using System.Text;
using DeepDrftAPI.Services;
using DeepDrftContent;
using DeepDrftContent.Processors;
using DeepDrftContent.Processors.Opus;
using DeepDrftData;
using DeepDrftModels.DTOs;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using Models.Common;
using NetBlocks.Models;
using FileDb = DeepDrftContent.FileDatabase.Services.FileDatabase;

namespace DeepDrftTests;

/// <summary>
/// Confirms the Phase 18.5 acceptance point that <see cref="UnifiedTrackService.ReplaceAudioAsync"/>
/// regenerates the Opus artifact: a replace must schedule a background Opus re-derive for the track, because
/// the stale Opus no longer matches the new source bytes (the same reason it regenerates the waveform datums
/// and re-derives duration). The enqueue was wired in 18.1; this test pins it so a future refactor cannot
/// silently drop it, leaving a track serving Opus that does not match its lossless source.
///
/// The vault + content + waveform collaborators are real (over a temp-dir <see cref="FileDb"/>); the SQL
/// service is a focused fake. The fake is used here rather than the in-memory EF store because the replace
/// path's duration write goes through <c>SetDuration</c> → <c>ExecuteUpdateAsync</c>, which the EF in-memory
/// provider does not support — the fake lets the orchestration run to the post-write enqueue under test.
/// </summary>
[TestFixture]
public class ReplaceAudioOpusRegenTests
{
    private string _testDir = string.Empty;

    [SetUp]
    public void SetUp()
    {
        _testDir = Path.Combine(Path.GetTempPath(), "ReplaceAudioOpusRegenTests", Guid.NewGuid().ToString());
        Directory.CreateDirectory(_testDir);
    }

    [TearDown]
    public void TearDown()
    {
        try { Directory.Delete(_testDir, recursive: true); }
        catch { /* Best-effort cleanup — ignore failures */ }
    }

    // A focused ITrackService fake: only GetById (returns the seeded track) and SetDuration (records the
    // write and reports success) are meaningful — the two members the replace path calls. Everything else
    // throws, documenting that the replace orchestration touches nothing else on the SQL boundary.
    private sealed class FakeTrackService : ITrackService
    {
        private readonly TrackDto _track;
        public double? LastDurationWritten { get; private set; }

        public FakeTrackService(TrackDto track) => _track = track;

        public Task<ResultContainer<TrackDto?>> GetById(long id) =>
            Task.FromResult(ResultContainer<TrackDto?>.CreatePassResult(id == _track.Id ? _track : null));

        public Task<ResultContainer<int>> SetDuration(long id, double durationSeconds, CancellationToken ct = default)
        {
            LastDurationWritten = durationSeconds;
            return Task.FromResult(ResultContainer<int>.CreatePassResult(1));
        }

        // Unused by the replace path — fail loudly if the orchestration ever reaches them.
        public Task<ResultContainer<TrackDto?>> GetByEntryKey(string entryKey) => throw new NotSupportedException();
        public Task<ResultContainer<TrackDto?>> GetRandom(CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<List<TrackDto>>> GetAll() => throw new NotSupportedException();
        public Task<ResultContainer<PagedResult<TrackDto>>> GetPaged(int p, int s, string? c, bool d, TrackFilter? f = null, CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<List<ReleaseDto>>> GetReleases(CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<List<GenreSummaryDto>>> GetDistinctGenres(CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<HomeStatsDto>> GetHomeStats(CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<List<TrackDto>>> GetTracksMissingDuration(CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<int>> UpdateDuration(long id, double d, CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<(ReleaseDto Release, bool WasCreated)>> FindOrCreateRelease(string t, string a, ReleaseDto r, CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<ReleaseDto?>> GetReleaseByTitleAndArtist(string t, string a, CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<TrackDto>> Create(TrackDto t) => throw new NotSupportedException();
        public Task<ResultContainer<TrackDto>> Update(TrackDto t) => throw new NotSupportedException();
        public Task<Result> Delete(long id) => throw new NotSupportedException();
        public Task<Result> DeleteRelease(long id, CancellationToken ct = default) => throw new NotSupportedException();
        public Task<ResultContainer<int>> CountLiveTracksByRelease(long releaseId, CancellationToken ct = default) => throw new NotSupportedException();
    }

    [Test]
    public async Task ReplaceAudio_EnqueuesOpusRegen_ForTheReplacedTrack()
    {
        var fileDatabase = await FileDb.FromAsync(_testDir);
        Assert.That(fileDatabase, Is.Not.Null);

        var content = new TrackContentService(
            fileDatabase!, new AudioProcessorRouter(
                new AudioProcessor(), new Mp3AudioProcessor(), new FlacAudioProcessor()));
        var waveforms = new WaveformProfileService(
            fileDatabase!, new AudioProcessor(), new RmsLoudnessAlgorithm(),
            Options.Create(new WaveformProfileOptions()), NullLogger<WaveformProfileService>.Instance);
        var resolver = new TrackFormatResolver(
            fileDatabase!, content, NullLogger<TrackFormatResolver>.Instance);
        var queue = new NoOpOpusTranscodeQueue();

        // Seed the source WAV in the vault and point a fake SQL row at the same EntryKey.
        var originalPath = Path.Combine(_testDir, Guid.NewGuid().ToString("N") + ".wav");
        await File.WriteAllBytesAsync(originalPath, BuildMinimalPcmWav(2.0));
        var unpersisted = await content.AddTrackAsync(originalPath, "Original", "Artist");
        Assert.That(unpersisted, Is.Not.Null);

        const long trackId = 42;
        var sql = new FakeTrackService(new TrackDto { Id = trackId, EntryKey = unpersisted!.EntryKey, TrackName = "Original" });

        var service = new UnifiedTrackService(
            content, sql, fileDatabase!, waveforms, queue, resolver,
            NullLogger<UnifiedTrackService>.Instance);

        // Replace the audio with a longer take.
        var replacementPath = Path.Combine(_testDir, Guid.NewGuid().ToString("N") + ".wav");
        await File.WriteAllBytesAsync(replacementPath, BuildMinimalPcmWav(6.0));

        var result = await service.ReplaceAudioAsync(trackId, replacementPath, CancellationToken.None);

        Assert.That(result.Success, Is.True, result.Messages.FirstOrDefault()?.Message);
        Assert.Multiple(() =>
        {
            Assert.That(queue.Enqueued, Does.Contain(unpersisted.EntryKey),
                "a replace must schedule an Opus re-derive so the artifact tracks the new source");
            Assert.That(sql.LastDurationWritten, Is.GreaterThan(0),
                "the replace must also write the new duration (the enqueue follows a successful duration write)");
        });
    }

    // Standard-PCM mono 16-bit 44.1 kHz WAV, full-scale square wave. Same layout as the other suites.
    private static byte[] BuildMinimalPcmWav(double durationSeconds)
    {
        const int sampleRate = 44100;
        const ushort channels = 1;
        const ushort bitsPerSample = 16;
        const ushort blockAlign = channels * (bitsPerSample / 8);
        const uint byteRate = sampleRate * blockAlign;

        var frames = (int)(sampleRate * durationSeconds);
        var data = new byte[frames * blockAlign];
        for (var i = 0; i < frames; i++)
        {
            var sample = (i % 2 == 0) ? short.MaxValue : short.MinValue;
            data[i * 2] = (byte)(sample & 0xFF);
            data[i * 2 + 1] = (byte)((sample >> 8) & 0xFF);
        }

        using var ms = new MemoryStream();
        using var w = new BinaryWriter(ms, Encoding.ASCII, leaveOpen: true);

        w.Write(Encoding.ASCII.GetBytes("RIFF"));
        w.Write((uint)(36 + data.Length));
        w.Write(Encoding.ASCII.GetBytes("WAVE"));

        w.Write(Encoding.ASCII.GetBytes("fmt "));
        w.Write(16u);
        w.Write((ushort)1); // PCM
        w.Write(channels);
        w.Write((uint)sampleRate);
        w.Write(byteRate);
        w.Write(blockAlign);
        w.Write(bitsPerSample);

        w.Write(Encoding.ASCII.GetBytes("data"));
        w.Write((uint)data.Length);
        w.Write(data);

        w.Flush();
        return ms.ToArray();
    }
}