export function createAudioAnalyser(stream, fftSize) {
    const AudioContextCtor = window.AudioContext || window.webkitAudioContext;
    const audioContext = new AudioContextCtor();
    const source = audioContext.createMediaStreamSource(stream);
    const analyser = audioContext.createAnalyser();
    analyser.fftSize = fftSize;
    source.connect(analyser);

    return {
        audioContext,
        analyser,
        dataArray: new Uint8Array(analyser.frequencyBinCount)
    };
}

export function getAudioLevel(analyser, dataArray) {
    analyser.getByteTimeDomainData(dataArray);

    let sum = 0;
    for (let i = 0; i < dataArray.length; i++) {
        const amplitude = dataArray[i] - 128;
        sum += amplitude * amplitude;
    }

    const rms = Math.sqrt(sum / dataArray.length);
    return rms / 128;
}

function formatPacketLossRate(packetsLost, packetsReceived) {
    if (packetsReceived <= 0) {
        return '0%';
    }

    return `${((packetsLost / (packetsLost + packetsReceived)) * 100).toFixed(2)}%`;
}

export function buildStatsLogPayload(networkQuality, statsSummary) {
    return {
        networkQuality,
        video: {
            'Packets Lost': statsSummary.video.packetsLost,
            'Packets Received': statsSummary.video.packetsReceived,
            'Packet Loss Rate': formatPacketLossRate(
                statsSummary.video.packetsLost,
                statsSummary.video.packetsReceived
            ),
            'Jitter': `${(statsSummary.video.jitter * 1000).toFixed(2)}ms`,
            'Round Trip Time': `${(statsSummary.video.roundTripTime * 1000).toFixed(2)}ms`,
            'FPS': statsSummary.video.fps.toFixed(1),
            'Bitrate': `${statsSummary.video.bitrate}kbps`
        },
        audio: {
            'Packets Lost': statsSummary.audio.packetsLost,
            'Packets Received': statsSummary.audio.packetsReceived,
            'Packet Loss Rate': formatPacketLossRate(
                statsSummary.audio.packetsLost,
                statsSummary.audio.packetsReceived
            ),
            'Jitter': `${(statsSummary.audio.jitter * 1000).toFixed(2)}ms`
        }
    };
}