"use strict";

let game = null;
let view = null;

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

exports.scenarios = [
	"1940",
	"1941",
	"1941-42",
	"Crusader",
	"Battleaxe",
	"1942",
	"Gazala",
	"Pursuit to Alamein",
];

exports.ready = function (scenario, options, players) {
	return players.length === 2;
}

function random(n) {
	return ((game.seed = game.seed * 69621 % 0x7fffffff) / 0x7fffffff) * n | 0;
}

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;
	}
}

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

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

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

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

function push_undo() {
	game.undo.push(JSON.stringify(game, (k,v) => {
		if (k === 'undo') return 0;
		if (k === 'log') return v.length;
		return v;
	}));
}

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

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;
	}
}

let states = {};

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

exports.action = function (state, current, action, arg) {
	game = state;
	update_aliases();
	let S = states[game.state];
	if (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;
}

exports.resign = function (state, current) {
	// No resigning allowed.
	return state;
}

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

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

	if (current === 'Observer' || game.active !== current) {
		view.prompt = `Waiting for ${game.active} \u2014 ${game.state}...`;
	} 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;
}