var Mine = function() {
	var ALIVE = 0, LOST = 1, ABORTED = 2, WON = 3;
	
	function defaultMeta() {
		return {
			Water: 0,
			Flooding: 0,
			Waterproof: 10,
		}
	}
	
	function repeat(str, n) {
		return new Array(n+1).join(str);
	}
	
	function Mine(map) {
		this.parse(map)
	};
	Mine.ALIVE = ALIVE;
	Mine.LOST = LOST;
	Mine.ABORTED = ABORTED;
	Mine.WON = WON;

	Mine.prototype.parse = function(map) {
		var lines, i, width, height, pair, x, line;
		this.orig_map = map;
		lines = map.split(/\r\n?|\r?\n/);
		
		width = 0;
		height = lines.length;
		for (i = 0; i < lines.length; ++i) {
			if (0 == lines[i].length) {
				height = i;
				lines.splice(i, 1);
				break;
			}
			width = Math.max(width, lines[i].length);
		}
		this.height = height;
		this.width = width;
		this.map = map = lines.splice(0, height).reverse();
		this.lambdas = 0;
		this.found_lambdas = 0;
		this.moves = 0;
		this.score = 0;
		this.moves_below_water = 0;
		this.lift = this.robot = false;
		for (i = 0; i < height; ++i) {
			// padding
			if (map[i].length < width) map[i] += repeat(' ', width - map[i].length);
			line = map[i] = map[i].split('');
			
			// scan
			for (x = 0; x < width; ++x) {
				switch (line[x]) {
				case ' ':
				case '*':
				case '#':
				case '.':
					break;
				case '\\':
					this.lambdas++;
					break;
				case 'L':
					if (this.lift !== false) throw "Only one lift is allowed";
					this.lift = { x: x, y: i };
					break;
				case 'R':
					if (this.robot !== false) throw "Only one robot is allowed";
					this.robot = { x: x, y: i };
					break;
				}
			}
		}
		
		// if (this.lift === false) throw "Need a lift";
		if (this.robot === false) throw "Need a robot";
		
		// meta data
		this.meta = defaultMeta();
		for (i = 0; i < lines.length; ++i) {
			if (0 == lines[i].length) continue;
			pair = lines[i].split(/ +/);
			this.meta[pair[0]] = pair.splice(1).join(" ");
		}
		this.state = ALIVE;
	};
	
	Mine.prototype.get = function (x, y) {
		if (x < 0 || y < 0 || x >= this.width || y >= this.height) return '#';
		return this.map[y][x];
	}
	
	Mine.prototype.validMove = function (command) {
		if (this.state != ALIVE) return false;
		var n;
		command = command.toUpperCase();
		switch (command) {
		case 'L':
		case 'R':
			n = (command == 'L' ? -1 : 1);
			if (this.robot.x + n < 0) return false;
			if (this.robot.x + n >= this.width) return false;
			switch (this.map[this.robot.y][this.robot.x+n]) {
			case '#': return false;
			case ' ':
			case '.':
			case '\\': return true;
			case 'L': return false;
			case 'O': return true;
			case '*':
				if (this.robot.x + 2*n < 0) return false;
				if (this.robot.x + 2*n >= this.width) return false;
				if (' ' == this.map[this.robot.y][this.robot.x+2*n]) return true;
			}
			break;
		case 'U':
		case 'D':
			n = (command == 'D' ? -1 : 1);
			if (this.robot.y + n < 0) return false;
			if (this.robot.y + n >= this.height) return false;
			switch (this.map[this.robot.y+n][this.robot.x]) {
			case '#': return false;
			case ' ':
			case '.':
			case '\\': return true;
			case 'L': return false;
			case 'O': return true;
			case '*': return false;
			" style="}
			break;
		case 'W':
		case 'A':
			return true;
		}
		return false;
	};
	
	Mine.prototype.move = function(command) {
		if (this.state != ALIVE) return false;
		var n;
		command = command.toUpperCase();
		if (this.validMove(command)) {
			switch (command.toUpperCase()) {
			case 'L':
			case 'R':
				n = (command == 'L' ? -1 : 1);
				this.map[this.robot.y][this.robot.x] = ' ';
				switch (this.map[this.robot.y][this.robot.x+n]) {
				case '*':
					this.map[this.robot.y][this.robot.x+2*n] = '*';
					break;
				case '\\':
					this.lambdas--;
					this.found_lambdas++;
					break;
				case 'O':
					this._foundLift();
					break;
				}
				this.robot.x += n;
				this.map[this.robot.y][this.robot.x] = 'R';
				break;
			case 'U':
			case 'D':
				n = (command == 'D' ? -1 : 1);
				this.map[this.robot.y][this.robot.x] = ' ';
				switch (this.map[this.robot.y+n][this.robot.x]) {
				case '\\':
					this.lambdas--;
					this.found_lambdas++;
					break;
				case 'O':
					this._foundLift();
					break;
				}
				this.robot.y += n;
				this.map[this.robot.y][this.robot.x] = 'R';
				break;
			case 'A':
				this._abort();
				return;
			}
		}
		this.moves++;
		if (0 == this.lambdas) {
			if (false !== this.lift) this.map[this.lift.y][this.lift.x] = 'O';
		}
		
		var newMap = [], x, y, below;
		for (y = 0; y < this.height; ++y) { newMap[y] = this.map[y].slice(); }
		
		for (y = 0; y < this.height; ++y) {
			for (x = 0; x < this.width; ++x) {
				if ('*' == this.map[y][x]) {
					below = this.get(x, y-1);
					if (' ' == below) {
						// fall down
						newMap[y-1][x] = '*';
						newMap[y][x] = ' ';
						if ('R' == this.get(x, y-2)) this._crushed();
					} else if ((below == '*' || below == '\\') && ' ' == this.get(x+1, y-1) && ' ' == this.map[y][x+1]) {
						// fall right
						newMap[y-1][x+1] = '*';
						newMap[y][x] = ' ';
						if ('R' == this.get(x+1, y-2)) this._crushed();
					} else if ((below == '*') && ' ' == this.get(x-1, y-1) && ' ' == this.map[y][x-1]) {
						// fall left
						newMap[y-1][x-1] = '*';
						newMap[y][x] = ' ';
						if ('R' == this.get(x-1, y-2)) this._crushed();
					}
				}
			}
		}
		this.map = newMap;
		
		if (this.robot.y < this.meta['Water']) {
			this.moves_below_water++;
			if (this.moves_below_water > this.meta['Waterproof']) this._drown();
		} else {
			this.moves_below_water = 0;
		}
		if (this.meta['Flooding'] > 0 && 0 == (this.moves % this.meta['Flooding'])) {
			this.meta['Water']++;
		}
		
		switch (this.state) {
		case LOST:
			this.score = 25*this.found_lambdas - this.moves;
			break;
		case WON:
			this.score = 75*this.found_lambdas - this.moves;
			break;
		case ALIVE:
		case ABORTED:
			this.score = 50*this.found_lambdas - this.moves;
			break;
		}
	};

	Mine.prototype._drown = function() {
		if (this.state < LOST) {
			this.state = LOST;
			this.reason = "Drowned";
		}
	};
	
	Mine.prototype._crushed = function() {
		if (this.state < LOST) {
			this.state = LOST;
			this.reason = "Crushed by rock";
		}
	};
	
	Mine.prototype._foundLift = function() {
		if (this.state < WON) {
			this.state = WON;
			this.reason = "Found lift";
		}
	};
	
	Mine.prototype._abort = function() {
		if (this.state < ABORTED) {
			this.state = ABORTED;
			this.reason = "Aborted";
		}
	};
	
	Mine.prototype.toString = function() {
		return this.map.map(function(l) { return l.join(''); }).reverse().join("\n");
	};
	
	Mine.prototype.metaText = function() {
		var k, keys = [], lines = [];
		for (k in this.meta) {
			if (this.meta.hasOwnProperty(k)) keys.push(k);
		}
		keys.sort();
		for (k = 0; k < keys.length; ++k) {
			lines[k] = keys[k] + " " + this.meta[keys[k]];
		}
		return lines.join("\n");
	};
	
	return Mine;
}();

if (typeof exports !== "undefined") {
	exports.Mine = Mine;
}