/*

	Copyright (c) 2020, 2023, The Unified Company.

	This code is part of Unify.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE,
	as published by the Free Software Foundation.
	See the GNU AFFERO GENERAL PUBLIC LICENSE, for more details.

	https://unifyjs.org

*/

import animation		from "./animation.js";


export default class animationManager{

	id 					= 0;

	start				= 0;


	animations			= new Array();

	element				= document.querySelector(".test");

	promises			= new Array();

	eventListener;


	constructor() {

		this.id	= document.animationID++;

	}

	createAnimation( name ) {

		var newAnimation				= new animation();

		newAnimation.animationManager	= this

		newAnimation.id					= document.keyframeID++;

		newAnimation.name 				= name + newAnimation.id;

		newAnimation.element 			= this.element;

		newAnimation.created			= false;


		this.animations[ newAnimation.name ] 	= newAnimation;


		this.createListeners( newAnimation );

		return newAnimation;

	}


	getAnimationClassName() {

		return "keyFrameAnimation" + this.id;

	}

	createListeners( animation ) {

		if( !animation.direction ) {

			animation.__direction = "normal"

		} else {

			animation.__direction = animation.direction;

		}

		var that = this;

		animation.__defineSetter__( "direction", function( value ){ 

			animation.__direction = value;

			var animationManager = animation.animationManager;

			var source = that.composeCss();

			animation.writeStyleToDOM( source );
	
		});
		 
		animation.__defineGetter__( "direction", function(){ 

			return animation.__direction;
			
		});

	}

	composeKeyFrameCss( source ) {

		var animations		= this.animations;

		for ( var i in animations ) {

			var currentAnimation = animations[i];

			//if( !currentAnimation.active ) {

				source	+= "@keyframes " + currentAnimation.name + "{ \n";

				var keyFrames = currentAnimation.keyFrames;

				for (var i = 0; i < keyFrames.length; i++) {

					var currentKeyFrame = keyFrames[i];


					source	+= "\t" + currentKeyFrame.percent + "% {";

					source	+= currentKeyFrame.composeCss();

					source	+= "}\n";

				}

				source += "} \n";

				currentAnimation.created = true;
				
			//}

		}

		return source;

	}

	composeAnimationCss( source ) {

		var names				= new Array();

		var durations			= new Array();

		var interationCounts	= new Array();

		var fillModes			= new Array();

		var directions			= new Array();


		var animations			= this.animations;


		for ( var i in animations ) {

			var currentAnimation = animations[i];

			if( currentAnimation.active ) {

				if( currentAnimation.duration ) { 

					names.push(  currentAnimation.name );

					durations.push(  currentAnimation.duration );

					directions.push(  currentAnimation.direction );


					if( !currentAnimation.iterationCount ) {

						currentAnimation.iterationCount = 1;

					}

					interationCounts.push( currentAnimation.iterationCount );

					if( !currentAnimation.fillMode ) {

						currentAnimation.fillMode		= "none";

					}

					fillModes.push( currentAnimation.fillMode );

				}

			}

		}


		source += ".keyFrameAnimation" + this.id + "{\n";

		source += "\tanimation-name: " + names.join(",") + ";\n";

		source += "\tanimation-duration: " + durations.join(",") + ";\n";

		source += "\tanimation-iteration-count: " + interationCounts.join(",") + ";\n";

		source += "\tanimation-fill-mode: " + fillModes.join(",") + ";\n";

		source += "\tanimation-direction: " + directions.join(",") + ";\n";

		source += "}";


		return source;

	}

	composeCss() {

		var source	= "";

		source += this.composeKeyFrameCss( source );

		source += this.composeAnimationCss( source );

		return source;

	}

	addPromise( promiseObject ) {
	
		this.promises[ promiseObject.id ] = promiseObject;

	}
	
	getPromiseByID( id ) {
	
		return this.promises[ id ];

	}
	
	createPromiseFunction( animationID ) {
		
		var that = this;

		function promiseFunction( resolveFunction ){

			var promiseObject 		= {};

			promiseObject.id 		= animationID;

			promiseObject.resolve 	= resolveFunction;

			that.addPromise( promiseObject );
		}

		return promiseFunction;

	}
	
	attach( object ){
		
		object.__proto__.animate = this.createCallback( object );

		var animationManager = this;

		object.createAnimation = function( name ) {

			return object.animationManager.createAnimation( name );

		}

		this.element = object.element;

	}
	
	createCallback( object ) {

		object.animationManager.object = object;
	
		return async function( from, to, callback ) {

			return object.animationManager.animate( from, to, callback );  
			
		}

	}
	
	async animate( from, to, callback, firstTick = true, animationID, value = false, start = false ) {

		var object = this.object;

		if( firstTick ) {
		
			animationID = document.animationID++;
				
		}

		var sign = Math.sign( from - to );

		var stop = false;

		if( sign > 0) {
		
			value = from - value;
			
			if( value < to ) {
			
				var stop = true;
			
			}
		
		} else {
		
			value = from + value;
		
			if( value > to ) {
			
				var stop = true;
			
			}
		
		}

		if( firstTick ) {

			this.object[ "animationCallback" + animationID ] = callback;

		}

		if( !stop ) {

			this.object[ "animationCallback" + animationID ]( value );
			
			window.requestAnimationFrame( function( timestamp ) {
			
				if( !start ) {
				
					start = timestamp;
				
				}

				var progress = ( timestamp - start );
				
				object.animationManager.animate( from, to, callback, false, animationID, progress, start );

			});
			
		} else {
		
			var promise = this.getPromiseByID( animationID );
			
			promise.resolve();
			
		}

		if( firstTick ) {

			this.object[ "animationCallback" + animationID ]( value );

			var promiseFunction = this.createPromiseFunction( animationID );

			await new Promise(  promiseFunction  )
			
			return true;

		}
		
	}

	createEventListener() {

		var that	= this;

		if( this.element.keyFrameEventListener ) {

			canvas.removeEventListener('click', this.element.keyFrameEventListener);

		}

		this.element.keyFrameEventListener = this.element.addEventListener("animationend", async function( event ) {

			var animations 		= that.animations;

			var animationName	= event.animationName;

			//console.log(animationName, that.promises);

			//console.log(animations, animationName)

			var currentAnimation = animations[ animationName ];

			console.log("turn off animation", currentAnimation);

			currentAnimation.active = false;

			//console.log("promise with animationName", animationName, "and animationID", currentAnimation.animationID, "removed");

			if( currentAnimation ) {

				var promise = that.promises[currentAnimation.id];
				
				if( promise ) {

					promise.resolve();

				} else {

					return false;

				}


			}

			//console.log("ended animation", currentAnimation);

			that.promises.splice( currentAnimation.id, 1, false )

			for (var i = 0; i < that.promises.length; i++) {

				if( that.promises[i] ) {

					return false

				}
			}

			//console.log("all promises are resolved resetting animation");

			//that.resetAnimation();

			var animationClassName = that.getAnimationClassName();

			that.element.classList.remove(animationClassName);

		}, false);

		return true;

	}

	resetAnimation() {

		//if( this.element.classList.contains("keyFrameAnimations") ) {

			this.element.classList.remove("keyFrameAnimations")

		//}

	}

}