/**
* 
* @module Kiwi
* @submodule Textures
*
*/

module Kiwi.Textures  {

	/**
	* A special type of TextureAtlas that is created when loading in images that are design to be SpriteSheets. A SpriteSheet will generally contain multiple cells and can also contain sequences which are then automatically added as Animations when this texture is used on a Sprite. 
	*
	* @class SpriteSheet
	* @extends TextureAtlas
	* @namespace Kiwi.Textures
	* @constructor
	* @param name {string} The name of the spritesheet.
	* @param texture {HTMLImageElement/HTMLCanvasElement} The image that is being used for the spritesheet.
	* @param cellWidth {number} The width of a single cell.
	* @param cellHeight {number} The height of a single cell.
	* @param [numCells] {number} The number of cells in total. 
	* @param [rows] {number} The number of cells that make up a row.
	* @param [cols] {number} The number of cells that make up a column.
	* @param [sheetOffsetX] {number} The offset of the whole sheet on the x axis. Useful if the image has a border you don't want to show.
	* @param [sheetOffsetY] {number} The offset of the whole sheet on the y axis. Useful if the image has a border you don't want to show.
	* @param [cellOffsetX] {number} An offset between cells on the x axis. Useful if there is a border between cells which is not to be shown.
	* @param [cellOffsetY] {number} An offset between cells on the y axis. Useful if there is a border between cells which is not to be shown.
	* @return {SpriteSheet} 
	*/
	export class SpriteSheet extends TextureAtlas {

		constructor(name: string, texture, cellWidth: number, cellHeight: number, numCells?:number,rows?:number,cols?:number,sheetOffsetX?: number, sheetOffsetY?:number,cellOffsetX?:number,cellOffsetY?:number) {
			
			this.cellWidth = cellWidth;
			this.cellHeight = cellHeight;

			this._cols = cols || texture.width / cellWidth;
			this._rows = rows || texture.height / cellHeight;
			this.numCells = numCells || this.cols * this.rows;
			
			this.sheetOffsetX = sheetOffsetX || 0;
			this.sheetOffsetY = sheetOffsetY || 0;

			this.cellOffsetX = cellOffsetX || 0;
			this.cellOffsetY = cellOffsetY || 0;
			
			super(name, Kiwi.Textures.TextureAtlas.SPRITE_SHEET, this.generateAtlasCells(), texture, this.sequences);
		}

		/**
		* The type of object that this is.
		* @method objType
		* @return {string} "SpriteSheet"
		* @public
		*/
		public objType(): string {
			return "SpriteSheet";
		}

		/**
		* The width of a single cell.
		* @property cellWidth
		* @type number
		* @private
		*/
		private cellWidth: number;

		/**
		* The height of a single cell.
		* @property cellHeight
		* @type number
		* @private
		*/
		private cellHeight: number;

		/**
		* The number of cells that are on this spritesheet
		* @property numCells
		* @type number
		* @private
		*/
		private numCells: number;

		/**
		* The number of rows for the spritesheet
		* @property rows
		* @type number
		* @private
		*/
		private _rows: number;
		
		/**
		* Get the number of rows.
		* @type number
		* @public
		*/
		public get rows(): number {
			return this._rows;
		}

		/**
		* The number of columns that are on this spritesheet
		* @property cols
		* @type number
		* @private
		*/
		private _cols: number;

		/**
		* Get the number of columns.
		* @type number
		* @public
		*/
		public get cols(): number {
			return this._cols;
		}

		/**
		* How much the whole spritesheet should be offset by on the X axis.
		* @property sheetOffsetX
		* @type number
		* @private
		*/
		private sheetOffsetX: number;

		/**
		* How much the whole spritesheet should be offset by on the Y axis.
		* @property sheetOffsetY
		* @type number
		* @private
		*/
		private sheetOffsetY: number;

		/**
		* How much each cell should be offset by on the X axis.
		* @property cellOffsetX
		* @type number
		* @private
		*/
		private cellOffsetX: number;

		/**
		* How much each cell should be offset by on the Y axis.
		* @property cellOffsetY
		* @type number
		* @private
		*/
		private cellOffsetY: number;

		/**
		* Generates the atlas cells based on the information that was provided. 
		* 
		* @method generateAtlasCells
		* @return {Array}
		* @public
		*/
		public generateAtlasCells(): Array<any> {

			var cells = new Array();
			var cellNumeric: number[] = new Array();

			var dx = this.sheetOffsetX;
			var dy = this.sheetOffsetY;
			var i = 0;

			for (var y = 0; y < this.rows; y++) {
				for (var x = 0; x < this.cols; x++) {

					if (i >= this.numCells) continue;

					cells.push({
						x: dx,
						y: dy,
						w: this.cellWidth,
						h: this.cellHeight,
						hitboxes: [
							{
								x: 0,
								y: 0,
								w: this.cellWidth,
								h: this.cellHeight
							}
						]
					});

					cellNumeric.push(i++);

					dx += this.cellOffsetX + this.cellWidth;
				}
				dx = this.sheetOffsetX;
				dy += this.cellOffsetY + this.cellHeight;
			}

			//generate default sequence
			this.sequences = new Array();
			this.sequences.push(new Kiwi.Animations.Sequence('default', cellNumeric)); 

			return cells;
		}

	}

}