const TARGET_NUMBER_OF_CHANNELS = 2;
const TARGET_SAMPLE_RATE = 48000;
function mixAudio(waves, length) {
    if (waves.length === 1 && waves[0].length === length) {
        return waves[0];
    }
    const mixed = new Int16Array(length);
    if (waves.length === 1) {
        mixed.set(waves[0].subarray(0, length));
        return mixed;
    }
    for (let i = 0; i < length; i++) {
        const sum = waves.reduce((acc, wave) => {
            var _a;
            return acc + ((_a = wave[i]) !== null && _a !== void 0 ? _a : 0);
        }, 0);
        // Clamp to Int16 range
        mixed[i] = Math.max(-32768, Math.min(32767, sum));
    }
    return mixed;
}
export const onlyInlineAudio = ({ assets, fps, frame, }) => {
    const inlineAudio = assets.filter((asset) => asset.type === 'inline-audio');
    if (inlineAudio.length === 0) {
        return null;
    }
    const expectedLength = Math.round((TARGET_NUMBER_OF_CHANNELS * TARGET_SAMPLE_RATE) / fps);
    for (const asset of inlineAudio) {
        if (asset.toneFrequency !== 1) {
            throw new Error('Setting the toneFrequency is not supported yet in web rendering.');
        }
    }
    const mixedAudio = mixAudio(inlineAudio.map((asset) => asset.audio), expectedLength);
    return new AudioData({
        data: mixedAudio,
        format: 's16',
        numberOfChannels: TARGET_NUMBER_OF_CHANNELS,
        numberOfFrames: expectedLength / TARGET_NUMBER_OF_CHANNELS,
        sampleRate: TARGET_SAMPLE_RATE,
        timestamp: (frame / fps) * 1000000,
    });
};