/*
* Tween
* Visit http://createjs.com/ for documentation, updates and examples.
*
* Copyright (c) 2010 gskinner.com, inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/

/**
 * @module EaselJS
 */

// namespace:
this.createjs = this.createjs||{};

(function() {
	"use strict";


// constructor
	/**
	 * Base class that both {{#crossLink "Tween"}}{{/crossLink}} and {{#crossLink "Timeline"}}{{/crossLink}} extend. Should not be instantiated directly.
	 * @class AbstractTween
	 * @param {Object} [props] The configuration properties to apply to this instance (ex. `{loop:-1, paused:true}`).
	 * Supported props are listed below. These props are set on the corresponding instance properties except where
	 * specified.
	 * @param {boolean} [props.useTicks=false]  See the {{#crossLink "AbstractTween/useTicks:property"}}{{/crossLink}} property for more information.
	 * @param {boolean} [props.ignoreGlobalPause=false] See the {{#crossLink "AbstractTween/ignoreGlobalPause:property"}}{{/crossLink}} for more information.
	 * @param {number|boolean} [props.loop=0] See the {{#crossLink "AbstractTween/loop:property"}}{{/crossLink}} for more information.
	 * @param {boolean} [props.reversed=false] See the {{#crossLink "AbstractTween/reversed:property"}}{{/crossLink}} for more information.
	 * @param {boolean} [props.bounce=false] See the {{#crossLink "AbstractTween/bounce:property"}}{{/crossLink}} for more information.
	 * @param {number} [props.timeScale=1] See the {{#crossLink "AbstractTween/timeScale:property"}}{{/crossLink}} for more information.
	 * @param {Function} [props.onChange] Adds the specified function as a listener to the {{#crossLink "AbstractTween/change:event"}}{{/crossLink}} event
	 * @param {Function} [props.onComplete] Adds the specified function as a listener to the {{#crossLink "AbstractTween/complete:event"}}{{/crossLink}} event
	 * @extends EventDispatcher
	 * @constructor
	 */
	function AbstractTween(props) {
		this.EventDispatcher_constructor();
		
	// public properties:
		/**
		 * Causes this tween to continue playing when a global pause is active. For example, if TweenJS is using {{#crossLink "Ticker"}}{{/crossLink}},
		 * then setting this to false (the default) will cause this tween to be paused when `Ticker.paused` is set to
		 * `true`. See the {{#crossLink "Tween/tick"}}{{/crossLink}} method for more info. Can be set via the `props`
		 * parameter.
		 * @property ignoreGlobalPause
		 * @type Boolean
		 * @default false
		 */
		this.ignoreGlobalPause = false;
	
		/**
		 * Indicates the number of times to loop. If set to -1, the tween will loop continuously.
		 *
		 * Note that a tween must loop at _least_ once to see it play in both directions when `{{#crossLink "AbstractTween/bounce:property"}}{{/crossLink}}`
		 * is set to `true`.
		 * @property loop
		 * @type {Number}
		 * @default 0
		 */
		this.loop = 0;
	
		/**
		 * Uses ticks for all durations instead of milliseconds. This also changes the behaviour of some actions (such as `call`).
		 * Changing this value on a running tween could have unexpected results.
		 * @property useTicks
		 * @type {Boolean}
		 * @default false
		 * @readonly
		 */
		this.useTicks = false;
		
		/**
		 * Causes the tween to play in reverse.
		 * @property reversed
		 * @type {Boolean}
		 * @default false
		 */
		this.reversed = false;
		
		/**
		 * Causes the tween to reverse direction at the end of each loop. Each single-direction play-through of the
		 * tween counts as a single bounce. For example, to play a tween once forward, and once back, set the
		 * `{{#crossLink "AbstractTween/loop:property"}}{{/crossLink}}` to `1`.
		 * @property bounce
		 * @type {Boolean}
		 * @default false
		 */
		this.bounce = false;
		
		/**
		 * Changes the rate at which the tween advances. For example, a `timeScale` value of `2` will double the
		 * playback speed, a value of `0.5` would halve it.
		 * @property timeScale
		 * @type {Number}
		 * @default 1
		 */
		this.timeScale = 1;
	
		/**
		 * Indicates the duration of this tween in milliseconds (or ticks if `useTicks` is true), irrespective of `loops`.
		 * This value is automatically updated as you modify the tween. Changing it directly could result in unexpected
		 * behaviour.
		 * @property duration
		 * @type {Number}
		 * @default 0
		 * @readonly
		 */
		this.duration = 0;
	
		/**
		 * The current normalized position of the tween. This will always be a value between 0 and `duration`.
		 * Changing this property directly will have unexpected results, use {{#crossLink "Tween/setPosition"}}{{/crossLink}}.
		 * @property position
		 * @type {Object}
		 * @default 0
		 * @readonly
		 */
		this.position = 0;
		
		/**
		 * The raw tween position. This value will be between `0` and `loops * duration` while the tween is active, or -1 before it activates.
		 * @property rawPosition
		 * @type {Number}
		 * @default -1
		 * @readonly
		 */
		this.rawPosition = -1;
		
		
	// private properties:
		/**
		 * @property _paused
		 * @type {Boolean}
		 * @default false
		 * @protected
		 */
		this._paused = true;
		
		/**
		 * @property _next
		 * @type {Tween}
		 * @default null
		 * @protected
		 */
		this._next = null;
		
		/**
		 * @property _prev
		 * @type {Tween}
		 * @default null
		 * @protected
		 */
		this._prev = null;
		
		/**
		 * @property _parent
		 * @type {Object}
		 * @default null
		 * @protected
		 */
		this._parent = null;

		/**
		 * @property _labels
		 * @type Object
		 * @protected
		 **/
		this._labels = null;

		/**
		 * @property _labelList
		 * @type Array[Object]
		 * @protected
		 **/
		this._labelList = null;

		if (props) {
			this.useTicks = !!props.useTicks;
			this.ignoreGlobalPause = !!props.ignoreGlobalPause;
			this.loop = props.loop === true ? -1 : (props.loop||0);
			this.reversed = !!props.reversed;
			this.bounce = !!props.bounce;
			this.timeScale = props.timeScale||1;
			props.onChange && this.addEventListener("change", props.onChange);
			props.onComplete && this.addEventListener("complete", props.onComplete);
		}
		
		// while `position` is shared, it needs to happen after ALL props are set, so it's handled in _init()
	};

	var p = createjs.extend(AbstractTween, createjs.EventDispatcher);

// events:
	/**
	 * Dispatched whenever the tween's position changes. It occurs after all tweened properties are updated and actions
	 * are executed.
	 * @event change
	 **/
	 
	/**
	 * Dispatched when the tween reaches its end and has paused itself. This does not fire until all loops are complete;
	 * tweens that loop continuously will never fire a complete event.
	 * @event complete
	 **/
	
// getter / setters:
	
	/**
	 * Use the {{#crossLink "AbstractTween/paused:property"}}{{/crossLink}} property instead.
	 * @method _setPaused
	 * @param {Boolean} [value=true] Indicates whether the tween should be paused (`true`) or played (`false`).
	 * @return {AbstractTween} This tween instance (for chaining calls)
	 * @protected
	 * @chainable
	 */
	p._setPaused = function(value) {
		createjs.Tween._register(this, value);
		return this;
	};
	p.setPaused = createjs.deprecate(p._setPaused, "AbstractTween.setPaused");
	
	/**
	 * Use the {{#crossLink "AbstractTween/paused:property"}}{{/crossLink}} property instead.
	 * @method _getPaused
	 * @protected
	 */
	p._getPaused = function() {
		return this._paused;
	};
	p.getPaused = createjs.deprecate(p._getPaused, "AbstactTween.getPaused");
	
	/**
	 * Use the {{#crossLink "AbstractTween/currentLabel:property"}}{{/crossLink}} property instead.
	 * @method _getCurrentLabel
	 * @protected
	 * @return {String} The name of the current label or null if there is no label
	 **/
	p._getCurrentLabel = function(pos) {
		var labels = this.getLabels();
		if (pos == null) { pos = this.position; }
		for (var i = 0, l = labels.length; i<l; i++) { if (pos < labels[i].position) { break; } }
		return (i===0) ? null : labels[i-1].label;
	};
	p.getCurrentLabel = createjs.deprecate(p._getCurrentLabel, "AbstractTween.getCurrentLabel");
	
	/**
	 * Pauses or unpauses the tween. A paused tween is removed from the global registry and is eligible for garbage
	 * collection if no other references to it exist.
	 * @property paused
	 * @type Boolean
	 **/
	 
	/**
	 * Returns the name of the label on or immediately before the current position. For example, given a tween with
	 * two labels, "first" on frame index 4, and "second" on frame 8, `currentLabel` would return:
	 * <UL>
	 * 		<LI>null if the current position is 2.</LI>
	 * 		<LI>"first" if the current position is 4.</LI>
	 * 		<LI>"first" if the current position is 7.</LI>
	 * 		<LI>"second" if the current position is 15.</LI>
	 * </UL>
	 * @property currentLabel
	 * @type String
	 * @readonly
	 **/
	 
	try {
		Object.defineProperties(p, {
			paused: { set: p._setPaused, get: p._getPaused },
			currentLabel: { get: p._getCurrentLabel }
		});
	} catch (e) {}

// public methods:
	/**
	 * Advances the tween by a specified amount.
	 * @method advance
	 * @param {Number} delta The amount to advance in milliseconds (or ticks if useTicks is true). Negative values are supported.
	 * @param {Number} [ignoreActions=false] If true, actions will not be executed due to this change in position.
	 */
	p.advance = function(delta, ignoreActions) {
		this.setPosition(this.rawPosition+delta*this.timeScale, ignoreActions);
	};
	
	/**
	 * Advances the tween to a specified position.
	 * @method setPosition
	 * @param {Number} rawPosition The raw position to seek to in milliseconds (or ticks if useTicks is true).
	 * @param {Boolean} [ignoreActions=false] If true, do not run any actions that would be triggered by this operation.
	 * @param {Boolean} [jump=false] If true, only actions at the new position will be run. If false, actions between the old and new position are run.
	 * @param {Function} [callback] Primarily for use with MovieClip, this callback is called after properties are updated, but before actions are run.
	 */
	p.setPosition = function(rawPosition, ignoreActions, jump, callback) {
		var d=this.duration, loopCount=this.loop, prevRawPos = this.rawPosition;
		var loop=0, t=0, end=false;
		
		// normalize position:
		if (rawPosition < 0) { rawPosition = 0; }
		
		if (d === 0) {
			// deal with 0 length tweens.
			end = true;
			if (prevRawPos !== -1) { return end; } // we can avoid doing anything else if we're already at 0.
		} else {
			loop = rawPosition/d|0;
			t = rawPosition-loop*d;
			
			end = (loopCount !== -1 && rawPosition >= loopCount*d+d);
			if (end) { rawPosition = (t=d)*(loop=loopCount)+d; }
			if (rawPosition === prevRawPos) { return end; } // no need to update
			
			var rev = !this.reversed !== !(this.bounce && loop%2); // current loop is reversed
			if (rev) { t = d-t; }
		}
		
		// set this in advance in case an action modifies position:
		this.position = t;
		this.rawPosition = rawPosition;
		
		this._updatePosition(jump, end);
		if (end) { this.paused = true; }
		
		callback&&callback(this);
		
		if (!ignoreActions) { this._runActions(prevRawPos, rawPosition, jump, !jump && prevRawPos === -1); }
		
		this.dispatchEvent("change");
		if (end) { this.dispatchEvent("complete"); }
	};
	
	/**
	 * Calculates a normalized position based on a raw position. For example, given a tween with a duration of 3000ms set to loop:
	 * 	console.log(myTween.calculatePosition(3700); // 700
	 * @method calculatePosition
	 * @param {Number} rawPosition A raw position.
	 */
	p.calculatePosition = function(rawPosition) {
		// largely duplicated from setPosition, but necessary to avoid having to instantiate generic objects to pass values (end, loop, position) back.
		var d=this.duration, loopCount=this.loop, loop=0, t=0;
		
		if (d===0) { return 0; }
		if (loopCount !== -1 && rawPosition >= loopCount*d+d) { t = d; loop = loopCount } // end
		else if (rawPosition < 0) { t = 0; }
		else { loop = rawPosition/d|0; t = rawPosition-loop*d;  }
		
		var rev = !this.reversed !== !(this.bounce && loop%2); // current loop is reversed
		return rev ? d-t : t;
	};
	
	/**
	 * Returns a list of the labels defined on this tween sorted by position.
	 * @method getLabels
	 * @return {Array[Object]} A sorted array of objects with label and position properties.
	 **/
	p.getLabels = function() {
		var list = this._labelList;
		if (!list) {
			list = this._labelList = [];
			var labels = this._labels;
			for (var n in labels) {
				list.push({label:n, position:labels[n]});
			}
			list.sort(function (a,b) { return a.position- b.position; });
		}
		return list;
	};
	

	/**
	 * Defines labels for use with gotoAndPlay/Stop. Overwrites any previously set labels.
	 * @method setLabels
	 * @param {Object} labels An object defining labels for using {{#crossLink "Timeline/gotoAndPlay"}}{{/crossLink}}/{{#crossLink "Timeline/gotoAndStop"}}{{/crossLink}}
	 * in the form `{myLabelName:time}` where time is in milliseconds (or ticks if `useTicks` is `true`).
	 **/
	p.setLabels = function(labels) {
		this._labels = labels;
		this._labelList = null;
	};

	/**
	 * Adds a label that can be used with {{#crossLink "Timeline/gotoAndPlay"}}{{/crossLink}}/{{#crossLink "Timeline/gotoAndStop"}}{{/crossLink}}.
	 * @method addLabel
	 * @param {String} label The label name.
	 * @param {Number} position The position this label represents.
	 **/
	p.addLabel = function(label, position) {
		if (!this._labels) { this._labels = {}; }
		this._labels[label] = position;
		var list = this._labelList;
		if (list) {
			for (var i= 0,l=list.length; i<l; i++) { if (position < list[i].position) { break; } }
			list.splice(i, 0, {label:label, position:position});
		}
	};
	
	/**
	 * Unpauses this timeline and jumps to the specified position or label.
	 * @method gotoAndPlay
	 * @param {String|Number} positionOrLabel The position in milliseconds (or ticks if `useTicks` is `true`)
	 * or label to jump to.
	 **/
	p.gotoAndPlay = function(positionOrLabel) {
		this.paused = false;
		this._goto(positionOrLabel);
	};

	/**
	 * Pauses this timeline and jumps to the specified position or label.
	 * @method gotoAndStop
	 * @param {String|Number} positionOrLabel The position in milliseconds (or ticks if `useTicks` is `true`) or label
	 * to jump to.
	 **/
	p.gotoAndStop = function(positionOrLabel) {
		this.paused = true;
		this._goto(positionOrLabel);
	};
	
	/**
	 * If a numeric position is passed, it is returned unchanged. If a string is passed, the position of the
	 * corresponding frame label will be returned, or `null` if a matching label is not defined.
	 * @method resolve
	 * @param {String|Number} positionOrLabel A numeric position value or label string.
	 **/
	p.resolve = function(positionOrLabel) {
		var pos = Number(positionOrLabel);
		if (isNaN(pos)) { pos = this._labels && this._labels[positionOrLabel]; }
		return pos;
	};
	

	/**
	 * Returns a string representation of this object.
	 * @method toString
	 * @return {String} a string representation of the instance.
	 */
	p.toString = function() {
		return "[AbstractTween]";
	};

	/**
	 * @method clone
	 * @protected
	 */
	p.clone = function() {
		throw("AbstractTween can not be cloned.")
	};


// private methods:
	/**
	 * Shared logic that executes at the end of the subclass constructor.
	 * @method _init
	 * @protected
	 */
	p._init = function(props) {
		if (!props || !props.paused) { this.paused = false; }
		if (props&&(props.position!=null)) { this.setPosition(props.position); }
	};

	/**
	 * @method _updatePosition
	 * @protected
	 */
	p._updatePosition = function(jump, end) {
		// abstract.
	};
	
	/**
	 * @method _goto
	 * @protected
	 **/
	p._goto = function(positionOrLabel) {
		var pos = this.resolve(positionOrLabel);
		if (pos != null) { this.setPosition(pos, false, true); }
	};
	
	/**
	 * @method _runActions
	 * @protected
	 */
	p._runActions = function(startRawPos, endRawPos, jump, includeStart) {
		// runs actions between startPos & endPos. Separated to support action deferral.
		
		//console.log(this.passive === false ? " > Tween" : "Timeline", "run", startRawPos, endRawPos, jump, includeStart);
		
		// if we don't have any actions, and we're not a Timeline, then return:
		// TODO: a cleaner way to handle this would be to override this method in Tween, but I'm not sure it's worth the overhead.
		if (!this._actionHead && !this.tweens) { return; } 
		
		var d=this.duration, reversed=this.reversed, bounce=this.bounce, loopCount=this.loop;
		var loop0, loop1, t0, t1;
		
		if (d === 0) {
			// deal with 0 length tweens:
			loop0 = loop1 = t0 = t1 = 0;
			reversed = bounce = false;
		} else {
			loop0=startRawPos/d|0;
			loop1=endRawPos/d|0;
			t0=startRawPos-loop0*d;
			t1=endRawPos-loop1*d;
		}
		
		// catch positions that are past the end:
		if (loopCount !== -1) {
			if (loop1 > loopCount) { t1=d; loop1=loopCount; }
			if (loop0 > loopCount) { t0=d; loop0=loopCount; }
		}
		
		// special cases:
		if (jump) { return this._runActionsRange(t1, t1, jump, includeStart); } // jump.
		else if (loop0 === loop1 && t0 === t1 && !jump && !includeStart) { return; } // no actions if the position is identical and we aren't including the start
		else if (loop0 === -1) { loop0 = t0 = 0; } // correct the -1 value for first advance, important with useTicks.
		
		var dir = (startRawPos <= endRawPos), loop = loop0;
		do {
			var rev = !reversed !== !(bounce && loop % 2);

			var start = (loop === loop0) ? t0 : dir ? 0 : d;
			var end = (loop === loop1) ? t1 : dir ? d : 0;
			
			if (rev) {
				start = d - start;
				end = d - end;
			}
			
			if (bounce && loop !== loop0 && start === end) { /* bounced onto the same time/frame, don't re-execute end actions */ }
			else if (this._runActionsRange(start, end, jump, includeStart || (loop !== loop0 && !bounce))) { return true; }
				
			includeStart = false;
		} while ((dir && ++loop <= loop1) || (!dir && --loop >= loop1));
	};
	
	p._runActionsRange = function(startPos, endPos, jump, includeStart) {
		// abstract
	};

	createjs.AbstractTween = createjs.promote(AbstractTween, "EventDispatcher");
}());