import { AudioDocument } from "@suaveplan/audio-core";

export function buildSineDoc(
    freq: number,
    sampleRate: number,
    durationSamples: number,
    channels = 1
): AudioDocument {
    const data: Float32Array[] = [];
    for (let c = 0; c < channels; c++) {
        const arr = new Float32Array(durationSamples);
        for (let i = 0; i < durationSamples; i++) {
            arr[i] = Math.sin((2 * Math.PI * freq * i) / sampleRate);
        }
        data.push(arr);
    }
    const doc = new AudioDocument({
        sampleRate,
        channels,
        sourceLength: 0,
    });
    doc.push(data);
    return doc;
}

export function buildSilentDoc(
    sampleRate: number,
    durationSamples: number,
    channels = 1
): AudioDocument {
    const data: Float32Array[] = [];
    for (let c = 0; c < channels; c++) {
        data.push(new Float32Array(durationSamples));
    }
    const doc = new AudioDocument({
        sampleRate,
        channels,
        sourceLength: 0,
    });
    doc.push(data);
    return doc;
}

export function buildChordDoc(
    pitches: number[],
    sampleRate: number,
    durationSamples: number
): AudioDocument {
    const arr = new Float32Array(durationSamples);
    for (let i = 0; i < durationSamples; i++) {
        let s = 0;
        for (const f of pitches)
            s += Math.sin((2 * Math.PI * f * i) / sampleRate);
        arr[i] = s / pitches.length;
    }
    const doc = new AudioDocument({
        sampleRate,
        channels: 1,
        sourceLength: 0,
    });
    doc.push([arr]);
    return doc;
}