annotate src/app/app.component.ts @ 350:524f5cd75737

Split AnalysisItem out into individual types for root audio items and features. This is messy as is, these need revising and should perhaps be actual concrete types with methods.

import {Component, OnDestroy} from '@angular/core';
import {
  AudioPlayerService,
  AudioResourceError, AudioResource
} from './services/audio-player/audio-player.service';
import {FeatureExtractionService} from './services/feature-extraction/feature-extraction.service';
import {ExtractorOutputInfo} from './feature-extraction-menu/feature-extraction-menu.component';
import {DomSanitizer} from '@angular/platform-browser';
import {MdIconRegistry} from '@angular/material';
import {Subscription} from 'rxjs/Subscription';
import {
  AnalysisItem, isRootAudioItem,
  Item, PendingAnalysisItem, PendingRootAudioItem, RootAudioItem
} from './analysis-item/analysis-item.component';
import {OnSeekHandler} from './playhead/PlayHeadHelpers';

class PersistentStack<T> {
  private stack: T[];
  private history: T[][];

  constructor() {
    this.stack = [];
    this.history = [];
  }

  shift(): T {
    this.history.push([...this.stack]);
    const item = this.stack[0];
    this.stack = this.stack.slice(1);
    return item;
  }

  unshift(item: T): number {
    this.history.push([...this.stack]);
    this.stack = [item, ...this.stack];
    return this.stack.length;
  }

  findIndex(predicate: (value: T,
                        index: number,
                        array: T[]) => boolean): number {
    return this.stack.findIndex(predicate);
  }

  filter(predicate: (value: T, index: number, array: T[]) => boolean): T[] {
    return this.stack.filter(predicate);
  }

  get(index: number): T {
    return this.stack[index];
  }

  set(index: number, value: T) {
    this.history.push([...this.stack]);
    this.stack = [
      ...this.stack.slice(0, index),
      value,
      ...this.stack.slice(index + 1)
    ];
  }

  toIterable(): Iterable<T> {
    return this.stack;
  }
}

@Component({
  selector: 'ugly-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnDestroy {
  audioBuffer: AudioBuffer; // TODO consider revising
  canExtract: boolean;
  private onAudioDataSubscription: Subscription;
  private onProgressUpdated: Subscription;
  private analyses: PersistentStack<Item>; // TODO some immutable state container describing entire session
  private nRecordings: number; // TODO user control for naming a recording
  private countingId: number; // TODO improve uniquely identifying items
  private rootAudioItem: RootAudioItem;
  private onSeek: OnSeekHandler;

  constructor(private audioService: AudioPlayerService,
              private featureService: FeatureExtractionService,
              private iconRegistry: MdIconRegistry,
              private sanitizer: DomSanitizer) {
    this.analyses = new PersistentStack<AnalysisItem>();
    this.canExtract = false;
    this.nRecordings = 0;
    this.countingId = 0;
    this.onSeek = (time) => this.audioService.seekTo(time);

    iconRegistry.addSvgIcon(
      'duck',
      sanitizer.bypassSecurityTrustResourceUrl('assets/duck.svg')
    );

    this.onAudioDataSubscription = this.audioService.audioLoaded$.subscribe(
      resource => {
        const wasError = (resource as AudioResourceError).message != null;
        if (wasError) {
          this.analyses.shift();
          this.canExtract = false;
        } else {
          this.audioBuffer = (resource as AudioResource).samples;
          this.rootAudioItem.audioData = this.audioBuffer;
          if (this.audioBuffer) {
            this.canExtract = true;
            const currentRootIndex = this.analyses.findIndex(val => {
              return isRootAudioItem(val) && val.uri === this.rootAudioItem.uri;
            });
            if (currentRootIndex !== -1) {
              this.analyses.set(
                currentRootIndex,
                Object.assign(
                  {},
                  this.analyses.get(currentRootIndex),
                  {audioData: this.audioBuffer}
                )
              );
            }
          }
        }
      }
    );
    this.onProgressUpdated = this.featureService.progressUpdated$.subscribe(
      progress => {
        const index = this.analyses.findIndex(val => val.id === progress.id);
        if (index === -1) {
          return;
        }

        this.analyses.set(
          index,
          Object.assign(
            {},
            this.analyses.get(index),
            {progress: progress.value}
          )
        );
      }
    );
  }

  onFileOpened(file: File | Blob) {
    this.canExtract = false;
    const url = this.audioService.loadAudio(file);
    // TODO is it safe to assume it is a recording?
    const title = (file instanceof File) ?
      (file as File).name : `Recording ${this.nRecordings++}`;

    if (this.analyses.filter(item => item.title === title).length > 0) {
      // TODO this reveals how brittle the current name / uri based id is
      // need something more robust, and also need to notify the user
      // in a suitable way in the actual event of a duplicate file
      console.warn('There is already a notebook based on this audio file.');
      return;
    }

    const pending = {
      uri: url,
      hasSharedTimeline: true,
      title: title,
      description: new Date().toLocaleString(),
      id: `${++this.countingId}`
    } as PendingRootAudioItem;
    this.rootAudioItem = pending as RootAudioItem; // TODO this is silly

    // TODO re-ordering of items for display
    // , one alternative is a Angular Pipe / Filter for use in the Template
    this.analyses.unshift(pending);
  }

  extractFeatures(outputInfo: ExtractorOutputInfo): void {
    if (!this.canExtract || !outputInfo) {
      return;
    }

    this.canExtract = false;

    const placeholderCard: PendingAnalysisItem = {
      parent: this.rootAudioItem,
      hasSharedTimeline: true,
      extractorKey: outputInfo.combinedKey,
      title: outputInfo.name,
      description: outputInfo.outputId,
      id: `${++this.countingId}`,
      progress: 0
    };
    this.analyses.unshift(placeholderCard);

    this.featureService.extract(`${this.countingId}`, {
      audioData: [...Array(this.audioBuffer.numberOfChannels).keys()]
        .map(i => this.audioBuffer.getChannelData(i)),
      audioFormat: {
        sampleRate: this.audioBuffer.sampleRate,
        channelCount: this.audioBuffer.numberOfChannels,
        length: this.audioBuffer.length
      },
      key: outputInfo.extractorKey,
      outputId: outputInfo.outputId
    }).then(() => {
      this.canExtract = true;
    }).catch(err => {
      this.canExtract = true;
      this.analyses.shift();
      console.error(`Error whilst extracting: ${err}`);
    });
  }

  ngOnDestroy(): void {
    this.onAudioDataSubscription.unsubscribe();
    this.onProgressUpdated.unsubscribe();
  }
}