dev@349: /**
dev@349:  * Created by lucast on 24/05/2017.
dev@349:  */
dev@349: 
dev@349: import {FeatureList} from 'piper/Feature';
dev@349: import {OutputDescriptor, toSeconds} from 'piper';
dev@349: import {
dev@349:   MatrixFeature,
dev@349:   SimpleResponse,
dev@349:   TracksFeature,
dev@349:   VectorFeature
dev@349: } from 'piper/HigherLevelUtilities';
dev@349: 
dev@349: 
dev@349: export type NoteLikeUnit = 'midi' | 'hz' ;
dev@349: export interface Note {
dev@349:   time: number;
dev@349:   duration: number;
dev@349:   pitch: number;
dev@349:   velocity?: number;
dev@349: }
dev@349: 
dev@349: export function getCanonicalNoteLikeUnit(unit: string): NoteLikeUnit | null {
dev@349:   const canonicalUnits: NoteLikeUnit[] = ['midi', 'hz'];
dev@349:   return canonicalUnits.find(canonicalUnit => {
dev@349:     return unit.toLowerCase().indexOf(canonicalUnit) >= 0;
dev@349:   });
dev@349: }
dev@349: 
dev@349: export function mapFeaturesToNotes(featureData: FeatureList,
dev@349:                                    descriptor: OutputDescriptor): Note[] {
dev@349:   const canonicalUnit = getCanonicalNoteLikeUnit(descriptor.configured.unit);
dev@349:   const isHz = canonicalUnit === 'hz';
dev@349:   return featureData.map(feature => ({
dev@349:     time: toSeconds(feature.timestamp),
dev@349:     duration: toSeconds(feature.duration),
dev@349:     pitch: isHz ?
dev@349:       frequencyToMidiNote(feature.featureValues[0]) : feature.featureValues[0]
dev@349:   }));
dev@349: }
dev@349: 
dev@349: export function frequencyToMidiNote(frequency: number,
dev@349:                                     concertA: number = 440.0): number {
dev@349:   return 69 + 12 * Math.log2(frequency / concertA);
dev@349: }
dev@349: 
dev@349: export function* createColourGenerator(colours) {
dev@349:   let index = 0;
dev@349:   const nColours = colours.length;
dev@349:   while (true) {
dev@349:     yield colours[index = ++index % nColours];
dev@349:   }
dev@349: }
dev@349: 
dev@349: export const defaultColourGenerator = createColourGenerator([
dev@349:   '#0868ac', // "sapphire blue", our waveform / header colour
dev@349:   '#c33c54', // "brick red"
dev@349:   '#17bebb', // "tiffany blue"
dev@349:   '#001021', // "rich black"
dev@349:   '#fa8334', // "mango tango"
dev@349:   '#034748' // "deep jungle green"
dev@349: ]);
dev@349: 
dev@349: // TODO this might belong somewhere else, or perhaps the stuff above ^^ does
dev@349: 
dev@349: export interface Instant {
dev@349:   time: number;
dev@349:   label: string;
dev@349: }
dev@349: 
dev@349: type CollectedShape = 'vector' | 'matrix' | 'tracks';
dev@349: 
dev@349: // TODO regions
dev@349: type ShapeDeducedFromList = 'instants' | 'notes';
dev@349: export type HigherLevelFeatureShape = CollectedShape | ShapeDeducedFromList;
dev@349: 
dev@349: export type ShapedFeatureData = VectorFeature
dev@349:   | MatrixFeature
dev@349:   | TracksFeature
dev@349:   | Note[]
dev@349:   | Instant[];
dev@349: 
dev@349: // These needn't be classes (could just be interfaces), just experimenting
dev@349: export abstract class ShapedFeature<Shape extends HigherLevelFeatureShape,
dev@349:   Data extends ShapedFeatureData> {
dev@349:   shape: Shape;
dev@349:   collected: Data;
dev@349: }
dev@349: 
dev@349: export class Vector extends ShapedFeature<'vector', VectorFeature> {}
dev@349: export class Matrix extends ShapedFeature<'matrix', MatrixFeature> {}
dev@349: export class Tracks extends ShapedFeature<'tracks', TracksFeature> {}
dev@349: export class Notes extends ShapedFeature<'notes', Note[]> {}
dev@349: export class Instants extends ShapedFeature<'instants', Instant[]> {}
dev@349: export type KnownShapedFeature = Vector
dev@349:   | Matrix
dev@349:   | Tracks
dev@349:   | Notes
dev@349:   | Instants;
dev@349: 
dev@349: function hasKnownShapeOtherThanList(shape: string): shape is CollectedShape {
dev@349:   return ['vector', 'matrix', 'tracks'].includes(shape);
dev@349: }
dev@349: 
dev@349: const throwShapeError = () => { throw new Error('No shape could be deduced'); };
dev@349: function deduceHigherLevelFeatureShape(response: SimpleResponse)
dev@349: : HigherLevelFeatureShape {
dev@349:   const collection = response.features;
dev@349:   const descriptor = response.outputDescriptor;
dev@349:   if (hasKnownShapeOtherThanList(collection.shape)) {
dev@349:     return collection.shape;
dev@349:   }
dev@349: 
dev@349: 
dev@349:   // TODO it's a shame that the types in piper don't make this easy for the
dev@349:   // compiler to deduce
dev@349:   if (collection.shape !== 'list' && collection.collected instanceof Array) {
dev@349:     throwShapeError();
dev@349:   }
dev@349: 
dev@349:   const featureData = collection.collected as FeatureList;
dev@349:   const hasDuration = descriptor.configured.hasDuration;
dev@349:   const binCount = descriptor.configured.binCount;
dev@349:   const isMarker = !hasDuration
dev@349:     && binCount === 0
dev@349:     && featureData[0].featureValues == null;
dev@349: 
dev@349:   const isMaybeNote = getCanonicalNoteLikeUnit(descriptor.configured.unit)
dev@349:     && [1, 2].find(nBins => nBins === binCount);
dev@349: 
dev@349:   // TODO any need to be directly inspecting features?
dev@349:   const isRegionLike = hasDuration && featureData[0].timestamp != null;
dev@349: 
dev@349:   const isNote = isMaybeNote && isRegionLike;
dev@349:   if (isMarker) {
dev@349:     return 'instants';
dev@349:   }
dev@349:   if (isNote) {
dev@349:     return 'notes';
dev@349:   }
dev@349:   throwShapeError();
dev@349: }
dev@349: 
dev@349: export function toKnownShape(response: SimpleResponse): KnownShapedFeature {
dev@349:   const deducedShape = deduceHigherLevelFeatureShape(response);
dev@349:   switch (deducedShape) {
dev@349:     case 'vector':
dev@349:       return response.features as Vector;
dev@349:     case 'matrix':
dev@349:       return response.features as Matrix;
dev@349:     case 'notes':
dev@349:       return {
dev@349:         shape: deducedShape,
dev@349:         collected: mapFeaturesToNotes(
dev@349:           response.features.collected as FeatureList,
dev@349:           response.outputDescriptor
dev@349:         )
dev@349:       };
dev@349:     case 'instants':
dev@349:       const featureData = response.features.collected as FeatureList;
dev@349:       return {
dev@349:         shape: deducedShape,
dev@349:         collected: featureData.map(feature => ({
dev@349:           time: toSeconds(feature.timestamp),
dev@349:           label: feature.label
dev@349:         }))
dev@349:       };
dev@349:   }
dev@349:   throwShapeError();
dev@349: }