path: root/rules.js

"use strict"

const FRENCH = "French"
const COALITION = "Coalition"

const P1 = FRENCH
const P2 = COALITION

exports.roles = [ P1, P2 ]

exports.scenarios = [ "June 16", "June 15", "June 15 (no special rules)" ]

const data = require("./data")

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

const OLD_GUARD = data.pieces.findIndex(pc => pc.name === "Old Guard")
const GRAND_BATTERY = data.pieces.findIndex(pc => pc.name === "Grand Battery")
const HILL_1 = data.pieces.findIndex(pc => pc.name === "II Corps (Hill*)")
const HILL_2 = data.pieces.findIndex(pc => pc.name === "II Corps (Hill**)")

function make_piece_list(f) {
	let list = []
	for (let p = 0; p < data.pieces.length; ++p)
		if (f(data.pieces[p]))
			list.push(p)
	return list
}

const p1_hqs = make_piece_list(p => p.side === P1 && p.type === "hq")
const p2_hqs = make_piece_list(p => p.side !== P1 && p.type === "hq")
const p1_cav = make_piece_list(p => p.side === P1 && p.type === "cav")
const p2_cav = make_piece_list(p => p.side !== P1 && p.type === "cav")
const p1_inf = make_piece_list(p => p.side === P1 && p.type === "inf")
const p2_inf = make_piece_list(p => p.side !== P1 && p.type === "inf")
const p1_det = make_piece_list(p => p.side === P1 && p.type === "det")
const p2_det = make_piece_list(p => p.side !== P1 && p.type === "det")
const p1_corps = make_piece_list(p => p.side === P1 && (p.type === "inf" || p.type === "cav"))
const p2_corps = make_piece_list(p => p.side !== P1 && (p.type === "inf" || p.type === "cav"))
const p1_units = make_piece_list(p => p.side === P1 && (p.type === "inf" || p.type === "cav" || p.type === "det"))
const p2_units = make_piece_list(p => p.side !== P1 && (p.type === "inf" || p.type === "cav" || p.type === "det"))

function friendly_hqs() { return (game.active === P1) ? p1_hqs : p2_hqs }
function enemy_hqs() { return (game.active !== P1) ? p1_hqs : p2_hqs }
function friendly_cavalry_corps() { return (game.active === P1) ? p1_cav : p2_cav }
function enemy_cavalry_corps() { return (game.active !== P1) ? p1_cav : p2_cavalry_corps }
function friendly_infantry_corps() { return (game.active === P1) ? p1_inf : p2_inf }
function enemy_infantry_corps() { return (game.active !== P1) ? p1_inf : p2_inf }
function friendly_detachments() { return (game.active === P1) ? p1_det : p2_det }
function enemy_detachments() { return (game.active !== P1) ? p1_det : p2_det }
function friendly_corps() { return (game.active === P1) ? p1_corps : p2_corps }
function enemy_corps() { return (game.active !== P1) ? p1_corps : p2_corps }
function friendly_units() { return (game.active === P1) ? p1_units : p2_units }
function enemy_units() { return (game.active !== P1) ? p1_units : p2_units }

function set_piece_hex(p, hex) {
	game.pieces[p] &= 1
	game.pieces[p] |= hex << 1
}

function set_piece_mode(p, mode) {
	game.pieces[p] &= ~1
	game.pieces[p] |= mode
}

function piece_hex(p) {
	return game.pieces[p] >> 1
}

function piece_mode(p) {
	return game.pieces[p] & 1
}

const data_rivers = []
const data_bridges = []

for (let [a, b] of data.map.rivers) {
	set_add(data_rivers, a * 10000 + b)
	set_add(data_rivers, b * 10000 + a)
}

for (let [a, b] of data.map.bridges) {
	set_delete(data_rivers, a * 10000 + b)
	set_delete(data_rivers, b * 10000 + a)
	set_add(data_bridges, a * 10000 + b)
	set_add(data_bridges, b * 10000 + a)
}

function is_river(a, b) {
	return set_has(data_rivers, a * 10000 + b)
}

function is_bridge(a, b) {
	return set_has(data_bridges, a * 10000 + b)
}

// === ZONE OF CONTROL / INFLUENCE ===

var zoc_valid = false
var zoc_cache = new Array(data.map.rows * 100).fill(0)

function is_friendly_zoc(x) { return game.active === P1 ? zoc_cache[x] & 1 : zoc_cache[x] & 4 }
function is_friendly_zoi(x) { return game.active === P1 ? zoc_cache[x] & 2 : zoc_cache[x] & 8 }
function is_friendly_zoc_zoi(x) { return game.active === P1 ? zoc_cache[x] & 3 : zoc_cache[x] & 12 }
function is_enemy_zoc(x) { return game.active !== P1 ? zoc_cache[x] & 1 : zoc_cache[x] & 4 }
function is_enemy_zoi(x) { return game.active !== P1 ? zoc_cache[x] & 2 : zoc_cache[x] & 8 }
function is_enemy_zoc_zoi(x) { return game.active !== P1 ? zoc_cache[x] & 3 : zoc_cache[x] & 12 }

function update_zoc_imp(zoc, zoi, units) {
	zoc_cache.fill(0)
	for (let p of units) {
		let a = piece_hex(p)
		let aa = a - 1000
		if (zoc_cache[aa] & zoc)
			continue
		zoc_cache[aa] = zoc | zoi
		for_each_adjacent(a, b => {
			let bb = b - 1000
			if (!(zoc_cache[bb] & zoc) && !is_river(a, b)) {
				zoc_cache[bb] |= zoc
				for_each_adjacent(b, c => {
					let cc = c - 1000
					if (!is_bridge(b, c)) {
						zoc_cache[cc] |= zoi
					}
				})
			}
		})
	}
}

function update_zoc() {
	if (!zoc_valid) {
		zoc_valid = true
		update_zoc_imp(1, 2, p1_units)
		update_zoc_imp(4, 8, p2_units)
	}
}

function piece_is_not_in_enemy_zoc_or_zoi(p) {
	let x = piece_hex(p)
	return is_map_hex(x) && !is_enemy_zoc_zoi(x)
}

function piece_is_not_in_enemy_zoc(p) {
	let x = piece_hex(p)
	return is_map_hex(x) && !is_enemy_zoc(x)
}

function piece_is_in_enemy_zoc(p) {
	let x = piece_hex(p)
	return is_map_hex(x) && is_enemy_zoc(x)
}

function is_map_hex(row, col) {
	return row >= 10 && row <= 40 && col >= 0 && col <= 41
}

function calc_distance(a, b) {
	let ac = a % 100
	let bc = b % 100
	let ay = a / 100 | 0
	let by = b / 100 | 0
	let ax = ac - (ay >> 1)
	let bx = bc - (by >> 1)
	let az = -ax - ay
	let bz = -bx - by
	return max(abs(bx-ax), abs(by-ay), abs(bz-az))
}

function for_each_adjacent(hex, fn) {
	let row = hex / 10 | 0
	let col = hex % 10
	if (col < 41)
		fn(hex + 1)
	if (col > 0)
		fn(hex - 1)
	if (row & 1) {
		if (row < 40) {
			if (col < 41)
				fn(hex + 101)
			fn(hex + 100)
		}
		if (row > 10) {
			fn(hex - 100)
			if (col < 41)
				fn(hex - 99)
		}
	} else {
		if (row < 40) {
			fn(hex + 100)
			if (col > 0)
				fn(hex + 99)
		}
		if (row > 10) {
			if (col > 0)
				fn(hex - 101)
			fn(hex - 100)
		}
	}
}

function set_next_player() {
	game.active = (game.active === P1) ? P2 : P1
}

function prompt(str) {
	view.prompt = str
}

// === SEQUENCE OF PLAY ===

/*

command phase:
	remove hq
	place hq
	return up to 2 blown corps
	flip exhausted cav to fresh (move to organization?)
	place 1 detachment per hq
	recall all, some, or no detachments
	angst: substitute Hill unit

organization
	advance formation: flip infantry corps to advance
	battle formation: flip infantry corps to battle
	alternate withdrawal: retreat or pass (3 remain)

movement
	alternate corps movement: move corps or pass

attack
	alternate corps to attack in zoc or pass

end phase
	if last turn - victory
	recall french grand battery
	new turn

*/

// === === COMMAND PHASE === ===

function goto_command_phase() {
	log("Command Phase")
	log("")
	goto_hq_placement_step()
}

// === A: HQ PLACEMENT STEP ===

function goto_hq_placement_step() {
	game.active = P1
	game.state = "hq_placement_step"
}

function end_hq_placement_step() {
	if (game.active === P1)
		game.active = P2
	else
		goto_blown_unit_return_step()
}

states.hq_placement_step = {
	prompt() {
		prompt("HQ Placement Step.")
		view.actions.next = 1
	},
	next() {
		end_hq_placement_step()
	},
}

// === B: BLOWN UNIT RETURN STEP ===

function goto_blown_unit_return_step() {
	game.active = P1
	game.state = "blown_unit_return_step"
	game.count = 2
}

function end_blown_unit_return_step() {
	if (game.active === P1) {
		game.active = P2
		game.count = 2
	} else {
		goto_cavalry_corps_recovery_step()
	}
}

states.blown_unit_return_step = {
	prompt() {
		prompt("Blown Unit Return Step.")
		view.actions.next = 1
	},
	next() {
		end_blown_unit_return_step()
	},
}

// === C: CAVALRY CORPS RECOVERY STEP ===

// TODO: merge with steps F and G to save time

function goto_cavalry_corps_recovery_step() {
	game.active = P1
	game.state = "cavalry_corps_recovery_step"
	resume_cavalry_corps_recovery_step()
}

function resume_cavalry_corps_recovery_step() {
	update_zoc()
	for (let p of friendly_cavalry_corps())
		if (piece_mode(p) && piece_is_not_in_enemy_zoc_or_zoi(p))
			return
	end_cavalry_corps_recovery_step()
}

function end_cavalry_corps_recovery_step() {
	if (game.active === P1) {
		game.active = P2
		resume_cavalry_corps_recovery_step()
	} else {
		goto_detachment_placement_step()
	}
}

states.cavalry_corps_recovery_step = {
	prompt() {
		prompt("Cavalry Corps Recovery Step.")
		for (let p of friendly_cavalry_corps())
			if (piece_mode(p) && piece_is_not_in_enemy_zoc_or_zoi(p))
				gen_action_piece(p)
	},
	piece(p) {
		set_piece_mode(p, 0)
		resume_cavalry_corps_recovery_step()
	},
}

// === D: DETACHMENT PLACEMENT STEP ===

function goto_detachment_placement_step() {
	game.active = P1
	game.state = "detachment_placement_step"
	game.count = 0
}

function end_detachment_placement_step() {
	if (game.active === P1) {
		game.active = P2
		game.count = 0
	} else {
		goto_detachment_recall_step()
	}
}

states.detachment_placement_step = {
	prompt() {
		prompt("Detachment Placement Step.")
		view.actions.next = 1
	},
	next() {
		end_detachment_placement_step()
	},
}

// === E: DETACHMENT RECALL STEP ===

function goto_detachment_recall_step() {
	game.active = P1
	game.state = "detachment_recall_step"
}

function end_detachment_recall_step() {
	if (game.active === P1) {
		game.active = P2
	} else {
		goto_british_line_of_communication_angst()
	}
}

states.detachment_recall_step = {
	prompt() {
		prompt("Detachment Recall Step.")
		view.actions.next = 1
	},
	next() {
		end_detachment_recall_step()
	},
}

function goto_british_line_of_communication_angst() {
	game.active = P2
	game.state = "british_line_of_communication_angst_1"
	// TODO
	goto_advance_formation()
}

states.british_line_of_communication_angst_1 = {
	prompt() {
		prompt("British Line of Communication Angst.")
		gen_action_piece(HILL_1)
	},
	piece(p) {
		set_piece_hex(HILL_2, piece_hex(HILL_1))
		set_piece_mode(HILL_2, piece_mode(HILL_1))
		set_piece_hex(HILL_1, 0)
		set_piece_mode(HILL_1, 0)
		goto_advance_formation()
	},
}

states.british_line_of_communication_angst_2 = {
	prompt() {
		prompt("British Line of Communication Angst.")
		gen_action_piece(HILL_2)
	},
	piece(p) {
		set_piece_hex(HILL_1, piece_hex(HILL_2))
		set_piece_mode(HILL_1, piece_mode(HILL_2))
		set_piece_hex(HILL_2, 0)
		set_piece_mode(HILL_2, 0)
		goto_advance_formation()
	},
}

// === === ORGANIZATION PHASE === ===

// === F: ADVANCE FORMATION ===
// === G: BATTLE FORMATION ===

// NOTE: merged step F and step G to save time
// TODO: move step C here

function goto_advance_formation() {
	game.active = P1
	resume_advance_formation()
}

function resume_advance_formation() {
	game.state = "advance_formation"
	update_zoc()
	for (let p of friendly_infantry_corps())
		if (piece_mode(p) && piece_is_not_in_enemy_zoc(p))
			return
	resume_battle_formation()
}

function resume_battle_formation() {
	game.state = "battle_formation"
	update_zoc()
	for (let p of friendly_infantry_corps())
		if (piece_mode(p) && piece_is_in_enemy_zoc(p))
			return
	end_battle_formation()
}

function end_battle_formation() {
	if (game.active === P1) {
		game.active = P2
		resume_advance_formation()
	} else {
		goto_withdrawal()
	}
}

states.advance_formation = {
	prompt() {
		prompt("Advance Formation.")
		for (let p of friendly_infantry_corps())
			if (piece_mode(p) && piece_is_not_in_enemy_zoc(p))
				gen_action_piece(p)
	},
	piece(p) {
		set_piece_mode(p, 0)
		resume_advance_formation()
	},
}

states.battle_formation = {
	prompt() {
		prompt("Battle Formation.")
		for (let p of friendly_infantry_corps())
			if (piece_mode(p) && piece_is_in_enemy_zoc(p))
				gen_action_piece(p)
	},
	piece(p) {
		set_piece_mode(p, 0)
		resume_battle_formation()
	},
}

// === H: WITHDRAWAL ===

function goto_withdrawal() {
	game.active = P1
	game.state = "withdrawal"
	game.remain = 0
}

function next_withdrawal() {
	game.state = "withdrawal"
	if (game.remain === 0)
		set_next_player()
	else if (--game.remain === 0)
		end_withdrawal()
}

function end_withdrawal() {
	goto_movement_phase()
}

states.withdrawal = {
	prompt() {
		prompt("Withdrawal.")
		view.actions.pass = 1
	},
	piece(p) {
		push_undo()
		game.who = p
		game.state = "withdrawal_to"
	},
	pass() {
		clear_undo()
		if (game.remain > 0) {
			end_withdrawal()
		} else {
			set_next_player()
			game.remain = 3
		}
	},
}

states.withdrawal_to = {
	prompt() {
		prompt("Withdrawal to.")
		view.actions.next = 1
	},
	next() {
		next_withdrawal()
	},
}

// === === MOVEMENT PHASE === ===

function goto_movement_phase() {
	log("")
	log("Movement Phase")
	log("")
	game.active = P1
	game.state = "movement"
	game.remain = 0
}

function next_movement() {
	game.state = "movement"
	if (game.remain === 0)
		set_next_player()
	else if (--game.remain === 0)
		end_movement()
}

function end_movement() {
	goto_attack_phase()
}

states.movement = {
	prompt() {
		prompt("Movement.")
		view.actions.pass = 1
	},
	piece(p) {
		push_undo()
		game.who = p
		game.state = "movement_to"
	},
	pass() {
		clear_undo()
		if (game.remain > 0) {
			end_movement()
		} else {
			set_next_player()
			game.remain = roll_die()
		}
	},
}

states.movement_to = {
	prompt() {
		prompt("Movement to.")
		view.actions.next = 1
	},
	next() {
		next_movement()
	},
}

// === === ATTACK PHASE === ===

function goto_attack_phase() {
	log("")
	log("Attack Phase")
	log("")
	game.active = P1
	game.state = "attack"
	game.remain = 0
}

// === SETUP ===

function setup_piece(side, name, hex, mode = 0) {
	let id = data.pieces.findIndex(pc => pc.side === side && pc.name === name)
	if (id < 0)
		throw new Error("INVALID PIECE NAME: " + name)
	set_piece_hex(id, hex)
	set_piece_mode(id, mode)
}

function setup_june_15() {
	game.turn = 1

	setup_piece("French", "Napoleon HQ", 1017)
	setup_piece("French", "II Corps (Reille)", 1)
	setup_piece("French", "I Corps (d'Erlon)", 1)
	setup_piece("French", "III Corps (Vandamme)", 1)
	setup_piece("French", "VI Corps (Lobau)", 1)
	setup_piece("French", "Guard Corps (Drouot)", 1)
	setup_piece("French", "Guard Cav Corps (Guyot)", 1)
	setup_piece("French", "Res Cav Corps (Grouchy)", 1)
	setup_piece("French", "IV Corps (Gerard)", 1)
	setup_piece("French", "Grouchy HQ", 2)
	setup_piece("French", "Ney HQ", 2)

	setup_piece("Anglo", "Wellington HQ", 3715)
	setup_piece("Anglo", "Reserve Corps (Wellington)", 3715)
	setup_piece("Anglo", "I Corps (Orange)", 3002)
	setup_piece("Anglo", "II Corps (Hill*)", 3)
	setup_piece("Anglo", "Cav Corps (Uxbridge)", 4)
	setup_piece("Anglo", "Cav Detachment (Collaert)", 1211)
	setup_piece("Anglo", "I Detachment (Perponcher)", 2618)

	setup_piece("Prussian", "Blucher HQ", 1737)
	setup_piece("Prussian", "Cav Corps (Gneisenau)", 1737)
	setup_piece("Prussian", "I Corps (Ziethen)", 1716)
	setup_piece("Prussian", "II Corps (Pirch)", 2840)
	setup_piece("Prussian", "III Corps (Thielmann)", 1340)
	setup_piece("Prussian", "IV Corps (Bulow)", 3)
	setup_piece("Prussian", "I Detachment (Steinmetz)", 1215)
	setup_piece("Prussian", "I Detachment (Pirch)", 1217)
	setup_piece("Prussian", "I Detachment (Lutzow)", 1221)
}

function setup_june_16() {
	game.turn = 3

	setup_piece("French", "Napoleon HQ", 1217)
	setup_piece("French", "Guard Corps (Drouot)", 1217)
	setup_piece("French", "Grouchy HQ", 1621)
	setup_piece("French", "Ney HQ", 2218)
	setup_piece("French", "II Corps (Reille)", 2218)
	setup_piece("French", "I Corps (d'Erlon)", 1617)
	setup_piece("French", "III Corps (Vandamme)", 1721)
	setup_piece("French", "IV Corps (Gerard)", 1221)
	setup_piece("French", "VI Corps (Lobau)", 1117)
	setup_piece("French", "Guard Cav Corps (Guyot)", 2317)
	setup_piece("French", "Res Cav Corps (Grouchy)", 1822)
	setup_piece("French", "I Detachment (Jacquinot)", 1314)

	setup_piece("Anglo", "Wellington HQ", 2818, 1)
	setup_piece("Anglo", "Reserve Corps (Wellington)", 3715)
	setup_piece("Anglo", "I Corps (Orange)", 3002)
	setup_piece("Anglo", "II Corps (Hill*)", 3)
	setup_piece("Anglo", "Cav Corps (Uxbridge)", 4)
	setup_piece("Anglo", "Cav Detachment (Collaert)", 1211)
	setup_piece("Anglo", "I Detachment (Perponcher)", 2618)

	setup_piece("Prussian", "Blucher HQ", 2324, 1)
	setup_piece("Prussian", "Cav Corps (Gneisenau)", 2324)
	setup_piece("Prussian", "I Corps (Ziethen)", 1922, 1)
	setup_piece("Prussian", "II Corps (Pirch)", 1928)
	setup_piece("Prussian", "III Corps (Thielmann)", 1737)
	setup_piece("Prussian", "IV Corps (Bulow)", 3)
	setup_piece("Prussian", "I Detachment (Lutzow)", 1623)
}

exports.setup = function (seed, scenario, options) {
	game = {
		seed,
		log: [],
		undo: [],
		active: P1,
		state: null,
		turn: 3,
		remain: 0,
		pieces: new Array(data.pieces.length).fill(0),
		who: -1,
		count: 0,
	}

	if (scenario === "June 15" || scenario === "June 15 (no special rules)")
		setup_june_15()
	else
		setup_june_16()

	goto_command_phase()

	return game
}

// === COMMON ===

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

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

function gen_action_hex(hex) {
	gen_action("hex", hex)
}

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

	view = {
		prompt: null,
		actions: null,
		log: game.log,
		pieces: game.pieces,
	}

	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 ${game.active} \u2014 ${inactive}.`
	} else {
		view.actions = {}
		view.who = game.who
		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
}

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

exports.resign = function (state, player) {
	game = state
	if (game.state !== 'game_over') {
		if (player === RED)
			goto_game_over(BLUE, RED + " resigned.")
		if (player === BLUE)
			goto_game_over(RED, BLUE + " resigned.")
	}
	return game
}

// === COMMON LIBRARY ===

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

function clear_undo() {
	game.undo.length = 0
}

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

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

function random(range) {
	// An MLCG using integer arithmetic with doubles.
	// https://www.ams.org/journals/mcom/1999-68-225/S0025-5718-99-00996-5/S0025-5718-99-00996-5.pdf
	// m = 2**35 − 31
	return (game.seed = game.seed * 200105 % 34359738337) % range
}

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

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

// Set as plain sorted array

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
		}
	}
}