from = game.location[b]
	if (is_friendly_space(to) || is_vacant_space(to))
		if (can_block_use_road(b, from, to))
			return true
	return false
}

function can_block_move(b) {
	if (block_owner(b) === game.active && !set_has(game.moved, b)) {
		let from = game.location[b]
		if (is_pinned(b))
			return false
		if (set_has(game.sea_moved, from) && count_friendly(from) <= 1)
			return false
		for (let to of SPACES[from].exits) {
			if (can_block_move_to(b, to)) {
				return true
			}
		}
	}
	return false
}

function can_block_continue(b, last_from) {
	let here = game.location[b]
	if (is_enemy_space(here) || is_contested_space(here))
		return false
	for (let to of SPACES[here].exits) {
		if (to !== last_from && can_block_continue_to(b, to))
			return true
	}
	return false
}

function can_sea_retreat(who, from, to) {
	if (game.sea_retreated)
		return false
	if (BLOCKS[who].type === 'navis')
		return false
	if (is_friendly_sea(to)) {
		for (let next of SPACES[to].exits)
			if (is_friendly_city(next))
				return true
	}
	return false
}

function can_attacker_retreat_to(who, from, to) {
	let e = edge_id(from, to)
	if (can_sea_retreat(who, from, to))
		return true
	if (is_vacant_space(to))
		if (can_block_use_road_to_retreat(who, from, to))
			if (did_active_last_use(e))
				return true
	if (is_friendly_space(to))
		if (can_block_use_road_to_retreat(who, from, to))
			return true
	return false
}

function can_defender_retreat_to(who, from, to) {
	let e = edge_id(from, to)
	if (BLOCKS[who].type === 'navis') {
		// Navis can only retreat to vacant seas, not ports!
		if (is_vacant_sea(to)) {
			if (can_block_use_road_to_retreat(who, from, to))
				if (!did_enemy_last_use(e))
					return true
		}
		// Navis can retreat to any friendly sea or port, even ones used by the attacker!
		if (is_friendly_space(to)) {
			if (can_block_use_road_to_retreat(who, from, to))
				return true
		}

	} else {
		if (can_sea_retreat(who, from, to))
			return true
		if (is_vacant_space(to) || is_friendly_space(to)) {
			if (can_block_use_road_to_retreat(who, from, to))
				if (!did_enemy_last_use(e))
					return true
		}
	}
	return false
}

function can_attacker_retreat(who) {
	let from = game.location[who]
	for (let to of SPACES[from].exits)
		if (can_attacker_retreat_to(who, from, to))
			return true
}

function can_defender_retreat(who) {
	let from = game.location[who]
	for (let to of SPACES[from].exits)
		if (can_defender_retreat_to(who, from, to))
			return true
}

function can_regroup(who) {
	let from = game.location[who]
	for (let to of SPACES[from].exits)
		if (can_regroup_to(who, from, to))
			return true
	return false
}

function can_navis_move_to_port(who) {
	let from = game.location[who]
	for (let to of SPACES[from].exits) {
		if (is_friendly_city(to))
			return true
	}
	return false
}

function can_levy_to(b, to) {
	if (is_friendly_city(to)) {
		if (BLOCKS[b].levy)
			return BLOCKS[b].levy === to
		if (BLOCKS[b].type === 'navis')
			return SPACES[to].type === 'major-port'
		if (b === B_OCTAVIAN)
			return is_dead(B_CAESAR) || is_dead(B_ANTONIUS)
		if (b === B_BRUTUS)
			return is_dead(B_POMPEIUS) || is_dead(B_SCIPIO)
		return true
	}
	return false
}

function can_levy(b) {
	let location = game.location[b]
	if (block_owner(b) !== game.active)
		return false
	if (location === LEVY) {
		for (let s = first_map_space; s < space_count; ++s)
			if (can_levy_to(b, s))
				return true
		return false
	}
	if (game.steps[b] === BLOCKS[b].steps)
		return false
	return is_friendly_city(game.location[b])
}

// === --- === --- === --- === --- === --- === //

let states = {}

function start_free_deployment() {
	game.active = CAESAR
	game.setup_limit = []
	for (let space = 0; space < space_count; ++space) {
		game.setup_limit[space] = count_friendly(space) + count_enemy(space)
	}
	validate_free_deployment()
	game.state = 'free_deployment'
	clear_undo()
}

function validate_free_deployment() {
	game.setup_error = []
	for (let space = first_map_space; space < space_count; ++space) {
		if (is_friendly_city(space)) {
			let n = count_friendly(space)
			let d = n - game.setup_limit[space]
			if (d > 0)
				game.setup_error.push(space + " +" + d)
			else if (d < 0)
				game.setup_error.push(space + " " + d)
		}
	}
}

function format_deployment_error(view) {
	view.prompt = "Free Deployment: " + game.setup_error.join(", ")
}

states.free_deployment = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to redeploy blocks..."
		gen_action_undo(view)
		if (game.setup_error.length === 0) {
			view.prompt = "Free Deployment: You may rearrange blocks on the map."
			gen_action_pass(view, "End deployment")
		} else {
			format_deployment_error(view)
		}
		for (let b = 0; b < block_count; ++b)
			if (block_owner(b) === game.active && is_map_space(game.location[b]))
				gen_action_block(view, b)
	},
	block: function (who) {
		push_undo()
		game.who = who
		game.state = 'free_deployment_to'
	},
	pass: function () {
		if (game.active === CAESAR) {
			clear_undo()
			game.moved = []
			game.active = POMPEIUS
		} else {
			game.moved = []
			delete game.setup_limit
			delete game.setup_error
			start_year()
		}
	},
	undo: pop_undo
}

states.free_deployment_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to redeploy blocks..."
		if (game.setup_error.length === 0) {
			view.prompt = "Free Deployment: You may rearrange blocks on the map."
		} else {
			format_deployment_error(view)
		}
		gen_action_undo(view)
		gen_action_block(view, game.who)
		for (let space = first_map_space; space < space_count; ++space) {
			if (game.setup_limit[space] > 0 && space !== game.location[game.who]) {
				if (!is_enemy_city(space)) {
					if (block_type(game.who) === 'navis') {
						if (is_port(space))
							gen_action_space(view, space)
					} else {
						gen_action_space(view, space)
					}
				}
			}
		}
	},
	space: function (where) {
		game.location[game.who] = where
		set_add(game.moved, game.who)
		validate_free_deployment()
		game.who = -1
		game.state = 'free_deployment'
	},
	block: pop_undo,
	undo: pop_undo
}

function start_year() {
	logbr()
	log(".h1 Year " + game.year)
	game.turn = 1
	let deck = reset_deck()
	game.c_hand = deal_cards(deck, 6)
	game.p_hand = deal_cards(deck, 6)
	game.prior_c_card = 0
	game.prior_p_card = 0
	game.c_card = 0
	game.p_card = 0
	game.c_discard = 0
	game.p_discard = 0
	game.active = BOTH
	game.state = 'discard_and_play_card'
	game.show_cards = false
}

function resume_discard_and_play_card() {
	if (game.c_card && game.p_card)
		start_first_turn()
	else if (game.c_card)
		game.active = POMPEIUS
	else if (game.p_card)
		game.active = CAESAR
	else
		game.active = BOTH
}

states.discard_and_play_card = {
	prompt: function (view, current) {
		if (current === "Observer")
			return view.prompt = "Waiting for players to discard one card and play one card."
		if (current === CAESAR) {
			if (!game.c_discard) {
				view.prompt = "Discard a card."
				for (let c of game.c_hand)
					gen_action(view, 'card', c)
			} else if (!game.c_card) {
				view.prompt = "Play a card."
				for (let c of game.c_hand)
					if (c !== APOLLO)
						gen_action(view, 'card', c)
				gen_action(view, 'undo')
			} else {
				view.prompt = "Waiting for Pompeius..."
			}
		}
		else if (current === POMPEIUS) {
			if (!game.p_discard) {
				view.prompt = "Discard a card."
				for (let c of game.p_hand)
					gen_action(view, 'card', c)
			} else if (!game.p_card) {
				view.prompt = "Play a card."
				for (let c of game.p_hand)
					if (c !== APOLLO)
						gen_action(view, 'card', c)
				gen_action(view, 'undo')
			} else {
				view.prompt = "Waiting for Caesar..."
			}
		}
	},
	card: function (c, current) {
		if (current === CAESAR) {
			if (!game.c_discard)
				game.c_discard = c
			else
				game.c_card = c
			set_delete(game.c_hand, c)
		}
		if (current === POMPEIUS) {
			if (!game.p_discard)
				game.p_discard = c
			else
				game.p_card = c
			set_delete(game.p_hand, c)
		}
		resume_discard_and_play_card()
	},
	undo: function (_, current) {
		if (current === CAESAR) {
			if (game.c_discard) {
				set_add(game.c_hand, game.c_discard)
				game.c_discard = 0
			}
			if (game.c_card) {
				set_add(game.c_hand, game.c_card)
				game.c_card = 0
			}
		}
		if (current === POMPEIUS) {
			if (game.p_discard) {
				set_add(game.p_hand, game.p_discard)
				game.p_discard = 0
			}
			if (game.p_card) {
				set_add(game.p_hand, game.p_card)
				game.p_card = 0
			}
		}
		resume_discard_and_play_card()
	}
}

function start_first_turn() {
	game.c_last_used = []
	game.p_last_used = []
	game.c_attacker = []
	game.p_attacker = []
	game.main_road = []
	game.moved = []
	game.reserves = []
	logbr()
	log(".h2 Turn " + game.turn + " of Year " + game.year)
	reveal_cards()
}

function start_turn() {
	game.c_last_used = []
	game.p_last_used = []
	game.c_attacker = []
	game.p_attacker = []
	game.main_road = []
	game.moved = []
	game.reserves = []
	game.c_card = 0
	game.p_card = 0
	game.active = BOTH
	game.state = 'play_card'
	game.show_cards = false
	game.surprise = 0
	logbr()
	log(".h2 Turn " + game.turn + " of Year " + game.year)
}

function resume_play_card() {
	if (game.c_card && game.p_card)
		reveal_cards()
	else if (game.c_card)
		game.active = POMPEIUS
	else if (game.p_card)
		game.active = CAESAR
	else
		game.active = BOTH
}

states.play_card = {
	prompt: function (view, current) {
		if (current === "Observer") {
			view.prior_c_card = game.prior_c_card
			view.prior_p_card = game.prior_p_card
			return view.prompt = "Waiting for players to play a card."
		}
		if (current === CAESAR) {
			view.prior_p_card = game.prior_p_card
			if (game.c_card) {
				view.prompt = "Waiting for Pompeius to play a card."
			} else {
				view.prior_c_card = game.prior_c_card
				view.prompt = "Play a card."
				for (let c of game.c_hand)
					gen_action(view, 'card', c)
			}
		}
		if (current === POMPEIUS) {
			view.prior_c_card = game.prior_c_card
			if (game.p_card) {
				view.prompt = "Waiting for Caesar to play a card."
			} else {
				view.prior_p_card = game.prior_p_card
				view.prompt = "Play a card."
				for (let c of game.p_hand)
					gen_action(view, 'card', c)
			}
		}
	},
	card: function (card, current) {
		if (current === CAESAR) {
			set_delete(game.c_hand, card)
			game.c_card = card
		}
		if (current === POMPEIUS) {
			set_delete(game.p_hand, card)
			game.p_card = card
		}
		resume_play_card()
	},
	undo: function (_, current) {
		if (current === CAESAR) {
			if (game.c_card) {
				set_add(game.c_hand, game.c_card)
				game.c_card = 0
			}
		}
		if (current === POMPEIUS) {
			if (game.p_card) {
				set_add(game.p_hand, game.p_card)
				game.p_card = 0
			}
		}
		resume_play_card()
	}
}

function reveal_cards() {
	delete game.mars
	delete game.mercury
	delete game.neptune
	delete game.pluto

	logbr()
	log("Caesar played " + CARDS[game.c_card].name + ".")
	log("Pompeius played " + CARDS[game.p_card].name + ".")

	if (CARDS[game.c_card].event && CARDS[game.p_card].event) {
		log("Events canceled each other.")
		game.prior_c_card = game.c_card
		game.prior_p_card = game.p_card
		end_turn()
		return
	}

	if (game.c_card === APOLLO) {
		game.c_card = game.prior_p_card
		log("Apollo copied " + CARDS[game.c_card].name + ".")
	}
	if (game.p_card === APOLLO) {
		game.p_card = game.prior_c_card
		log("Apollo copied " + CARDS[game.p_card].name + ".")
	}

	game.prior_c_card = game.c_card
	game.prior_p_card = game.p_card

	if (CARDS[game.c_card].event) {
		game.p1 = CAESAR
		game.p2 = POMPEIUS
	} else if (CARDS[game.p_card].event) {
		game.p1 = POMPEIUS
		game.p2 = CAESAR
	} else if (CARDS[game.p_card].move > CARDS[game.c_card].move) {
		game.p1 = POMPEIUS
		game.p2 = CAESAR
	} else {
		game.p1 = CAESAR
		game.p2 = POMPEIUS
	}

	// Caesar always goes first on the first turn of the game.
	if (game.year === 705 && game.turn === 1) {
		if (game.p1 !== CAESAR) {
			game.p1 = CAESAR
			game.p2 = POMPEIUS
		}
	}

	game.show_cards = true
	game.active = game.p1
	start_player_turn()
}

function start_player_turn() {
	logbr()
	log(".h3 " + game.active)
	reset_road_limits()
	game.activated = []

	let card = (game.active === CAESAR ? CARDS[game.c_card] : CARDS[game.p_card])
	if (card.event) {
		switch (card.event) {
		// Apollo has already been handled in reveal_cards!
		case 'Jupiter':
			game.state = 'jupiter'
			break
		case 'Vulcan':
			game.state = 'vulcan'
			break
		case 'Mercury':
			game.mercury = game.active
			game.moves = 1
			game.levies = 0
			game.amphibious_available = false
			game.state = 'move_who'
			game.turn_log = []
			break
		case 'Pluto':
			game.pluto = game.active
			game.moves = 1
			game.levies = 0
			game.amphibious_available = false
			game.state = 'move_who'
			game.turn_log = []
			break
		case 'Mars':
			game.mars = game.active
			game.moves = 1
			game.levies = 0
			game.amphibious_available = false
			game.state = 'move_who'
			game.turn_log = []
			break
		case 'Neptune':
			game.neptune = game.active
			game.moves = 1
			game.levies = 0
			game.amphibious_available = false
			game.state = 'move_who'
			game.turn_log = []
			break
		}
	} else {
		game.moves = card.move
		game.levies = card.levy
		game.amphibious_available = true
		game.state = 'move_who'
		game.turn_log = []
	}

	clear_undo()
}

function jupiter_block(b) {
	let type = BLOCKS[b].type
	if (type === 'navis' || type === 'leader') {
		log("Jupiter reduced " + block_name(b) + ".")
		reduce_block(b)
		end_player_turn()
	} else {
		set_toggle(game.traitor, b)
		game.who = b
		game.state = 'jupiter_to'
	}
}

states.jupiter = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + "..."
		view.prompt = "Jupiter: Choose an enemy city adjacent to a friendly city."
		for (let s = first_map_space; s < space_count; ++s) {
			if (is_friendly_city(s)) {
				for (let to of SPACES[s].exits)
					if (is_enemy_city(to) || is_contested_city(to))
						gen_action_space(view, to)
			}
		}
		gen_action_pass(view, "Pass")
	},
	space: function (where) {
		/* pick a random block */
		let list = []
		for (let b = 0; b < block_count; ++b)
			if (game.location[b] === where)
				list.push(b)
		let i = random(list.length)
		jupiter_block(list[i])
	},
	pass: function () {
		end_player_turn()
	},
}

states.jupiter_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + "..."
		view.prompt = "Jupiter: Move " + block_name(game.who) + " to your city."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits)
			if (is_friendly_city(to))
				gen_action_space(view, to)
	},
	space: function (to) {
		log(block_name(game.who) + " joined " + game.active + ":")
		logi("#"+game.location[game.who] + " \u2192 #" + to + ".")
		game.location[game.who] = to
		game.who = -1
		end_player_turn()
	},
}

states.vulcan = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + "..."
		view.prompt = "Vulcan: Choose an enemy city to suffer a volcanic eruption."
		for (let s = first_map_space; s < space_count; ++s)
			if (is_enemy_city(s))
				gen_action_space(view, s)
	},
	space: function (city) {
		log("Vulcan struck #" + city + "!")
		game.where = city
		game.vulcan = []
		for (let b = 0; b < block_count; ++b) {
			if (game.location[b] === city) {
				// Exception: Cleopatra at strength 1 is not affected.
				if (b === B_CLEOPATRA && game.steps[b] === 1)
					continue
				game.vulcan.push(b)
			}
		}
		game.active = enemy(game.active)
		game.state = 'apply_vulcan'
	},
}

states.apply_vulcan = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + "..."
		view.prompt = "Apply Vulcan hits in " + space_name(game.where) + "."
		for (let i = 0; i < game.vulcan.length; ++i)
			gen_action_block(view, game.vulcan[i])
	},
	block: function (who) {
		reduce_block(who)
		// NOTE: Cleopatra cannot switch sides in 2nd edition
		remove_from_array(game.vulcan, who)
		if (game.vulcan.length === 0) {
			delete game.vulcan
			game.where = -1
			game.active = enemy(game.active)
			end_player_turn()
		}
	},
}

function goto_mars_and_neptune() {
	game.surprise_list = []
	for (let s = first_map_space; s < space_count; ++s)
		if (is_contested_space(s))
			game.surprise_list.push(s)
	if (game.surprise_list.length === 0) {
		delete game.surprise_list
		return end_player_turn()
	}
	if (game.surprise_list.length === 1) {
		game.surprise = game.surprise_list[0]
		log("Surprise attack in #" + game.surprise + ".")
		delete game.surprise_list
		return end_player_turn()
	}
	game.state = 'mars_and_neptune'
}

states.mars_and_neptune = {
	prompt: function (view, current) {
		let god = game.mars === game.active ? "Mars: " : "Neptune: "
		if (is_inactive_player(current))
			return view.prompt = god + ": Waiting for " + game.active + "."
		view.prompt = god + "Select battle for surprise attack."
		for (let space of game.surprise_list)
			gen_action_space(view, space)
	},
	space: function (where) {
		game.surprise = where
		log("Surprise attack in #" + game.surprise + ".")
		delete game.surprise_list
		end_player_turn()
	},
}

function is_amphibious_move(who, from, to) {
	if (BLOCKS[who].type === 'navis')
		return false
	let e = edge_id(from, to)
	if (EDGES[e] === 'sea')
		return true
	return false
}

function move_or_attack(to) {
	let from = game.location[game.who]
	move_to(game.who, from, to)
	if (is_enemy_space(to) || is_contested_space(to)) {
		let attacker = get_attacker(to)
		let e = edge_id(from, to)
		if (!attacker) {
			set_attacker(to, game.active)
			set_add(game.main_road, e)
			return ATTACK_MARK
		} else {
			if (attacker !== game.active || !set_has(game.main_road, e)) {
				game.reserves.push(game.who)
				return RESERVE_MARK
			}
			return ATTACK_MARK
		}
	}
	return false; // not a combat move
}

states.move_who = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to move..."
		if (game.pluto === game.active)
			view.prompt = "Pluto: Move one group. Road limits increase for attacks. No Navis movement."
		else if (game.mars === game.active)
			view.prompt = "Mars: Move one group. No Navis movement."
		else if (game.neptune === game.active)
			view.prompt = "Neptune: Move only the Navis in one group."
		else if (game.mercury === game.active)
			view.prompt = "Mercury: Move one group three cities, or two cities and attack. No Navis movement."
		else if (game.amphibious_available)
			view.prompt = "Choose an army to group or amphibious move. "+game.moves+"MP left."
		else
			view.prompt = "Choose an army to group move. "+game.moves+"MP left."
		if (game.moves === 0) {
			for (let b = 0; b < block_count; ++b) {
				let from = game.location[b]
				if (game.activated.includes(from))
					if (can_block_move(b))
						gen_action_block(view, b)
			}
		} else {
			let have_amphibious = false
			for (let b = 0; b < block_count; ++b) {
				let can_move = false
				if (game.amphibious_available && can_amphibious_move(b)) {
					can_move = true
					have_amphibious = true
				}
				if (can_block_move(b))
					can_move = true
				if (can_move)
					gen_action_block(view, b)
			}
			if (!have_amphibious)
				game.amphibious_available = false
		}
		gen_action_pass(view, "End movement phase")
		gen_action_undo(view)
	},
	block: function (who) {
		push_undo()
		game.who = who
		if (game.mercury === game.active)
			game.state = 'mercury_move_1'
		else
			game.state = 'move_where'
	},
	pass: function () {
		push_undo()
		end_movement()
	},
	undo: pop_undo,
}

states.move_where = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to move..."
		view.prompt = "Move " + block_name(game.who) + "."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits) {
			let can_move_to = false
			if (game.amphibious_available && can_amphibious_move_to(game.who, from, to))
				can_move_to = true
			if (can_block_move_to(game.who, to))
				can_move_to = true
			if (can_move_to)
				gen_action_space(view, to)
		}
		gen_action_block(view, game.who); // for canceling move
		gen_action_undo(view)
	},
	space: function (to) {
		let from = game.location[game.who]
		if (is_amphibious_move(game.who, from, to)) {
			game.moves --
			game.location[game.who] = to
			game.last_from = from
			log_move_start(from, to)
			logp("amphibious moved.")
			if (is_sea(to)) {
				set_add(game.sea_moved, to)
				game.state = 'amphibious_move_to'
			} else {
				set_add(game.moved, game.who)
				game.who = -1
				game.state = 'move_who'
				log_move_end()
			}
		} else {
			if (!game.activated.includes(from)) {
				logp("activated #" + from + ".")
				game.moves --
				game.activated.push(from)
			}
			game.amphibious_available = false
			let mark = move_or_attack(to)
			log_move_start(from, to, mark)
			if (can_block_continue(game.who, game.last_from)) {
				game.state = 'move_where_2'
			} else {
				set_add(game.moved, game.who)
				game.who = -1
				game.state = 'move_who'
				log_move_end()
			}
		}
	},
	block: pop_undo,
	undo: pop_undo,
}

states.move_where_2 = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to move..."
		view.prompt = "Move " + block_name(game.who) + "."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits)
			if (to !== game.last_from && can_block_continue_to(game.who, to))
				gen_action_space(view, to)
		gen_action_space(view, from); // For ending move early.
		gen_action_undo(view)
	},
	space: function (to) {
		let from = game.location[game.who]
		if (to !== from) {
			log_move_continue(to)
			move_to(game.who, from, to)
		}
		set_add(game.moved, game.who)
		game.who = -1
		game.state = 'move_who'
		log_move_end()
	},
	undo: pop_undo,
}

states.amphibious_move_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to move..."
		view.prompt = "Move " + block_name(game.who) + " to a friendly sea or port."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits)
			if (to !== game.last_from && can_amphibious_move_to(game.who, from, to))
				gen_action_space(view, to)
		gen_action_undo(view)
	},
	space: function (to) {
		let from = game.location[game.who]
		game.last_from = from
		game.location[game.who] = to
		log_move_continue(to)
		if (is_sea(to)) {
			set_add(game.sea_moved, to)
			game.state = 'amphibious_move_to'
		} else {
			set_add(game.moved, game.who)
			game.who = -1
			game.state = 'move_who'
			log_move_end()
		}
	},
	undo: pop_undo,
}

states.mercury_move_1 = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to move..."
		view.prompt = "Mercury: Move " + block_name(game.who) + "."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits)
			if (can_block_move_to(game.who, to))
				gen_action_space(view, to)
		gen_action_undo(view)
	},
	space: function (to) {
		let from = game.location[game.who]
		if (!game.activated.includes(from)) {
			logp("activated #" + from + ".")
			game.moves --
			game.activated.push(from)
		}
		let mark = move_or_attack(to)
		log_move_start(from, to, mark)
		if (!is_contested_space(to) && can_block_move(game.who)) {
			game.state = 'mercury_move_2'
		} else {
			game.who = -1
			game.state = 'move_who'
			log_move_end()
		}
	},
	undo: pop_undo,
}

states.mercury_move_2 = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to move..."
		view.prompt = "Mercury: Move " + block_name(game.who) + "."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits)
			if (to !== game.last_from && can_block_move_to(game.who, to))
				gen_action_space(view, to)
		gen_action_space(view, from); // For ending move early.
		gen_action_undo(view)
	},
	space: function (to) {
		let from = game.location[game.who]
		if (to !== from) {
			let mark = move_or_attack(to)
			log_move_continue(to, mark)
			if (can_block_continue(game.who, game.last_from)) {
				game.state = 'mercury_move_3'
			} else {
				set_add(game.moved, game.who)
				game.who = -1
				game.state = 'move_who'
				log_move_end()
			}
		} else {
			set_add(game.moved, game.who)
			game.who = -1
			game.state = 'move_who'
			log_move_end()
		}
	},
	undo: pop_undo,
}

states.mercury_move_3 = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to move..."
		view.prompt = "Mercury: Move " + block_name(game.who) + "."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits)
			if (to !== game.last_from && can_block_continue_to(game.who, to))
				gen_action_space(view, to)
		gen_action_space(view, from); // For ending move early.
		gen_action_undo(view)
	},
	space: function (to) {
		let from = game.location[game.who]
		if (to !== from) {
			log_move_continue(to)
			move_to(game.who, from, to)
		}
		set_add(game.moved, game.who)
		game.who = -1
		game.state = 'move_who'
		log_move_end()
	},
	undo: pop_undo,
}

function end_movement() {
	print_turn_log("moved")

	if (game.mars === game.active || game.neptune === game.active)
		return goto_mars_and_neptune()

	if (game.pluto === game.active || game.mercury === game.active)
		return end_player_turn()

	game.who = -1
	game.moves = 0
	game.state = 'levy'
	game.turn_log = []
}

states.levy = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to levy..."
		view.prompt = "Choose an army to levy. "+game.levies+"LP left."
		let is_levy_possible = false
		if (game.levies > 0) {
			for (let b = 0; b < block_count; ++b) {
				if (can_levy(b)) {
					gen_action_block(view, b)
					is_levy_possible = true
				}
			}
		}
		if (!is_levy_possible)
			gen_action_pass(view, "End levy phase")
		gen_action_undo(view)
	},
	block: function (who) {
		push_undo()
		if (game.location[who] === LEVY) {
			if (BLOCKS[who].levy) {
				let to = BLOCKS[who].levy
				log_levy(to)
				game.levies --
				game.steps[who] = 1
				game.location[who] = to
			} else {
				game.who = who
				game.state = 'levy_where'
			}
		} else {
			log_levy(game.location[who])
			game.levies --
			game.steps[who]++
			game.state = 'levy'
		}
	},
	pass: function () {
		end_player_turn()
	},
	undo: pop_undo,
}

states.levy_where = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to levy..."
		view.prompt = "Choose a friendly city to levy " + block_name(game.who) + " in."
		for (let s = first_map_space; s < space_count; ++s)
			if (can_levy_to(game.who, s))
				gen_action_space(view, s)
		gen_action_block(view, game.who); // for canceling levy
		gen_action_undo(view)
	},
	space: function (to) {
		log_levy(to)
		game.levies --
		game.steps[game.who] = 1
		game.location[game.who] = to
		game.who = -1
		game.state = 'levy'
	},
	block: pop_undo,
	undo: pop_undo,
}

function end_player_turn() {
	clear_undo()

	if (game.turn_log)
		print_turn_log("levied")

	if (game.active === game.p1) {
		game.active = game.p2
		start_player_turn()
	} else {
		goto_pick_battle()
	}
}

function goto_pick_battle() {
	reset_road_limits()
	game.active = game.p1
	if (have_contested_spaces())
		game.state = 'pick_battle'
	else
		end_turn()
}

states.pick_battle = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to pick a battle..."
		view.prompt = "Choose the next battle to fight!"
		for (let s = first_map_space; s < space_count; ++s)
			if (is_contested_city(s) || is_contested_sea(s))
				gen_action_space(view, s)
	},
	space: function (where) {
		game.where = where
		start_battle()
	},
}

function is_attacker(b) {
	if (game.location[b] === game.where && block_owner(b) === get_attacker(game.where))
		return !game.reserves.includes(b)
	return false
}

function is_defender(b) {
	if (game.location[b] === game.where && block_owner(b) !== get_attacker(game.where))
		return !game.reserves.includes(b)
	return false
}

function count_attackers() {
	let count = 0
	for (let b = 0; b < block_count; ++b) {
		if (is_attacker(b))
			++count
	}
	return count
}

function count_defenders() {
	let count = 0
	for (let b = 0; b < block_count; ++b) {
		if (is_defender(b))
			++count
	}
	return count
}

function start_battle() {
	game.battle_round = 0
	game.flash = ""
	game.hits = 0
	logbr()
	log(".h4 Battle in #" + game.where)
	if (game.surprise === game.where)
		log("Surprise attack.")
	game.state = 'battle_round'
	start_battle_round()
}

function resume_battle() {
	game.who = -1
	game.state = 'battle_round'
	pump_battle_round()
}

function bring_on_reserves() {
	for (let b = 0; b < block_count; ++b) {
		if (game.location[b] === game.where) {
			remove_from_array(game.reserves, b)
		}
	}
}

function goto_disrupt_reserves() {
	game.flash = "Reserves were disrupted."
	game.disrupted = []
	for (let b = 0; b < block_count; ++b)
		if (game.location[b] === game.where && block_owner(b) === get_attacker(game.where))
			if (game.reserves.includes(b))
				game.disrupted.push(b)
	game.active = get_attacker(game.where)
	game.state = 'disrupt_reserves'
}

function disrupt_block(who) {
	game.flash = "Reserves were disrupted."
	reduce_block(who)
	remove_from_array(game.disrupted, who)
	if (game.disrupted.length === 0)
		end_disrupt_reserves()
}

function end_disrupt_reserves() {
	game.state = 'battle_round'
	game.flash = ""
	delete game.disrupted
	bring_on_reserves()
	log(".h5 Battle Round " + game.battle_round)
	pump_battle_round()
}

states.disrupt_reserves = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to apply disruption hits..."
		view.prompt = "Apply disruption hits to reserves."
		for (let b of game.disrupted) {
			gen_action_battle(view, 'battle_hit', b)
			gen_action_block(view, b)
		}
	},
	block: disrupt_block,
	battle_hit: disrupt_block,
}

function start_battle_round() {
	if (++game.battle_round <= 4) {
		if (game.turn_log && game.turn_log.length > 0)
			print_turn_log_no_active("Retreated from #" + game.where + ":")
		game.turn_log = []

		reset_road_limits()
		game.moved = []

		if (game.battle_round === 2) {
			if (game.surprise === game.where)
				game.surprise = 0
			if (count_defenders() === 0) {
				log("Defending main force was eliminated.")
				log("Defending reserves were disrupted.")
				log("Battlefield control changed.")
				set_attacker(game.where, enemy(get_attacker(game.where)))
				return goto_disrupt_reserves()
			} else if (count_attackers() === 0) {
				log("Attacking main force was eliminated.")
				log("Attacking reserves were disrupted.")
				return goto_disrupt_reserves()
			}
			bring_on_reserves()
		}

		log(".h5 Battle Round " + game.battle_round)

		pump_battle_round()
	} else {
		end_battle()
	}
}

function pump_battle_round() {
	function filter_battle_blocks(ci, is_candidate) {
		let output = null
		for (let b = 0; b < block_count; ++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 true
		}
		return false
	}

	if (is_friendly_space(game.where) || is_enemy_space(game.where)) {
		end_battle()
	} else if (count_attackers() === 0 || count_defenders() === 0) {
		start_battle_round()
	} else {
		let attacker = get_attacker(game.where)
		let defender = enemy(attacker)

		if (game.surprise === game.where) {
			if (battle_step(attacker, 'A', is_attacker)) return
			if (battle_step(attacker, 'B', is_attacker)) return
			if (battle_step(attacker, 'C', is_attacker)) return
			if (battle_step(attacker, 'D', is_attacker)) return
			if (battle_step(defender, 'A', is_defender)) return
			if (battle_step(defender, 'B', is_defender)) return
			if (battle_step(defender, 'C', is_defender)) return
			if (battle_step(defender, 'D', is_defender)) return
		} else {
			if (battle_step(defender, 'A', is_defender)) return
			if (battle_step(attacker, 'A', is_attacker)) return
			if (battle_step(defender, 'B', is_defender)) return
			if (battle_step(attacker, 'B', is_attacker)) return
			if (battle_step(defender, 'C', is_defender)) return
			if (battle_step(attacker, 'C', is_attacker)) return
			if (battle_step(defender, 'D', is_defender)) return
			if (battle_step(attacker, 'D', is_attacker)) return
		}

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

		start_battle_round()
	}
}

function end_battle() {
	if (game.turn_log && game.turn_log.length > 0)
		print_turn_log_no_active("Retreated from #" + game.where + ":")
	if (game.surprise === game.where)
		game.surprise = 0
	game.flash = ""
	game.battle_round = 0
	reset_road_limits()
	game.moved = []
	goto_regroup()
}

function can_fire_with_block(b) {
	if (is_attacker(b))
		return game.battle_round < 4
	if (is_defender(b))
		return true
	return false
}

function count_enemy_hp_in_battle() {
	let is_candidate = (game.active === get_attacker(game.where)) ? is_defender : is_attacker
	let n = 0
	for (let b = 0; b < block_count; ++b)
		if (is_candidate(b))
			n += game.steps[b]
	return n
}

function must_apply_hits() {
	if (game.immediate)
		return game.hits > 0
	return game.hits >= count_enemy_hp_in_battle()
}

function fire_with_block(b) {
	set_add(game.moved, b)
	let strength = block_strength(b)
	let fire = block_fire_power(b)
	let name = block_name(b) + " " + block_initiative(b) + fire

	let rolls = []
	let hits = 0
	for (let i = 0; i < strength; ++i) {
		let die = roll_d6()
		if (die <= fire) {
			rolls.push(DIE_HIT[die])
			++hits
		} else {
			rolls.push(DIE_MISS[die])
		}
	}
	game.hits += hits

	log_battle(name + " fired " + rolls.join("") + ".")

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

	if (must_apply_hits()) {
		game.active = enemy(game.active)
		goto_battle_hits()
	} else {
		resume_battle()
	}
}

function can_retreat_with_block(who) {
	if (game.location[who] === game.where) {
		if (game.battle_round > 1) {
			if (block_owner(who) === get_attacker(game.where))
				return can_attacker_retreat(who)
			else
				return can_defender_retreat(who)
		}
	}
	return false
}

function must_retreat_with_block(who) {
	if (game.location[who] === game.where)
		if (game.battle_round === 4)
			return (block_owner(who) === get_attacker(game.where))
	return false
}

function retreat_with_block(who) {
	if (can_retreat_with_block(who)) {
		game.who = who
		game.state = 'retreat'
	} else {
		eliminate_block(who)
		resume_battle()
	}
}

function pass_with_block(who) {
	game.flash = block_name(who) + " passed."
	log_battle(block_name(who) + " passed.")
	set_add(game.moved, who)
	resume_battle()
}

states.battle_round = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to choose a combat action..."
		let can_fire = false
		let can_retreat = false
		let must_retreat = false
		let can_pass = false
		if (game.active === get_attacker(game.where)) {
			if (game.battle_round < 4) can_fire = true
			if (game.battle_round > 1) can_retreat = true
			if (game.battle_round < 4) can_pass = true
			if (game.battle_round === 4) must_retreat = true
		} else {
			can_fire = true
			if (game.battle_round > 1) can_retreat = true
			can_pass = true
		}
		if (can_fire && can_retreat)
			view.prompt = "Fire, retreat, or pass with an army."
		else if (can_fire)
			view.prompt = "Fire or pass with an army."
		else
			view.prompt = "Retreat with an army."
		for (let b of game.battle_list) {
			if (can_fire) gen_action_battle(view, 'battle_fire', b)
			if (must_retreat || (can_retreat && can_retreat_with_block(b)))
				gen_action_battle(view, 'battle_retreat', b)
			if (can_pass) gen_action_battle(view, 'battle_pass', b)
			gen_action_block(view, 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_battle_hits()
	},
	block: function (who) {
		if (can_fire_with_block(who))
			fire_with_block(who)
		else if (can_retreat_with_block(who))
			retreat_with_block(who)
		else if (must_retreat_with_block(who))
			retreat_with_block(who)
		else
			pass_with_block(who)
	},
	battle_fire: function (who) {
		fire_with_block(who)
	},
	battle_retreat: function (who) {
		retreat_with_block(who)
	},
	battle_pass: function (who) {
		pass_with_block(who)
	},
}

function goto_battle_hits() {
	game.battle_list = list_victims(game.active)

	if (game.autohit) {
		let n = 0
		while (game.hits >= game.battle_list.length && game.battle_list.length > 0) {
			while (game.battle_list.length > 0) {
				let who = game.battle_list.pop()
				log_battle(block_name(who) + " took a hit.")
				reduce_block(who, 'combat')
				game.hits--
				++n
			}
			if (game.hits > 0)
				game.battle_list = list_victims(game.active)
		}
		if (n > 0)
			game.flash += ` Assigned ${n}.`
	}

	if (game.battle_list.length === 0) {
		game.hits = 0
		resume_battle()
	} else {
		game.state = 'battle_hits'
	}
}

function list_victims(p) {
	let is_candidate = (p === get_attacker(game.where)) ? is_attacker : is_defender
	let max = 0
	for (let b = 0; b < block_count; ++b)
		if (is_candidate(b) && block_strength(b) > max)
			max = block_strength(b)
	let list = []
	for (let b = 0; b < block_count; ++b)
		if (is_candidate(b) && block_strength(b) === max)
			list.push(b)
	return list
}

function apply_hit(who) {
	game.flash = block_name(who) + " took a hit."
	log_battle(block_name(who) + " took a hit.")
	reduce_block(who)
	game.hits--
	if (game.hits === 0)
		resume_battle()
	else {
		game.battle_list = list_victims(game.active)
		if (game.battle_list.length === 0) {
			game.hits = 0
			resume_battle()
		} else {
			game.flash += " " + game.hits + (game.hits === 1 ? " hit left." : " hits left.")
		}
	}
}

states.battle_hits = {
	show_battle: true,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to apply hits..."
		view.prompt = "Assign " + game.hits + (game.hits !== 1 ? " hits" : " hit") + " to your armies."
		for (let b of game.battle_list) {
			gen_action_battle(view, 'battle_hit', b)
			gen_action_block(view, b)
		}
	},
	block: function (who) {
		apply_hit(who)
	},
	battle_hit: function (who) {
		apply_hit(who)
	},
}

states.retreat = {
	show_battle: false,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to retreat..."
		view.prompt = "Retreat " + block_name(game.who) + "."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits) {
			if (block_owner(game.who) === get_attacker(from)) {
				if (can_attacker_retreat_to(game.who, from, to))
					gen_action_space(view, to)
			} else {
				if (can_defender_retreat_to(game.who, from, to))
					gen_action_space(view, to)
			}
		}
		gen_action(view, 'undo')
		gen_action_block(view, game.who)
	},
	space: function (to) {
		let from = game.location[game.who]
		if (is_sea(to) && !is_navis(game.who)) {
			push_undo()
			move_to(game.who, from, to)
			game.sea_retreated = true
			game.state = 'sea_retreat'
		} else {
			move_to(game.who, from, to)
			game.flash = block_name(game.who) + " retreated."
			log_battle(game.flash)
			game.turn_log.push([game.active, to])
			set_add(game.moved, game.who)
			resume_battle()
		}
	},
	block: function () {
		resume_battle()
	},
	undo: function () {
		resume_battle()
	},
}

states.sea_retreat = {
	show_battle: false,
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to retreat..."
		view.prompt = "Retreat " + block_name(game.who) + " to a friendly port."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits) {
			if (is_friendly_city(to))
				gen_action_space(view, to)
		}
		gen_action(view, 'undo')
	},
	space: function (to) {
		clear_undo()
		let from = game.location[game.who]
		game.flash = block_name(game.who) + " retreated."
		log_battle(game.flash)
		game.turn_log.push([game.active, from, to])
		move_to(game.who, from, to)
		set_add(game.moved, game.who)
		resume_battle()
	},
	undo: pop_undo,
}

function goto_regroup() {
	game.active = get_attacker(game.where)
	if (is_enemy_space(game.where))
		game.active = enemy(game.active)
	log(game.active + " won the battle in #" + game.where + "!")
	game.state = 'regroup'
	game.turn_log = []
	clear_undo()
}

states.regroup = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to regroup..."
		view.prompt = "Regroup: Choose an army to move."
		for (let b = 0; b < block_count; ++b) {
			if (game.location[b] === game.where) {
				if (can_regroup(b))
					gen_action_block(view, b)
			}
		}
		gen_action_pass(view, "End regroup")
		gen_action_undo(view)
	},
	block: function (who) {
		push_undo()
		game.who = who
		game.state = 'regroup_to'
	},
	pass: function () {
		print_turn_log("regrouped")
		clear_undo()
		game.where = -1
		goto_pick_battle()
	},
	undo: pop_undo,
}

states.regroup_to = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to regroup..."
		view.prompt = "Regroup: Move " + block_name(game.who) + " to a friendly or vacant location."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits) {
			if (can_regroup_to(game.who, from, to))
				gen_action_space(view, to)
		}
		gen_action_block(view, game.who); // for canceling move
		gen_action_undo(view)
	},
	space: function (to) {
		let from = game.location[game.who]
		game.turn_log.push([from, to])
		move_to(game.who, from, to)
		game.who = -1
		game.state = 'regroup'
	},
	block: pop_undo,
	undo: pop_undo,
}

function end_turn() {
	game.moved = []
	if (game.turn === 5) {
		cleopatra_goes_home()
		check_victory()
	} else {
		game.turn ++
		start_turn()
	}
}

function cleopatra_goes_home() {
	game.active = CAESAR
	if (game.location[B_CLEOPATRA] !== ALEXANDRIA)
		log("Cleopatra went home to Alexandria.")
	if (is_friendly_space(ALEXANDRIA))
		set_add(game.traitor, B_CLEOPATRA)
	else
		set_delete(game.traitor, B_CLEOPATRA)
	game.location[B_CLEOPATRA] = ALEXANDRIA
}

function check_victory() {
	count_vp()
	if (game.c_vp >= 10) {
		game.result = CAESAR
		game.active = null
		game.state = 'game_over'
		game.victory = "Caesar won an early victory."
		logbr()
		log(game.victory)
	} else if (game.p_vp >= 10) {
		game.victory = "Pompeius won an early victory."
		game.result = POMPEIUS
		game.active = null
		game.state = 'game_over'
		logbr()
		log(game.victory)
	} else {
		if (game.year === 709) {
			end_game()
		} else {
			logbr()
			log(".h2 Winter Turn of Year " + game.year)
			logbr()
			start_navis_to_port()
		}
	}
}

function count_navis_to_port() {
	let count = 0
	for (let b = 0; b < block_count; ++b) {
		if (block_owner(b) === game.active && BLOCKS[b].type === 'navis')
			if (SPACES[game.location[b]].type === 'sea')
				if (can_navis_move_to_port(b))
					++count
	}
	return count
}

function start_navis_to_port() {
	game.active = CAESAR
	let count = count_navis_to_port()
	if (count > 0) {
		game.state = 'navis_to_port'
		game.turn_log = []
		clear_undo()
	} else {
		next_navis_to_port()
	}
}

function next_navis_to_port() {
	if (game.active === CAESAR) {
		game.active = POMPEIUS
		let count = count_navis_to_port()
		if (count > 0) {
			game.state = 'navis_to_port'
			game.turn_log = []
			clear_undo()
			return
		}
	}
	clear_undo()
	winter_supply()
}

states.navis_to_port = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to move navis to port..."
		view.prompt = "Move all Navis to a friendly port."
		let count = 0
		for (let b = 0; b < block_count; ++b) {
			if (block_owner(b) === game.active && BLOCKS[b].type === 'navis') {
				if (SPACES[game.location[b]].type === 'sea') {
					if (can_navis_move_to_port(b)) {
						gen_action_block(view, b)
						++count
					}
				}
			}
		}
		if (count > 0)
			view.prompt += " " + count + " left."
		if (count === 0)
			gen_action_pass(view, "End navis to port")
		gen_action_undo(view)
	},
	block: function (who) {
		push_undo()
		game.who = who
		game.state = 'navis_to_port_where'
	},
	pass: function () {
		print_turn_log("moved to port")
		next_navis_to_port()
	},
	undo: pop_undo,
}

states.navis_to_port_where = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to move navis to port..."
		view.prompt = "Move " + block_name(game.who) + " to a friendly port."
		let from = game.location[game.who]
		for (let to of SPACES[from].exits) {
			if (is_friendly_city(to))
				gen_action_space(view, to)
		}
		gen_action_block(view, game.who); // for canceling move
		gen_action_undo(view)
	},
	space: function (to) {
		let from = game.location[game.who]
		game.turn_log.push([from, to])
		game.location[game.who] = to
		game.who = -1
		game.state = 'navis_to_port'
	},
	block: pop_undo,
	undo: pop_undo,
}

function winter_supply() {
	game.active = CAESAR
	game.state = 'disband'
	game.turn_log = []
	clear_undo()
}

states.disband = {
	prompt: function (view, current) {
		if (is_inactive_player(current))
			return view.prompt = "Waiting for " + game.active + " to disband..."
		let okay_to_end = true
		for (let b = 0; b < block_count; ++b) {
			if (block_owner(b) === game.active && is_map_space(game.location[b]) && b !== B_CLEOPATRA) {
				if (is_over_supply_limit(game.location[b])) {
					okay_to_end = false
					gen_action_block(view, b)
				}
			}
		}

		if (!okay_to_end) {
			view.prompt = "Disband armies in excess of supply."
		} else {
			view.prompt = "You may disband armies to your levy pool."
			for (let b = 0; b < block_count; ++b) {
				if (is_map_space(game.location[b]))
					if (block_owner(b) === game.active && b !== B_CLEOPATRA)
						gen_action_block(view, b)
			}
			gen_action_pass(view, "End disbanding")

		}
		gen_action_undo(view)
	},
	block: function (who) {
		push_undo()
		game.turn_log.push([game.location[who]])
		disband_block(who)
	},
	pass: function () {
		print_turn_log("disbanded")
		if (game.active === CAESAR) {
			game.turn_log = []
			game.active = POMPEIUS
			clear_undo()
		} else {
			clear_undo()
			end_year()
		}
	},
	undo: pop_undo,
}

function end_year() {
	game.year ++
	for (let b = 0; b < block_count; ++b) {
		if (game.location[b] === DEAD && BLOCKS[b].type !== 'leader') {
			disband_block(b)
		}
	}
	start_year()
}

function end_game() {
	count_vp()
	if (game.c_vp > game.p_vp) {
		game.result = CAESAR
	} else if (game.c_vp < game.p_vp) {
		game.result = POMPEIUS
	} else {
		game.active = CAESAR
		if (is_friendly_space(ROMA))
			game.result = CAESAR
		else if (is_enemy_space(ROMA))
			game.result = POMPEIUS
		else
			game.result = null
	}
	if (game.result === CAESAR)
		game.victory = "Caesar won!"
	else if (game.result === POMPEIUS)
		game.victory = "Pompeius won!"
	else
		game.victory = "The game ended in a draw."
	game.active = null
	game.state = 'game_over'
	logbr()
	log(game.victory)
}

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

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

		c_hand: [],
		p_hand: [],
		c_card: 0,
		p_card: 0,
		state: null,
		show_cards: false,
		year: 705,
		turn: 0,
		location: [],
		steps: [],
		traitor: [],
		moved: [],
		limits: [],
		c_last_used: [],
		p_last_used: [],
		c_attacker: [],
		p_attacker: [],
		sea_moved: [],
		main_road: [],
		reserves: [],
	}

	if (scenario === "Historical")
		log(".h1 Historical Deployment")
	else
		log(".h1 " + scenario)
	logbr()

	if (options.max_2_events) {
		log("At most 2 events per hand.")
		game.max_2_events = 1
	}

	game.removed = []

	if (options.remove_apollo || options.remove_all_events) {
		log("Apollo removed from deck.")
		game.removed.push(APOLLO)
	}

	if (options.remove_jupiter || options.remove_all_events) {
		log("Jupiter removed from deck.")
		game.removed.push(JUPITER)
	}

	if (options.remove_mars || options.remove_all_events) {
		log("Mars removed from deck.")
		game.removed.push(MARS)
	}

	if (options.remove_mercury || options.remove_all_events) {
		log("Mercury removed from deck.")
		game.removed.push(MERCURY)
	}

	if (options.remove_neptune || options.remove_all_events) {
		log("Neptune removed from deck.")
		game.removed.push(NEPTUNE)
	}

	if (options.remove_pluto || options.remove_all_events) {
		log("Pluto removed from deck.")
		game.removed.push(PLUTO)
	}

	if (options.remove_vulcan || options.remove_all_events) {
		log("Vulcan removed from deck.")
		game.removed.push(VULCAN)
	}

	if (game.removed.length === 0)
		delete game.removed

	logbr()

	// Option for backwards compatible replays.
	if (options.autohit)
		game.autohit = 1
	if (options.immediate)
		game.immediate = 1

	setup_historical_deployment()
	if (scenario === "Free Deployment")
		start_free_deployment()
	else
		start_year()
	return game
}

function deploy_block(owner, location, name) {
	for (let b = 0; b < block_count; ++b) {
		if (block_original_owner(b) === owner && BLOCKS[b].name === name) {
			game.steps[b] = BLOCKS[b].steps
			game.location[b] = find_space(location)
			return
		}
	}
}

function setup_historical_deployment() {
	for (let b = 0; b < block_count; ++b) {
		game.location[b] = LEVY
		game.steps[b] = BLOCKS[b].steps
	}

	deploy_block("Caesar", "Ravenna", "Caesar")
	deploy_block("Caesar", "Ravenna", "Legio 13")
	deploy_block("Caesar", "Ravenna", "Navis 2")
	deploy_block("Caesar", "Genua", "Antonius")
	deploy_block("Caesar", "Genua", "Legio 8")
	deploy_block("Caesar", "Genua", "Legio 12")
	deploy_block("Caesar", "Massilia", "Legio 11")
	deploy_block("Caesar", "Massilia", "Legio 14")
	deploy_block("Caesar", "Massilia", "Navis 1")
	deploy_block("Caesar", "Narbo", "Legio 7")
	deploy_block("Caesar", "Narbo", "Legio 9")
	deploy_block("Caesar", "Narbo", "Legio 10")
	deploy_block("Caesar", "Lugdunum", "Legio 16")
	deploy_block("Caesar", "Lugdunum", "Equitatus 1")

	deploy_block("Pompeius", "Neapolis", "Pompeius")
	deploy_block("Pompeius", "Neapolis", "Legio 1")
	deploy_block("Pompeius", "Neapolis", "Navis 1")
	deploy_block("Pompeius", "Brundisium", "Legio 3")
	deploy_block("Pompeius", "Syracusae", "Legio 37")
	deploy_block("Pompeius", "Antiochia", "Scipio")
	deploy_block("Pompeius", "Antiochia", "Legio 34")
	deploy_block("Pompeius", "Alexandria", "Cleopatra")
	deploy_block("Pompeius", "Alexandria", "Navis 2")
	deploy_block("Pompeius", "Utica", "Legio 39")
	deploy_block("Pompeius", "Utica", "Navis 3")
	deploy_block("Pompeius", "Carthago Nova", "Legio 2")
	deploy_block("Pompeius", "Carthago Nova", "Legio 4")
	deploy_block("Pompeius", "Tarraco", "Legio 5")
	deploy_block("Pompeius", "Tarraco", "Legio 6")
	deploy_block("Pompeius", "Tarraco", "Equitatus 1")
}

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_battle_view() {
	let attacker = get_attacker(game.where)
	let bv = {
		A: attacker,
		CF: [], CR: [],
		PF: [], PR: [],
		flash: game.flash,
		where: game.where
	}

	bv.title = attacker
	if (game.surprise === game.where)
		bv.title += " surprise attacks "
	else
		bv.title += " attacks "
	bv.title += space_name(game.where)
	bv.title += " \u2014 round " + game.battle_round + " of 4"

	function is_battle_reserve(b) {
		return game.battle_round === 1 && game.reserves.includes(b)
	}

	function fill_cell(name, p, fn) {
		for (let b = 0; b < block_count; ++b) {
			if (game.location[b] === game.where & block_owner(b) === p && fn(b)) {
				bv[name].push(b)
			}
		}
	}

	fill_cell("CR", CAESAR, b => is_battle_reserve(b))
	fill_cell("CF", CAESAR, b => !is_battle_reserve(b))
	fill_cell("PR", POMPEIUS, b => is_battle_reserve(b))
	fill_cell("PF", POMPEIUS, b => !is_battle_reserve(b))

	return bv
}

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

exports.dont_snap = function(state) {
	if (state.state === "play_card" && state.active !== BOTH)
		return true
	if (state.state === "discard_and_play_card" && state.active !== BOTH)
		return true
	return false
}

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

	count_vp()

	let view = {
		log: game.log,
		year: game.year,
		turn: game.turn,
		active: game.active,
		c_vp: game.c_vp,
		p_vp: game.p_vp,
		c_card: (game.show_cards || current === CAESAR) ? game.c_card : 0,
		p_card: (game.show_cards || current === POMPEIUS) ? game.p_card : 0,
		hand: (current === CAESAR) ? game.c_hand : (current === POMPEIUS) ? game.p_hand : observer_hand(),
		who: (game.active === current) ? game.who : -1,
		location: game.location,
		traitor: game.traitor,
		steps: game.steps,
		moved: game.moved,
		limits: game.limits,
		last_used: [ game.c_last_used, game.p_last_used ],
		battle: null,
		prompt: null,
		actions: null,
	}

	if (game.main_road && game.main_road.length > 0)
		view.main_road = game.main_road

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

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

	if (game.mars && game.surprise) {
		view.mars = game.p1
		view.surprise = game.surprise
	}
	if (game.neptune && game.surprise) {
		view.neptune = game.p1
		view.surprise = game.surprise
	}

	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) {
		game.undo.length = 0
	}
}

function push_undo() {
	if (game.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() {
	if (game.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
	}
}