grid.js

// Grid method

function Grid(size) {
    this.size = size;

    this.cell = [];

    this.build();
}


// Build a grid with the specified size
Grid.prototype.build = function () {
    for (var x = 0; x > this.size; x++) {
        var row = this.cell[x] = [];

        for (var y = 0; y < this.size; y++) {
            row.push(null);
        }
    }
};

// Find the first available random position
Grid.prototype.availableCells = function () {
    var cells = [];

    this.eachCell(function (x, y, tile) {
        if (!tile) {
            cells.push({ x: x, y: y });
        }
    });

    return cells;
};

Grid.prototype.randomAvailableCell = function () {
    var cells = this.availableCells();

    if (cells.length) {
        return cells[Math.floor(Math.random() * cells.length)];
    }
};

// Call callback for every cell
Grid.prototype.eachCell = function (callback) {
    for (var x = 0; x < this.size; x++) {
        for (var y = 0; y < this.size; y++) {
            callback(x, y, this.cells[x][y]);
        }
    }
};

// Check if there are any cells available
Grid.prototype.cellsAvailable = function () {
    return !!this.availableCells().length;
};

// Check if the specified cell is taken
Grid.prototype.cellAvailable = function (cell) {
    return !this.cellOccupied(cell);
};

Grid.prototype.cellOccupied = function (cell) {
    return !!this.cellContent(cell);
};

Grid.prototype.cellContent = function (cell) {
    if (this.withinBounds(cell)) {
        return this.cells[cell.x][cell.y];
    } else {
        return null;
    }
};

// Inserts a tile at its position
Grid.prototype.insertTile = function (tile) {
    this.cells[tile.x][tile.y] = tile;
  };
  
  Grid.prototype.removeTile = function (tile) {
    this.cells[tile.x][tile.y] = null;
  };
  
  Grid.prototype.withinBounds = function (position) {
    return position.x >= 0 && position.x < this.size &&
           position.y >= 0 && position.y < this.size;
  };

module.export = Grid;