#include "../Sources/Core/player.h"
#include <algorithm>
#include <array>
#include <chrono>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <memory>
#include <string>
#include <thread>
#include <vector>

namespace {
std::array<float, 48000 * 8 * 2> capture{};
size_t capturedFrames = 0;
void require(bool condition, const char *message) {
    if (!condition) { std::fprintf(stderr, "FAIL audio: %s\n", message); std::exit(1); }
}
void play(const std::string &path, float volume = 1, bool changeWhilePlaying = false) {
    capturedFrames = 0;
    std::unique_ptr<Player, decltype(&player_destroy)> player(player_create(), player_destroy);
    require(bool(player), "create fixture player");
    require(player_set_volume(player.get(), volume), "set fixture volume");
    for (float invalid : {NAN, INFINITY, -INFINITY, -.01f, 1.01f}) {
        require(!player_set_volume(player.get(), invalid), "invalid volume rejected");
        require(player_get_volume(player.get()) == volume, "invalid volume leaves target unchanged");
    }
    require(player_open(player.get(), path.c_str()), "open fixture");
    bool started = false, ended = false, sought = false, changed = false;
    uint64_t seekRevision = 0;
    auto deadline = std::chrono::steady_clock::now() + std::chrono::seconds(12);
    while (std::chrono::steady_clock::now() < deadline) {
        auto state = player_get_state(player.get());
        if (state.status == PLAYER_ERROR) {
            std::fprintf(stderr, "%s\n", state.error);
            require(false, "playback error");
        }
        if (state.status == PLAYER_PAUSED && !started) {
            require(player_get_volume(player.get()) == volume, "volume survives open and seek");
            if (volume != 1 && !sought) {
                seekRevision = state.revision;
                require(player_seek(player.get(), 0), "seek with gain configured");
                sought = true;
                continue;
            }
            if (sought && state.revision == seekRevision) {
                std::this_thread::sleep_for(std::chrono::milliseconds(2));
                continue;
            }
            require(player_play(player.get()), "play fixture");
            started = true;
        }
        if (changeWhilePlaying && !changed && state.status == PLAYER_PLAYING && state.position > .3) {
            require(player_set_volume(player.get(), .25f), "change volume during playback");
            changed = true;
        }
        if (state.status == PLAYER_ENDED) {
            require(state.position >= state.duration - .01, "gain does not shorten the media timeline");
            ended = true;
            break;
        }
        std::this_thread::sleep_for(std::chrono::milliseconds(2));
    }
    require(ended, "playback completes");
    require(!changeWhilePlaying || changed, "live volume change was exercised");
    const float finalVolume = changeWhilePlaying ? .25f : volume;
    require(player_get_volume(player.get()) == finalVolume, "volume survives playback");
    require(player_close(player.get()), "close fixture");
    while (std::chrono::steady_clock::now() < deadline && player_get_state(player.get()).status != PLAYER_EMPTY)
        std::this_thread::sleep_for(std::chrono::milliseconds(2));
    require(player_get_state(player.get()).status == PLAYER_EMPTY, "close completes");
    require(player_get_volume(player.get()) == finalVolume, "volume survives close");
    player.reset(); // Stop/join before inspecting callback-owned capture storage.
}
size_t firstActive(const float *samples, size_t frames, float threshold = .002f) {
    size_t first = 0;
    while (first < frames && std::abs(samples[first * 2]) < threshold) ++first;
    require(first < frames, "tone is present");
    return first;
}
void playStepped(const std::string &path, const std::vector<float> &reference) {
    capturedFrames = 0;
    std::unique_ptr<Player, decltype(&player_destroy)> player(player_create(), player_destroy);
    require(bool(player), "create stepped audio player");
    auto wait = [&](auto ready) {
        const auto deadline = std::chrono::steady_clock::now() + std::chrono::seconds(12);
        while (std::chrono::steady_clock::now() < deadline) {
            auto state = player_get_state(player.get());
            require(state.status != PLAYER_ERROR, state.error);
            if (ready(state)) return state;
            std::this_thread::sleep_for(std::chrono::milliseconds(2));
        }
        require(false, "stepped audio operation completes");
        return PlayerState{};
    };
    require(player_open(player.get(), path.c_str()), "open video with PCM audio");
    wait([](auto s) { return s.status == PLAYER_PAUSED; });
    require(player_step_frame(player.get(), -1), "establish first frame");
    wait([](auto s) { return !s.seek_pending; });
    for (int i = 0; i < 32; ++i) require(player_step_frame(player.get(), 1), "queue forward audio frame steps");
    for (int i = 0; i < 19; ++i) require(player_step_frame(player.get(), -1), "queue backward audio frame steps");
    auto selected = wait([](auto s) { return !s.seek_pending; });
    require(std::abs(selected.position - 13.0 / 24) < .0001, "resume starts at selected video frame");
    require(capturedFrames == 0, "frame stepping never starts audio output");
    require(player_play(player.get()), "resume audio after repeated steps");
    auto ended = wait([](auto s) { return s.status == PLAYER_ENDED; });
    require(std::abs(ended.position - 2) < .0001, "stepped audio reaches original media end");
    player.reset(); // Stop/join before inspecting callback-owned storage.
    constexpr size_t sourceStart = 26000; // 13 / 24 seconds at 48 kHz.
    const size_t remaining = reference.size() / 2 - sourceStart;
    const size_t offset = firstActive(capture.data(), capturedFrames);
    require(capturedFrames >= offset + remaining, "all remaining PCM reaches the callback");
    float maximumError = 0;
    for (size_t i = 0; i < remaining * 2; ++i)
        maximumError = std::max(maximumError,
            std::abs(capture[offset * 2 + i] - reference[sourceStart * 2 + i]));
    std::printf("stepped resume: max remaining PCM error %.8f\n", maximumError);
    require(maximumError < .00003f, "resume audio matches selected-frame suffix, without stale or dropped samples");
}
}

// Linked only into the check build. No allocation, locks, or file I/O in callback.
void player_check_audio(const float *samples, size_t frames) {
    size_t count = std::min(frames, capture.size() / 2 - capturedFrames);
    std::memcpy(capture.data() + capturedFrames * 2, samples, count * 2 * sizeof(float));
    capturedFrames += count;
}

int main(int argc, char **argv) {
    require(argc == 2, "fixture directory required");
    require(!player_set_volume(nullptr, .5f) && player_get_volume(nullptr) == 0, "null volume handle");
    std::string directory = argv[1];
    for (const char *name : {"tone441.wav", "tone480.wav", "tone441.mka", "tone-aac.m4a", "tone-jitter.ts"}) {
        std::string path = directory + "/" + name;
        std::ifstream input(path + ".f32", std::ios::binary | std::ios::ate);
        require(bool(input), "PCM reference exists");
        auto bytes = input.tellg();
        require(bytes > 0 && bytes % (2 * sizeof(float)) == 0, "stereo reference format");
        std::vector<float> reference(static_cast<size_t>(bytes) / sizeof(float));
        input.seekg(0);
        require(bool(input.read(reinterpret_cast<char *>(reference.data()), bytes)), "read PCM reference");
        play(path);
        size_t frames = reference.size() / 2;
        size_t start = firstActive(capture.data(), capturedFrames);
        size_t referenceStart = firstActive(reference.data(), frames);
        require(start >= referenceStart, "capture alignment");
        size_t offset = start - referenceStart;
        require(capturedFrames >= offset + frames, "all output samples reach callback");
        float maximumError = 0;
        for (size_t i = 0; i < reference.size(); ++i)
            maximumError = std::max(maximumError, std::abs(capture[offset * 2 + i] - reference[i]));
        std::printf("%s: max sample error %.8f\n", name, maximumError);
        require(maximumError < .00003f, "continuous callback PCM matches reference (no inserted/dropped samples)");
        if (std::string(name) == "tone480.wav") {
            playStepped(directory + "/tone-step.mov", reference);
            play(path, .25f);
            size_t quietStart = firstActive(capture.data(), capturedFrames, .002f * .25f);
            require(quietStart >= referenceStart, "fractional-volume alignment");
            size_t quietOffset = quietStart - referenceStart;
            require(capturedFrames >= quietOffset + frames, "fractional volume consumes all media");
            float gainError = 0;
            for (size_t sample = 0; sample < reference.size(); ++sample)
                gainError = std::max(gainError, std::abs(capture[quietOffset * 2 + sample] - reference[sample] * .25f));
            require(gainError < .00003f, "volume set while stopped applies from the first sample");
            play(path, 0);
            require(capturedFrames >= frames, "mute consumes the entire media timeline");
            for (size_t sample = 0; sample < capturedFrames * 2; ++sample)
                require(capture[sample] == 0, "muted startup never leaks audible samples");
            std::printf("volume: max quarter-gain error %.8f; mute silent from startup\n", gainError);

            play(path, 1, true);
            size_t liveOffset = firstActive(capture.data(), capturedFrames) - referenceStart;
            require(capturedFrames >= liveOffset + frames, "live volume change preserves all media samples");
            size_t firstChange = frames, settled = frames, previousFrame = 0;
            float previousGain = 1;
            for (size_t frame = 1; frame < frames; ++frame) {
                float expected = reference[frame * 2];
                if (std::abs(expected) < .003f) continue; // Gain is undefined at zero crossings.
                float gain = capture[(liveOffset + frame) * 2] / expected;
                require(gain >= .2499f && gain <= 1.0001f, "live gain never overshoots");
                require(std::abs(gain - previousGain) / (frame - previousFrame) < .01f,
                        "live gain changes smoothly rather than popping");
                if (firstChange == frames && gain < .9999f) firstChange = frame;
                if (firstChange != frames && settled == frames && std::abs(gain - .25f) < .0001f)
                    settled = frame;
                previousGain = gain;
                previousFrame = frame;
            }
            require(firstChange > 12000 && settled < frames && settled - firstChange <= 256,
                    "live gain reaches its target within approximately five milliseconds");
            for (size_t sample = (settled + 1) * 2; sample < reference.size(); ++sample)
                require(std::abs(capture[liveOffset * 2 + sample] - reference[sample] * .25f) < .00003f,
                        "live gain settles without corrupting subsequent PCM");
        }
    }
    // Continuity must not erase a real 250 ms PTS gap in the source.
    play(directory + "/tone-gap.mka");
    size_t offset = firstActive(capture.data(), capturedFrames) - 1;
    require(capturedFrames > offset + 48000 * 2, "gapped media is presented");
    for (size_t i = 51840; i < 57600; ++i)
        require(std::abs(capture[(offset + i) * 2]) < 1e-6f, "real timestamp gap remains silent");
    double energy = 0;
    for (size_t i = 62000; i < 66800; ++i) {
        double value = capture[(offset + i) * 2];
        energy += value * value;
    }
    require(energy / 4800 > .001, "audible tone resumes after real gap");
    std::puts("PASS callback PCM continuity, 5 ms volume ramp, fractional gain, mute, and unchanged timeline");
}