var Maze = Class({
    $statics: {
        N: 1,
        S: 2,
        E: 4,
        W: 8,
        DX: {
            E: 1,
            W: -1,
            N: 0,
            S: 0
        },
        DY: {
            E: 0,
            W: 0,
            N: -1,
            S: 1
        },
        OPPOSITE: {
            E: this.W,
            W: this.E,
            N: this.S,
            S: this.N
        },
        directions: ['N', 'S', 'E', 'W'],
        dirVal: {
            E: this.E,
            W: this.W,
            N: this.N,
            S: this.S
        },
        shuffle: function(arr) {
            for (var j, x, i = arr.length; i; j = parseInt(Math.random() * i), x = arr[--i], arr[i] = arr[j], arr[j] = x);
            return arr;
        },
        create2DArray: function(h, w) {
            var array = [];
            for (var i = 0; i < h; i++) {
                array[i] = [];
            }
            for (i = 0; i < h; i++) {
                for (var j = 0; j < w; j++) {
                    array[i][j] = 0;
                }
            }
            return array;
        }
    },

    constructor: function(width, height) {
        this.width = width;
        this.height = height;

        this.grid = this.create2DArray(this.height, this.width);
        this.maze = this.create2DArray(2 * this.height + 1, 2 * this.width + 1);


        this.carve_pass();
        this.toBlocks();

        this.toArray();

    },

    carve_pass: function(cx, cy) {
        cx = cx ? cx : 0;
        cy = cy ? cy : 0;

        this.directions = this.shuffle(this.directions);
        for (var i = 0; i < 4; i++) {
            var direction = this.directions[i];
            var nx = cx + this.DX[direction],
                ny = cy + this.DY[direction];
            if (this.grid && ny >= 0 && ny <= ((this.grid).length - 1) && nx >= 0 && nx <= ((this.grid).length - 1) && this.grid[ny][nx] === 0) {
                this.grid[cy][cx] |= this.dirVal[direction];
                this.grid[ny][nx] |= this.OPPOSITE[direction];
                this.carve_pass(nx, ny);
            }
        }
    },

    toBlocks: function() {
        if (this.maze) {
            for (var i = 0; i < 2 * this.width + 1; i++) {
                this.maze[0][i] = 1;
                this.maze[2 * this.height][i] = 1;
                this.maze[i][0] = 1;
                this.maze[i][this.width * 2] = 1;
            }
            var x, y;
            for (i = 0; i < this.height; i++) {
                for (var j = 0; j < this.width; j++) {
                    x = i * 2 + 1;
                    y = j * 2 + 1;
                    this.maze[x + 1][y] = (this.grid[i][j] & this.S) === 0;
                    if (this.grid[i][j] & this.E)
                        this.maze[x + 1][y + 1] = ((this.grid[i][j] | this.grid[i][j + 1]) & this.S) === 0;
                    else
                        this.maze[x][y + 1] = this.maze[x + 1][y + 1] = 1;
                }
            }
        }
    },

    toArray: function() {
        if (this.maze) {
            for (var i = 0; i < 2 * this.height + 1; i++) {
                var line = '';
                for (var j = 0; j < 2 * this.width + 1; j++) {
                    line += ((this.maze[i][j]) ? '#' : '.');
                }
                document.write(line + "<br>");
            }
        }
    },

    getMazeArray: function() {
        // console.log(this.width);
        return this.maze;
    }


});