"use strict"

// unit state: location (8 bits), steps (2 bits), supplied, disrupted, moved

const max = Math.max
const min = Math.min
const abs = Math.abs

var states = {}
var game = null
var view = null

let { hex_exists, hex_road, side_road, side_limit, hex_name, units, regions } = require("./data")

function debug_hexes3(n, list) {
	console.log("--", n, "--")
	list = list.map((x,i) => hex_exists[i] ? x : "")
	for (let y = 0; y < hexh; ++y)
		console.log("".padStart(y*2," ") + list.slice(y*hexw, (y+1)*hexw).map(x=>String(x).padStart(3, ' ')).join(" "))
}

function debug_hexes2(n, list) {
	console.log("--", n, "--")
	list = list.map((x,i) => hex_exists[i] ? x : "")
	for (let y = 0; y < hexh; ++y)
		console.log("".padStart(y*2," ") + list.slice(y*hexw, (y+1)*hexw).map(x=>String(x).padStart(3, ' ')).join(" "))
}

function debug_hexes(n, list) {
	console.log("--", n, "--")
	list = list.map((x,i) => hex_exists[i] ? x : "")
	for (let y = 0; y < hexh; ++y)
		console.log("".padStart(y," ") + list.slice(y*hexw, (y+1)*hexw).map(x=>String(x).padStart(2, ' ')).join(""))
}

// Card deck has 42 cards, of which 28 are supply cards, and 14 are dummy cards.
// Represent draw pile and hands as [ dummy_supply_count, real_supply_count ]
const REAL_SUPPLY_COUNT = 28
const DUMMY_SUPPLY_COUNT = 14

const hexw = 25
const hexh = 9

const first_hex = 7
const last_hex = 215

const hexdeploy = hexw * hexh
const hexnext = [ 1, hexw, hexw-1, -1, -hexw, -(hexw-1) ]

const hexcount = last_hex + 1
const sidecount = hexcount * 3

const AXIS = 'Axis'
const ALLIED = 'Allied'

const CLEAR = 2
const PASS = 1
const ROUGH = 0

const NO_ROAD = 0
const TRAIL = 1
const TRACK = 2
const HIGHWAY = 4

const SUPPLY_RANGE = [ 1, 2, 3, -1, 3 ]

const EL_AGHEILA = 151
const ALEXANDRIA = 74
const BENGHAZI = 54
const TOBRUK = 37
const BARDIA = 40
const FT_CAPUZZO = 64
const MERSA_BREGA = 152
const BARDIA_FT_CAPUZZO = 122

const region_egypt = regions["Egypt"]
const region_el_agheila = regions["El Agheila"]
const region_tobruk = regions["Tobruk"]
const region_egypt_and_libya = regions["Libya"].concat(regions["Egypt"])
const region_libya_and_sidi_omar = regions["Libya"].concat(regions["Sidi Omar"])
const region_libya_and_sidi_omar_and_sollum = regions["Libya"].concat(regions["Sidi Omar"]).concat(regions["Sollum"])
const region_egypt_and_tobruk = regions["Egypt"].concat(regions["Tobruk"])
const region_libya_except_tobruk = regions["Libya"].filter(r => r !== TOBRUK)

const region_all = []
for (let x = first_hex; x <= last_hex; ++x)
	region_all.push(x)

function calc_distance(a, b) {
	let ax = a % hexw, ay = (a / hexw)|0, az = -ax - ay
	let bx = b % hexw, by = (b / hexw)|0, bz = -bx - by
	return max(abs(bx-ax), abs(by-ay), abs(bz-az))
}

function calc_distance_map(supply) {
	let map = new Array(hexcount)
	for (let x = 0; x < hexcount; ++x)
		map[x] = calc_distance(supply, x)
	return map
}

const distance_to = {
	[EL_AGHEILA]: calc_distance_map(EL_AGHEILA),
	[ALEXANDRIA]: calc_distance_map(ALEXANDRIA),
	[BENGHAZI]: calc_distance_map(BENGHAZI),
	[TOBRUK]: calc_distance_map(TOBRUK),
	[BARDIA]: calc_distance_map(BARDIA),
}

function draw_supply_card(pile) {
	let x = random(pile[0] + pile[1])
	if (x < pile[0]) {
		pile[0] --
		return 0
	} else {
		pile[1] --
		return 1
	}
}

function deal_axis_supply_cards(n) {
	for (let i = 0; i < n; ++i)
		game.axis_hand[draw_supply_card(game.draw_pile)]++
}

function deal_allied_supply_cards(n) {
	for (let i = 0; i < n; ++i)
		game.allied_hand[draw_supply_card(game.draw_pile)]++
}

function find_unit(name) {
	for (let u = 0; u < units.length; ++u)
		if (units[u].name === name)
			return u
	throw new Error("cannot find named block: " + name)
}

function is_map_hex(x) {
	return next >= first_hex && next <= last_hex && hex_exists[next] === 1
}

function is_hex_or_adjacent_to(x, where) {
	if (x === where) return true
	for (let s = 0; s < 6; ++s)
		if (x === where + hexnext[s])
			return true
	return false
}

function find_units(list) {
	return list.map(name => find_unit(name))
}

function unit_name(u) {
	return units[u].name
}

function unit_speed(u) {
	return units[u].speed
}

function unit_hex(u) {
	return game.units[u] >>> 5
}

function set_unit_hex(u, x) {
	game.units[u] = (game.units[u] & 31) | (x << 5)
}

function unit_lost_steps(u) {
	return game.units[u] & 3
}

function set_unit_lost_steps(u, n) {
	game.units[u] = (game.units[u] & ~3) | n
}

function is_unit_supplied(u) {
	return (game.units[u] & 4) === 4
}

function set_unit_supplied(u) {
	game.units[u] |= 4
}

function clear_unit_supplied(u) {
	game.units[u] &= ~4
}

function is_unit_disrupted(u) {
	return (game.units[u] & 8) === 8
}

function set_unit_disrupted(u) {
	game.units[u] |= 8
}

function clear_unit_disrupted(u) {
	game.units[u] &= ~8
}

function is_unit_moved(u) {
	return (game.units[u] & 16) === 16
}

function set_unit_moved(u) {
	game.units[u] |= 16
}

function clear_unit_moved(u) {
	game.units[u] &= ~16
}

function unit_steps(u) {
	return units[u].steps - unit_lost_steps(u)
}

function set_unit_steps(u, n) {
	set_unit_lost_steps(u, units[u].steps - n)
}

function is_friendly_unit(u) {
	if (game.active === AXIS)
		return is_axis_unit(u)
	return is_allied_unit(u)
}

function is_enemy_unit(u) {
	if (game.active === ALLIED)
		return is_axis_unit(u)
	return is_allied_unit(u)
}

function is_friendly_hex(x) {
	if (game.active === AXIS)
		return is_axis_hex(x)
	return is_allied_hex(x)
}

function is_enemy_hex(x) {
	if (game.active === ALLIED)
		return is_axis_hex(x)
	return is_allied_hex(x)
}

function is_allied_unit(u) {
	return units[u].nationality === 'allied'
}

function is_axis_unit(u) {
	return units[u].nationality !== 'allied'
}

function is_axis_hex(x) {
	if (!hex_exists[x])
		return false
	let has_axis = false, has_allied = false
	for (let u = 0; u < units.length; ++u) {
		if (unit_hex(u) === x) {
			if (is_axis_unit(u))
				has_axis = true
			else
				has_allied = true
		}
	}
	return has_axis && !has_allied
}

function is_allied_hex(x) {
	if (!hex_exists[x])
		return false
	let has_axis = false, has_allied = false
	for (let u = 0; u < units.length; ++u) {
		if (unit_hex(u) === x) {
			if (is_axis_unit(u))
				has_axis = true
			else
				has_allied = true
		}
	}
	return !has_axis && has_allied
}

function is_battle_hex(x) {
	if (!hex_exists[x])
		return false
	let has_axis = false, has_allied = false
	for (let u = 0; u < units.length; ++u) {
		if (unit_hex(u) === x) {
			if (is_axis_unit(u))
				has_axis = true
			else
				has_allied = true
		}
	}
	return has_axis && has_allied
}

function is_empty_hex(x) {
	if (!hex_exists[x])
		return false
	let has_axis = false, has_allied = false
	for (let u = 0; u < units.length; ++u) {
		if (unit_hex(u) === x) {
			if (is_axis_unit(u))
				has_axis = true
			else
				has_allied = true
		}
	}
	return !has_axis && !has_allied
}

function has_axis_unit(x) {
	if (!hex_exists[x])
		return false
	for (let u = 0; u < units.length; ++u)
		if (unit_hex(u) === x)
			if (is_axis_unit(u))
				return true
	return false
}

function has_allied_unit(x) {
	if (!hex_exists[x])
		return false
	for (let u = 0; u < units.length; ++u)
		if (unit_hex(u) === x)
			if (is_allied_unit(u))
				return true
	return false
}

function has_friendly_unit(x) {
	if (game.active === AXIS)
		return has_axis_unit(x)
	return has_allied_unit(x)
}

function has_enemy_unit(x) {
	if (game.active === ALLIED)
		return has_axis_unit(x)
	return has_allied_unit(x)
}

function claim_hexside_control(side) {
	if (game.active === AXIS) {
		set_add(game.axis_sides, side)
		set_delete(game.allied_sides, side)
	} else {
		set_add(game.allied_sides, side)
		set_delete(game.axis_sides, side)
	}
}

function release_hex_control(a) {
	// no longer a battle hex: release hexsides if possible
	set_delete(game.axis_hexes, a)
	set_delete(game.allied_hexes, a)
	for (let s = 0; s < 6; ++s) {
		let b = a + hexnext[s]
		if (b >= first_hex && b <= last_hex && hex_exists[b]) {
			if (!is_battle_hex(b)) {
				let side = to_side_id(a, b)
				set_delete(game.axis_sides, side)
				set_delete(game.allied_sides, side)
			}
		}
	}
}

function is_new_battle_hex(a) {
	if (is_battle_hex(a))
		return !set_has(game.axis_hexes) && !set_has(game.allied_hexes)
	return false
}

function claim_hex_control_for_defender(a) {
	// a new battle hex: claim hex and hexsides for defender

	if (game.active === AXIS)
		set_add(game.allied_hexes, a)
	else
		set_add(game.axis_hexes, a)

	for (let s = 0; s < 6; ++s) {
		let b = a + hexnext[s]
		if (b >= first_hex && b <= last_hex && hex_exists[b]) {
			let side = to_side_id(a, b)
			if (side_limit[side] > 0) {
				if (game.active === AXIS) {
					if (!set_has(game.axis_sides, side))
						set_add(game.allied_sides, side)
				} else {
					if (!set_has(game.allied_sides, side))
						set_add(game.axis_sides, side)
				}
			}
		}
	}
}

function claim_stuff() {
	for (let x = first_hex; x <= last_hex; ++x)
		if (hex_exists[x])
			if (is_new_battle_hex(x))
				claim_hex_control_for_defender(x)
}

// === SUPPLY NETWORK ===

function is_side_unit(side, u) {
	if (side === AXIS)
		return is_axis_unit(u)
	return is_allied_unit(u)
}

function list_control_hexes(side) {
	let control = new Array(hexcount).fill(0)
	for (let u = 0; u < units.length; ++u) {
		if (is_side_unit(side, u)) {
			let x = unit_hex(u)
			if (x > 0 && x < hexdeploy)
				control[x] = 1
		}
	}
	return control
}

function to_side(a, b, s) {
	if (s < 3)
		return a * 3 + s
	return b * 3 + s - 3
}

function to_side_id(a, b) {
	if (a > b) {
		let c = b
		b = a
		a = c
	}
	if (a + hexnext[0] === b)
		return a * 3 + 0
	else if (a + hexnext[1] === b)
		return a * 3 + 1
	else if (a + hexnext[2] === b)
		return a * 3 + 2
	throw new Error("not a hexside " + a + " to " + b);
}

function ind(d, msg, here, ...extra) {
	console.log(new Array(d).fill("-").join("") + msg, here, "("+hex_name[here]+")", extra.join(" "))
}

var supply_visited, supply_friendly, supply_enemy, supply_src, supply_net, supply_line
var trace_total
var trace_highway
var trace_chain

function trace_supply_highway(here, d) {
	trace_highway++
	ind(d, "> highway", here)

	// TODO: hoist to call sites to avoid function call overhead
	if (supply_src[here]) {
		ind(d, "! source highway", here)
		return true
	}

	let has_supply = false

	supply_visited[here] = true

	for (let s = 0; s < 6; ++s) {
		let next = here + hexnext[s]
		let side = to_side(here, next, s)

		if (side_limit[side] === 0)
			continue
		if (supply_visited[next])
			continue
		if (supply_enemy[next])
			continue

		let road = side_road[side]
		if (road === HIGHWAY) {
			if (supply_friendly[next]) {
				ind(d, "? highway head", next)
				if (trace_supply_chain(next, d+1, 0, 3)) {
					ind(d, "< highway chain", here, next)
					supply_line[side] = 1
					has_supply = true
				}
			} else {
				if (trace_supply_highway(next, d+1)) {
					ind(d, "< highway", here, next)
					supply_line[side] = 1
					has_supply = true
				}
			}
		}
	}

	supply_visited[here] = false

	if (has_supply) {
		supply_net[here] = 1
		supply_src[here] = 1
	}

	return has_supply
}

function trace_supply_chain(here, d, n, range) {
	ind(d, "> chain", here, n, range)
	trace_chain++

	if (supply_src[here]) {
		ind(d, "! source chain", here)
		return true
	}

	let has_supply = false

	supply_visited[here] = true

	for (let s = 0; s < 6; ++s) {
		let next = here + hexnext[s]
		let side = to_side(here, next, s)

		if (side_limit[side] === 0)
			continue
		if (supply_visited[next])
			continue
		if (supply_enemy[next])
			continue

		let road = side_road[side]

		if (road === HIGHWAY) {
			ind(d, "? chain highway", next)
			if (supply_friendly[next]) {
				ind(d, "? chain highway head", next)
				if (trace_supply_chain(next, d+1, 0, 3)) {
					ind(d, "< highway chain", here, next)
					supply_line[side] = 1
					has_supply = true
				}
			} else {
				if (trace_supply_highway(next, d+1)) {
					ind(d, "< chain highway", here, next)
					supply_line[side] = 1
					has_supply = true
				}
			}
		} else {
			let next_range = min(range, SUPPLY_RANGE[road])
			if (n + 1 <= next_range) {
				if (supply_friendly[next]) {
					ind(d, "? chain head", next)
					if (trace_supply_chain(next, d+1, 0, 3)) {
						ind(d, "< highway chain", here, next)
						supply_line[side] = 1
						has_supply = true
					}
				} else {
					if (trace_supply_chain(next, d+1, n+1, next_range)) {
						ind(d, "< chain trail", here, next_range)
						supply_line[side] = 1
						has_supply = true
					}
				}
			}
		}
	}

	supply_visited[here] = false

	if (has_supply) {
		supply_net[here] = 1
		if (supply_friendly[here])
			supply_src[here] = 1
	}

	return has_supply
}

function trace_supply_network(start) {
	supply_visited = new Array(hexcount).fill(false)
	supply_net = new Array(hexcount).fill(0)
	supply_line = new Array(sidecount).fill(0)
	supply_src = new Array(hexcount).fill(0)

	supply_src[start] = 1
	supply_net[start] = 1

	console.log("=== SUPPLY NETWORK ===")
	// debug_hexes("FH", supply_friendly)
	// debug_hexes("EH", supply_enemy)
	// debug_hexes("SS1", supply_src)

	trace_total = 0
	for (let x = first_hex; x <= last_hex; ++x) {
		if (supply_friendly[x]) {
			trace_highway = trace_chain = 0
			ind(0, "START", x)
			trace_supply_chain(x, 0, 0, 3)
			console.log("END", trace_highway, trace_chain)
			trace_total += trace_highway + trace_chain
		}
	}
	console.log("VISITS", trace_total)

	debug_hexes("SS", supply_src)
	debug_hexes("SN", supply_net)
}

function update_axis_supply_network() {
	supply_friendly = list_control_hexes(AXIS)
	supply_enemy = list_control_hexes(ALLIED)
	trace_supply_network(EL_AGHEILA)
	game.axis_supply = supply_net
	game.axis_supply_line = supply_line
}

function update_allied_supply_network() {
	supply_friendly = list_control_hexes(ALLIED)
	supply_enemy = list_control_hexes(AXIS)
	trace_supply_network(ALEXANDRIA)
	game.allied_supply = supply_net
	game.allied_supply_line = supply_line
}

function update_supply_networks() {
	update_axis_supply_network()
	update_allied_supply_network()
}

function clear_supply_networks() {
	game.axis_supply = null
	game.axis_supply_line = null
	game.allied_supply = null
	game.allied_supply_line = null
}

// === MOVEMENT ===

const path_from = [ new Array(hexcount), new Array(hexcount), new Array(hexcount), null, new Array(hexcount) ]
const path_cost = [ new Array(hexcount), new Array(hexcount), new Array(hexcount), null, new Array(hexcount) ]
const path_valid = new Array(hexcount)
const path_enemy = new Array(hexcount)

function search_move(start, start_cost, start_road) {
	// recon=4, forced march=+1, rommel bonus=+1
	let limit = 6

	path_enemy.fill(0)
	for (let u = 0; u < units.length; ++u) {
		if (is_enemy_unit(u)) {
			let x = unit_hex(u)
			if (x >= first_hex && x <= last_hex)
				path_enemy[x] = 1
		}
	}

	search_move_bfs(path_from[0], path_cost[0], start, start_cost, 0, limit)
	if (start_road >= 1)
		search_move_bfs(path_from[1], path_cost[1], start, start_cost, 1, limit + 1)
	if (start_road >= 2)
		search_move_bfs(path_from[2], path_cost[2], start, start_cost, 2, limit + 2)
	if (start_road >= 4)
		search_move_bfs(path_from[4], path_cost[4], start, start_cost, 4, limit + 4)

	let grid = new Array(hexcount).fill('-')
	for (let x = first_hex; x <= last_hex; ++x) {
		for (let speed = 4; speed >= 1; --speed) {
			if (path_cost[0][x] <= speed)
				grid[x] = speed
			if (path_cost[1][x] <= speed + 1)
				grid[x] = speed
			if (path_cost[2][x] <= speed + 2)
				grid[x] = speed
			if (path_cost[4][x] <= speed + 4)
				grid[x] = speed
		}
	}
	grid[start] = '@'

	debug_hexes2("reach", path_cost[0])
}

// Breadth First Search
function search_move_bfs(from, cost, start, start_cost, road, max_cost) {
	let queue = [ start << 4 | start_cost ]

	from.fill(0)
	cost.fill(15)
	cost[start] = start_cost

	while (queue.length > 0) {
		let item = queue.shift()
		let here = item >> 4
		let here_cost = item & 15
		let next_cost = here_cost + 1

		for (let s = 0; s < 6; ++s) {
			let next = here + hexnext[s]

			// can't go off-map
			if (next < first_hex || next > last_hex || !hex_exists[next])
				continue

			// already seen
			if (cost[next] < 15)
				continue

			let side = to_side(here, next, s)
			let max_side = side_limit[side]

			// can't cross this hexside
			if (max_side === 0)
				continue

			// must stay on road for current bonus
			if (side_road[side] < road)
				continue

			// check hexside limit
			if (path_enemy[next] && (game.side_limit[side] | 0) >= max_side)
				continue

			from[next] = here
			cost[next] = next_cost

			// must stop
			if (path_enemy[next])
				continue

			// enough movement allowance to keep going
			if (next_cost < max_cost)
				queue.push(next << 4 | next_cost)
		}
	}
}

function can_move_to(to, road, speed) {
	// TODO: engagement & hexside limit
	if (road >= 4 && path_cost[4][to] <= speed + 4)
		return true
	if (road >= 2 && path_cost[2][to] <= speed + 2)
		return true
	if (road >= 1 && path_cost[1][to] <= speed + 1)
		return true
	if (path_cost[0][to] <= speed)
		return true
	return false
}

function can_move_from(from, road, speed) {
	// TODO: engagement & hexside limit
	return can_move_to(from, road, speed)
}

function can_force_march_to(to, road, speed) {
	if (road >= 4 && path_cost[4][to] <= speed + 5)
		return true
	if (road >= 2 && path_cost[2][to] <= speed + 3)
		return true
	if (road >= 1 && path_cost[1][to] <= speed + 2)
		return true
	if (path_cost[0][to] <= speed + 1)
		return true
	return false
}

function pick_path(to, road, speed) {
	let next_cost = 15, next_road = 0
	if (path_cost[0][to] <= speed) {
		next_cost = path_cost[0][to]
		next_road = 0
	}
	if (road >= 1 && path_cost[1][to] <= speed + 1) {
		if (path_cost[1][to] <= next_cost) {
			next_cost = path_cost[1][to]
			next_road = 1
		}
	}
	if (road >= 2 && path_cost[2][to] <= speed + 2) {
		if (path_cost[2][to] <= next_cost) {
			next_cost = path_cost[2][to]
			next_road = 2
		}
	}
	if (road >= 4 && path_cost[4][to] <= speed + 4) {
		if (path_cost[4][to] <= next_cost) {
			next_cost = path_cost[4][to]
			next_road = 4
		}
	}
	return next_road
}

function pay_movement_cost(to, this_road, speed) {
}

function neighbor_has_friendly_unit(here) {
	for (let s = 0; s < 6; ++s) {
		let next = here + hexnext[s]
		if (next >= first_hex && next <= last_hex)
			if (has_friendly_unit(next))
				return true
	}
	return false
}

function for_each_hex_and_adjacent_hex(here, fn) {
	fn(here)
	for (let s = 0; s < 6; ++s) {
		let next = here + hexnext[s]
		if (next >= first_hex && next <= last_hex && hex_exists[next])
			fn(next)
	}
}

function for_each_friendly_unit_in_hex(x, fn) {
	for (let u = 0; u < units.length; ++u)
		if (is_friendly_unit(u) && unit_hex(u) === x)
			fn(u)
}

function max_speed_of_friendly_unit_in_hex(from) {
	let max = 0
	for_each_friendly_unit_in_hex(from, u => {
		let s = unit_speed(u)
		if (s > max)
			max = s
	})
	return max
}

function find_valid_regroup_destinations(from, rommel) {
	let speed = max_speed_of_friendly_unit_in_hex(from)
	if (speed > 0) {
		search_move(from, 0, 4)
		for (let x = first_hex; x <= last_hex; ++x)
			if (!path_valid[x])
				if (can_move_to(x, 4, speed + rommel))
					path_valid[x] = 1
	}
}

// === TURN ===

// Supply check
// Turn option
// Movement
// Combat
// Blitz Movement
// Blitz Combat
// Final supply check
// Reveal supply cards -> next player

function end_player_turn() {
	// TODO: end when both pass
	if (game.phasing === AXIS)
		game.phasing = ALLIED
	else
		game.phasing = AXIS
	game.active = game.phasing
	goto_player_turn()
}

function goto_player_turn() {
	game.rommel = 0
	game.from1 = game.from2 = 0
	game.to1 = game.to2 = 0
	goto_supply_check()
}

function goto_supply_check() {
	goto_turn_option()
}

function goto_turn_option() {
	game.state = 'turn_option'
}

states.turn_option = {
	inactive: "turn option",
	prompt() {
		view.prompt = "Select Turn Option"
		gen_action('basic')
		gen_action('offensive')
		gen_action('assault')
		gen_action('blitz')
		gen_action('pass')
	},
	basic() {
		push_undo()
		game.turn_option = 'basic'
		goto_move_phase()
	},
	offensive() {
		push_undo()
		game.turn_option = 'offensive'
		goto_move_phase()
	},
	assault() {
		push_undo()
		game.turn_option = 'assault'
		goto_move_phase()
	},
	blitz() {
		push_undo()
		game.turn_option = 'blitz'
		goto_move_phase()
	},
	pass() {
		push_undo()
		game.turn_option = 'pass'
		goto_move_phase()
	},
}

function goto_move_phase() {
	game.state = 'select_moves'
	if (game.active === AXIS) {
		// Automatically select Rommel Move for 1-move turn options
		if (game.turn_option !== 'offensive' && game.turn_option !== 'blitz')
			game.rommel = 1
	}
}

states.select_moves = {
	inactive: "move phase",
	prompt() {
		if (game.turn_option === 'offensive') {
			if (game.from1)
				view.prompt = `Designate second offensive move.`
			else
				view.prompt = `Designate first offensive move.`
		} else {
			view.prompt = `Designate ${game.turn_option} move.`
		}
		gen_action('group')
		gen_action('regroup')
	},
	group() {
		push_undo()
		game.state = 'group_move_from'
	},
	regroup() {
		push_undo()
		game.state = 'regroup_move_command_point'
	},
}

function gen_rommel_move() {
	if (game.active === AXIS)
		view.actions.rommel = game.rommel ? 0 : 1
}

states.group_move_from = {
	inactive: "group move (from)",
	prompt() {
		view.prompt = `Group Move: Select hex to move from.`
		gen_rommel_move()
		for (let x = first_hex; x <= last_hex; ++x) {
			if (x === game.from1 && !game.to1)
				continue
			if (has_friendly_unit(x))
				gen_action_hex(x)
		}
	},
	rommel() {
		push_undo()
		if (game.from1 === 0)
			game.rommel = 1
		else
			game.rommel = 2
	},
	hex(x) {
		push_undo()
		if (game.from1 === 0)
			game.from1 = x
		else
			game.from2 = x
		if (game.turn_option === 'offensive' && !game.from2)
			game.state = 'select_moves'
		else
			goto_move_who()
	},
}

states.regroup_move_command_point = {
	inactive: "regroup move (command point)",
	prompt() {
		view.prompt = `Regroup Move: Designate the command point hex.`
		gen_rommel_move()
		for (let x = first_hex; x <= last_hex; ++x) {
			if (!is_enemy_hex(x)) {
				if (has_friendly_unit(x) || neighbor_has_friendly_unit(x))
					gen_action_hex(x)
			}
		}
	},
	rommel() {
		push_undo()
		if (game.from1 === 0)
			game.rommel = 1
		else
			game.rommel = 2
	},
	hex(x) {
		push_undo()
		if (game.from1 === 0)
			game.from1 = x
		else
			game.from2 = x
		game.state = 'regroup_move_destination'
	},
}

states.regroup_move_destination = {
	inactive: "regroup move (destination)",
	prompt() {
		view.prompt = `Regroup Move: Select destination hex.`
		gen_rommel_move()
		let cp, rommel = false
		if (game.from2 === 0)
			cp = game.from1, rommel = (game.rommel === 1 ? 1 : 0)
		else
			cp = game.from2, rommel = (game.rommel === 2 ? 1 : 0)
		path_valid.fill(0)
		for_each_hex_and_adjacent_hex(cp, x => {
			find_valid_regroup_destinations(x, rommel)
		})
		for (let x = first_hex; x <= last_hex; ++x)
			if (path_valid[x])
				gen_action_hex(x)
	},
	rommel() {
		push_undo()
		if (game.from2 === 0)
			game.rommel = 1
		else
			game.rommel = 2
	},
	hex(x) {
		push_undo()
		if (game.from2 === 0)
			game.to1 = x
		else
			game.to2 = x
		if (game.turn_option === 'offensive' && !game.from2)
			game.state = 'select_moves'
		else
			goto_move_who()
	},
}

function goto_move_who() {
	if (game.rommel === 1) {
		if (game.from1 && game.to1)
			log(`Regroup move from ${game.from1} to ${game.to1} (Rommel).`)
		else if (game.from1)
			log(`Group move from ${game.from1} (Rommel).`)
	} else {
		if (game.from1 && game.to1)
			log(`Regroup move from ${game.from1} to ${game.to1}.`)
		else if (game.from1)
			log(`Group move from ${game.from1}.`)
	}
	if (game.rommel === 2) {
		if (game.from2 && game.to2)
			log(`Regroup move from ${game.from2} to ${game.to2} (Rommel).`)
		else if (game.from2)
			log(`Group move from ${game.from2} (Rommel).`)
	} else {
		if (game.from2 && game.to2)
			log(`Regroup move from ${game.from2} to ${game.to2}.`)
		else if (game.from2)
			log(`Group move from ${game.from2}.`)
	}
	game.state = 'move_who'
}

function gen_group_move_who(from) {
	for_each_friendly_unit_in_hex(from, u => {
		if (!is_unit_moved(u))
			gen_action_unit(u)
	})
}

function gen_regroup_move_who(command_point, destination, rommel) {
	search_move(destination, 0, 4)
	for_each_hex_and_adjacent_hex(command_point, x => {
		if (x !== destination) {
			for_each_friendly_unit_in_hex(x, u => {
				if (!is_unit_moved(u) && can_move_from(x, 4, unit_speed(u) + rommel))
					gen_action_unit(u)
			})
		}
	})
}

states.move_who = {
	inactive: "move (who)",
	prompt() {
		view.prompt = `Move: Select unit to move.`
		if (game.from1) {
			if (game.to1)
				gen_regroup_move_who(game.from1, game.to1, game.rommel === 1 ? 1 : 0)
			else
				gen_group_move_who(game.from1)
		}
		if (game.from2) {
			if (game.to2)
				gen_regroup_move_who(game.from2, game.to2, game.rommel === 2 ? 1 : 0)
			else
				gen_group_move_who(game.from2)
		}
		// TODO: retreat
		gen_action('retreat')
		gen_action('end_move')
	},
	unit(who) {
		push_undo()
		game.selected = [ who ]
		game.state = 'move_to'
		game.move_used = 0
		game.move_road = 4
	},
	end_move() {
		clear_supply_networks()
	}
}

function rommel_group_move_bonus(from) {
	if (game.rommel === 1 && from === game.from1 && !game.to1)
		return 1
	if (game.rommel === 2 && from === game.from2 && !game.to2)
		return 1
	return 0
}

function print_path(who, from, to, road) {
	let p = [ hex_name[to] ]
	while (to && to !== from) {
		to = path_from[road][to]
		p.unshift(hex_name[to])
	}
	log(unit_name(who) + " moved " + p.join(", ") + ".")
}

function print_pathX(who, start, to, road) {
	let from = path_from[road][to]
	log(`M ${hex_name[from]} to ${hex_name[to]}`)
	while (from && from !== start) {
		to = from
		from = path_from[road][from]
		log(`M ${hex_name[from]} to ${hex_name[to]}`)
	}
}

function apply_move(move, who, from, to) {
	let speed = unit_speed(who) + (move === game.rommel ? 1 : 0)
	let road = pick_path(to, game.move_road, speed)

	print_path(who, unit_hex(who), to, road)

	game.move_road = road
	game.move_used = path_cost[road][to]

	set_unit_moved(who)
	set_unit_hex(who, to)

	pay_movement_cost(to, game.move_road, speed)

	if (is_battle_hex(to)) {
		let side = to_side_id(to, path_from[road][to])

		log(`cross ${side} ${hex_name[to]}/${hex_name[path_from[road][to]]}`)

		if (game.side_limit[side])
			game.side_limit[side] = 2
		else
			game.side_limit[side] = 1

		claim_hexside_control(side)
		if (is_new_battle_hex(to)) {
			claim_hex_control_for_defender(to)
			game.battles.push(to)
		}
		return true
	}

	if (game.move_used === speed + game.move_road)
		return true

	return false
}

function unit_speed_1(who) {
	return unit_speed(who) + (game.rommel === 1 ? 1 : 0)
}

function unit_speed_2(who) {
	return unit_speed(who) + (game.rommel === 2 ? 1 : 0)
}

function can_move_regroup_1(who, from, to) {
	if (to === game.to1 && is_hex_or_adjacent_to(from, game.from1))
		if (can_move_to(game.to1, 4, unit_speed_1(who)))
			return true
	return false
}

function can_move_regroup_2(who, from, to) {
	if (to === game.to2 && is_hex_or_adjacent_to(from, game.from2))
		if (can_move_to(game.to2, 4, unit_speed_2(who)))
			return true
	return false
}

function can_move_group_1(who, from, to) {
	if (from === game.from1 && !game.to1)
		if (can_move_to(to, game.move_road, unit_speed_1(who)))
			return true
	return false
}

function can_move_group_2(who, from, to) {
	if (from === game.from2 && !game.to2)
		if (can_move_to(to, game.move_road, unit_speed_2(who)))
			return true
	return false
}

states.move_to = {
	inactive: "move (to)",
	prompt() {
		view.prompt = `Move: Select where to move.`
		let who = game.selected[0]
		let from = unit_hex(who)

		search_move(from, 0, 4)

		if (from === game.from1 && !game.to1)
			for (let to = first_hex; to <= last_hex; ++to)
				if (to != from && hex_exists[to] && can_move_group_1(who, from, to))
					gen_action_hex(to)

		if (from === game.from2 && !game.to2)
			for (let to = first_hex; to <= last_hex; ++to)
				if (to != from && hex_exists[to] && can_move_group_2(who, from, to))
					gen_action_hex(to)

		if (can_move_regroup_1(who, from, game.to1))
			gen_action_hex(game.to1)

		if (can_move_regroup_2(who, from, game.to2))
			gen_action_hex(game.to2)
	},
	hex(to) {
		push_undo()
		let who = game.selected[0]
		let from = unit_hex(who)

		search_move(from, 0, 4)

		if (can_move_group_1(who, from, to)) {
			log(`group moved ${who} to ${to}`)
			game.move_from = from
			if (apply_move(1, who, from, to))
				stop_move(who)
			else
				game.state = 'group_move_to'
			return
		}

		if (can_move_group_2(who, from, to)) {
			log(`group moved ${who} to ${to}`)
			game.move_from = from
			if (apply_move(2, who, from, to))
				stop_move(who)
			else
				game.state = 'group_move_to'
			return
		}

		if (can_move_regroup_1(who, from, to)) {
			log(`regrouped ${who} to ${to}`)
			apply_move(1, who, from, to)
			stop_move(who)
			game.state = 'move_who'
			return
		}

		if (can_move_regroup_2(who, from, to)) {
			log(`regrouped ${who} to ${to}`)
			apply_move(2, who, from, to)
			stop_move(who)
			game.state = 'move_who'
			return
		}
	},
}

states.group_move_to = {
	inactive: "group move (to)",
	prompt() {
		view.prompt = `Group Move: Select where to move.`
		let who = game.selected[0]
		let from = unit_hex(who)
		if (game.move_used > 0)
			gen_action('stop')

		search_move(from, game.move_used, game.move_road)

		if (game.move_from === game.from1 && !game.to1)
			for (let to = first_hex; to <= last_hex; ++to)
				if (to != from && hex_exists[to] && can_move_group_1(who, game.move_from, to))
					gen_action_hex(to)

		if (game.move_from === game.from2 && !game.to2)
			for (let to = first_hex; to <= last_hex; ++to)
				if (to != from && hex_exists[to] && can_move_group_2(who, game.move_from, to))
					gen_action_hex(to)
	},
	hex(to) {
		let who = game.selected[0]
		let from = unit_hex(who)

		search_move(from, game.move_used, game.move_road)

		if (can_move_group_1(who, game.move_from, to)) {
			log(`group continued ${who} to ${to}`)
			if (apply_move(1, who, from, to))
				stop_move(who)
			return
		}

		if (can_move_group_2(who, game.move_from, to)) {
			log(`group continued ${who} to ${to}`)
			if (apply_move(2, who, from, to))
				stop_move(who)
			return
		}
	},
	stop() {
		let who = game.selected[0]
		stop_move(who)
	}
}

function stop_move(who) {
	set_unit_moved(who)
	game.move_from = 0
	game.move_road = 4
	game.move_used = 0
	game.selected = []
	game.state = 'move_who'
}

// === DEPLOYMENT ===

states.free_deployment = {
	inactive: "free deployment",
	prompt() {
		let scenario = SCENARIOS[game.scenario]
		let deploy = hexdeploy + scenario.start
		let done = true

		if (game.active === AXIS)
			view.prompt = "Axis Free Deployment"
		else
			view.prompt = "Allied Free Deployment"

		// TODO: first/last_axis_unit
		for (let u = 0; u < units.length; ++u) {
			if (is_friendly_unit(u)) {
				if (unit_hex(u) === deploy) {
					done = false
					gen_action_unit(u)
				}
			}
		}

		if (game.selected.length > 0) {
			let list
			if (game.active === AXIS)
				list = scenario.axis_deployment
			else
				list = scenario.allied_deployment
			// TODO: scenario.deployment_limit
			for (let i = 0; i < list.length; ++i)
				if (!is_enemy_hex(list[i]))
					gen_action_hex(list[i])
		}

		if (done)
			gen_action_next()
	},
	unit(u) {
		if (game.selected.includes(u))
			remove_from_array(game.selected, u)
		else
			game.selected.push(u)
	},
	hex(x) {
		push_undo()
		for (let i = 0; i < game.selected.length; ++i) {
			let u = game.selected[i]
			set_unit_hex(u, x)
		}
		game.selected.length = 0
	},
	next() {
		clear_undo()
		if (game.active === AXIS)
			game.active = ALLIED
		else
			end_free_deployment()
	}
}

function end_free_deployment() {
	game.phasing = game.first_player_turn
	game.active = game.phasing

	let scenario = SCENARIOS[game.scenario]
	deal_axis_supply_cards(scenario.axis_initial_supply)
	deal_allied_supply_cards(scenario.allied_initial_supply)

	// TODO: mulligan

	// No buildup first month
	// No initiative first month
	goto_player_turn()
}

// === SETUP ===

function find_axis_units(a) {
	let list = []
	for (let u = 0; u < units.length; ++u)
		if (units[u].nationality !== 'allied' && units[u].appearance === a)
			list.push(u)
	return list
}

function find_allied_units(a) {
	let list = []
	for (let u = 0; u < units.length; ++u)
		if (units[u].nationality === 'allied' && units[u].appearance === a)
			list.push(u)
	return list
}

function setup_reinforcements(m) {
	for (let u = 0; u < units.length; ++u) {
		if (units[u].appearance === m) {
			if (m === 'M')
				set_unit_hex(u, 4)
			else
				set_unit_hex(u, hexdeploy + (m > 10 ? m - 10 : m))
		}
	}
}

function setup_units(where, steps, list) {
	if (where < 0)
		where = hexdeploy - where
	for (let u of list) {
		if (typeof u === 'string')
			u = find_unit(u)
		set_unit_hex(u, where)
		if (steps < 0)
			set_unit_steps(u, units[u].steps + steps)
		else if (steps > 0)
			set_unit_steps(u, steps)
	}
}

const SCENARIOS = {
	1940: {
		year: 1940,
		start: 1,
		end: 6,
		axis_deployment: region_all, // XXX region_libya_and_sidi_omar,
		allied_deployment: region_all, // XXX region_egypt,
		axis_initial_supply: 6,
		allied_initial_supply: 3,
		special: {
			no_rommel_bonus: true,
			only_one_die_for_buildup: true,
		}
	},
	"1941": {
		year: 1941,
		start: 1,
		end: 10,
		axis_deployment: [],
		allied_deployment: region_egypt_and_libya,
		axis_initial_supply: 6,
		allied_initial_supply: 6,
	},
	"Crusader": {
		year: 1941,
		start: 8,
		end: 10,
		axis_deployment: region_libya_and_sidi_omar_and_sollum,
		allied_deployment: region_egypt_and_tobruk,
		axis_initial_supply: 10,
		allied_initial_supply: 12,
		deployment_limit: {
			[TOBRUK]: 5,
		},
		special: {
			allies_first_turn: true,
			tobruk_minefield: true,
		}
	},
	"Battleaxe": {
		year: 1941,
		start: 4,
		end: 10,
		axis_deployment: region_libya_except_tobruk,
		allied_deployment: region_egypt_and_tobruk,
		axis_initial_supply: 4,
		allied_initial_supply: 8,
		deployment_limit: {
			[TOBRUK]: 5,
		},
	},
	"1942": {
		year: 1942,
		start: 11,
		end: 20,
		axis_deployment: [ EL_AGHEILA, MERSA_BREGA ],
		allied_deployment: region_egypt_and_libya,
		axis_initial_supply: 5,
		allied_initial_supply: 5,
		deployment_limit: {
			[EL_AGHEILA]: 14,
			[MERSA_BREGA]: 10,
		},
	},
	"Gazala": {
		year: 1942,
		start: 14,
		end: 15,
		axis_deployment: regions["West Line"],
		allied_deployment: regions["East Line"],
		axis_initial_supply: 10,
		allied_initial_supply: 12,
		special: {
			gazala_pre_build: true,
		}
	},
	"Pursuit to Alamein": {
		year: 1942,
		start: 15,
		end: 20,
		axis_deployment: regions["Libya"],
		allied_deployment: regions["Egypt"],
		axis_initial_supply: 8,
		allied_initial_supply: 8,
	},
	"1941-42": {
		year: 1941,
		start: 1,
		end: 20,
		axis_deployment: [],
		allied_deployment: region_egypt_and_libya,
		axis_initial_supply: 6,
		allied_initial_supply: 6,
	},
}

const SETUP = {
	"1940" (DEPLOY) {
		setup_units(DEPLOY, 0, [ "Pav", "Bre", "Tre", "Bol", "Sav", "Sab", "Fas", "Ita" ])
		setup_units(-3, 0, [ "Ari", "Pis"])
		setup_units(-5, 0, [ "Lit", "Cen"])

		setup_units(DEPLOY, 0, [ "7/7", "7", "7/SG", "4IN/3m" ])
		setup_units(-2, 0, [ "4IN/5", "4IN/11" ])
		setup_units(-4, 0, [ "Matilda/A", "7/4", "4IN/7m", "/Tob" ])
	},

	"1941" (DEPLOY) {
		setup_units(EL_AGHEILA, 0, find_axis_units('S'))
		setup_reinforcements(3)
		setup_reinforcements(5)
		setup_reinforcements(7)

		setup_units(DEPLOY, 0, find_allied_units('S'))
		setup_units(TOBRUK, 0, find_allied_units('T'))
		setup_reinforcements(2)
		setup_reinforcements(4)
		setup_reinforcements(6)
		setup_reinforcements(8)
		setup_reinforcements(10)
	},

	"Crusader" (DEPLOY) {
		setup_units(DEPLOY, 0, find_axis_units('S'))
		setup_units(DEPLOY, 0, find_axis_units(3))
		setup_units(DEPLOY, 0, find_axis_units(5))
		setup_units(DEPLOY, 0, find_axis_units(7))

		setup_units(DEPLOY, 0, find_allied_units('S'))
		setup_units(DEPLOY, 0, find_allied_units('T'))
		setup_units(DEPLOY, 0, find_allied_units(2))
		setup_units(DEPLOY, 0, find_allied_units(4))
		setup_units(DEPLOY, 0, find_allied_units(6))
		setup_units(DEPLOY, 0, find_allied_units(8))
		setup_units(0, 0, [ "2/3", "2/SG", "9AU/20", "7AU/18" ])
		setup_reinforcements(10)
	},

	"Battleaxe" (DEPLOY) {
		setup_units(DEPLOY, 0, [ "21/5", "21/3", "15/33", "90/155", "15/115", "88mm/A" ])
		setup_units(DEPLOY, -1, [ "21/104" ])
		setup_units(DEPLOY, 0, [ "Ari", "Lit", "Pav", "Bre", "Tre", "Bol", "Ita" ])
		setup_reinforcements(5)
		setup_reinforcements(7)

		setup_units(DEPLOY, 0, [ "4IN/3m", "9AU/20", "70/14+16", "70/23",
			"7/22G", "7/SG", "7AU/18", "Matilda/A", "/Tob", "/Pol",
			"7/7", "4IN/5", "4IN/7m", "4IN/11", "Matilda/B", "/1AT",
			"7/4", "7" ])
		setup_reinforcements(6)
		setup_reinforcements(8)
		setup_reinforcements(10)
	},

	"1942" (DEPLOY) {
		setup_units(DEPLOY, 0, [
			"21/3",
			"15/33",
			"90/580",
			"90/sv288",
			"90/346",
			"88mm/A",
		])
		setup_units(DEPLOY, 1, [
			"21/5",
			"15/8",
			"15/115",
			"90/155"
		])
		setup_units(DEPLOY, 1, [
			"90/361",
			"90/200",
			"88mm/B",
			"50mm",
			"/104"
		])
		setup_units(DEPLOY, 0, [ "Lit" ])
		setup_units(DEPLOY, -1, [ "Ari", "Tri", "Pav", "Bre", "Tre", "Bol", "Sab", "Ita" ])
		setup_reinforcements(17)
		setup_reinforcements(19)
		setup_reinforcements('M')

		setup_units(TOBRUK, 0, [
			"1/22",
			"/1AT",
			"Matilda/B",
			"1SA/2+5",
			"70/14+16",
			"1SA/1",
			"1SA/3",
			"2SA/4+6",
			"70/23",
			"/Tob",
		])
		setup_units(ALEXANDRIA, 1, [
			"7/4",
			"/32AT",
			"2NZ/4",
			"2NZ/5",
			"2NZ/6",
			"7/SG",
			"4IN/5",
			"/Pol",
		])
		setup_reinforcements(12)
		setup_reinforcements(14)
		setup_reinforcements(16)
		setup_reinforcements(18)
		setup_reinforcements(20)
	},

	"Gazala" (DEPLOY) {
		setup_units(DEPLOY, -1, [
			"21/5",
			"15/8",
			"15/115",
			"90/155",
			"88mm/B",
			"50mm",
			"/104",
		])
		setup_units(DEPLOY, 0, [
			"21/3",
			"15/33",
			"90/580",
			"90/sv288",
			"90/346",
			"90/361",
			"90/200",
			"88mm/A",
		])
		setup_units(DEPLOY, 0, [ "Lit" ])
		setup_units(DEPLOY, -1, [
			"Ari", "Tri", "Pav", "Bre", "Tre", "Bol", "Sab", "Ita"
		])

		setup_units(DEPLOY, 0, [
			"Grant",
			"/1AT",
			"1/22",
			"Matilda/B",
			"1SA",
			"1/201G",
			"4IN/7m",
			"4IN/3m",
			"1/SG",
			"1SA/2+5",
			"70/14+16",
			"1SA/1",
			"1SA/3",
			"2SA/4+6",
			"70/23",
			"4IN/11",
			"5IN/29",
			"6#/A",
			"2#",
			"/Tob",
		])
		setup_units(ALEXANDRIA, 1, [
			"1/2",
			"7/4",
			"/32AT",
			"2NZ/4",
			"2NZ/5",
			"2NZ/6",
			"7/SG",
			"7/22G",
			"4IN/5",
			"/Pol",
		])
		setup_units(ALEXANDRIA, 0, [
			"10IN/161m",
			"8IN/18",
			"B",
			"FF/2",
			"5IN/9+10",
			"10IN/21+25",
		])
	},

	"Pursuit to Alamein" (DEPLOY) {
		setup_units(DEPLOY, 0, [
			"21/3",
			"15/33",
		])
		setup_units(DEPLOY, -1, [
			"21/5",
			"15/8",
			"15/115",
			"90/346",
			"90/sv288",
			"90/361",
			"90/200",
			"88mm/A",
			"88mm/B",
			"50mm",
		])
		setup_units(DEPLOY, 3, [
			"Ari",
			"Tri",
			"Pav",
			"Bre",
			"Tre",
		])
		setup_units(DEPLOY, 2, [
			"Lit",
			"Bol",
		])
		setup_units(DEPLOY, 1, [
			"Sab",
			"Ita",
		])
		setup_reinforcements(17)
		setup_reinforcements(19)
		setup_reinforcements('M')

		setup_units(DEPLOY, 0, [
			"10IN/161m",
			"10IN/21+25",
			"70/14+16",
			"8IN/18",
			"B",
		])
		setup_units(DEPLOY, -1, [
			"1/22",
			"7/4",
			"2NZ/4",
			"2NZ/5",
			"2NZ/6",
			"1SA/2+5",
			"1SA/1",
			"1SA/3",
			"70/23",
			"5IN/29",
			"6#/A",
		])
		setup_units(ALEXANDRIA, 1, [
			"Grant",
			"1/2",
			"/1AT",
			"1SA",
			"7/SG",
			"1/SG",
			"FF/2",
			"5IN/9+10",
			"4IN/5",
			"4IN/11",
			"/Pol",
			"2#",
		])
		setup_reinforcements(16)
		setup_reinforcements(18)
		setup_reinforcements(20)
	},

	"1941-42" (DEPLOY) {
		SETUP["1941"](-1)

		setup_reinforcements(11)
		setup_reinforcements(17)
		setup_reinforcements(19)
		setup_reinforcements('M')

		setup_reinforcements(12)
		setup_reinforcements(14)
		setup_reinforcements(16)
		setup_reinforcements(18)
		setup_reinforcements(20)
	},

}

function setup(name) {
	let scenario = SCENARIOS[name]
	game.month = scenario.start

	SETUP[name](-scenario.start)

	game.active = 'Axis'
	game.state = 'free_deployment'
	game.selected = []
}

// === PUBLIC FUNCTIONS ===

exports.roles = [ "Axis", "Allied" ]

exports.scenarios = Object.keys(SCENARIOS)

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

		state: null,
		phasing: AXIS,
		active: AXIS,
		selected: null,

		scenario: scenario,
		month: 0,
		first_player_turn: AXIS,

		draw_pile: [ DUMMY_SUPPLY_COUNT, REAL_SUPPLY_COUNT ],
		axis_hand: [ 0, 0 ],
		allied_hand: [ 0, 0 ],

		units: new Array(units.length).fill(0),

		axis_minefields: [],
		allied_minefields: [],

		// supply networks
		axis_supply: null,
		axis_supply_line: null,
		allied_supply: null,
		allied_supply_line: null,

		// battle hexes (defender)
		axis_hexes: [],
		allied_hexes: [],

		// hexside control (for battle hexes)
		axis_sides: [],
		allied_sides: [],

		// current turn option and moves
		turn_option: null,
		side_limit: {},
		battles: [],
		rommel: 0,
		from1: 0,
		to1: 0,
		from2: 0,
		to2: 0,

		// current group move state
		move_from: 0,
		move_used: 0,
		move_road: 4,
	}

	setup(scenario)

	return game
}

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

	// update_supply_networks()

	view = {
		month: game.month,
		units: game.units,
		axis_hexes: game.axis_hexes,
		allied_hexes: game.allied_hexes,
		axis_sides: game.axis_sides,
		allied_sides: game.allied_sides,
		selected: game.selected,
		// axis_supply: game.axis_supply,
		// axis_supply_line: game.axis_supply_line,
		// allied_supply: game.allied_supply,
		// allied_supply_line: game.allied_supply_line,
	}

	if (game.rommel) view.rommel = game.rommel
	if (game.from1) view.from1 = game.from1
	if (game.from2) view.from2 = game.from2
	if (game.to1) view.to1 = game.to1
	if (game.to2) view.to2 = game.to2

	return common_view(current)
}

function gen_action_next() {
	gen_action('next')
}

function gen_action_unit(u) {
	gen_action('unit', u)
}

function gen_action_hex(x) {
	gen_action('hex', x)
}

// === COMMON TEMPLATE ===

function random(n) {
	// https://www.ams.org/journals/mcom/1999-68-225/S0025-5718-99-00996-5/S0025-5718-99-00996-5.pdf
	return (game.seed = game.seed * 200105 % 34359738337) % n
}

function shuffle(deck) {
	for (let i = deck.length - 1; i > 0; --i) {
		let j = random(i + 1)
		let tmp = deck[j]
		deck[j] = deck[i]
		deck[i] = tmp
	}
}

// Sorted array treated as Set (for JSON)
function set_index(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 m
	}
	return -1
}

function set_has(set, item) {
	return set_index(set, item) >= 0
}

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.splice(a, 0, item)
}

function set_delete(set, item) {
	let i = set_index(set, item)
	if (i >= 0)
		set.splice(i, 1)
}

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

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

function deep_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] = deep_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] = deep_copy(v)
			else
				copy[i] = v
		}
		return copy
	}
}

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

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

function clear_undo() {
	game.undo = []
}

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

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

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

function goto_game_over(result, victory) {
	game.state = 'game_over'
	game.active = "None"
	game.result = result
	game.victory = victory
	logbr()
	log(game.victory)
}

states.game_over = {
	get inactive() {
		return game.victory
	},
	prompt() {
		view.prompt = game.victory
	}
}

exports.resign = function (state, current) {
	game = state
	if (game.state !== 'game_over') {
		for (let opponent of exports.roles) {
			if (opponent !== current) {
				goto_game_over(opponent, current + " resigned.")
				break
			}
		}
	}
	return game
}

exports.action = function (state, current, action, arg) {
	game = state
	// Object.seal(game) // XXX: don't allow adding properties
	let S = states[game.state]
	if (S && action in S) {
		S[action](arg, current)
	} else {
		if (action === 'undo' && game.undo && game.undo.length > 0)
			pop_undo()
		else
			throw new Error("Invalid action: " + action)
	}
	return game
}

function common_view(current) {
	view.log = game.log
	if (current === 'Observer' || game.active !== current) {
		let inactive = states[game.state].inactive || game.state
		view.prompt = `Waiting for ${game.active} \u2014 ${inactive}...`
	} else {
		view.actions = {}
		if (states[game.state])
			states[game.state].prompt()
		else
			view.prompt = "Unknown state: " + game.state
		if (game.undo && game.undo.length > 0)
			view.actions.undo = 1
		else
			view.actions.undo = 0
	}
	return view
}