#pragma once
#include <algorithm>
#include <cstdint>

/* Резерв готового PCM desktop: bufferMs = 20..80, кратно 20 (проверяет VoiceAudioIo::start).
 * Размер callback и настроенный запас задают нижнюю границу; недостача добавляет
 * один блок, 10 секунд стабильного вывода убирают один. Частично сыгранный блок — сверх резерва.
 * Только RX worker; время монотонное. Четыре PCM-слота доступны в AudioEventQueue<Playback, 12>. */
class VoicePlaybackBuffer {
public:
    explicit VoicePlaybackBuffer(unsigned bufferMs = 20) : minimumBlocks(bufferMs / 20) { reset(); }
    unsigned blocks = 1;
    unsigned callbackFrames = 960;
    void reset() { blocks = minimumBlocks; callbackFrames = 960; stableSince = 0; lastGrowth = 0; lastSample = 0; probeUs = 10000000; }
    void sample(int64_t nowUs, unsigned frames, bool missing) {
        callbackFrames = frames;
        unsigned minimum = std::max(minimumBlocks, std::clamp((frames + 959) / 960, 1u, 4u));
        if (!stableSince || nowUs - lastSample > 1000000) stableSince = nowUs;
        lastSample = nowUs;
        if (minimum > blocks) { blocks = minimum; stableSince = nowUs; }
        if (missing) {
            stableSince = nowUs;
            if (!lastGrowth || nowUs - lastGrowth >= 500000) {
                blocks = std::min(blocks + 1, 4u); lastGrowth = nowUs;
                probeUs = std::min(probeUs * 2, int64_t(300000000));
            }
        } else if (blocks > minimum && nowUs - stableSince >= probeUs) {
            --blocks; stableSince = nowUs;
        }
    }
private:
    unsigned minimumBlocks;
    int64_t stableSince = 0, lastGrowth = 0, lastSample = 0, probeUs = 10000000;
};