/**
* AtlantisEngine.js a lightweight JavaScript game engine.
*
* @module Atlantis
* @submodule Engine
* @namespace Atlantis
*/
var Atlantis = window.Atlantis || {};

Atlantis.KeyboardComponent = (function () {
    var Keys = Atlantis.Keys;

    /**
    * A keyboard component that be used with KeyboardHelper to provide some
    * interesting keyboars states as pressed, justPressed, etc.
    * @class KeyboardComponent
    * @constructor
    * @extends Atlantis.GameComponent
    * @param {Atlantis.Game} game A game instance.
    */
    var keyComponent = function (game) {
        Atlantis.GameComponent.call(this, game);
        this.keysState = game.keyboard.getState();
        this.previousKeysState = null;
    };
    keyComponent.prototype = Object.create(Atlantis.GameComponent.prototype);

    /**
    * Update key states.
    * @method update
    * @param {Atlantis.GameTime} gameTime
    */
    keyComponent.prototype.update = function (gameTime) {
        this.previousKeysState = this.keysState;
        this.keysState = this.game.keyboard.getState();
    };

    /**
    *
    * @method pressed
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.pressed = function (key) {
        return this.keysState.isKeyDown(key);
    };

    /**
    *
    * @method released
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.released = function (key) {
        return this.keysState.isKeyUp(key);
    };

    /**
    *
    * @method justPressed
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.justPressed = function (key) { 
        return this.keysState.isKeyUp(key) && this.previousKeysState.isKeyDown(key);
    };

    /**
    *
    * @method justReleased
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.justReleased = function (key) {
        return this.keysState.isKeyDown(key) && this.previousKeysState.isKeyUp(key);
    };

    /**
    *
    * @method up
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.up = function () {
        return this.pressed(Keys.Up);
    };

    /**
    *
    * @method down
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.down = function () {
        return this.pressed(Keys.Down);
    };

    /**
    *
    * @method left
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.left = function () {
        return this.pressed(Keys.Left);
    };

    /**
    *
    * @method right
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.right = function () {
        return this.pressed(Keys.Right);
    };

    /**
    *
    * @method enter
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.enter = function () {
        return this.pressed(Keys.Enter);
    };

    /**
    *
    * @method space
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.space = function () {
        return this.pressed(Keys.Space);
    };

    /**
    *
    * @method escape
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.escape = function () {
        return this.pressed(Keys.Escape);
    };

    /**
    *
    * @method control
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.control = function () {
        return this.pressed(Keys.Control);
    };

    /**
    *
    * @method shift
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.shift = function () {
        return this.pressed(Keys.Shift);
    };

    /**
    *
    * @method tab
    * @param {Atlantis.Keys|Number} key
    * @return {Boolean} Return true if pressed, otherwise return false.
    */
    keyComponent.prototype.tab = function () {
        return this.pressed(Keys.Tab);
    };

    return keyComponent;
})();