Huljo / MowItNow

"use strict";

var Position = require('./position');

// Expose `Grid`

module.exports = Grid;

/**

 * Set up Grid with `topRightPos`

 *

 * Parameters:

 *

 *   - `topRightPos` coordinates of the cell at the top right of the grid. ({x:1,y:1})

 *

 * @param {Object} topRightPos

 * @api public

 */

function Grid(topRightPos) {

    this.width = topRightPos.x;

    this.height = topRightPos.y;

    this.occupation = {};

    this.isValid();

}

/**

 * Types validator

 *

 * @api public

 */

Grid.prototype.isValid = function() {

    if(!isCoordinates(this.width,this.height)) {

        throw new Error('Coordinates are not valid');

    }

};

/**

 * Save item's position inside the grid

 *

 * @param {Number} id

 * @param {Object} position

 * @api public

 */

Grid.prototype.setItemPosition = function(id, position) {

    this.occupation[id] = position;

};

/**

 * Get cell occupation as a boolean

 *

 * @param {Object} position

 * @api public

 */

Grid.prototype.getCellOccupation = function(position) {

    if(isPosition(position)){

        for(var id in this.occupation){

            if(this.occupation[id].x === position.x && this.occupation[id].y === position.y){

                return parseInt(id);

            }

        }

        return null;

    }

    else {

        throw new Error('Position is not valid');

    }

};

/**

 * Coordinates validator helper

 *

 * @param {Number} x

 * @param {Number} y

 * @api protected

 */

function isCoordinates(x,y) {

    return (x === parseInt(x, 10) && x > -1) && (y === parseInt(y, 10) && y > -1);

}

/**

 * Position validator helper

 *

 * @param {Object} position

 * @api protected

 */

function isPosition(position) {

    return position instanceof Position;

}