/**
 *
 * Reusable set of Tracks that represent an animation.
 *
 * @author Ben Houston / http://clara.io/
 * @author David Sarno / http://lighthaus.us/
 */

THREE.AnimationClip = function ( name, duration, tracks ) {

	this.name = name || THREE.Math.generateUUID();
	this.tracks = tracks;
	this.duration = ( duration !== undefined ) ? duration : -1;

	// this means it should figure out its duration by scanning the tracks
	if ( this.duration < 0 ) {

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

			var track = this.tracks[i];
			this.duration = Math.max( track.times[ track.times.length - 1 ] );

		}

	}

	// maybe only do these on demand, as doing them here could potentially slow down loading
	// but leaving these here during development as this ensures a lot of testing of these functions
	this.trim();
	this.optimize();

};

THREE.AnimationClip.prototype = {

	constructor: THREE.AnimationClip,

	trim: function() {

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

			this.tracks[ i ].trim( 0, this.duration );

		}

		return this;

	},

	optimize: function() {

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

			this.tracks[ i ].optimize();

		}

		return this;

	}

};

// Static methods:

Object.assign( THREE.AnimationClip, {

	parse: function( json ) {

		var tracks = [],
			jsonTracks = json.tracks,
			frameTime = 1.0 / ( json.fps || 1.0 );

		for ( var i = 0, n = jsonTracks.length; i !== n; ++ i ) {

			tracks.push( THREE.KeyframeTrack.parse( jsonTracks[ i ] ).scale( frameTime ) );

		}

		return new THREE.AnimationClip( json.name, json.duration, tracks );

	},


	toJSON: function( clip ) {

		var tracks = [],
			clipTracks = clip.tracks;

		var json = {

			'name': clip.name,
			'duration': clip.duration,
			'tracks': tracks

		};

		for ( var i = 0, n = clipTracks.length; i !== n; ++ i ) {

			tracks.push( THREE.KeyframeTrack.toJSON( clipTracks[ i ] ) );

		}

		return json;

	},


	CreateFromMorphTargetSequence: function( name, morphTargetSequence, fps ) {

		var numMorphTargets = morphTargetSequence.length;
		var tracks = [];

		for ( var i = 0; i < numMorphTargets; i ++ ) {

			var times = [];
			var values = [];

			times.push(
					( i + numMorphTargets - 1 ) % numMorphTargets,
					i,
					( i + 1 ) % numMorphTargets );

			values.push( 0, 1, 0 );

			var order = THREE.AnimationUtils.getKeyframeOrder( times );
			times = THREE.AnimationUtils.sortedArray( times, 1, order );
			values = THREE.AnimationUtils.sortedArray( values, 1, order );

			// if there is a key at the first frame, duplicate it as the
			// last frame as well for perfect loop.
			if ( times[ 0 ] === 0 ) {

				times.push( numMorphTargets );
				values.push( values[ 0 ] );

			}

			tracks.push(
					new THREE.NumberKeyframeTrack(
						'.morphTargetInfluences[' + morphTargetSequence[ i ].name + ']',
						times, values
					).scale( 1.0 / fps ) );
		}

		return new THREE.AnimationClip( name, -1, tracks );

	},

	findByName: function( clipArray, name ) {

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

			if ( clipArray[ i ].name === name ) {

				return clipArray[ i ];

			}
		}

		return null;

	},

	CreateClipsFromMorphTargetSequences: function( morphTargets, fps ) {

		var animationToMorphTargets = {};

		// tested with https://regex101.com/ on trick sequences
		// such flamingo_flyA_003, flamingo_run1_003, crdeath0059
		var pattern = /^([\w-]*?)([\d]+)$/;

		// sort morph target names into animation groups based
		// patterns like Walk_001, Walk_002, Run_001, Run_002
		for ( var i = 0, il = morphTargets.length; i < il; i ++ ) {

			var morphTarget = morphTargets[ i ];
			var parts = morphTarget.name.match( pattern );

			if ( parts && parts.length > 1 ) {

				var name = parts[ 1 ];

				var animationMorphTargets = animationToMorphTargets[ name ];
				if ( ! animationMorphTargets ) {

					animationToMorphTargets[ name ] = animationMorphTargets = [];

				}

				animationMorphTargets.push( morphTarget );

			}

		}

		var clips = [];

		for ( var name in animationToMorphTargets ) {

			clips.push( THREE.AnimationClip.CreateFromMorphTargetSequence( name, animationToMorphTargets[ name ], fps ) );

		}

		return clips;

	},

	// parse the animation.hierarchy format
	parseAnimation: function( animation, bones, nodeName ) {

		if ( ! animation ) {

			console.error( "  no animation in JSONLoader data" );
			return null;

		}

		var addNonemptyTrack = function(
				trackType, trackName, animationKeys, propertyName, destTracks ) {

			// only return track if there are actually keys.
			if ( animationKeys.length !== 0 ) {

				var times = [];
				var values = [];

				THREE.AnimationUtils.flattenJSON(
						animationKeys, times, values, propertyName );

				// empty keys are filtered out, so check again
				if ( times.length !== 0 ) {

					destTracks.push( new trackType( trackName, times, values ) );

				}

			}

		};

		var tracks = [];

		var clipName = animation.name || 'default';
		// automatic length determination in AnimationClip.
		var duration = animation.length || -1;
		var fps = animation.fps || 30;

		var hierarchyTracks = animation.hierarchy || [];

		for ( var h = 0; h < hierarchyTracks.length; h ++ ) {

			var animationKeys = hierarchyTracks[ h ].keys;

			// skip empty tracks
			if ( ! animationKeys || animationKeys.length == 0 ) continue;

			// process morph targets in a way exactly compatible
			// with AnimationHandler.init( animation )
			if ( animationKeys[0].morphTargets ) {

				// figure out all morph targets used in this track
				var morphTargetNames = {};
				for ( var k = 0; k < animationKeys.length; k ++ ) {

					if ( animationKeys[k].morphTargets ) {

						for ( var m = 0; m < animationKeys[k].morphTargets.length; m ++ ) {

							morphTargetNames[ animationKeys[k].morphTargets[m] ] = -1;
						}

					}

				}

				// create a track for each morph target with all zero
				// morphTargetInfluences except for the keys in which
				// the morphTarget is named.
				for ( var morphTargetName in morphTargetNames ) {

					var times = [];
					var values = [];

					for ( var m = 0;
							m !== animationKeys[k].morphTargets.length; ++ m ) {

						var animationKey = animationKeys[k];

						times.push( animationKey.time );
						values.push( ( animationKey.morphTarget === morphTargetName ) ? 1 : 0 )

					}

					tracks.push( new THREE.NumberKeyframeTrack(
							'.morphTargetInfluence[' + morphTargetName + ']', times, values ) );

				}

				duration = morphTargetNames.length * ( fps || 1.0 );

			} else {
				// ...assume skeletal animation

				var boneName = '.bones[' + bones[ h ].name + ']';

				addNonemptyTrack(
						THREE.VectorKeyframeTrack, boneName + '.position',
						animationKeys, 'pos', tracks );

				addNonemptyTrack(
						THREE.QuaternionKeyframeTrack, boneName + '.quaternion',
						animationKeys, 'rot', tracks );

				addNonemptyTrack(
						THREE.VectorKeyframeTrack, boneName + '.scale',
						animationKeys, 'scl', tracks );

			}

		}

		if ( tracks.length === 0 ) {

			return null;

		}

		var clip = new THREE.AnimationClip( clipName, duration, tracks );

		return clip;

	}

} );