dev@40: /**
dev@40:  * Created by lucas on 01/12/2016.
dev@40:  */
dev@40: 
dev@324: import {PiperVampService, ListRequest, ListResponse} from 'piper';
dev@72: import {
dev@226:   SimpleRequest
dev@72: } from 'piper/HigherLevelUtilities';
dev@44: import { VampExamplePlugins } from 'piper/ext/VampExamplePluginsModule';
dev@243: import {
dev@243:   AvailableLibraries
dev@243: } from './feature-extraction.service';
dev@226: import {
dev@226:   DedicatedWorkerGlobalScope,
dev@226:   WebWorkerStreamingServer
dev@236: } from 'piper/servers/WebWorkerStreamingServer';
dev@226: import {
dev@226:   PiperStreamingService,
dev@226:   StreamingResponse,
dev@226:   StreamingService
dev@236: } from 'piper/StreamingService';
dev@236: import {Observable} from 'rxjs/Observable';
dev@236: import {EmscriptenModule} from 'piper/PiperVampService';
dev@243: import {streamingResponseReducer} from './FeatureReducers';
dev@40: 
dev@40: interface MessageEvent {
dev@40:   readonly data: any;
dev@40: }
dev@40: 
dev@72: type LibraryUri = string;
dev@72: type LibraryKey = string;
dev@72: 
dev@72: type RequireJs = (libs: string[], callback: (...libs: any[]) => void) => void;
dev@322: type Factory<T> = () => T;
dev@72: 
dev@324: function waterfall<T>(tasks: (() => Promise<T>)[]): Promise<T[]> {
dev@324:   const reducer = (running: T[], next: Promise<T>): Promise<T[]> => {
dev@324:     return next.then(response => {
dev@324:       running = running.concat(response);
dev@324:       return running;
dev@324:     });
dev@324:   };
dev@324: 
dev@324:   return tasks.reduce((runningResponses, nextResponse) => {
dev@324:     return runningResponses.then(response => {
dev@324:       return reducer(response, nextResponse());
dev@324:     })
dev@324:   }, Promise.resolve([]));
dev@324: }
dev@324: 
dev@226: class AggregateStreamingService implements StreamingService {
dev@322:   private services: Map<LibraryKey, Factory<PiperStreamingService>>;
dev@226: 
dev@226:   constructor() {
dev@322:     this.services = new Map<LibraryKey, Factory<PiperStreamingService>>();
dev@322:     this.services.set(
dev@322:       'vamp-example-plugins',
dev@322:       () => new PiperStreamingService(
dev@322:         new PiperVampService(VampExamplePlugins())
dev@322:       )
dev@322:     );
dev@226:   }
dev@226: 
dev@322:   addService(key: LibraryKey, service: Factory<PiperStreamingService>): void {
dev@226:     this.services.set(key, service);
dev@226:   }
dev@226: 
dev@324:   hasRemoteService(key: LibraryKey): boolean {
dev@324:     return this.services.has(key);
dev@324:   }
dev@324: 
dev@226:   list(request: ListRequest): Promise<ListResponse> {
dev@323:     const listThunks: (() => Promise<ListResponse>)[] = [
dev@323:       ...this.services.values()
dev@323:     ].map(client => () => client().list({}));
dev@323: 
dev@324:     return waterfall(listThunks).then(responses => {
dev@324:       return responses.reduce((allAvailable, res) => {
dev@324:         allAvailable.available = allAvailable.available.concat(res.available);
dev@324:         return allAvailable;
dev@324:       }, {available: []});
dev@324:     })
dev@226:   }
dev@226: 
dev@226:   process(request: SimpleRequest): Observable<StreamingResponse> {
dev@248:     return this.dispatch('process', request);
dev@226:   }
dev@226: 
dev@305:   protected dispatch(method: 'process',
dev@248:                      request: SimpleRequest): Observable<StreamingResponse> {
dev@226:     const key = request.key.split(':')[0];
dev@322:     return this.services.has(key) ? this.services.get(key)()[method](request) :
dev@322:       Observable.throw('Invalid key');
dev@226:   }
dev@226: }
dev@226: 
dev@250: class ThrottledReducingAggregateService extends AggregateStreamingService {
dev@243:   constructor() {
dev@243:     super();
dev@243:   }
dev@243: 
dev@305:   protected dispatch(method: 'process',
dev@248:                      request: SimpleRequest): Observable<StreamingResponse> {
dev@243:     let lastPercentagePoint = 0;
dev@305:     let shouldClear = false;
dev@248:     return super.dispatch(method, request)
dev@305:       .scan((acc, value) => {
dev@305:         if (shouldClear) {
dev@305:           acc.features = [];
dev@305:         }
dev@305:         return streamingResponseReducer(acc, value);
dev@305:       })
dev@243:       .filter(val => {
dev@305:         const progress = val.progress;
dev@243:         const percentage =
dev@305:           100 * (progress.processedBlockCount / progress.totalBlockCount) | 0;
dev@243:         const pointDifference = (percentage - lastPercentagePoint);
dev@249:         const shouldEmit = pointDifference === 1 || percentage === 100;
dev@249:         if (shouldEmit) {
dev@243:           lastPercentagePoint = percentage;
dev@243:         }
dev@305:         shouldClear = shouldEmit;
dev@249:         return shouldEmit;
dev@243:       });
dev@243:   }
dev@243: }
dev@243: 
dev@40: export default class FeatureExtractionWorker {
dev@226:   private workerScope: DedicatedWorkerGlobalScope;
dev@72:   private remoteLibraries: Map<LibraryKey, LibraryUri>;
dev@226:   private server: WebWorkerStreamingServer;
dev@226:   private service: AggregateStreamingService;
dev@40: 
dev@226:   constructor(workerScope: DedicatedWorkerGlobalScope,
dev@226:               private requireJs: RequireJs) {
dev@40:     this.workerScope = workerScope;
dev@324:     this.remoteLibraries = new Map<LibraryKey, LibraryUri>();
dev@250:     this.service = new ThrottledReducingAggregateService();
dev@226:     this.setupImportLibraryListener();
dev@226:     this.server = new WebWorkerStreamingServer(
dev@226:       this.workerScope,
dev@226:       this.service
dev@72:     );
dev@226:   }
dev@72: 
dev@226:   private setupImportLibraryListener(): void {
dev@229: 
dev@44:     this.workerScope.onmessage = (ev: MessageEvent) => {
dev@44:       switch (ev.data.method) {
dev@72:         case 'addRemoteLibraries': // TODO rename
dev@72:           const available: AvailableLibraries = ev.data.params;
dev@324:           const importThunks = Object.keys(available).map(libraryKey => {
dev@324:             return () => {
dev@324:               this.remoteLibraries.set(libraryKey, available[libraryKey]);
dev@324:               return this.import(libraryKey).then(key => {
dev@324:                 return key;
dev@324:               });
dev@324:             };
dev@72:           });
dev@324:           waterfall(importThunks).then(() => {
dev@324:             this.service.list({}).then(response => {
dev@324:               this.workerScope.postMessage({
dev@324:                 method: 'import',
dev@324:                 result: response
dev@324:               });
dev@324:             });
dev@324:           })
dev@44:       }
dev@44:     };
dev@40:   }
dev@324: 
dev@324:   private import(key: LibraryKey): Promise<LibraryKey> { // TODO return type?
dev@324:     return new Promise((res, rej) => {
dev@324:       if (this.remoteLibraries.has(key)) {
dev@324:         // TODO RequireJs can fail... need to reject the promise then
dev@324:         this.requireJs([this.remoteLibraries.get(key)], (plugin) => {
dev@324: 
dev@324:           const service = () => {
dev@324:             // TODO a factory with more logic probably belongs in piper-js
dev@324:             const lib: any | EmscriptenModule = plugin.createLibrary();
dev@324:             const isEmscriptenModule = typeof lib.cwrap === 'function';
dev@324:             return new PiperStreamingService(
dev@324:               isEmscriptenModule ? new PiperVampService(lib) : lib // TODO
dev@324:             );
dev@324:           };
dev@324:           this.service.addService(key, service);
dev@324:           res(key);
dev@324:         });
dev@324:       } else {
dev@324:         rej('Invalid remote library key');
dev@324:       }
dev@324:     });
dev@324:   }
dev@40: }