using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;
using TeleWave.Application.Broadcast.Bumpers;
using TeleWave.Application.Broadcast.Scheduling;
using TeleWave.Application.Common.Interfaces;
using TeleWave.Application.Streaming;
using TeleWave.Domain.Broadcast;
using TeleWave.Domain.Broadcast.Scheduling;
using TeleWave.Domain.Library;
using TeleWave.Domain.Media;
using TeleWave.Infrastructure.Persistence;
using Xunit;

namespace TeleWave.Integration.Tests;

[Collection("postgres")]
public sealed class ScheduleGeneratorIntegrationTests(PostgresFixture fixture)
{
    private static readonly DateTimeOffset Now = new(2026, 3, 1, 0, 0, 0, TimeSpan.Zero);
    private const int Seg = 2;

    private static MediaAsset ReadyAsset(string name, int seconds)
    {
        var a = MediaAsset.Register(name, ".mkv", MediaSource.Upload);
        a.MarkReady(
            TimeSpan.FromSeconds(seconds),
            Seg,
            seconds / Seg,
            1920,
            1080,
            "h264",
            "aac",
            $"assets/{a.Id}"
        );
        return a;
    }

    private static ScheduleGenerator NewGenerator(
        AppDbContext db,
        IRandomSource random,
        IBumperRenderQueue queue
    )
    {
        var streaming = Options.Create(new StreamingOptions { SegmentSeconds = Seg });
        var resolver = new ScheduleBumperResolver(
            db,
            queue,
            Options.Create(new BumperOptions()),
            streaming
        );
        return new ScheduleGenerator(
            db,
            random,
            resolver,
            Options.Create(new SchedulerOptions { HorizonDays = 1, RetentionHours = 24 }),
            streaming
        );
    }

    private sealed class RecordingQueue : IBumperRenderQueue
    {
        public List<Guid> Enqueued { get; } = [];

        public void Enqueue(Guid assetId) => Enqueued.Add(assetId);

        public ValueTask WaitAsync(CancellationToken cancellationToken) => ValueTask.CompletedTask;
    }

    [SkippableFact]
    public async Task GenerateAsync_MaterializesProgramSchedule()
    {
        Skip.IfNot(fixture.Available, "Docker недоступен");
        var channel = Channel.Create("Prog", $"prog-{Guid.NewGuid():N}", Now);
        var show = Show.Create("Show A", ShowKind.Series);
        var a1 = ReadyAsset("a1.mkv", 1200);
        var a2 = ReadyAsset("a2.mkv", 1200);
        show.AddEpisode(a1.Id);
        show.AddEpisode(a2.Id);
        channel.AddShow(show.Id, 1, BlockMode.Count, 1);

        await using (var seed = fixture.CreateContext())
        {
            seed.Shows.Add(show);
            seed.MediaAssets.AddRange(a1, a2);
            seed.Channels.Add(channel);
            await seed.SaveChangesAsync(CancellationToken.None);
        }

        int added;
        await using (var db = fixture.CreateContext())
        {
            added = await NewGenerator(db, new SequenceRandom(0), new RecordingQueue())
                .GenerateAsync(channel.Id, Now, regenerate: false, CancellationToken.None);
        }

        Assert.True(added > 0);
        await using var verify = fixture.CreateContext();
        var entries = await verify
            .ScheduleEntries.AsNoTracking()
            .Where(e => e.ChannelId == channel.Id)
            .ToListAsync();
        Assert.NotEmpty(entries);
        Assert.Contains(entries, e => e.Kind == ScheduleEntryKind.Program);
        Assert.All(entries, e => Assert.True(e.EndsAtUtc <= Now.AddDays(1).AddSeconds(Seg)));
    }

    [SkippableFact]
    public async Task GenerateAsync_CreatesPendingBumperAssets_ForShowTransitions()
    {
        Skip.IfNot(fixture.Available, "Docker недоступен");
        // Канал с двумя шоу и включёнными заставками — на смене шоу планировщик ставит заставку;
        // её ассет должен создаться в Pending (Generated) и попасть в очередь фонового рендера.
        var channel = Channel.Create("Bump", $"bump-{Guid.NewGuid():N}", Now);
        channel.UpdateSettings(channel.Name, true, AdInsertion.BetweenBlocks, 0, true, null);
        var showA = Show.Create("A", ShowKind.Series);
        var showB = Show.Create("B", ShowKind.Series);
        var a1 = ReadyAsset("a1.mkv", 1200);
        var b1 = ReadyAsset("b1.mkv", 1200);
        showA.AddEpisode(a1.Id);
        showB.AddEpisode(b1.Id);
        channel.AddShow(showA.Id, 1, BlockMode.Count, 1);
        channel.AddShow(showB.Id, 1, BlockMode.Count, 1);

        await using (var seed = fixture.CreateContext())
        {
            seed.Shows.AddRange(showA, showB);
            seed.MediaAssets.AddRange(a1, b1);
            seed.Channels.Add(channel);
            await seed.SaveChangesAsync(CancellationToken.None);
        }

        var queue = new RecordingQueue();
        await using (var db = fixture.CreateContext())
        {
            // Чередуем выбор шоу (0,1,0,1…), чтобы гарантированно были переходы «A→B».
            await NewGenerator(db, new SequenceRandom(0, 1), queue)
                .GenerateAsync(channel.Id, Now, regenerate: false, CancellationToken.None);
        }

        await using var verify = fixture.CreateContext();
        var bumperCache = await verify
            .BumperAssets.AsNoTracking()
            .Where(b => b.ChannelId == channel.Id)
            .ToListAsync();
        Assert.NotEmpty(bumperCache);

        var bumperAssetIds = bumperCache.Select(b => b.MediaAssetId).ToList();
        var bumperAssets = await verify
            .MediaAssets.AsNoTracking()
            .Where(a => bumperAssetIds.Contains(a.Id))
            .ToListAsync();
        Assert.All(
            bumperAssets,
            a =>
            {
                Assert.Equal(MediaSource.Generated, a.Source);
                Assert.Equal(MediaAssetStatus.Pending, a.Status);
            }
        );
        Assert.NotEmpty(queue.Enqueued);
    }

    [SkippableFact]
    public async Task ConcurrentGenerate_SerializedByAdvisoryLock_NoOverlappingEntries()
    {
        Skip.IfNot(fixture.Available, "Docker недоступен");
        var channel = Channel.Create("Race", $"race-{Guid.NewGuid():N}", Now);
        var show = Show.Create("Show", ShowKind.Series);
        var a1 = ReadyAsset("r1.mkv", 1200);
        var a2 = ReadyAsset("r2.mkv", 1200);
        show.AddEpisode(a1.Id);
        show.AddEpisode(a2.Id);
        channel.AddShow(show.Id, 1, BlockMode.Count, 1);

        await using (var seed = fixture.CreateContext())
        {
            seed.Shows.Add(show);
            seed.MediaAssets.AddRange(a1, a2);
            seed.Channels.Add(channel);
            await seed.SaveChangesAsync(CancellationToken.None);
        }

        // Два параллельных прогона на РАЗНЫХ соединениях — advisory-lock должен их сериализовать,
        // иначе оба дописали бы хвост от одной точки продолжения и записи бы перекрылись.
        await using var db1 = fixture.CreateContext();
        await using var db2 = fixture.CreateContext();
        var g1 = NewGenerator(db1, new SequenceRandom(0), new RecordingQueue())
            .GenerateAsync(channel.Id, Now, regenerate: false, CancellationToken.None);
        var g2 = NewGenerator(db2, new SequenceRandom(0), new RecordingQueue())
            .GenerateAsync(channel.Id, Now, regenerate: false, CancellationToken.None);
        await Task.WhenAll(g1, g2);

        await using var verify = fixture.CreateContext();
        var entries = await verify
            .ScheduleEntries.AsNoTracking()
            .Where(e => e.ChannelId == channel.Id)
            .OrderBy(e => e.StartsAtUtc)
            .ToListAsync();

        Assert.NotEmpty(entries);
        for (var i = 1; i < entries.Count; i++)
            Assert.True(
                entries[i].StartsAtUtc >= entries[i - 1].EndsAtUtc,
                $"Записи перекрываются: [{entries[i - 1].StartsAtUtc:o}..{entries[i - 1].EndsAtUtc:o}] и [{entries[i].StartsAtUtc:o}..{entries[i].EndsAtUtc:o}]"
            );
    }
}