/**
* The HUD (Heads Up Display) is a section that handles the displayment of information that you always want visible to user. 
* This section is managed differently to normal GameObjects, where the difference being that HUD items aren't added to a Canvas but are DOM elements instead. Since they DOM elements you can style these elements using a CSS sheet if you wish. 
*
* @module Kiwi
* @submodule HUD
* @main HUD
*/

module Kiwi.HUD {

	/**
	* This class manages all of the various HUDDisplays that are currently used on this Managers game.
	* Using this class you can create/add and remove HUDDisplays from this game,
	* change the HUDDisplay that is currently being display (also known as the currentHUD) and show/hide the currentHUD.
	* Each HUDManager also has at least one HUDDisplay which is called the 'defaultHUD' you cannot remove,
	* but you can reassign the defaultHUD to be a different HUDDisplay if you want. 
	* 
	*
	* @class HUDManager
	* @namespace Kiwi.HUD
	* @constructor
	* @param game {Kiwi.Game} game
	* @return {Kiwi.HUD.HUDManager}
	*/
	export class HUDManager {

		constructor(game: Kiwi.Game) {
			this._game = game;
			this._device = this._game.deviceTargetOption;
		}

		/**
		* The game that this HUDManager belongs to.
		* @property _game
		* @type Kiwi.Game
		* @private
		*/
		private _game: Kiwi.Game;

		/**
		* The device that this game is being target at. The same as the deviceTargetOption property on the root Game.
		* This is needed as it detirmines if HUD is supported on the device or not and if so, how it is implemented. 
		* @property _device
		* @type number
		* @private
		*/
		private _device: number;

		/**
		* If the HUD is supported on the DEVICE that is being targeted. Gets set during the BOOT sequence.
		* @property _supported
		* @type boolean
		* @private
		*/
		private _supported: boolean;

		/**
		* Returns the _supported property indicating whether HUD is supported or not.
		* @property supported
		* @type boolean
		* @public
		*/
		public get supported():boolean {
			return this._supported;
		}

		/**
		* The HTMLDivElement that is being used as the container for the whole manager.
		* @property _hudContainer
		* @type HTMLDivElement
		* @private
		*/
		private _hudContainer: HTMLDivElement;

		/**
		* The DOM is ready, so if the current state is pending we can boot up the HUD now.
		* @method boot
		* @public
		*/
		public boot() {

			if (this._device === Kiwi.TARGET_BROWSER) {
				this._supported = true;

				this._hudContainer = <HTMLDivElement>document.createElement("div");
				this._hudContainer.id = "HUDContainer";
				this._hudContainer.style.position = "absolute";
				this._hudContainer.style.width = "100%";
				this._hudContainer.style.height = "100%";
				this._hudContainer.style.top = '0';
				this._hudContainer.style.left = '0';
				this._game.stage.container.appendChild(this._hudContainer);

				this._huds = new Array<HUDDisplay>();

				this._defaultHUD = this.createHUD("defaultHUD");
				this._currentHUD = this._defaultHUD;
				this.setHUD(this._defaultHUD);

			} else {
				this._supported = false;
			}

		}

		/**
		* Returns the type of object this is.
		* @method objType
		* @return {String} "HUDManager"
		* @public
		*/
		public objType():string {
			return "HUDManager";
		}

		/**
		* An array containing all of the HUDDisplays that are currently active on this HUDManager.
		* @property _huds
		* @type Array
		* @private
		*/
		private _huds: Kiwi.HUD.HUDDisplay[];

		/**
		* The defaultHUD that is being used.
		* The defaultHUD cannot be removed, but can be swapped out for another HUDDisplay.
		* @property _defaultHUD
		* @type Kiwi.HUD.HUDDisplay
		* @private
		*/
		private _defaultHUD: Kiwi.HUD.HUDDisplay;

		/**
		* The currentHUD that is in use. Can be the same as the defaultHUD.
		* @property _currentHUD
		* @type Kiwi.HUD.HUDDisplay
		* @private
		*/
		private _currentHUD: Kiwi.HUD.HUDDisplay;

		/**
		* The default HUDDisplay that is to be used.
		* The defaultHUD cannot be removed, and a game (that supports HUDS) will always contain the defaultHUD.
		*
		* @property defaultHUD
		* @type Kiwi.HUD.HUDDisplay
		* @public
		*/
		public set defaultHUD(value: Kiwi.HUD.HUDDisplay) {
			if (this._currentHUD === this._defaultHUD) {
				this._currentHUD = value;
				this.setHUD(this._currentHUD);
			}
			this._defaultHUD = value;
		}
		public get defaultHUD(): Kiwi.HUD.HUDDisplay {
			return this._defaultHUD;
		}

		/**
		* Changes the currentHUD that is being displayed to one that is passed.
		* @method setHUD
		* @param hud {Kiwi.HUD.HUDDisplay} The HUD you want to display. 
		* @public
		*/
		public setHUD(hud: Kiwi.HUD.HUDDisplay) {
			if (this.supported) {
				this.hideHUD();
				this._currentHUD = hud;
				this.showHUD();
			}
		}

		/**
		* Shows the currentHUD (if nothing is passed) or shows a HUDDisplay that is passed.
		* @method showHUD
		* @param [hud=currentHUD] {Kiwi.HUD.HUDDisplay} The HUDDisplay you want to show. Defaults to the currentHUD if nothing is passed.
		* @public
		*/
		public showHUD(hud:Kiwi.HUD.HUDDisplay=this._currentHUD) {
			hud.show();
		}

		/**
		* Hides the currentHUD (if nothing is passed) or shows a HUDDisplay that is passed.
		* @method hideHUD 
		* @param [hud=currentHUD] {Kiwi.HUD.HUDDisplay} The HUDDisplay you want to hude. Defaults to the currentHUD if nothing is passed.
		* @public
		*/
		public hideHUD(hud:Kiwi.HUD.HUDDisplay=this._currentHUD) {
			hud.hide();
		}

		/**
		* Creates a new HUDDisplay on this HUDManager.
		* 
		* @method createHUD
		* @param name {string} Name of the new HUDDisplay that is being creates.
		* @param [switchTo=false] {boolean} Switch to the new HUD that was created. DE
		* @return {Kiwi.HUD.HUDDisplay} The HUDDisplay that was created.
		* @public
		*/
		public createHUD(name: string, switchTo:boolean=false): Kiwi.HUD.HUDDisplay {
			
			if (this.supported) {

				var hud: Kiwi.HUD.HUDDisplay = new Kiwi.HUD.HUDDisplay(this._game, name);
				hud.hide();
				this.addToContainer(hud);
				this._huds.push(hud);
				
				if(switchTo === true) this.setHUD(hud);

				return hud;

			}
		}

		/**
		* Removes a HUDDisplay off this manager. Returns a boolean indicating whether or not this method was a success.
		*
		* @method removeHUD
		* @param hud {Kiwi.HUD.HUDDisplay} The hud you want to remove.
		* @returns {boolean} If this method succeeded or not.
		* @public
		*/
		public removeHUD(hud: Kiwi.HUD.HUDDisplay):boolean {
			if (this.supported) {
				if (hud === this._defaultHUD) {
					return false;
				}

				if (this._currentHUD === hud) {
					this.setHUD(this._defaultHUD);
				}

				this.removeFromContainer(hud);

				var i = this._huds.indexOf(hud);

				if (i !== -1) {
					this._huds.splice(i, 1);
				}

				return true;
			}
		}

		/**
		* Adds a HUDDisplays HTMLDivElement to this HUDManagers container element.
		* @method addToContainer
		* @param hud {Kiwi.HUD.HUDDisplay} The HUDDisplay that is to be added.
		* @private
		*/
		private addToContainer(hud:Kiwi.HUD.HUDDisplay) {
			if (this._device == Kiwi.TARGET_BROWSER) {
				this._hudContainer.appendChild(hud.container);
			}
		}

		/**
		* Removes the hud that is passed from this HUD Manager. Checks to see if that hud has this container as a parent first.
		* @method removeFromContainer
		* @param hud {Kiwi.HUD.HUDDisplay} The hud to be removed
		* @private
		*/
		private removeFromContainer(hud: Kiwi.HUD.HUDDisplay) {
			if (this._device == Kiwi.TARGET_BROWSER) {
				if (this._hudContainer.contains(hud.container)) {
					this._hudContainer.removeChild(hud.container);
				}
			}

		}

		/**
		* Game loop
		* @method update
		* @public
		*/
		public update() {
			if (this._supported) {
				for (var i = 0; i < this._huds.length; i++) {
					this._huds[i].update();
				}
			}
		}

	}
}