/**
 * @author Luis Fraguada / https://github.com/fraguada
 */

import {
	BufferAttribute,
	BufferGeometry,
	BufferGeometryLoader,
	FileLoader,
	Loader
} from "../../../build/three.module.js";

var Rhino3dmLoader = function ( manager ) {

    Loader.call( this, manager );

	this.libraryPath = '';
	this.libraryPending = null;
	this.libraryBinary = null;
	this.libraryConfig = {};

	this.workerLimit = 4;
	this.workerPool = [];
	this.workerNextTaskID = 1;
	this.workerSourceURL = '';
	this.workerConfig = {};

};

Rhino3dmLoader.taskCache = new WeakMap();

Rhino3dmLoader.prototype = Object.assign( Object.create( Loader.prototype ), {

    constructor: Rhino3dmLoader,

    setLibraryPath: function ( path ) {

		this.libraryPath = path;

		return this;

	},

	setWorkerLimit: function ( workerLimit ) {

		this.workerLimit = workerLimit;

		return this;

	},

	load: function ( url, onLoad, onProgress, onError ) {

		var loader = new FileLoader( this.manager );

		loader.setPath( this.path );
		loader.setResponseType( 'arraybuffer' );

		loader.load( url, ( buffer ) => {

			// Check for an existing task using this buffer. A transferred buffer cannot be transferred
			// again from this thread.
			if ( Rhino3dmLoader.taskCache.has( buffer ) ) {

				var cachedTask = Rhino3dmLoader.taskCache.get( buffer );

				return cachedTask.promise.then( onLoad ).catch( onError );

			}

			this.decodeObjects( buffer, url )
				.then( onLoad )
				.catch( onError );

		}, onProgress, onError );


	},

	debug: function () {

		console.log( 'Task load: ', this.workerPool.map( ( worker ) => worker._taskLoad ) );

	},

	decodeObjects: function ( buffer, url ) {

		var worker;
		var taskID;

		var taskCost = buffer.byteLength;

		var objectPending = this._getWorker( taskCost )
			.then( ( _worker ) => {

				worker = _worker;
				taskID = this.workerNextTaskID ++; //hmmm

				return new Promise( ( resolve, reject ) => {

					worker._callbacks[ taskID ] = { resolve, reject };

					worker.postMessage( { type: 'decode', id: taskID, buffer }, [ buffer ] );

					//this.debug();

				} );

			} )
			.then( ( message ) => this._createGeometry( message.geometryList ) );

		// Remove task from the task list.
		// Note: replaced '.finally()' with '.catch().then()' block - iOS 11 support (#19416)
		objectPending
			.catch( () => true )
			.then( () => {

				if ( worker && taskID ) {

					this._releaseTask( worker, taskID );

					//this.debug();

				}

			} );

		// Cache the task result.
		Rhino3dmLoader.taskCache.set( buffer, {

			url: url,
			promise: objectPending

		} );

		return objectPending;
	},

	parse: function ( ) {

		// parsing logic goes here
		console.log('3dm parsing');

	},

	_createGeometry: function ( geometryData ) {

		var geometries = [];
		let loader = new BufferGeometryLoader();

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

			var geometry = loader.parse( geometryData[i] );

			geometries.push( geometry );

		}
		
		return geometries;

	},

	_initLibrary: function () {

		if ( ! this.libraryPending ) {

			// Load rhino3dm wrapper.
			var jsLoader = new FileLoader( this.manager );
			jsLoader.setPath( this.libraryPath );
			var jsContent = new Promise( ( resolve, reject ) => {

				jsLoader.load( 'rhino3dm.js', resolve, undefined, reject );

			} );

			// Load rhino3dm WASM binary.
			var binaryLoader = new FileLoader( this.manager );
			binaryLoader.setPath( this.libraryPath );
			binaryLoader.setResponseType( 'arraybuffer' );
			var binaryContent = new Promise( ( resolve, reject ) => {

				binaryLoader.load( 'rhino3dm.wasm', resolve, undefined, reject );

			} );

			this.libraryPending = Promise.all( [ jsContent, binaryContent ] )
				.then( ( [ jsContent, binaryContent ] ) => {

					//this.libraryBinary = binaryContent;
					this.libraryConfig.wasmBinary = binaryContent;

					var fn = Rhino3dmLoader.Rhino3dmWorker.toString();

					var body = [
						'/* rhino3dm.js */',
						jsContent,
						'/* worker */',
						fn.substring( fn.indexOf( '{' ) + 1, fn.lastIndexOf( '}' ) )
					].join( '\n' );

					this.workerSourceURL = URL.createObjectURL( new Blob( [ body ] ) );

				} );

		}

		return this.libraryPending;

	},

	_getWorker: function ( taskCost ) {

		return this._initLibrary().then( () => {

			if ( this.workerPool.length < this.workerLimit ) {

				var worker = new Worker( this.workerSourceURL );

				worker._callbacks = {};
				worker._taskCosts = {};
				worker._taskLoad = 0;

				worker.postMessage( {
					type: 'init',
					libraryConfig: this.libraryConfig
				} );

				worker.onmessage = function ( e ) {

					var message = e.data;

					switch ( message.type ) {

						case 'decode':
							worker._callbacks[ message.id ].resolve( message );
							break;

						case 'error':
							worker._callbacks[ message.id ].reject( message );
							break;

						default:
							console.error( 'THREE.Rhino3dmLoader: Unexpected message, "' + message.type + '"' );

					}

				};

				this.workerPool.push( worker );

			} else {

				this.workerPool.sort( function ( a, b ) {

					return a._taskLoad > b._taskLoad ? - 1 : 1;

				} );

			}

			var worker = this.workerPool[ this.workerPool.length - 1 ];

			worker._taskLoad += taskCost;

			return worker;

		} );
	},

	_releaseTask: function ( worker, taskID ) {

		worker._taskLoad -= worker._taskCosts[ taskID ];
		delete worker._callbacks[ taskID ];
		delete worker._taskCosts[ taskID ];

	},

	dispose: function () {

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

			this.workerPool[ i ].terminate();

		}

		this.workerPool.length = 0;

		return this;

	}

} );

/* WEB WORKER */

Rhino3dmLoader.Rhino3dmWorker = function () {

	var libraryPending;
	var libraryConfig;
	var rhino;

	onmessage = function ( e ) {

		var message = e.data;

		switch ( message.type ) {

			case 'init':

				libraryConfig = message.libraryConfig;
				var wasmBinary = libraryConfig.wasmBinary;
				var RhinoModule;
				libraryPending = new Promise( function ( resolve ) { 

					/* Like Basis Loader */
					RhinoModule = { wasmBinary, onRuntimeInitialized: resolve };

					rhino3dm( RhinoModule );


				 } ).then( () => {

					rhino = RhinoModule;

				 });
				 
				break;

			case 'decode':

				var buffer = message.buffer;
				libraryPending.then( () => {

					var arr = new Uint8Array(buffer);
					var doc = rhino.File3dm.fromByteArray(arr);

					var objects = doc.objects();
					var geometryList = [];
					
					for ( var i = 0; i < objects.count; i++ ) {
						var obj = objects.get(i).geometry();
						if( obj instanceof rhino.Mesh ) {

							var geometry = obj.toThreejsJSON();
							geometryList.push( geometry );

						}

						/*
					
						if(obj instanceof rhino.PointCloud){
							let threePts = pointsToThreejs(obj, ptMat);
							scene.add(threePts);
						}

						*/
						
					}

					self.postMessage( { type: 'decode', id: message.id, geometryList } );

				} );
				
				break;
		}
	}

};

export { Rhino3dmLoader };