"use strict"

const R_FREDERICK = "Frederick"
const R_ELISABETH = "Elisabeth"
const R_MARIA_THERESA = "Maria Theresa"
const R_POMPADOUR = "Pompadour"

const SCENARIO_INDEX = {
	"4P": 4,
	"3P": 3,
	"The War in the West": 1,
	"The Austrian Theatre": 2,
}

const ROLE_NAME_1 = [
	R_FREDERICK,
	R_POMPADOUR,
]

const ROLE_NAME_2 = [
	R_FREDERICK,
	R_MARIA_THERESA,
]

const ROLE_NAME_3 = [
	R_FREDERICK,
	R_ELISABETH,
	R_MARIA_THERESA,
]

const ROLE_NAME_4 = [
	R_FREDERICK,
	R_ELISABETH,
	R_MARIA_THERESA,
	R_POMPADOUR,
]

exports.roles = function (scenario, _options) {
	let n = SCENARIO_INDEX[scenario]
	switch (n) {
		case 1: return ROLE_NAME_1
		case 2: return ROLE_NAME_2
		case 3: return ROLE_NAME_3
		case 4: return ROLE_NAME_4
	}
	return [ "Nobody" ]
}

exports.scenarios = Object.keys(SCENARIO_INDEX)

/* DATA */

var game
var view
var states = {}

const data = require("./data")

function find_city(city) {
	let n = data.cities.name.length
	let x = -1
	for (let c = 0; c < n; ++c) {
		if (data.cities.name[c] === city) {
			if (x < 0)
				x = c
			else
				throw "TWO CITIES: " + city
		}
	}
	if (x < 0)
		throw "CITY NOT FOUND: " + city
	return x
}

function find_city_list(names) {
	let list = []
	for (let n of names)
		set_add(list, find_city(n))
	return list
}

let suit_name = [ "\u2660", "\u2663", "\u2665", "\u2666", "\u2641" ]

const P_PRUSSIA = 0
const P_HANOVER = 1
const P_RUSSIA = 2
const P_SWEDEN = 3
const P_AUSTRIA = 4
const P_IMPERIAL = 5
const P_FRANCE = 6

const POWER_NAME = [ "Prussia", "Hanover", "Russia", "Sweden", "Austria", "Imperial Army", "France" ]

const SPADES = 0
const CLUBS = 1
const HEARTS = 2
const DIAMONDS = 3
const RESERVE = 4

// Strokes of Fate cards
const FC_POEMS = 13
const FC_LORD_BUTE = 14
const FC_ELISABETH = 15
const FC_SWEDEN = 16
const FC_INDIA = 17
const FC_AMERICA = 18

const ELIMINATED = data.cities.name.length
const REMOVED = ELIMINATED + 1

const max_power_troops_4 = [ 32, 12, 16, 4, 30, 6, 20 ]

function max_power_troops(pow) {
	if (game.scenario === 1 && pow === P_PRUSSIA)
		return 3
	if (game.scenario === 2 && pow === P_PRUSSIA)
		return 24
	let max = max_power_troops_4[pow]
	let n = 0
	for (let p of all_power_generals[pow])
		if (game.pos[p] < REMOVED)
			n += 8
	return Math.min(n, max)
}

const all_powers = [ 0, 1, 2, 3, 4, 5, 6 ]

const all_home_or_depot_cities = [
	data.country.Prussia,
	data.country.Hanover,
	find_city_list([ "Sierpc", "Warszawa" ]),
	data.country.Sweden,
	data.country.Austria,
	set_union(data.country.Empire, data.country.Saxony),
	find_city_list([ "Hildburghausen" ]),
	find_city_list([ "Koblenz", "Gemünden" ]),
]

const all_power_depots = [
	find_city_list([ "Berlin" ]),
	find_city_list([ "Stade" ]),
	find_city_list([ "Sierpc", "Warszawa" ]),
	find_city_list([ "Stralsund" ]),
	find_city_list([ "Tabor", "Brünn" ]),
	find_city_list([ "Hildburghausen" ]),
	find_city_list([ "Koblenz", "Gemünden" ]),
]

const MUNSTER_Y = data.cities.y[find_city("Munster")]

const all_power_re_entry_cities = [
	data.sectors.spades_berlin,
	data.sectors.diamonds_stade.filter(s => data.cities.y[s] < MUNSTER_Y),
	data.sectors.spades_warszawa,
	data.country.Sweden,
	set_intersect(data.sectors.diamonds_brunn, data.country.Austria),
	data.sectors.spades_south_of_hildburghausen,
	data.sectors.hearts_south_of_koblenz,
]

const piece_name = [
	"P1", "P2", "P3", "P4", "P5", "P6", "P7", "P8",
	"H1", "H2",
	"R1", "R2", "R3", "R4",
	"S1",
	"A1", "A2", "A3", "A4", "A5",
	"IA1",
	"F1", "F2", "F3",
	"PT1", "PT2", "HT", "RT1", "RT2", "ST", "AT1", "AT2", "IAT", "FT1", "FT2",
]

const all_power_generals = [
	/* P */ [ 0, 1, 2, 3, 4, 5, 6, 7 ],
	/* H */ [ 8, 9 ],
	/* R */ [ 10, 11, 12, 13 ],
	/* S */ [ 14 ],
	/* A */ [ 15, 16, 17, 18, 19 ],
	/* I */ [ 20 ],
	/* F */ [ 21, 22, 23 ],
]

const GEN_FRIEDRICH = 0
const GEN_SEYDLITZ = 5
const GEN_CUMBERLAND = 9
const GEN_APRAXIN = 12
const GEN_TOTTLEBEN = 13
const GEN_EHRENSVAERD = 14
const GEN_DAUN = 15
const GEN_LAUDON = 18
const GEN_HILDBURGHAUSEN = 20

const all_power_generals_rev = all_power_generals.map(list => list.slice().reverse())

const all_power_trains = [
	/* P */ [ 24, 25 ],
	/* H */ [ 26 ],
	/* R */ [ 27, 28 ],
	/* S */ [ 29 ],
	/* A */ [ 30, 31 ],
	/* I */ [ 32 ],
	/* F */ [ 33, 34 ],
]

function is_general(p) {
	return p < 24
}

const all_pieces = [ ...all_power_generals.flat(), ...all_power_trains.flat() ]
const all_generals = [ ...all_power_generals.flat() ]

const all_prussia_trains = [
	...all_power_trains[P_PRUSSIA],
	...all_power_trains[P_HANOVER],
]

const all_anti_prussia_trains = [
	...all_power_trains[P_RUSSIA],
	...all_power_trains[P_SWEDEN],
	...all_power_trains[P_AUSTRIA],
	...all_power_trains[P_IMPERIAL],
	...all_power_trains[P_FRANCE],
]

const all_friendly_trains = [
	all_prussia_trains,
	all_prussia_trains,
	all_anti_prussia_trains,
	all_anti_prussia_trains,
	all_anti_prussia_trains,
	all_anti_prussia_trains,
	all_anti_prussia_trains,
]

const all_enemy_trains = [
	all_anti_prussia_trains,
	all_anti_prussia_trains,
	all_prussia_trains,
	all_prussia_trains,
	all_prussia_trains,
	all_prussia_trains,
	all_prussia_trains,
]

const all_prussia_generals = [
	...all_power_generals[P_PRUSSIA],
	...all_power_generals[P_HANOVER],
]

const all_anti_prussia_generals = [
	...all_power_generals[P_RUSSIA],
	...all_power_generals[P_SWEDEN],
	...all_power_generals[P_AUSTRIA],
	...all_power_generals[P_IMPERIAL],
	...all_power_generals[P_FRANCE],
]

const all_enemy_generals = [
	all_anti_prussia_generals,
	all_anti_prussia_generals,
	all_prussia_generals,
	all_prussia_generals,
	all_prussia_generals,
	all_prussia_generals,
	all_prussia_generals,
]

function is_supply_train(p) {
	return p >= 24
}

function to_deck(c) {
	return c >> 7
}

function to_suit(c) {
	return (c >> 4) & 7
}

function to_value(c) {
	return c & 15
}

function is_reserve(c) {
	return to_suit(c) === RESERVE
}

function format_cards(list) {
	return list.map(c => to_value(c) + suit_name[to_suit(c)]).join(", ")
}

function format_selected() {
	if (game.selected.length === 0)
		return "nobody"
	return game.selected.map(p => piece_name[p]).join(" and ")
}

/* OBJECTIVES */

const all_objectives = []
set_add_all(all_objectives, data.type.objective1_austria)
set_add_all(all_objectives, data.type.objective2_austria)
set_add_all(all_objectives, data.type.objective1_imperial)
set_add_all(all_objectives, data.type.objective2_imperial)
set_add_all(all_objectives, data.type.objective1_sweden)
set_add_all(all_objectives, data.type.objective2_sweden)
set_add_all(all_objectives, data.type.objective_france)
set_add_all(all_objectives, data.type.objective_prussia)
set_add_all(all_objectives, data.type.objective_russia)

const protect_range = []
for (let s of all_objectives)
	make_protect_range(protect_range[s] = [], s, s, 3)

function make_protect_range(result, start, here, range) {
	for (let next of data.cities.adjacent[here]) {
		if (next !== start)
			set_add(result, next)
		if (range > 1)
			make_protect_range(result, start, next, range - 1)
	}
}

const primary_objective = [ [], [], [], [], [], [], [] ]
const secondary_objective = [ [], [], [], [], [], [], [] ]
const protect = [ [], [], [], [], [], [], [] ]

for (let s of data.type.objective_prussia) set_add(primary_objective[P_PRUSSIA], s)
for (let s of data.type.objective_russia) set_add(primary_objective[P_RUSSIA], s)
for (let s of data.type.objective1_sweden) set_add(primary_objective[P_SWEDEN], s)
for (let s of data.type.objective2_sweden) set_add(secondary_objective[P_SWEDEN], s)
for (let s of data.type.objective1_austria) set_add(primary_objective[P_AUSTRIA], s)
for (let s of data.type.objective2_austria) set_add(secondary_objective[P_AUSTRIA], s)
for (let s of data.type.objective1_imperial) set_add(primary_objective[P_IMPERIAL], s)
for (let s of data.type.objective2_imperial) set_add(secondary_objective[P_IMPERIAL], s)
for (let s of data.type.objective_france) set_add(primary_objective[P_FRANCE], s)

const full_objective = [
	set_union(primary_objective[0], secondary_objective[0]),
	set_union(primary_objective[1], secondary_objective[1]),
	set_union(primary_objective[2], secondary_objective[2]),
	set_union(primary_objective[3], secondary_objective[3]),
	set_union(primary_objective[4], secondary_objective[4]),
	set_union(primary_objective[5], secondary_objective[5]),
	set_union(primary_objective[6], secondary_objective[6]),
]

function make_protect(power, country) {
	for (let s of all_objectives)
		if (set_has(country, s))
			set_add(protect[power], s)
}

make_protect(P_PRUSSIA, data.country.Prussia)
make_protect(P_PRUSSIA, data.country.Saxony)
make_protect(P_HANOVER, data.country.Hanover)
make_protect(P_AUSTRIA, data.country.Austria)

function is_conquest_space(pow, s) {
	return set_has(full_objective[pow], s)
}

function is_reconquest_space(pow, s) {
	return set_has(protect[pow], s)
}

function is_protected_from_conquest(s) {
	for (let pow of all_powers) {
		if (set_has(protect[pow], s)) {
			let range = protect_range[s]
			for (let p of all_power_generals[pow])
				if (set_has(range, game.pos[p]))
					return true
			if (pow === P_IMPERIAL) {
				for (let p of all_power_trains[pow])
					if (set_has(range, game.pos[p]))
						return true
			}
		}
	}
	return false
}

function is_protected_from_reconquest(s) {
	for (let pow of all_powers) {
		if (set_has(full_objective[pow], s)) {
			let range = protect_range[s]
			for (let p of all_power_generals[pow])
				if (set_has(range, game.pos[p]))
					return true
			if (pow === P_IMPERIAL) {
				for (let p of all_power_trains[pow])
					if (set_has(range, game.pos[p]))
						return true
			}
		}
	}
	return false
}

/* STATE */

function turn_power_draw() {
	let n = 0

	if (game.scenario === 1 && game.power === P_PRUSSIA) {
		if (set_has(game.fate, FC_LORD_BUTE) || set_has(game.fate, FC_POEMS))
			return 1
		return 2
	}

	if (game.scenario === 2 && game.power === P_PRUSSIA) {
		n = 5
		if (set_has(game.fate, FC_LORD_BUTE))
			n -= 1
		if (set_has(game.fate, FC_POEMS))
			n -= 1
		return n
	}

	switch (game.power) {
		case P_PRUSSIA:
			n = 7
			if (set_has(game.fate, FC_LORD_BUTE))
				n = Math.max(4, n - 2)
			if (set_has(game.fate, FC_POEMS))
				n = Math.max(4, n - 2)
			break
		case P_HANOVER:
			n = 2
			if (set_has(game.fate, FC_INDIA) && set_has(game.fate, FC_AMERICA))
				n = 1
			break
		case P_RUSSIA:
			n = 4
			break
		case P_SWEDEN:
			n = 1
			break
		case P_AUSTRIA:
			n = 5
			if (set_has(game.fate, FC_INDIA) || set_has(game.fate, FC_AMERICA))
				n = 4
			break
		case P_IMPERIAL:
			n = 1
			break
		case P_FRANCE:
			n = 4
			if (set_has(game.fate, FC_INDIA) || set_has(game.fate, FC_AMERICA))
				n = 4
			break
	}
	return n
}

function has_power_dropped_out(pow) {
	if (game.scenario === 1)
		return pow !== P_PRUSSIA && pow !== P_HANOVER && pow !== P_FRANCE
	if (game.scenario === 2)
		return pow !== P_PRUSSIA && pow !== P_AUSTRIA && pow !== P_IMPERIAL
	switch (pow) {
		case P_RUSSIA: return has_russia_dropped_out()
		case P_SWEDEN: return has_sweden_dropped_out()
		case P_FRANCE: return has_france_dropped_out()
	}
	return false
}

function has_russia_dropped_out() {
	return set_has(game.fate, FC_ELISABETH)
}

function has_sweden_dropped_out() {
	return set_has(game.fate, FC_SWEDEN)
}

function has_france_dropped_out() {
	return set_has(game.fate, FC_INDIA) && set_has(game.fate, FC_AMERICA)
}

function has_imperial_army_switched_players() {
	return (has_russia_dropped_out() && has_sweden_dropped_out()) || has_france_dropped_out()
}

function has_removed_all_pieces(pow) {
	for (let p of all_power_generals[pow])
		if (game.pos[p] !== REMOVED)
			return false
	for (let p of all_power_trains[pow])
		if (game.pos[p] !== REMOVED)
			return false
	return true
}

function player_from_power(pow) {
	let role = null

	if (game.scenario === 2 && pow === P_IMPERIAL)
		return R_MARIA_THERESA

	switch (pow) {
		case P_PRUSSIA:
		case P_HANOVER:
			role = R_FREDERICK
			break
		case P_RUSSIA:
		case P_SWEDEN:
			role = R_ELISABETH
			break
		case P_AUSTRIA:
			role = R_MARIA_THERESA
			break
		case P_IMPERIAL:
			if (has_russia_dropped_out() && has_sweden_dropped_out())
				role = R_ELISABETH
			else if (has_france_dropped_out())
				role = R_POMPADOUR
			else
				role = R_MARIA_THERESA
			break
		case P_FRANCE:
			role = R_POMPADOUR
			break
	}

	if (game.scenario === 3 && role === R_POMPADOUR)
		role = R_ELISABETH
	return role
}

function set_active_to_power(power) {
	game.power = power
	game.active = current_player()
}

function current_player() {
	return player_from_power(game.power)
}

function get_top_piece(s) {
	for (let p of all_pieces)
		if (game.pos[p] === s)
			return p
	return -1
}

function get_supreme_commander(s) {
	for (let p of all_generals)
		if (game.pos[p] === s)
			return p
	return -1
}

function get_stack_power(s) {
	for (let pow of all_powers)
		for (let p of all_power_generals[pow])
			if (game.pos[p] === s)
				return pow
	throw "IMPOSSIBLE"
}

function is_space_suit(s, ranges) {
	for (let [a, b] of ranges)
		if (s >= a && s <= b)
			return true
	return false
}

function get_space_suit(s) {
	if (s >= ELIMINATED)
		return SPADES
	if (is_space_suit(s, data.suit.spades))
		return SPADES
	if (is_space_suit(s, data.suit.clubs))
		return CLUBS
	if (is_space_suit(s, data.suit.hearts))
		return HEARTS
	if (is_space_suit(s, data.suit.diamonds))
		return DIAMONDS
	throw "IMPOSSIBLE"
}

function count_eliminated_trains() {
	let n = 0
	for (let p of all_power_trains[game.power])
		if (game.pos[p] === ELIMINATED)
			++n
	return n
}

function count_used_troops() {
	let current = 0
	for (let p of all_power_generals[game.power])
		current += game.troops[p]
	return current
}

function count_unused_generals() {
	let n = 0
	for (let p of all_power_generals[game.power])
		if (game.pos[p] !== REMOVED && game.troops[p] === 0)
			++n
	return n
}

function has_any_piece(to) {
	for (let s of game.pos)
		if (s === to)
			return true
	return false
}

function has_friendly_supply_train(to) {
	for (let p of all_friendly_trains[game.power])
		if (game.pos[p] === to)
			return true
	return false
}

function has_enemy_supply_train(to) {
	for (let p of all_enemy_trains[game.power])
		if (game.pos[p] === to)
			return true
	return false
}

function has_enemy_piece(to) {
	for (let p of all_enemy_generals[game.power])
		if (game.pos[p] === to)
			return true
	for (let p of all_enemy_trains[game.power])
		if (game.pos[p] === to)
			return true
	return false
}

function has_any_other_general(to) {
	for (let other of all_powers)
		if (other !== game.power)
			for (let p of all_power_generals[other])
				if (game.pos[p] === to)
					return true
	return false
}

function has_own_general(to) {
	for (let p of all_power_generals[game.power])
		if (game.pos[p] === to)
			return true
	return false
}

function count_pieces(to) {
	let n = 0
	for (let s of game.pos)
		if (s === to)
			++n
	return n
}

function add_one_troop(p) {
	for (let x of all_power_generals[game.power]) {
		if (game.pos[x] === game.pos[p] && game.troops[x] < 8) {
			game.troops[x] ++
			break
		}
	}
}

function remove_one_troop(p) {
	for (let x of all_power_generals_rev[game.power]) {
		if (game.pos[x] === game.pos[p] && game.troops[x] > 1) {
			game.troops[x] --
			break
		}
	}
}

function retire_general(p) {
	log("P" + p + " retired.")

	// save troops if possible
	let s = game.pos[p]
	let n = game.troops[p]
	game.pos[p] = REMOVED
	game.troops[p] = 0

	if (s < ELIMINATED) {
		for (let p of all_power_generals[game.power]) {
			if (game.pos[p] === s) {
				let x = Math.min(n, 8 - game.troops[p])
				game.troops[p] += x
				n -= x
			}
		}
		if (n > 0)
			log("Lost " + n + " troops.")
	}
}

/* SEQUENCE OF PLAY */

const POWER_FROM_ACTION_STEP = [
	P_PRUSSIA,
	P_HANOVER,
	P_RUSSIA,
	P_SWEDEN,
	P_AUSTRIA,
	P_IMPERIAL,
	P_FRANCE,
]

function set_active_to_current_action_step() {
	set_active_to_power(POWER_FROM_ACTION_STEP[game.step])
}

function goto_start_turn() {
	game.step = 0

	// Check before drawing a fate card.
	if (check_victory())
		return

	if (++game.turn <= 5) {
		log("# \u2014 " + game.turn + " \u2014")
		log("$" + (game.turn - 1 + 48 + 6))
	} else {
		// remove non-stroke of fate card from last turn
		for (let i = 1; i <= 12; ++i)
			set_delete(game.fate, i)

		let fc = game.clock.pop()

		let fs = SPADES
		if (game.scenario >= 3)
			fs = get_space_suit(game.pos[game.vg])

		if (fc > 12) {
			log("# " + strokes_of_fate_name[fc-13])
			log("$" + (fc - 13 + 48))
			game.fx = 0
		} else {
			game.fx = (fc - 1) * 4 + fs
			log("# Card of Fate " + fc + suit_name[fs])
			log("$" + game.fx)
		}

		set_add(game.fate, fc)

		// Check again in case of eased victory conditions.
		if (check_victory())
			return

		if (fate_effect_immediate[game.fx]) {
			fate_effect_immediate[game.fx]()
			return
		}

		// dropped out powers are virtual in 2p scenarios
		if (game.scenario === 1 || game.scenario === 2) {
			resume_start_turn()
			return
		}

		if (fc === FC_ELISABETH) {
			set_active_to_power(P_PRUSSIA)
			game.state = "russia_quits_the_game_1"
			return
		}

		if (fc === FC_SWEDEN) {
			set_active_to_power(P_PRUSSIA)
			game.state = "sweden_quits_the_game_1"
			return
		}

		if ((fc === FC_INDIA && set_has(game.fate, FC_AMERICA)) || (fc === FC_AMERICA && set_has(game.fate, FC_INDIA))) {
			set_active_to_power(P_HANOVER)
			game.state = "france_quits_the_game_1"
			return
		}
	}

	resume_start_turn()
}

function resume_start_turn() {
	game.selected = null
	delete game.ia_lost

	// MARIA: politics
	// MARIA: hussars

	goto_action_stage()
}

function goto_action_stage() {
	set_active_to_current_action_step()

	clear_undo()

	if (has_power_dropped_out(game.power)) {
		end_action_stage()
		return
	}

	log("=" + game.power)
	goto_tactical_cards()
}

function end_action_stage() {
	clear_undo()

	if (++game.step === 7)
		goto_end_of_turn()
	else
		goto_action_stage()
}

function goto_end_of_turn() {
	if (game.scenario === 1 || game.scenario === 2) {
		log("Imaginary player draws 5 TC.")
		for (let i = 0; i < 5; ++i)
			draw_next_tc()
	}

	goto_start_turn()
}

/* VICTORY */

function has_conquered_all_of(list) {
	for (let s of list)
		if (!set_has(game.conquest, s))
			return false
	return true
}

function check_power_victory(victory, city_list, power) {
	if (has_conquered_all_of(city_list[power]))
		set_add(victory, power)
}

function check_victory_list(victory) {
	if (victory.length > 0) {
		goto_game_over(
			victory.map(player_from_power).join(", "),
			victory.map(p => POWER_NAME[p]).join(" and ") + " won."
		)
		return true
	} else {
		return false
	}
}

function check_victory() {
	if (game.scenario === 1)
		return check_victory_the_war_in_the_west()
	if (game.scenario === 2)
		return check_victory_the_austrian_theatre()
	return check_victory_4()
}

function check_victory_the_war_in_the_west() {
	if (has_france_dropped_out()) {
		goto_game_over(R_FREDERICK, "Prussia won.")
		return true
	}
	if (has_conquered_all_of(full_objective[P_FRANCE])) {
		goto_game_over(R_POMPADOUR, "France won.")
		return true
	}
	return false
}

function check_victory_the_austrian_theatre() {
	if (has_russia_dropped_out() && has_sweden_dropped_out() && has_france_dropped_out()) {
		goto_game_over(R_FREDERICK, "Prussia won.")
		return true
	}

	let victory = []

	check_power_victory(victory, full_objective, P_AUSTRIA)
	check_power_victory(victory, full_objective, P_IMPERIAL)
	check_power_victory(victory, full_objective, P_PRUSSIA)

	return check_victory_list(victory)
}

function check_victory_4() {
	// Prussian victory
	if (has_russia_dropped_out() && has_sweden_dropped_out() && has_france_dropped_out()) {
		goto_game_over(R_FREDERICK, "Prussia won.")
		return true
	}

	let victory = []

	check_power_victory(victory, full_objective, P_RUSSIA)
	check_power_victory(victory, full_objective, P_FRANCE)

	if (has_russia_dropped_out()) {
		check_power_victory(victory, primary_objective, P_SWEDEN)
	} else {
		check_power_victory(victory, full_objective, P_SWEDEN)
	}

	if (has_imperial_army_switched_players()) {
		check_power_victory(victory, primary_objective, P_AUSTRIA)
		check_power_victory(victory, primary_objective, P_IMPERIAL)
	} else {
		check_power_victory(victory, full_objective, P_AUSTRIA)
		check_power_victory(victory, full_objective, P_IMPERIAL)
	}

	return check_victory_list(victory)
}

/* TACTICAL CARDS */

function find_largest_discard(u) {
	for (let i = 0; i < 5; ++i)
		if (u[i] <= u[0] && u[i] <= u[1] && u[i] <= u[2] && u[i] <= u[3] && u[i] <= u[4])
			return i
	throw "OUT OF CARDS"
}

function next_tactics_deck() {
	let held = [ 0, 0, 0, 0, 0 ]

	// count cards in hands
	for (let pow of all_powers) {
		for (let c of game.hand[pow])
			held[to_deck(c)]++
	}
	if (game.draw)
		for (let c of game.draw)
			held[to_deck(c)]++

	// find next unused deck
	for (let i = 1; i < 5; ++i) {
		if (held[i] === 0) {
			game.deck = make_tactics_deck(i)
			shuffle_bigint(game.deck)
			return
		}
	}

	log("Discards " + held.map(x=>50-x).join(", "))
	log("Deck 1: " + make_tactics_discard(0).map(x=>"C"+x).join(" "))
	log("Deck 2: " + make_tactics_discard(1).map(x=>"C"+x).join(" "))
	log("Deck 3: " + make_tactics_discard(2).map(x=>"C"+x).join(" "))
	log("Deck 4: " + make_tactics_discard(3).map(x=>"C"+x).join(" "))
	log("Deck 5: " + make_tactics_discard(4).map(x=>"C"+x).join(" "))

	// find two largest discard piles
	let a = find_largest_discard(held)
	if (held[a] === 50)
		return
	held[a] = 100

	let b = find_largest_discard(held)
	log("Deck " + b + ": " + held[b])
	if (held[b] === 50)
		return

	log("Shuffled new deck from discards " + (a+1) + " and " + (b+1) + ".")

	game.deck = [
		make_tactics_discard(a),
		make_tactics_discard(b)
	].flat()

	shuffle_bigint(game.deck)
}

function draw_next_tc() {
	if (game.deck.length === 0)
		next_tactics_deck()
	if (game.deck.length === 0)
		return -1
	return game.deck.pop()
}

function goto_tactical_cards() {
	let n = turn_power_draw()

	game.draw = []
	for (let i = 0; i < n; ++i) {
		let c = draw_next_tc()
		if (c >= 0)
			set_add(game.draw, c)
	}

	if (game.draw.length < n)
		log("Draw " + game.draw.length + " / " + n + " TC.")
	else
		log("Draw " + n + " TC.")

	if (should_power_discard_tc() && game.draw.length > 0)
		game.state = "tactical_cards_discard"
	else
		game.state = "tactical_cards_show"
}

function should_power_discard_tc() {
	if (game.power === P_FRANCE && !set_has(FC_AMERICA) && !set_has(FC_INDIA))
		return game.draw.length === 4
	if (game.scenario === 1 && game.power === P_PRUSSIA)
		return game.draw.length === 2
	return false
}

states.tactical_cards_discard = {
	prompt() {
		view.draw = game.draw
		prompt("Draw " + format_cards(game.draw) + ". Discard one of them.")
		for (let c of game.draw)
			gen_action_card(c)
	},
	card(c) {
		push_undo()
		log("Discarded 1 TC.")
		set_delete(game.draw, c)
		game.state = "tactical_cards_discard_done"
	},
}

states.tactical_cards_discard_done = {
	prompt() {
		view.draw = game.draw
		prompt("Draw " + format_cards(game.draw) + ".")
		view.actions.end_cards = 1
	},
	end_cards() {
		end_tactical_cards()
	},
}

states.tactical_cards_show = {
	prompt() {
		view.draw = game.draw
		prompt("Draw " + format_cards(game.draw) + ".")
		view.actions.end_cards = 1
	},
	end_cards() {
		end_tactical_cards()
	},
}

function end_tactical_cards() {
	for (let c of game.draw)
		set_add(game.hand[game.power], c)
	delete game.draw

	// MARIA: supply is before movement

	goto_movement()
}

/* TRANSFER TROOPS */

function count_stacked_take() {
	let n = 0
	for (let p of game.selected)
		n += 8 - game.troops[p]
	return n
}

function count_unstacked_take() {
	let here = game.pos[game.selected[0]]
	let n = 0
	for (let p of all_power_generals[game.power])
		if (game.pos[p] === here && !set_has(game.selected, p))
			n += 8 - game.troops[p]
	return n
}

function count_stacked_give() {
	let n = 0
	for (let p of game.selected)
		n += game.troops[p] - 1
	return n
}

function count_unstacked_give() {
	let here = game.pos[game.selected[0]]
	let n = 0
	for (let p of all_power_generals[game.power])
		if (game.pos[p] === here && !set_has(game.selected, p))
			n += game.troops[p] - 1
	return n
}

function take_troops(total) {
	let here = game.pos[game.selected[0]]

	let n = total
	for (let p of game.selected) {
		let x = Math.max(0, Math.min(n, 8 - game.troops[p]))
		game.troops[p] += x
		n -= x
	}

	n = total
	for (let p of all_power_generals_rev[game.power]) {
		if (game.pos[p] === here && !set_has(game.selected, p)) {
			let x = Math.max(0, Math.min(n, game.troops[p] - 1))
			game.troops[p] -= x
			n -= x
		}
	}
}

function give_troops(total) {
	let here = game.pos[game.selected[0]]

	let n = total
	for (let p of all_power_generals[game.power]) {
		if (game.pos[p] === here && !set_has(game.selected, p)) {
			let x = Math.max(0, Math.min(n, 8 - game.troops[p]))
			game.troops[p] += x
			n -= x
		}
	}

	n = total
	for (let p of game.selected) {
		let x = Math.max(0, Math.min(n, game.troops[p] - 1))
		game.troops[p] -= x
		n -= x
	}
}

/* MOVEMENT */

function goto_movement() {
	game.state = "movement"
	set_clear(game.moved)
}

function is_supreme_commander(p) {
	let s = game.pos[p]
	for (let other of all_generals)
		if (game.pos[other] === s)
			return other === p
	return false
}

states.movement = {
	prompt() {
		let done = true
		for (let p of all_power_generals[game.power]) {
			if (!set_has(game.moved, p) && is_supreme_commander(p) && game.pos[p] < ELIMINATED) {
				gen_action_piece(p)
				done = false
			}
		}

		for (let p of all_power_trains[game.power]) {
			if (!set_has(game.moved, p) && game.pos[p] < ELIMINATED) {
				gen_action_piece(p)
				done = false
			}
		}

		if (done)
			prompt("Movement done.")
		else
			prompt("Move your generals and supply trains.")

		view.actions.end_movement = 1
	},
	piece(p) {
		push_undo()

		game.selected = [ p ]
		let here = game.pos[p]
		for (let other of all_power_generals[game.power])
			if (other > p && game.pos[other] === here)
				game.selected.push(other)

		game.count = 0

		if (data.cities.major_roads[here].length > 0)
			game.major = 1
		else
			game.major = 0

		if (is_supply_train(p))
			resume_move_supply_train()
		else
			resume_move_general()
	},
	end_movement() {
		push_undo()
		goto_recruit()
	},
}

function format_move(max) {
	let n = max - game.count
	if (game.major)
		return ` up to ${n} + 1 cities.`
	return ` up to ${n} cities.`
}

function can_move_train_to(to) {
	return !has_any_piece(to)
}

function can_continue_train_from(_) {
	return true
}

function can_move_general_to(to) {
	if (has_friendly_supply_train(to))
		return false
	if (has_any_other_general(to))
		return false
	if (game.selected.length + count_pieces(to) > 3)
		return false
	return true
}

function can_continue_general_from(from) {
	if (has_enemy_supply_train(from))
		return false
	if (has_own_general(from))
		return false
	return true
}

function search_move(from, range, road_type, can_move_to, can_continue_from) {
	let seen = [ from, -1 ]
	let queue = [ from << 4 ]
	while (queue.length > 0) {
		let item = queue.shift()
		let here = item >> 4
		let dist = (item & 15) + 1
		for (let next of data.cities[road_type][here]) {
			if (map_has(seen, next))
				continue
			if (!can_move_to(next))
				continue
			if (dist <= range) {
				map_set(seen, next, here)
				if (can_continue_from(next))
					queue.push((next << 4) | dist)
			}
		}
	}
	return seen
}

function resume_move_supply_train() {
	if (game.count === 2 + game.major) {
		end_move_piece()
	} else {
		let here = game.pos[game.selected[0]]
		game.state = "move_supply_train"
		if (game.major && game.count < 3)
			game.move_major = search_move(here, 3 - game.count, "major_roads", can_move_train_to, can_continue_train_from)
		else
			game.move_major = []
		if (game.count < 2)
			game.move_minor = search_move(here, 2 - game.count, "adjacent", can_move_train_to, can_continue_train_from)
		else
			game.move_minor = []
	}
}

function resume_move_general() {
	if (game.count === 3 + game.major) {
		end_move_piece()
	} else {
		let here = game.pos[game.selected[0]]
		game.state = "move_general"
		if (game.major && game.count < 4)
			game.move_major = search_move(here, 4 - game.count, "major_roads", can_move_general_to, can_continue_general_from)
		else
			game.move_major = []
		if (game.count < 3)
			game.move_minor = search_move(here, 3 - game.count, "adjacent", can_move_general_to, can_continue_general_from)
		else
			game.move_minor = []
	}
}

function move_general_to(to) {
	let pow = game.power
	let who = game.selected[0]
	let from = game.pos[who]
	let stop = false

	for (let p of game.selected) {
		set_add(game.moved, p)
		game.pos[p] = to
	}

	// uniting stacks (turn all oos if one is oos)
	let oos = false
	for (let p of all_power_generals[game.power])
		if (game.pos[p] === to && is_out_of_supply(p))
			oos = true
	if (oos)
		for (let p of all_power_generals[game.power])
			if (game.pos[p] === to)
				set_out_of_supply(p)

	// conquer space
	if (is_conquest_space(pow, from) && !set_has(game.conquest, from)) {
		if (is_protected_from_conquest(from)) {
			set_add(game.retro, from)
		} else {
			log("Conquered S" + from)
			set_add(game.conquest, from)
		}
	}

	// re-conquer space
	if (is_reconquest_space(pow, from) && set_has(game.conquest, from)) {
		if (is_protected_from_reconquest(from)) {
			set_add(game.retro, from)
		} else {
			log("Reconquered S" + from)
			set_delete(game.conquest, from)
		}
	}

	// eliminate supply train
	for (let p of all_enemy_trains[pow]) {
		if (game.pos[p] === to) {
			log("Eliminate P" + p)
			game.pos[p] = ELIMINATED
			stop = true
		}
	}

	// uniting stacks: flag all as moved and stop moving
	for (let p of all_power_generals[pow]) {
		if (game.pos[p] === to && !set_has(game.selected, p)) {
			set_add(game.moved, p)
			stop = true
		}
	}

	return stop
}

function move_general_immediately(to) {
	let who = game.selected[0]
	let from = game.pos[who]

	// uniting stacks (turn all oos if one is oos)
	let oos = false
	for (let p of all_power_generals[game.power])
		if (game.pos[p] === to && is_out_of_supply(p))
			oos = true
	if (oos)
		for (let p of all_power_generals[game.power])
			if (game.pos[p] === to)
				set_out_of_supply(p)

	// eliminate supply train
	for (let p of all_enemy_trains[game.power]) {
		if (game.pos[p] === to) {
			log("Eliminate P" + p)
			game.pos[p] = ELIMINATED
		}
	}
}

states.move_supply_train_NEW = {
	prompt() {
		prompt("Move " + format_selected() + format_move(2))
		view.selected = game.selected

		let who = game.selected[0]
		let here = game.pos[who]

		if (game.move_major)
			map_for_each_key(game.move_major, s => { if (s !== here) gen_action_space(s) })
		if (game.move_minor)
			map_for_each_key(game.move_minor, s => { if (s !== here) gen_action_space(s) })

		view.move_major = game.move_major
		view.move_minor = game.move_minor

		/*
		if (game.count < 2 + game.major)
			for (let next of data.cities.major_roads[here])
				if (!has_any_piece(next))
					gen_action_space(next)
		if (game.count < 2)
			for (let next of data.cities.roads[here])
				if (!has_any_piece(next))
					gen_action_space(next)
		*/

		if (game.count > 0) {
			gen_action_piece(who)
			view.actions.stop = 1
		}
	},
	piece(_) {
		this.stop()
	},
	stop() {
		end_move_piece()
	},
	space(to) {
		let who = game.selected[0]

		set_add(game.moved, who)
		game.pos[who] = to

		log("P" + who + " to S" + to)

		let m = map_get(game.move_major, to, 0)
		if (m > 0) {
			while (m > 0) {
				// TODO: reverse
				log(">S" + m)
				m = map_get(game.move_major, m)
				++ game.count
			}
		} else {
			m = map_get(game.move_minor, to, 0)
			while (m > 0) {
				// TODO: reverse
				log(">S" + m)
				m = map_get(game.move_minor, m)
				++ game.count
			}
			game.major = 0
		}

		resume_move_supply_train()
	},
}

states.move_supply_train_OLD = {
	prompt() {
		prompt("Move " + format_selected() + format_move(2))
		view.selected = game.selected

		let who = game.selected[0]
		let here = game.pos[who]

		if (game.count < 2 + game.major)
			for (let next of data.cities.major_roads[here])
				if (!has_any_piece(next))
					gen_action_space(next)
		if (game.count < 2)
			for (let next of data.cities.roads[here])
				if (!has_any_piece(next))
					gen_action_space(next)

		if (game.count > 0) {
			gen_action_piece(who)
			view.actions.stop = 1
		}
	},
	piece(_) {
		this.stop()
	},
	stop() {
		end_move_piece()
	},
	space(to) {
		let who = game.selected[0]
		let here = game.pos[who]

		log("P" + who + " to S" + to)

		if (!set_has(data.cities.major_roads[here], to))
			game.major = 0

		set_add(game.moved, who)
		game.pos[who] = to

		if (++game.count === 2 + game.major)
			end_move_piece()
	},
}

states.move_general_NEW = {
	prompt() {
		prompt("Move " + format_selected() + format_move(3))
		view.selected = game.selected

		let who = game.selected[0]
		let here = game.pos[who]

		if (game.count === 0) {
			if (game.selected.length > 1)
				view.actions.detach = 1
			else
				view.actions.detach = 0

			let s_take = count_stacked_take()
			let s_give = count_stacked_give()
			let u_take = count_unstacked_take()
			let u_give = count_unstacked_give()
			if (s_take > 0 && u_give > 0)
				view.actions.take = 1
			if (s_give > 0 && u_take > 0)
				view.actions.give = 1
		} else {
			gen_action_piece(who)
			view.actions.stop = 1
		}

		view.move_major = game.move_major
		view.move_minor = game.move_minor

		if (game.move_major)
			map_for_each_key(game.move_major, s => { if (s !== here) gen_action_space_or_piece(s) })
		if (game.move_minor)
			map_for_each_key(game.move_minor, s => { if (s !== here) gen_action_space_or_piece(s) })
	},
	take() {
		game.state = "move_take"
	},
	give() {
		game.state = "move_give"
	},
	detach() {
		game.state = "move_detach"
	},
	piece(p) {
		if (p === game.selected[0])
			this.stop()
		else
			this.space(game.pos[p])
	},
	stop() {
		for (let p of game.selected)
			set_add(game.moved, p)
		end_move_piece()
	},
	space(to) {
		let who = game.selected[0]
		let path = [ to ]

		let m = map_get(game.move_major, to, -1)
		if (m >= 0) {
			while (m >= 0) {
				path.unshift(m)
				m = map_get(game.move_major, m, -1)
				++game.count
			}
		} else {
			m = map_get(game.move_minor, to, -1)
			while (m >= 0) {
				path.unshift(m)
				m = map_get(game.move_minor, m, -1)
				++game.count
			}
			game.major = 0
		}

		log("P" + who + " " + path.map(s => "S" + s).join(" > "))

		let stop = false
		path.shift() // skip start space
		for (let s of path)
			stop ||= move_general_to(s)

		if (stop)
			this.stop()
		else
			resume_move_general()
	},
}

states.move_general_OLD = {
	prompt() {
		prompt("Move " + format_selected() + format_move(3))
		view.selected = game.selected

		let who = game.selected[0]
		let here = game.pos[who]

		if (game.count === 0) {
			if (game.selected.length > 1)
				view.actions.detach = 1
			else
				view.actions.detach = 0

			let s_take = count_stacked_take()
			let s_give = count_stacked_give()
			let u_take = count_unstacked_take()
			let u_give = count_unstacked_give()

			if (s_take > 0 && u_give > 0)
				view.actions.take = 1
			if (s_give > 0 && u_take > 0)
				view.actions.give = 1
		} else {
			gen_action_piece(who)
			view.actions.stop = 1
		}

		if (game.count < 3 + game.major)
			for (let next of data.cities.major_roads[here])
				if (can_move_general_to(next))
					gen_action_space_or_piece(next)

		if (game.count < 3)
			for (let next of data.cities.roads[here])
				if (can_move_general_to(next))
					gen_action_space_or_piece(next)
	},
	take() {
		game.state = "move_take"
	},
	give() {
		game.state = "move_give"
	},
	detach() {
		game.state = "move_detach"
	},
	piece(p) {
		if (p === game.selected[0])
			this.stop()
		else
			this.space(game.pos[p])
	},
	stop() {
		for (let p of game.selected)
			set_add(game.moved, p)
		end_move_piece()
	},
	space(to) {
		let who = game.selected[0]
		let from = game.pos[who]

		log("P" + who + " to S" + to)

		if (!set_has(data.cities.major_roads[from], to))
			game.major = 0

		if (move_general_to(to) || ++game.count === 3 + game.major)
			end_move_piece()
	},
}

states.move_general = states.move_general_OLD
states.move_supply_train = states.move_supply_train_OLD
//states.move_general = states.move_general_NEW
//states.move_supply_train = states.move_supply_train_NEW

states.move_detach = {
	prompt() {
		prompt("Move " + format_selected() + ". Detach general from stack.")
		for (let p of game.selected)
			gen_action_piece(p)
	},
	piece(p) {
		set_delete(game.selected, p)
		game.state = "move_general"
	},
}

states.move_take = {
	prompt() {
		prompt("Transfer troops to " + format_selected() + ".")
		let take = count_stacked_take()
		let give = count_unstacked_give()
		let n = Math.min(take, give)
		view.actions.value = []
		for (let i = 1; i <= n; ++i)
			view.actions.value.push(i)
	},
	value(v) {
		take_troops(v)
		if (game.state === "laudon_take")
			game.state = "austria_may_move_laudon_by_one_city_immediately"
		else
			game.state = "move_general"
	},
}

states.move_give = {
	prompt() {
		prompt("Transfer troops from " + format_selected() + ".")
		let take = count_unstacked_take()
		let give = count_stacked_give()
		let n = Math.min(take, give)
		view.actions.value = []
		for (let i = 1; i <= n; ++i)
			view.actions.value.push(i)
	},
	value(v) {
		give_troops(v)
		if (game.state === "laudon_give")
			game.state = "austria_may_move_laudon_by_one_city_immediately"
		else
			game.state = "move_general"
	},
}

function end_move_piece() {
	game.selected = null
	delete game.move_major
	delete game.move_minor
	game.state = "movement"
}

/* RECRUITMENT */

function troop_cost() {
	if (game.re_enter !== undefined)
		return 8
	return 6
}

function has_available_depot() {
	for (let s of all_power_depots[game.power])
		if (!has_enemy_piece(s))
			return true
	return false
}

function goto_recruit() {
	push_undo()
	game.count = 0

	// TODO: reveal too much if we skip recruitment phase?
	if (count_eliminated_trains() === 0 && count_used_troops() === max_power_troops(game.power)) {
		end_recruit()
		return
	}

	// if all depots have enemy pieces, choose ONE city in XXX sector and COST is 8
	if (has_available_depot())
		game.state = "recruit"
	else
		game.state = "re_enter_choose_city"
}

states.re_enter_choose_city = {
	prompt() {
		prompt("Choose city to re-enter troops.")
		for (let s of all_power_re_entry_cities[game.power])
			if (!has_enemy_piece(s))
				gen_action_space(s)
	},
	space(s) {
		push_undo()
		game.re_enter = s
		game.state = "recruit"
	},
}

function has_re_entry_space(p) {
	let can_re_enter_at = is_general(p) ? can_re_enter_general : can_re_enter_supply_train
	if (game.re_enter !== undefined)
		return can_re_enter_at(game.re_enter)
	for (let s of all_power_depots[game.power])
		if (can_re_enter_at(s))
			return true
	return false
}

states.recruit = {
	prompt() {
		let cost = troop_cost()
		let buy_amount = (game.count / cost) | 0
		let n_troops = count_used_troops()
		let av_troops = max_power_troops(game.power) - n_troops
		let av_trains = count_eliminated_trains()

		if (av_trains === 0 && av_troops === 0)
			prompt(`Nothing to recruit. ${n_troops}/${max_power_troops(game.power)} troops.`)
		else
			prompt(`Recruit supply trains and/or troops. ${n_troops}/${max_power_troops(game.power)} troops. ${game.count} points.`)

		if (buy_amount < av_troops + av_trains) {
			for (let c of game.hand[game.power])
				gen_action_card(c)
		}

		if (game.count >= cost) {
			if (av_troops > 0) {
				for (let p of all_power_generals[game.power]) {
					if (game.troops[p] > 0 && game.troops[p] < 8)
						gen_action_supreme_commander(game.pos[p])
					else if (game.pos[p] === ELIMINATED && has_re_entry_space(p))
						gen_action_piece(p)
				}
			}
			if (av_trains > 0) {
				for (let p of all_power_trains[game.power]) {
					if (game.pos[p] === ELIMINATED && has_re_entry_space(p))
						gen_action_piece(p)
				}
			}
		}

		// don't force buying a T
		if (buy_amount === 0 || av_troops === 0)
			view.actions.end_recruit = 1
	},
	card(c) {
		push_undo()
		log("Recruit with C" + c)
		array_remove_item(game.hand[game.power], c)
		game.count += is_reserve(c) ? 10 : to_value(c)
	},
	piece(p) {
		push_undo()
		game.count -= troop_cost()
		if (game.pos[p] === ELIMINATED) {
			game.selected = [ p ]
			game.state = "re_enter"
		} else {
			add_one_troop(p)
		}
	},
	end_recruit() {
		push_undo()
		end_recruit()
	},
}

function end_recruit() {
	delete game.re_enter
	goto_combat()
}

function can_re_enter_general(to) {
	if (has_friendly_supply_train(to))
		return false
	if (has_any_other_general(to))
		return false
	if (1 + count_pieces(to) > 3)
		return false
	return true
}

function can_re_enter_supply_train(s) {
	return !has_any_piece(s)
}

states.re_enter = {
	prompt() {
		prompt("Re-enter " + format_selected() + ".")
		let p = game.selected[0]
		let can_re_enter_at = is_general(p) ? can_re_enter_general : can_re_enter_supply_train

		if (game.re_enter !== undefined) {
			if (can_re_enter_at(game.re_enter))
				gen_action_space(game.re_enter)
		} else {
			for (let s of all_power_depots[game.power])
				if (can_re_enter_at(s))
					gen_action_space(s)
		}
	},
	space(s) {
		let p = game.selected[0]
		log("Re-entered P" + p + " at S" + s + ".")
		game.pos[p] = s
		if (set_has(all_power_generals[game.power], p))
			game.troops[p] = 1
		game.selected = null
		game.state = "recruit"
	},
}

/* COMBAT */

function goto_combat() {
	set_clear(game.moved)

	let from = []
	let to = []

	for (let p of all_power_generals[game.power])
		if (game.pos[p] < ELIMINATED)
			set_add(from, game.pos[p])

	for (let p of all_enemy_generals[game.power])
		if (game.pos[p] < ELIMINATED)
			set_add(to, game.pos[p])

	game.combat = []
	for (let a of from) {
		for (let b of to) {
			if (set_has(data.cities.adjacent[a], b)) {
				game.combat.push(a)
				game.combat.push(b)
			}
		}
	}

	if (game.combat.length > 0)
		game.state = "combat"
	else
		goto_retroactive_conquest()
}

states.combat = {
	prompt() {
		prompt("Combat!")
		for (let i = 0; i < game.combat.length; i += 2)
			gen_action_supreme_commander(game.combat[i])
	},
	piece(p) {
		push_undo()
		game.attacker = game.pos[p]
		game.state = "combat_target"
	},
}

states.combat_target = {
	prompt() {
		prompt("Choose enemy stack to fight.")
		for (let i = 0; i < game.combat.length; i += 2)
			if (game.combat[i] === game.attacker)
				gen_action_supreme_commander(game.combat[i+1])
	},
	piece(p) {
		clear_undo()

		game.defender = game.pos[p]

		for (let i = 0; i < game.combat.length; i += 2) {
			if (game.combat[i] === game.attacker && game.combat[i+1] === game.defender) {
				array_remove_pair(game.combat, i)
				break
			}
		}

		goto_combat_play()
	},
}

function set_active_attacker() {
	set_active_to_power(get_stack_power(game.attacker))
}

function set_active_defender() {
	set_active_to_power(get_stack_power(game.defender))
}

function goto_combat_play() {
	let a_troops = 0
	let d_troops = 0

	for (let p of all_generals) {
		if (game.pos[p] === game.attacker)
			a_troops += game.troops[p]
		if (game.pos[p] === game.defender)
			d_troops += game.troops[p]
	}

	log_br()

	let a = get_supreme_commander(game.attacker)
	let d = get_supreme_commander(game.defender)
	log(`P${a} (${a_troops}) at S${game.attacker}`)
	log(`P${d} (${d_troops}) at S${game.defender}`)

	game.count = a_troops - d_troops

	if (game.count <= 0) {
		set_active_attacker()
		game.state = "combat_attack"
	} else {
		set_active_defender()
		game.state = "combat_defend"
	}
}

function resume_combat_attack() {
	if (game.count >= 0) {
		//set_active_defender()
		//game.state = "combat_defend"
		game.state = "combat_attack_swap"
	} else {
		game.state = "combat_attack"
	}
}

function resume_combat_defend() {
	if (game.count <= 0) {
		//set_active_attacker()
		//game.state = "combat_attack"
		game.state = "combat_defend_swap"
	} else {
		game.state = "combat_defend"
	}
}

function gen_play_card(suit) {
	let has_suit = false
	for (let c of game.hand[game.power]) {
		let c_suit = to_suit(c)
		if (c_suit === suit) {
			has_suit = true
			gen_action_card(c)
		}
		else if (c_suit === RESERVE)
			gen_action_card(c)
	}
	return has_suit
}

states.combat_attack = {
	prompt() {
		prompt("Attack: " + game.count)
		view.selected = [ get_supreme_commander(game.attacker) ]
		let has_suit = gen_play_card(get_space_suit(game.attacker))
		if (game.count === 0 && has_suit)
			view.actions.pass = 0
		else
			view.actions.pass = 1
	},
	card(c) {
		push_undo()

		array_remove_item(game.hand[game.power], c)
		let c_suit = to_suit(c)
		if (c_suit === RESERVE) {
			game.state = "combat_attack_reserve"
		} else {
			game.count += to_value(c)
			log(POWER_NAME[game.power] + " C" + c + " = " + (game.count))
			resume_combat_attack()
		}
	},
	pass() {
		clear_undo()
		resolve_combat()
	},
}

states.combat_defend = {
	prompt() {
		prompt("Defend: " + (-game.count))

		view.selected = [ get_supreme_commander(game.defender) ]
		let has_suit = gen_play_card(get_space_suit(game.defender))
		if (game.count === 0 && has_suit)
			view.actions.pass = 0
		else
			view.actions.pass = 1
	},
	card(c) {
		push_undo()

		array_remove_item(game.hand[game.power], c)
		let c_suit = to_suit(c)
		if (c_suit === RESERVE) {
			game.state = "combat_defend_reserve"
		} else {
			game.count -= to_value(c)
			log(POWER_NAME[game.power] + " C" + c + " = " + (game.count))
			resume_combat_defend()
		}
	},
	pass() {
		clear_undo()
		resolve_combat()
	},
}

states.combat_attack_reserve = {
	prompt() {
		prompt("Attack: Choose value. " + game.count)
		view.selected = [ get_supreme_commander(game.attacker)]
		view.actions.value = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
	},
	value(v) {
		log(POWER_NAME[game.power] + " reserve " + v)
		game.count += v
		resume_combat_attack()
	},
}

states.combat_defend_reserve = {
	prompt() {
		prompt("Defend: Choose value." + (-game.count))
		view.selected = [ get_supreme_commander(game.defender) ]
		view.actions.value = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
	},
	value(v) {
		log(POWER_NAME[game.power] + " reserve " + v)
		game.count -= v
		resume_combat_defend()
	},
}

states.combat_attack_swap = {
	prompt() {
		prompt("Attack: " + game.count)
		view.selected = [ get_supreme_commander(game.attacker) ]
		view.actions.next = 1
	},
	next() {
		clear_undo()
		set_active_defender()
		game.state = "combat_defend"
	},
}

states.combat_defend_swap = {
	prompt() {
		prompt("Defend: " + (-game.count))
		view.selected = [ get_supreme_commander(game.defender) ]
		view.actions.next = 1
	},
	next() {
		clear_undo()
		set_active_attacker()
		game.state = "combat_attack"
	},
}

function select_stack(s) {
	let list = []
	for (let p of all_generals)
		if (game.pos[p] === s)
			list.push(p)
	return list
}

function resolve_combat() {
	if (game.count === 0) {
		log("Tie.")
		next_combat()
	} else if (game.count > 0) {
		if (get_supreme_commander(game.defender) == GEN_HILDBURGHAUSEN)
			game.ia_lost = 1
		game.vg = get_supreme_commander(game.attacker)
		game.selected = select_stack(game.defender)
		goto_retreat()
	} else {
		if (get_supreme_commander(game.attacker) == GEN_HILDBURGHAUSEN)
			game.ia_lost = 1
		game.vg = get_supreme_commander(game.defender)
		game.selected = select_stack(game.attacker)
		goto_retreat()
	}
}

function next_combat() {
	clear_undo()
	log_br()
	set_active_to_current_action_step()
	game.count = 0
	delete game.attacker
	delete game.defender
	if (game.combat.length > 0)
		game.state = "combat"
	else
		game.state = "combat_done"
}

states.combat_done = {
	prompt() {
		prompt("Combat done.")
		view.actions.end_combat = 1
	},
	end_combat() {
		goto_retroactive_conquest()
	},
}

/* RETREAT */

function get_winner() {
	return game.count > 0 ? game.attacker : game.defender
}

function get_loser() {
	return game.count < 0 ? game.attacker : game.defender
}

function set_active_winner() {
	if (game.count > 0)
		set_active_attacker()
	else
		set_active_defender()
}

function goto_retreat() {
	let hits = Math.abs(game.count)

	let loser = get_loser()

	// no more fighting for the loser
	for (let i = game.combat.length - 2; i >= 0; i -= 2)
		if (game.combat[i] === loser || game.combat[i+1] === loser)
			array_remove_pair(game.combat, i)

	log("P" + get_supreme_commander(loser) + " lost " + hits + " troops.")

	// apply hits
	for (let i = game.selected.length - 1; i >= 0 && hits > 0; --i) {
		let p = game.selected[i]
		while (game.troops[p] > 1 && hits > 0) {
			--game.troops[p]
			--hits
		}
	}

	for (let i = game.selected.length - 1; i >= 0 && hits > 0; --i) {
		let p = game.selected[i]
		while (game.troops[p] > 0 && hits > 0) {
			--game.troops[p]
			--hits
		}
	}

	resume_retreat()
}

function resume_retreat() {
	// eliminate generals with no more hits
	for (let p of game.selected) {
		if (game.troops[p] === 0) {
			game.state = "retreat_eliminate_hits"
			return
		}
	}

	// retreat remaining generals
	if (game.selected.length > 0) {
		game.retreat = search_retreat(get_loser(), get_winner(), Math.abs(game.count))
		if (game.retreat.length > 0) {
			// victor chooses retreat destination
			set_active_winner()
			game.state = "retreat"
		} else {
			// eliminate if there are no retreat possibilities
			delete game.retreat
			game.state = "retreat_eliminate_trapped"
		}
		return
	}

	// no retreat if generals wiped out
	next_combat()
}

states.retreat_eliminate_hits = {
	prompt() {
		prompt("Eliminate generals without troops.")
		// remove eliminated generals
		for (let p of game.selected)
			if (game.troops[p] === 0)
				gen_action_piece(p)
	},
	piece(p) {
		log("P" + p + " eliminated.")
		game.pos[p] = ELIMINATED
		set_delete(game.selected, p)
		resume_retreat()
	},
}

states.retreat_eliminate_trapped = {
	prompt() {
		prompt("Eliminate " + format_selected() + " without a retreat path.")
		for (let p of game.selected)
			gen_action_piece(p)
	},
	piece(_) {
		log("Trapped.")
		for (let p of game.selected) {
			game.pos[p] = ELIMINATED
			game.troops[p] = 0
		}
		next_combat()
	},
}

// search distances from winner within retreat range
function search_retreat_distance(from, range) {
	let seen = [ from, 0 ]
	let queue = [ from << 4 ]
	while (queue.length > 0) {
		let item = queue.shift()
		let here = item >> 4
		let dist = (item & 15) + 1
		for (let next of data.cities.adjacent[here]) {
			if (map_has(seen, next))
				continue
			if (dist <= range) {
				map_set(seen, next, dist)
				queue.push((next << 4) | dist)
			}
		}
	}
	return seen
}

// search all possible retreat paths of given length
function search_retreat_possible_dfs(result, seen, here, range) {
	for (let next of data.cities.adjacent[here]) {
		if (seen.includes(next))
			continue
		if (has_any_piece(next))
			continue
		if (range === 1) {
			map_set(result, next, seen.slice())
		} else {
			seen.push(next)
			search_retreat_possible_dfs(result, seen, next, range - 1)
			seen.pop()
		}
	}
}

function search_retreat_possible(from, range) {
	let result = []
	search_retreat_possible_dfs(result, [from], from, range)
	return result
}

function search_retreat(loser, winner, range) {
	let distance = search_retreat_distance(winner, range + 1)
	let possible = search_retreat_possible(loser, range)

	let max = 0
	for (let s of possible) {
		let d = map_get(distance, s, -1)
		if (d > max)
			max = d
	}

	let result = []
	map_for_each(possible, (s, path) => {
		if (map_get(distance, s, -1) === max) {
			result.push(s)
			result.push(path)
		}
	})
	return result
}

states.retreat = {
	prompt() {
		prompt("Retreat " + format_selected() + " " + Math.abs(game.count) + " cities.")
		view.selected = game.selected
		view.retreat = game.retreat
		map_for_each_key(game.retreat, gen_action_space)
	},
	space(to) {
		push_undo()
		log("Retreated to S" + to + ".")
		for (let p of game.selected) {
			game.pos[p] = to
		}
		delete game.retreat
		next_combat()
	},
}

states.retreat_done = {
	prompt() {
		prompt("Retreat done.")
		view.actions.next = 1
	},
	next() {
		next_combat()
	},
}

/* RETRO-ACTIVE CONQUEST */

function goto_retroactive_conquest() {
	delete game.combat

	for (let s of game.retro) {
		if (is_conquest_space(game.power, s)) {
			if (!is_protected_from_conquest(s)) {
				log("Conquered S" + s)
				set_add(game.conquest, s)
			}
		}
		if (is_reconquest_space(game.power, s)) {
			if (!is_protected_from_reconquest(s)) {
				log("Reconquered S" + s)
				set_delete(game.conquest, s)
			}
		}
	}

	set_clear(game.retro)

	// MARIA: supply is before movement

	goto_supply()
}

/* SUPPLY */

function search_supply_bfs(from, range) {
	let seen = [ from ]
	let queue = [ from << 4 ]
	while (queue.length > 0) {
		let item = queue.shift()
		let here = item >> 4
		let dist = (item & 15) + 1
		for (let next of data.cities.adjacent[here]) {
			if (set_has(seen, next))
				continue
			if (has_enemy_piece(next))
				continue
			set_add(seen, next)
			if (dist < range)
				queue.push((next << 4) | dist)
		}
	}
	return seen
}

function search_supply(range) {
	for (let p of all_power_trains[game.power]) {
		let here = game.pos[p]
		if (here >= ELIMINATED)
			continue
		if (!game.supply)
			game.supply = search_supply_bfs(here, range)
		else
			set_add_all(game.supply, search_supply_bfs(here, range))
	}
}

function is_out_of_supply(p) {
	return (game.oos & (1 << p)) !== 0
}

function set_out_of_supply(p) {
	return game.oos |= (1 << p)
}

function set_in_supply(p) {
	return game.oos &= ~(1 << p)
}

function has_supply_line(p) {
	if (!game.supply)
		return false
	let s = game.pos[p]
	if (set_has(all_home_or_depot_cities[game.power], s))
		return true
	if (game.supply && set_has(game.supply, s))
		return true
	return false
}

function should_flip_generals() {
	for (let p of all_power_generals[game.power]) {
		if (game.pos[p] >= ELIMINATED)
			continue
		if (set_has(game.moved, p))
			continue
		if (is_out_of_supply(p) || !has_supply_line(p))
			return true
	}
	return false
}

function goto_supply() {
	set_clear(game.moved)
	search_supply(6)
	if (should_flip_generals())
		game.state = "supply"
	else
		end_supply()
}

states.supply = {
	prompt() {
		prompt("Supply.")
		for (let p of all_power_generals[game.power]) {
			if (game.pos[p] >= ELIMINATED)
				continue
			if (set_has(game.moved, p))
				continue
			if (is_out_of_supply(p) || !has_supply_line(p))
				gen_action_supreme_commander(game.pos[p])
		}
	},
	piece(x) {
		let s = game.pos[x]
		for (let p of all_power_generals[game.power]) {
			if (game.pos[p] === s) {
				set_add(game.moved, p)
				if (is_out_of_supply(p)) {
					set_in_supply(p)
					if (!has_supply_line(p)) {
						log("P" + p + " eliminated.")
						game.pos[p] = ELIMINATED
						game.troops[p] = 0
					} else {
						log("P" + p + " in supply.")
					}
				} else {
					log("P" + p + " out of supply.")
					set_out_of_supply(p)
				}
			}
		}
		if (!should_flip_generals())
			game.state = "supply_done"
	},
}

states.supply_done = {
	prompt() {
		prompt("Supply done.")
		view.actions.end_supply = 1
	},
	end_supply() {
		end_supply()
	},
}

function end_supply() {
	set_clear(game.moved)
	delete game.supply
	end_action_stage()
}

/* STROKES OF FATE */

const strokes_of_fate_name = [
	"Poems",
	"Lord Bute",
	"Elisabeth",
	"Sweden",
	"India",
	"America",
]

states.russia_quits_the_game_1 = {
	prompt() {
		prompt("Russia quits the game. Remove all Russian pieces.")
		for (let p of all_power_generals[P_RUSSIA])
			gen_action_piece(p)
		for (let p of all_power_trains[P_RUSSIA])
			gen_action_piece(p)
	},
	piece(p) {
		game.pos[p] = REMOVED
		if (is_general(p))
			game.troops[p] = 0
		if (has_removed_all_pieces(P_RUSSIA))
			game.state = "russia_quits_the_game_2"
	},
}

states.russia_quits_the_game_2 = {
	prompt() {
		prompt("Russia quits the game. Retire one Prussian general.")
		for (let p of all_power_generals[game.power])
			if (p !== GEN_FRIEDRICH && game.pos[p] < ELIMINATED)
				gen_action_piece(p)
	},
	piece(p) {
		push_undo()
		retire_general(p)
		game.state = "russia_quits_the_game_3"
	},
}

states.russia_quits_the_game_3 = {
	prompt() {
		prompt("Russia quits the game.")
		view.actions.done = 1
	},
	done() {
		remove_power_from_play(P_RUSSIA)
		resume_start_turn()
	},
}

states.sweden_quits_the_game_1 = {
	prompt() {
		prompt("Sweden quits the game. Remove all Swedish pieces.")
		for (let p of all_power_generals[P_SWEDEN])
			gen_action_piece(p)
		for (let p of all_power_trains[P_SWEDEN])
			gen_action_piece(p)
	},
	piece(p) {
		game.pos[p] = REMOVED
		if (is_general(p))
			game.troops[p] = 0
		if (has_removed_all_pieces(P_SWEDEN))
			game.state = "sweden_quits_the_game_2"
	},
}

states.sweden_quits_the_game_2 = {
	prompt() {
		prompt("Sweden quits the game. Retire one Prussian general.")
		for (let p of all_power_generals[game.power])
			if (p !== GEN_FRIEDRICH && game.pos[p] < ELIMINATED)
				gen_action_piece(p)
	},
	piece(p) {
		push_undo()
		retire_general(p)
		game.state = "sweden_quits_the_game_3"
	},
}

states.sweden_quits_the_game_3 = {
	prompt() {
		prompt("Sweden quits the game.")
		view.actions.done = 1
	},
	done() {
		remove_power_from_play(P_SWEDEN)
		resume_start_turn()
	},
}

states.france_quits_the_game_1 = {
	prompt() {
		prompt("France quits the game. Remove all French pieces.")
		for (let p of all_power_generals[P_FRANCE])
			gen_action_piece(p)
		for (let p of all_power_trains[P_FRANCE])
			gen_action_piece(p)
	},
	piece(p) {
		game.pos[p] = REMOVED
		if (is_general(p))
			game.troops[p] = 0
		if (has_removed_all_pieces(P_FRANCE))
			game.state = "france_quits_the_game_2"
	},
}

states.france_quits_the_game_2 = {
	prompt() {
		prompt("France quits the game. Retire Cumberland.")
		gen_action_piece(GEN_CUMBERLAND)
	},
	piece(p) {
		retire_general(p)
		remove_power_from_play(P_FRANCE)
		resume_start_turn()
	},
}

/* CARDS OF FATE (IMMEDIATE) */

const fate_effect_immediate = [
	null,
	any_one_russian_on_map_general_receives_a_new_troop_for_free,
	austria_and_russia_may_exchange_one_tc_with_each_other,
	tottleben_receives_a_new_troop_for_free,

	null,
	null,
	apraxin_immediately_loses_one_troop,
	null,

	null,
	null,
	null,
	null,

	null,
	null,
	france_may_discard_any_one_tc_for_a_new_one_from_the_draw_deck,
	null,

	null,
	null,
	null,
	null,

	austria_may_move_laudon_by_one_city_immediately,
	daun_receives_one_new_troop,
	null,
	austria_may_flip_any_one_prussian_general_or_stack_in_austria_or_saxony,

	null,
	null,
	null,
	null,

	any_one_prussian_on_map_general_receives_a_new_troop_for_free,
	null,
	null,
	null,

	all_russian_generals_5_or_6_cities_distant_from_their_nearest_supply_train_are_immediately_out_of_supply,
	null,
	null,
	prussia_may_draw_randomly_one_tc_from_austria_after_first_giving_one_tc_of_her_choice_to_austria,

	null,
	any_one_prussian_general_with_2_or_more_troops_loses_one_troop_immediately,
	null,
	null,

	null,
	any_one_hanoverian_on_map_general_receives_a_new_troop,
	null,
	null,

	null,
	if_ehrensvärd_is_5_or_6_cities_distant_from_his_supply_train_he_is_immediately_out_of_supply,
	if_hildburghausen_has_lost_a_battle_this_turn_prussia_may_move_him_2_cities_westwards,
	null,
]

function any_one_russian_on_map_general_receives_a_new_troop_for_free() {
	goto_receive_a_new_troop(P_RUSSIA, all_power_generals[P_RUSSIA])
}

function tottleben_receives_a_new_troop_for_free() {
	goto_receive_a_new_troop(P_RUSSIA, [ GEN_TOTTLEBEN ])
}

function daun_receives_one_new_troop() {
	goto_receive_a_new_troop(P_AUSTRIA, [ GEN_DAUN ])
}

function any_one_prussian_on_map_general_receives_a_new_troop_for_free() {
	goto_receive_a_new_troop(P_PRUSSIA, all_power_generals[P_PRUSSIA])
}

function any_one_hanoverian_on_map_general_receives_a_new_troop() {
	goto_receive_a_new_troop(P_HANOVER, all_power_generals[P_HANOVER])
}

function apraxin_immediately_loses_one_troop() {
	goto_lose_one_troop(P_RUSSIA, [ GEN_APRAXIN ])
}

function any_one_prussian_general_with_2_or_more_troops_loses_one_troop_immediately() {
	goto_lose_one_troop(P_PRUSSIA, all_power_generals[P_PRUSSIA])
}

function all_russian_generals_5_or_6_cities_distant_from_their_nearest_supply_train_are_immediately_out_of_supply() {
	goto_flip_5_or_6_from_nearest_train(P_RUSSIA, all_power_generals[P_RUSSIA])
}

function if_ehrensvärd_is_5_or_6_cities_distant_from_his_supply_train_he_is_immediately_out_of_supply() {
	goto_flip_5_or_6_from_nearest_train(P_SWEDEN, [ GEN_EHRENSVAERD ])
}

function austria_may_flip_any_one_prussian_general_or_stack_in_austria_or_saxony() {
	set_active_to_power(P_AUSTRIA)

	game.selected = []
	for (let p of all_power_generals[P_PRUSSIA])
		if (!is_out_of_supply(p) && (set_has(data.country.Austria, p) || set_has(data.country.Saxony, p)))
			game.selected.push(p)

	if (game.selected.length > 0) {
		game.state = "flip_any_one_prussian_general_or_stack_in_austria_or_saxony"
	} else {
		resume_start_turn()
	}
}

function austria_and_russia_may_exchange_one_tc_with_each_other() {
	set_active_to_power(P_AUSTRIA)
	if (!has_power_dropped_out(P_RUSSIA))
		game.state = "austria_and_russia_may_exchange_one_tc_with_each_other_1"
	else
		resume_start_turn()
}

function france_may_discard_any_one_tc_for_a_new_one_from_the_draw_deck() {
	set_active_to_power(P_FRANCE)
	if (!has_power_dropped_out(P_FRANCE))
		game.state = "france_may_discard_any_one_tc_for_a_new_one_from_the_draw_deck"
	else
		resume_start_turn()
}

function prussia_may_draw_randomly_one_tc_from_austria_after_first_giving_one_tc_of_her_choice_to_austria() {
	set_active_to_power(P_PRUSSIA)
	game.state = "prussia_may_draw_randomly_one_tc_from_austria_after_first_giving_one_tc_of_her_choice_to_austria"
}

function austria_may_move_laudon_by_one_city_immediately() {
	set_active_to_power(P_AUSTRIA)
	if (game.pos[GEN_LAUDON] < ELIMINATED) {
		game.state = "austria_may_move_laudon_by_one_city_immediately"
		game.selected = [ GEN_LAUDON ]
	} else {
		resume_start_turn()
	}
}

function if_hildburghausen_has_lost_a_battle_this_turn_prussia_may_move_him_2_cities_westwards() {
	set_active_to_power(P_PRUSSIA)
	if (game.ia_lost)
		game.state = "prussia_may_move_hildburghausen_2_cities_westwards"
	else
		resume_start_turn()
}

function goto_receive_a_new_troop(power, list) {
	set_active_to_power(power)

	if (count_used_troops() === max_power_troops(power)) {
		resume_start_turn()
		return
	}

	game.selected = []
	for (let p of list)
		if (game.pos[p] < ELIMINATED && game.troops[p] < 8)
			game.selected.push(p)

	if (game.selected.length > 0) {
		game.state = "receive_a_new_troop"
	} else {
		resume_start_turn()
	}
}

states.receive_a_new_troop = {
	prompt() {
		prompt("Receive a new troop for free.")
		for (let p of game.selected)
			gen_action_supreme_commander(game.pos[p])
	},
	piece(p) {
		add_one_troop(p)
		resume_start_turn()
	}
}

function goto_lose_one_troop(power, list) {
	set_active_to_power(power)

	game.selected = []
	for (let p of list)
		if (game.pos[p] < ELIMINATED && game.troops[p] > 1)
			game.selected.push(p)

	if (game.selected.length > 0) {
		game.state = "lose_one_troop"
	} else {
		resume_start_turn()
	}
}

states.lose_one_troop = {
	prompt() {
		prompt("Lose one troop.")
		for (let p of game.selected)
			gen_action_supreme_commander(game.pos[p])
	},
	piece(p) {
		remove_one_troop(p)
		resume_start_turn()
	}
}

function goto_flip_5_or_6_from_nearest_train(power, list) {
	set_active_to_power(power)

	search_supply(4)

	game.selected = []
	for (let p of list)
		if (game.pos[p] < ELIMINATED && !is_out_of_supply(p))
			if (!set_has(game.supply, game.pos[p]))
				game.selected.push(p)

	delete game.supply

	if (game.selected.length > 0) {
		game.state = "flip_5_or_6_from_nearest_train"
	} else {
		resume_start_turn()
	}
}

states.flip_5_or_6_from_nearest_train = {
	prompt() {
		prompt("Flip " + format_selected() + " out of supply.")
		for (let p of game.selected)
			gen_action_supreme_commander(game.pos[p])
	},
	piece(p) {
		flip_stack_out_of_supply(p)
		if (game.selected.length === 0)
			resume_start_turn()
	}
}

states.flip_any_one_prussian_general_or_stack_in_austria_or_saxony = {
	prompt() {
		prompt("Flip any one Prussian general/stack in Austria or Saxony out of supply.")
		for (let p of game.selected)
			gen_action_supreme_commander(game.pos[p])
	},
	piece(p) {
		flip_stack_out_of_supply(p)
		resume_start_turn()
	}
}

function flip_stack_out_of_supply(p) {
	for (let x of all_power_generals[game.power]) {
		if (game.pos[x] === game.pos[p]) {
			set_out_of_supply(x)
			set_delete(game.selected, x)
		}
	}
}

states.austria_and_russia_may_exchange_one_tc_with_each_other_1 = {
	prompt() {
		prompt("You may exchange one TC with Russia.")
		for (let c of game.hand[P_AUSTRIA])
			gen_action_card(c)
		view.actions.pass = 1
	},
	card(c) {
		set_delete(game.hand[P_AUSTRIA], c)
		game.exchange = c
		set_active_to_power(P_RUSSIA)
		game.state = "austria_and_russia_may_exchange_one_tc_with_each_other_2"
	},
	pass() {
		resume_start_turn()
	},
}

states.austria_and_russia_may_exchange_one_tc_with_each_other_2 = {
	prompt() {
		prompt("You may exchange one TC with Austria.")
		for (let c of game.hand[P_RUSSIA])
			gen_action_card(c)
		view.actions.pass = 1
	},
	card(c) {
		set_add(game.hand[P_RUSSIA], game.exchange)
		delete game.exchange

		set_delete(game.hand[P_RUSSIA], c)
		set_add(game.hand[P_AUSTRIA], c)

		log("Austria and Russia exchanged TC.")
		resume_start_turn()
	},
	pass() {
		log("Austria and Russia did not exchange TC.")
		set_add(game.hand[P_AUSTRIA], game.exchange)
		delete game.exchange
		resume_start_turn()
	},
}

states.france_may_discard_any_one_tc_for_a_new_one_from_the_draw_deck = {
	prompt() {
		prompt("You may discard one TC to draw a new one.")
		for (let c of game.hand[P_FRANCE])
			gen_action_card(c)
		view.actions.pass = 1
	},
	card(c) {
		log("France discarded one TC.")
		log("France drew one TC.")
		set_delete(game.hand[P_FRANCE], c)
		c = draw_next_tc()
		if (c >= 0)
			set_add(game.hand[P_FRANCE], c)
		resume_start_turn()
	},
	pass() {
		resume_start_turn()
	},
}

states.prussia_may_draw_randomly_one_tc_from_austria_after_first_giving_one_tc_of_her_choice_to_austria = {
	prompt() {
		prompt("You may give Austria one TC to draw a random TC from her.")
		for (let c of game.hand[P_PRUSSIA])
			gen_action_card(c)
		view.actions.pass = 1
	},
	card(c) {
		log("Prussia gave one TC to Austria.")
		log("Prussia took one random TC from Austria.")

		set_delete(game.hand[P_PRUSSIA], c)
		set_add(game.hand[P_AUSTRIA], c)

		let x = random_bigint(game.hand[P_AUSTRIA].length)
		c = game.hand[P_AUSTRIA][x]
		set_delete(game.hand[P_AUSTRIA], c)
		set_add(game.hand[P_PRUSSIA], c)

		resume_start_turn()
	},
	pass() {
		resume_start_turn()
	},
}

states.austria_may_move_laudon_by_one_city_immediately = {
	prompt() {
		prompt("You may move Laudon by one city.")
		view.selected = game.selected

		let here = game.pos[GEN_LAUDON]
		for (let next of data.cities.adjacent[here])
			// TODO: may capture supply trains?
			if (can_move_general_to(next))
				gen_action_space(next)

		let s_take = count_stacked_take()
		let s_give = count_stacked_give()
		let u_take = count_unstacked_take()
		let u_give = count_unstacked_give()
		if (s_take > 0 && u_give > 0)
			view.actions.take = 1
		if (s_give > 0 && u_take > 0)
			view.actions.give = 1
	},
	take() {
		push_undo()
		game.state = "laudon_take"
	},
	give() {
		push_undo()
		game.state = "laudon_give"
	},
	space(s) {
		push_undo()
		log("P" + GEN_LAUDON + " to S" + s)
		// no conquest, but may capture supply trains?
		move_general_immediately(s)
		game.state = "laudon_done"
	},
}

states.laudon_take = states.move_take
states.laudon_give = states.move_give

states.laudon_done = {
	prompt() {
		prompt("You may move Laudon by one city.")
		view.selected = game.selected
		view.actions.done = 1
	},
	done() {
		clear_undo()
		resume_start_turn()
	},
}

function is_west_of(here, there) {
	let dx = data.cities.x[there] - data.cities.x[here]
	let dy = data.cities.y[there] - data.cities.y[here]
	// more west than north/south
	return dx < 0 && Math.abs(dx) >= Math.abs(dy)
}

states.prussia_may_move_hildburghausen_2_cities_westwards = {
	prompt() {
		prompt("You may move Hildburghausen two cities westwards.")
		view.selected = game.selected
		view.actions.pass = 1

		let here = game.pos[GEN_HILDBURGHAUSEN]
		for (let a of data.cities.adjacent[here])
			if (!has_any_piece(a))
				for (let b of data.cities.adjacent[a])
					if (is_west_of(here, b) && !has_any_piece(b))
						gen_action_space(b)
	},
	space(s) {
		log("P" + GEN_HILDBURGHAUSEN + " to S" + s)
		game.pos[GEN_HILDBURGHAUSEN] = s
		resume_start_turn()
	},
	pass() {
		resume_start_turn()
	},
}

/* CARDS OF FATE (PASSIVE) */

// immobilize
// reduce move
// no unstacking
// no attack and no elim space
// no attack and no elim general
// no receive troops (friedrich)
// no receive troops (if attacking)
// 4 protect range

// avoid battle
// soubise and hildburg not attack with same tc-symbol
// tc mod

const fate_effect_passive = [
	null,
	null,
	null,
	null,

	null,
	"If Fermor starts his move in Küstrin (H6) or in an adjacent city, he may not move next turn.",
	null,
	"Next turn, Saltikov may move only 2 cities (3 on main roads).",

	null,
	"Next turn, if Prussia and France fight each other, they may not use TCs with values of 10 or more.",
	"Next turn, Soubise and Hildburghausen may not attack with the same TC-symbol.",
	"Next turn, no general may be attacked in the city of Halle (E4) and no supply train may be eliminated in the city of Halle.",

	"Next turn, the first TC played by France is worth an additional point.",
	null,
	null,
	"Next turn, Cumberland may not move into attack position; he may not eliminate a supply train.",

	"Next turn, Soubise may not move into attack position; he may not eliminate a supply train.",
	null,
	"Next turn, Richelieu may move 2 cities only (3 on main roads).",
	"If stacked, Chevert may not unstack next turn.",

	null,
	null,
	null,
	null,

	"Next turn, Friedrich may not move into attack position and may not eliminate a supply train.",
	null,
	"Next turn, Friedrich may not receive any new troops.",
	"If Friedrich is involved in combat next turn, Prussia must reach a positive score with the first TC(s) she plays (if possible).",

	null,
	"Next turn, any Prussians who are attacked by Daun may move to any empty adjacent city (before the combat is resolved); by doing so they avoid all combat.",
	null,
	"If Friedrich attacks next turn, his first TC is worth 5 additional points.",

	null,
	"Next turn, Friedrich may move 4 cities, even as a stack (5 on main roads).",
	null,
	null,

	"Next turn, every Prussian general who receives new troops may not move into attack position.",
	null,
	"If Friedrich is attacked next turn, the first TC played by Prussia is worth nothing (0 points).",
	null,

	"Next turn, Prussia may play the 11 of spades (Seydlitz) once at double value.",
	null,
	"Next turn, Prinz Heinrich protects objectives up to 4 cities distant.",
	null,

	"Next turn, Daun may move only 2 cities (3 on main roads).",
	null,
	null,
	null,
]

/* SETUP */

const POWER_FROM_SETUP_STEP_4 = [
	P_PRUSSIA,
	P_HANOVER,
	P_RUSSIA,
	P_SWEDEN,
	P_AUSTRIA,
	P_IMPERIAL,
	P_FRANCE,
]

const POWER_FROM_SETUP_STEP_3 = [
	P_PRUSSIA,
	P_HANOVER,
	P_RUSSIA,
	P_SWEDEN,
	P_FRANCE,
	P_AUSTRIA,
	P_IMPERIAL,
]

function set_active_setup_power() {
	if (game.scenario === 3)
		game.power = POWER_FROM_SETUP_STEP_3[game.step]
	else
		game.power = POWER_FROM_SETUP_STEP_4[game.step]
	game.active = current_player()
}

const SETUP_POSITION = [
	// P
	find_city("Oschatz"),
	find_city("Oschatz"),
	find_city("Berlin"),
	find_city("Strehlen"),
	find_city("Strehlen"),
	find_city("Brandenburg"),
	find_city("Arnswalde"),
	find_city("Mohrungen"),

	// H
	find_city("Stade"),
	find_city("Alfeld"),

	// R
	find_city("Bydgoszcz"),
	find_city("Bydgoszcz"),
	find_city("Łomża"),
	find_city("Sierpc"),

	// S
	find_city("Stralsund"),

	// A
	find_city("Brünn"),
	find_city("Melnik"),
	find_city("Melnik"),
	find_city("Olmütz"),
	find_city("Tabor"),

	// IA
	find_city("Hildburghausen"),

	// F
	find_city("Iserlohn"),
	find_city("Fulda"),
	find_city("Iserlohn"),

	// Supply Train
	find_city("Grünberg"),
	find_city("Jüterbog"),

	find_city("Gifhorn"),

	find_city("Toruń"),
	find_city("Warszawa"),

	find_city("Wismar"),

	find_city("Beraun"),
	find_city("Pardubitz"),

	find_city("Erlangen"),

	find_city("Gemünden"),
	find_city("Koblenz"),
]

const SETUP_TROOPS = [
	/* P (32) */ 0, 0, 0, 0, 0, 0, 0, 0,
	/* H (02) */ 0, 0,
	/* R (06) */ 0, 0, 0, 0,
	/* S  (4) */ 4,
	/* A (30) */ 0, 0, 0, 0, 0,
	/* IA (6) */ 6,
	/* F (20) */ 0, 0, 0,
]

function make_fate_deck() {
	let deck = []
	for (let i = 1; i <= 18; ++i)
		deck.push(i)
	shuffle_bigint(deck)
	return deck
}

function make_seeded_fate_deck() {
	let deck = []

	for (let i = 1; i <= 18; ++i) {
		if (i === FC_ELISABETH || i === FC_POEMS || i === FC_AMERICA)
			continue
		deck.push(i)
	}
	shuffle_bigint(deck)

	let aside = []
	for (let i = 0; i < 4; ++i)
		aside.push(deck.pop())

	deck.push(FC_ELISABETH)
	deck.push(FC_POEMS)
	deck.push(FC_AMERICA)
	shuffle_bigint(deck)

	for (let i = 0; i < 4; ++i)
		deck.push(aside.pop())

	return deck
}

function make_tactics_deck(n) {
	let deck = []
	for (let suit = 0; suit <= 3; ++suit)
		for (let value = 2; value <= 13; ++value)
			deck.push((n << 7) | (suit << 4) | value)
	deck.push((n << 7) | (RESERVE << 4) | 2)
	deck.push((n << 7) | (RESERVE << 4) | 3)
	return deck
}

function make_tactics_discard(n) {
	return make_tactics_deck(n).filter(c => {
		if (game.draw && set_has(game.draw, c))
			return false
		for (let pow of all_powers)
			if (set_has(game.hand[pow], c))
				return false
		return true
	})
}

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

		scenario: 4,
		state: "setup",
		active: "Frederick",
		power: P_PRUSSIA,

		turn: 0,
		step: 0,
		clock: null,
		fate: [],
		vg: 0, // last victorious general for fate effect selection
		fx: 0, // current card of fate effect
		deck: null,
		hand: [ [], [], [], [], [], [], [] ],

		pos: SETUP_POSITION.slice(),
		oos: 0,
		troops: SETUP_TROOPS.slice(),
		conquest: [],

		moved: [],
		retro: [],

		selected: [],
		count: 0,
	}

	game.scenario = SCENARIO_INDEX[scenario]

	if (options.seeded)
		game.clock = make_seeded_fate_deck()
	else
		game.clock = make_fate_deck()

	game.deck = make_tactics_deck(0)

	shuffle_bigint(game.deck)

	if (game.scenario === 1)
		log("# The War in the West")
	if (game.scenario === 2)
		log("# The Austrian Theatre")

	if (game.scenario === 1)
		setup_the_war_in_the_west()

	if (game.scenario === 2)
		setup_the_austrian_theatre()

	return game
}

function remove_power_from_play(pow) {
	for (let p of all_power_generals[pow]) {
		game.pos[p] = REMOVED
		game.troops[p] = 0
	}
	for (let p of all_power_trains[pow])
		game.pos[p] = REMOVED
	for (let s of full_objective[pow])
		set_delete(game.conquest, s)
	if (game.hand[pow].length > 0)
		log("Discarded " + game.hand[pow].length + " TCs.")
	game.hand[pow] = []
}

function setup_the_war_in_the_west() {
	remove_power_from_play(P_RUSSIA)
	remove_power_from_play(P_SWEDEN)
	remove_power_from_play(P_AUSTRIA)
	remove_power_from_play(P_IMPERIAL)

	remove_power_from_play(P_PRUSSIA)
	game.pos[GEN_SEYDLITZ] = find_city("Brandenburg")
	game.troops[GEN_SEYDLITZ] = 3
	game.pos[24] = find_city("Jüterbog")
}

function setup_the_austrian_theatre() {
	remove_power_from_play(P_HANOVER)
	remove_power_from_play(P_RUSSIA)
	remove_power_from_play(P_SWEDEN)
	remove_power_from_play(P_FRANCE)

	game.pos[5] = REMOVED
	game.pos[6] = REMOVED
	game.pos[7] = REMOVED
}

states.setup = {
	prompt() {
		prompt("Setup troops: " + count_used_troops() + " / " + max_power_troops(game.power))
		let done = true
		for (let p of all_power_generals[game.power]) {
			if (game.pos[p] < ELIMINATED && game.troops[p] === 0) {
				if (is_supreme_commander(p)) {
					gen_action_piece(p)
					done = false
				}
			}
		}
		if (done)
			view.actions.end_setup = 1
	},
	piece(p) {
		push_undo()
		game.selected = select_stack(game.pos[p])
		game.state = "setup_general"
	},
	end_setup() {
		clear_undo()
		end_setup()
	},
}

states.setup_general = {
	prompt() {
		prompt("Setup troops.")
		view.selected = game.selected

		let n_selected = game.selected.length
		let n_other = count_unused_generals() - game.selected.length
		let n_troops = max_power_troops(game.power) - count_used_troops()

		// leave at least 1 for each remaining general
		let take_max = Math.min(8 * n_selected, n_troops - n_other)

		// leave no more than 8 for each remaining general
		let take_min = Math.max(1 * n_selected, n_troops - n_other * 8)

		view.actions.value = []
		for (let i = take_min; i <= take_max; ++i)
			view.actions.value.push(i)
	},
	value(v) {
		let save = game.selected.length - 1
		for (let p of game.selected) {
			let n = Math.min(8, v - save)
			game.troops[p] = n
			v -= n
			--save
		}
		game.selected = null
		game.state = "setup"
	},
}

function end_setup() {
	if (++game.step === 7) {
		goto_start_turn()
	} else {
		set_active_setup_power()
		if (count_unused_generals() === 0)
			end_setup()
	}
}

/* VIEW */

function mask_troops(player) {
	let view_troops = []
	for (let pow of all_powers) {
		if (player_from_power(pow) === player) {
			for (let p of all_power_generals[pow])
				view_troops.push(game.troops[p])
		} else {
			for (let p of all_power_generals[pow]) {
				let s = game.pos[p]
				if (game.attacker === s || game.defender === s)
					view_troops.push(game.troops[p])
				else
					view_troops.push(0)
			}
		}
	}
	return view_troops
}

function mask_hand(player) {
	let view_hand = []
	for (let pow of all_powers) {
		if (player_from_power(pow) === player)
			view_hand[pow] = game.hand[pow]
		else
			view_hand[pow] = game.hand[pow].map(c => c & ~127)
	}
	return view_hand
}

exports.view = function (state, player) {
	game = state
	view = {
		prompt: null,
		actions: null,
		log: game.log,

		fate: game.turn <= 5 ? game.turn : game.fate,
		pos: game.pos,
		oos: game.oos,
		conquest: game.conquest,
		troops: mask_troops(player),
		hand: mask_hand(player),

		power: game.power,
		retro: game.retro,
	}

	if (game.attacker !== undefined && game.defender !== undefined) {
		view.attacker = game.attacker
		view.defender = game.defender
	}

	if (game.state === "game_over") {
		view.prompt = game.victory
	} else if (game.active !== player) {
		let inactive = states[game.state].inactive || game.state
		view.prompt = `Waiting for ${POWER_NAME[game.power]} to ${inactive}.`
	} else {
		view.actions = {}
		if (states[game.state])
			states[game.state].prompt()
		else
			view.prompt = "Unknown state: " + game.state
		if (view.actions.undo === undefined) {
			if (game.undo && game.undo.length > 0)
				view.actions.undo = 1
			else
				view.actions.undo = 0
		}
	}

	return view
}

/* COMMON FRAMEWORK */

function goto_game_over(result, victory) {
	game.active = "None"
	game.state = "game_over"
	game.result = result
	game.victory = victory
	log("# Game Over")
	log(game.victory)
	return true
}

function prompt(str) {
	view.prompt = POWER_NAME[game.power] + ": " + str
}

exports.action = function (state, _player, action, arg) {
	game = state
	let S = states[game.state]
	if (S && action in S) {
		S[action](arg)
	} else {
		if (action === "undo" && game.undo && game.undo.length > 0)
			pop_undo()
		else
			throw new Error("Invalid action: " + action)
	}
	return game
}

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

function gen_action_piece(p) {
	gen_action("piece", p)
}

function gen_action_space(s) {
	gen_action("space", s)
}

function gen_action_supreme_commander(s) {
	let p = get_supreme_commander(s)
	if (p >= 0)
		gen_action_piece(p)
}

function gen_action_space_or_piece(s) {
	let p = get_top_piece(s)
	if (p >= 0)
		gen_action_piece(p)
	else
		gen_action_space(s)
}

function gen_action_card(c) {
	gen_action("card", c)
}

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

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

/* COMMON LIBRARY */

function clear_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
	}
}

function random_bigint(range) {
	// 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)) % range
}

function shuffle_bigint(list) {
	// Fisher-Yates shuffle
	for (let i = list.length - 1; i > 0; --i) {
		let j = random_bigint(i + 1)
		let tmp = list[j]
		list[j] = list[i]
		list[i] = tmp
	}
}

// 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
	}
}

// Array remove and insert (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
}

function array_remove_item(array, item) {
	let n = array.length
	for (let i = 0; i < n; ++i)
		if (array[i] === item)
			return array_remove(array, i)
}

function array_insert(array, index, item) {
	for (let i = array.length; i > index; --i)
		array[i] = array[i - 1]
	array[index] = item
}

function array_remove_pair(array, index) {
	let n = array.length
	for (let i = index + 2; i < n; ++i)
		array[i - 2] = array[i]
	array.length = n - 2
}

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
}

// Set as plain sorted array

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
	}
	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 {
			array_remove(set, m)
			return
		}
	}
}

function set_add_all(set, other) {
	for (let item of other)
		set_add(set, item)
}

function set_union(one, two) {
	let set = []
	for (let item of one)
		set_add(set, item)
	for (let item of two)
		set_add(set, item)
	return set
}

function set_intersect(one, two) {
	let set = []
	for (let item of one)
		if (set_has(two, item))
			set_add(set, item)
	return set
}

// Map as plain sorted array of key/value pairs

function map_has(map, key) {
	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 true
	}
	return false
}

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)
}

function map_for_each_key(map, f) {
	for (let i = 0; i < map.length; i += 2)
		f(map[i])
}

function map_for_each(map, f) {
	for (let i = 0; i < map.length; i += 2)
		f(map[i], map[i+1])
}