"use strict"

const FLN = "FLN"
const GOV = "Government"
const BOTH = "Both"

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

exports.scenarios = [ "1954", "1958", "1960" ]

exports.roles = [ FLN, GOV ]

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

function gen_action_token(token) {
	gen_action("token", token)
}

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

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

	if (game.state === "game_over") {
		view.prompt = game.victory
	} else if (player !== game.active && game.active !== BOTH) {
		let inactive = states[game.state].inactive || game.state
		view.prompt = `Waiting for ${game.active} \u2014 ${inactive}...`
	} else {
		view.actions = {}
		states[game.state].prompt()
		if (game.undo && game.undo.length > 0)
			view.actions.undo = 1
		else
			view.actions.undo = 0
	}

	return view
}

exports.resign = function (state, player) {
	game = state
	if (game.state !== 'game_over') {
		if (player === FLN)
			goto_game_over(GOV, "FLN resigned.")
		if (player === GOV)
			goto_game_over(FLN, "Government resigned.")
	}
	return game
}

function goto_game_over(result, victory) {
	game.state = "game_over"
	game.current = -1
	game.active = "None"
	game.result = result
	game.victory = victory
	log("")
	log(game.victory)
	return false
}

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

// === SETUP ===

exports.setup = function (seed, scenario, options) {
	game = {
		seed: seed,
		log: [],
		undo: [],
		active: null,
		selected: -1,

		current: 0,
		state: null,
		scenario: null,
		turn: 0,

		// game board state
		fln_ap: 0,
		fln_psl: 0,
		gov_psl: 0,
		gov_air: 0,
		gov_helo: 0,
		gov_naval: 0,

		is_morocco_tunisia_independent: false,
		border_zone: 0,

		// event related effects
		had_suez_crisis: false,
		is_amnesty: false,
		is_fln_move_restricted: false,

		// logging
		summary: null,
	}

	game.scenario = scenario
	log_h1("Scenario: " + scenario)
	load_scenario(game)

	goto_scenario_setup()

	return game
}

function load_scenario(game) {
	switch (game.scenario) {
	case "1954":
		game.gov_psl = 65
		game.gov_air = 0
		game.gov_helo = 0
		game.gov_naval = 0
		game.fln_psl = 50
		game.fln_ap = roll_2d6()
		game.is_morocco_tunisia_independent = false
		break
	case "1958":
		game.gov_psl = 50
		game.gov_air = 6
		game.gov_helo = 4
		game.gov_naval = 2
		game.fln_psl = 60
		game.fln_ap = roll_2d6()
		game.is_morocco_tunisia_independent = true
		game.border_zone = -2
		break
	case "1960":
		game.gov_psl = 45
		game.gov_air = 7
		game.gov_helo = 5
		game.gov_naval = 3
		game.fln_psl = 45
		game.fln_ap = roll_2d6()
		game.is_morocco_tunisia_independent = true
		game.border_zone = -3
		break
	}
}

function goto_scenario_setup() {
	game.active = GOV
	game.state = "scenario_setup"
}

states.scenario_setup = {
	inactive: "setup",
	prompt() {
		view.prompt = `Setup: ${game.active} Deployment.`
		gen_action("end_deployment")
	},
	end_deployment() {
		log(`Deployed`)
		let keys = Object.keys(game.summary).map(Number).sort((a,b)=>a-b)
		for (let x of keys)
			log(`>${game.summary[x]} at #${x}`)
		game.summary = null

		end_scenario_setup()
	}
}

function end_scenario_setup() {
	game.turn = 1
	goto_random_event()
}

// === FLOW OF PLAY ===

function goto_random_event() {
	game.active = BOTH
	game.state = "random_event"
}

states.random_event = {
	prompt() {
		view.prompt = "Roll for a random event."
		gen_action("roll")
		gen_action("restart")
	},
	roll() {
		clear_undo()
		let rnd = 10 * roll_d6() + roll_d6()
		log("Random event roll " + rnd)
		// goto_reinforcement_phase()

		if (rnd <= 26) {
			goto_no_event()
		} else if (rnd <= 33) {
			goto_fln_foreign_arms_shipment()
		} else if (rnd <= 36) {
			goto_jealousy_and_paranoia()
		} else if (rnd <= 42) {
			goto_elections_in_france()
		} else if (rnd <= 44) {
			goto_un_debate()
		} else if (rnd <= 46) {
			goto_fln_factional_purge()
		} else if (rnd <= 54) {
			goto_morocco_tunisia_independence()
		} else if (rnd <= 56) {
			goto_nato_pressure()
		} else if (rnd <= 62) {
			goto_suez_crisis()
		} else if (rnd <= 64) {
			goto_amnesty()
		} else if (rnd <= 66) {
			goto_jean_paul_sartre()
		} else {
			log("Invalid random value, out of range (11-66)")
		}
	},
	restart() {
		// XXX debug
		log("Restarting...")
		goto_restart()
	}
}

function goto_restart() {
	// XXX debug only
	exports.setup(game.seed, game.scenario)
}

function goto_no_event() {
	log(".h2 No Event. Lucky you.")
	end_random_event()
}

function goto_fln_foreign_arms_shipment() {
	log(".h2 FLN Foreign arms shipment.")
	// The FLN player adds 2d6 AP, minus the current number of Naval Points.
	let roll = roll_2d6()
	let delta_ap = Math.max(roll - game.gov_naval, 0)
	log(`FLN adds ${roll} AP, minus ${game.gov_naval} Naval Points = ${delta_ap} AP`)
	game.fln_ap += delta_ap
	end_random_event()
}

function goto_jealousy_and_paranoia() {
	log(".h2 Jealousy and Paranoia. TODO")
	// TODO FLN units may not Move across wilaya borders this turn only (they may move across international borders)
	game.is_fln_move_restricted = true
	end_random_event()
}

function goto_elections_in_france() {
	log(".h2 Elections in France. TODO")
	// Government player rolls on the Coup Table (no DRM) and adds or subtracts
	// the number of PSP indicated: no units are mobilized or removed.
	end_random_event()
}

function goto_un_debate() {
	log(".h2 UN debates Algerian Independence. TODO")
	// Player with higher PSL raises FLN or lowers Government PSL by 1d6.
	end_random_event()
}

function goto_fln_factional_purge() {
	log(".h2 FLN Factional Purge. TODO")
	// The Government player chooses one wilaya and rolls 1d6, neutralizing
	// that number of FLN units there (the FLN player's choice which ones).
	end_random_event()
}

function goto_morocco_tunisia_independence() {
	log(".h2 Morocco & Tunisia Gains Independence. TODO")

	if (game.is_morocco_tunisia_independent || game.scenario === "1958" || game.scenario === "1960") {
		// If this event is rolled again, or if playing the 1958 or 1960 scenarios,
		// FLN player instead rolls on the Mission Success Table (no DRM) and gets that number of AP
		// (represents infiltration of small numbers of weapons and troops through the borders).

		// TODO

		end_random_event()
	}

	// Raise both FLN and Government PSL by 2d6;
	let fln_roll = roll_2d6()
	log(`Raising FLN PSL by ${fln_roll}`)
	game.fln_psl += fln_roll

	let gov_roll = roll_2d6()
	log(`Raising Government PSL by ${gov_roll}`)
	game.gov_psl += gov_roll

	// FLN player may now Build/Convert units in these two countries as if a Front were there
	// and Government may begin to mobilize the Border Zone. See 11.22.
	game.is_morocco_tunisia_independent = true
	end_random_event()
}

function goto_nato_pressure() {
	log(".h2 NATO pressures France to boost European defense. TODO")
	// The Government player rolls 1d6 and must remove that number of French Army brigades
	// (a division counts as three brigades) from the map.
	// The units may be re-mobilized at least one turn later.
	end_random_event()
}

function goto_suez_crisis() {
	log(".h2 Suez Crisis. TODO")
	if (game.had_suez_crisis || game.scenario === "1958" || game.scenario === "1960") {
		// Treat as "No Event" if rolled again, or playing 1958 or 1960 scenarios.
		log("Re-roll. No Event.")
		end_random_event()
		return
	}
	// The Government player must remove 1d6 elite units from the map, up to the number actually available:
	// they will return in the Reinforcement Phase of the next turn automatically
	// - they do not need to be mobilized again but do need to be activated.

	game.had_suez_crisis = true
	end_random_event()
}

function goto_amnesty() {
	log(".h2 Amnesty. TODO")
	// The French government offers "the peace of the brave" to FLN rebels.
	// TODO All Government Civil Affairs or Suppression missions get a +1 DRM this turn.
	game.is_amnesty = true
	end_random_event()
}

function goto_jean_paul_sartre() {
	log(".h2 Jean-Paul Sartre writes article condemning the war.")
	// Reduce Government PSL by 1 PSP.
	game.gov_psl -= 1
	end_random_event()
}

function end_random_event() {
	goto_reinforcement_phase()
}

function goto_reinforcement_phase() {
	game.state = "reinforcement"
}

states.reinforcement = {
	inactive: "to do reinforcement",
	prompt() {
		view.prompt = "Do reinforcement."
		gen_action("done")
	},
	done() {
		// XXX debug
		log("End of turn...")
		goto_next_turn()
	}
}

function goto_next_turn() {
	game.turn += 1

	// make sure single-turn effects are disabled
	game.is_amnesty = false
	game.is_fln_move_restricted = false

	goto_random_event()
}

// === LOGGING ===

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

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

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

function log_h1(msg) {
	log_br()
	log(".h1 " + msg)
	log_br()
}

function log_h2(msg) {
	log_br()
	log(".h2 " + msg)
	log_br()
}

function log_h3(msg) {
	log_br()
	log(".h3 " + msg)
}

function log_sep() {
	log(".hr")
}

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

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

function roll_2d6() {
	return roll_d6() + roll_d6()
}

// 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)
}