using ClaudeDo.Data;
using ClaudeDo.Data.Git;
using ClaudeDo.Data.Models;
using ClaudeDo.Data.Repositories;
using ClaudeDo.Worker.Config;
using ClaudeDo.Worker.External;
using ClaudeDo.Worker.Hub;
using ClaudeDo.Worker.Queue;
using ClaudeDo.Worker.Runner;
using ClaudeDo.Worker.Tests.Infrastructure;
using ClaudeDo.Worker.Usage;
using Microsoft.Extensions.Logging.Abstractions;
using TaskStatus = ClaudeDo.Data.Models.TaskStatus;

namespace ClaudeDo.Worker.Tests.External;

public sealed class QueueStateMcpToolsTests : IDisposable
{
    private readonly DbFixture _db = new();
    private readonly ClaudeDoDbContext _ctx;
    private readonly TaskRepository _taskRepo;
    private readonly ListRepository _listRepo;
    private readonly WorkerConfig _cfg;
    private readonly string _tempDir;

    public QueueStateMcpToolsTests()
    {
        _ctx = _db.CreateContext();
        _taskRepo = new TaskRepository(_ctx);
        _listRepo = new ListRepository(_ctx);
        _tempDir = Path.Combine(Path.GetTempPath(), $"claudedo_test_{Guid.NewGuid():N}");
        Directory.CreateDirectory(_tempDir);
        _cfg = new WorkerConfig
        {
            SandboxRoot = Path.Combine(_tempDir, "sandbox"),
            LogRoot = Path.Combine(_tempDir, "logs"),
            QueueBackstopIntervalMs = 50,
        };
    }

    public void Dispose()
    {
        _ctx.Dispose();
        _db.Dispose();
        try { Directory.Delete(_tempDir, true); } catch { }
    }

    private (QueueService queue, QueueStateMcpTools sut) CreateSut(
        Func<string, string, IReadOnlyList<string>, Func<string, Task>, CancellationToken, Task<RunResult>>? handler = null,
        UsageState? usageState = null)
    {
        var dbFactory = _db.CreateFactory();
        var fake = new FakeClaudeProcess(handler);
        var broadcaster = new HubBroadcaster(new CapturingHubContext());
        var wtManager = new WorktreeManager(new GitService(), dbFactory, _cfg, NullLogger<WorktreeManager>.Instance);
        var built = TaskStateServiceBuilder.Build(dbFactory);
        var runner = new TaskRunner(fake, dbFactory, broadcaster, wtManager, new ClaudeArgsBuilder(), _cfg,
            NullLogger<TaskRunner>.Instance, built.State, new TaskRunTokenRegistry(), new AttachmentStore(),
            new FakeSessionSkillSeeder(), new FakeTranscriptUsageReader());
        var picker = new QueuePicker(dbFactory);
        var overrideSlot = new OverrideSlotService(dbFactory, runner, NullLogger<OverrideSlotService>.Instance, built.RunCancels);
        var queue = new QueueService(dbFactory, runner, _cfg, NullLogger<QueueService>.Instance, new QueueWaker(), picker,
            overrideSlot, built.State, built.RunCancels, new FakeUsageGate(), usageState ?? new UsageState(), broadcaster);
        return (queue, new QueueStateMcpTools(queue, dbFactory));
    }

    private async Task<string> SeedListAsync()
    {
        var listId = Guid.NewGuid().ToString();
        await _listRepo.AddAsync(new ListEntity { Id = listId, Name = "Test", CreatedAt = DateTime.UtcNow });
        return listId;
    }

    private async Task<TaskEntity> SeedTaskAsync(
        string listId, TaskStatus status, int sortOrder = 0, DateTime? createdAt = null,
        bool isManual = false, string? blockedByTaskId = null, DateTime? scheduledFor = null)
    {
        var task = new TaskEntity
        {
            Id = Guid.NewGuid().ToString(),
            ListId = listId,
            Title = "Test task",
            Status = status,
            SortOrder = sortOrder,
            CreatedAt = createdAt ?? DateTime.UtcNow,
            IsManual = isManual,
            BlockedByTaskId = blockedByTaskId,
            ScheduledFor = scheduledFor,
        };
        // Bypass TaskRepository.AddAsync, which overwrites SortOrder with max(listId)+1 --
        // these tests need to control SortOrder directly to exercise queue pick order.
        _ctx.Tasks.Add(task);
        await _ctx.SaveChangesAsync();
        return task;
    }

    private async Task SetMaxParallelAsync(int maxParallel, int softPct = 0, int hardPct = 0)
    {
        using var ctx = _db.CreateContext();
        var repo = new AppSettingsRepository(ctx);
        var settings = await repo.GetAsync();
        settings.MaxParallelExecutions = maxParallel;
        settings.UsageThrottleSoftPct = softPct;
        settings.UsageThrottleHardPct = hardPct;
        await repo.UpdateAsync(settings);
    }

    [Fact]
    public async Task GetQueueState_NoThrottle_EffectiveEqualsConfigured()
    {
        await SetMaxParallelAsync(maxParallel: 3);
        var (_, sut) = CreateSut();

        var result = await sut.GetQueueState(CancellationToken.None);

        Assert.Equal(3, result.ConfiguredSlots);
        Assert.Equal(3, result.EffectiveSlots);
    }

    [Fact]
    public async Task GetQueueState_UsageThrottleActive_EffectiveBelowConfigured()
    {
        await SetMaxParallelAsync(maxParallel: 3, softPct: 50, hardPct: 65);

        var usageState = new UsageState();
        usageState.ReportSuccess(new UsageSnapshot(
            new UsageBucket(60, null), new UsageBucket(0, null), Array.Empty<UsageLimitRow>(), DateTime.UtcNow));

        var (_, sut) = CreateSut(usageState: usageState);

        var result = await sut.GetQueueState(CancellationToken.None);

        Assert.Equal(3, result.ConfiguredSlots);
        Assert.Equal(2, result.EffectiveSlots);
    }

    [Fact]
    public async Task GetQueueState_ActiveSlots_ReflectsOverrideSlot()
    {
        var listId = await SeedListAsync();
        var tcs = new TaskCompletionSource<RunResult>();
        var (queue, sut) = CreateSut((_, _, _, _, _) => tcs.Task);

        var task = await SeedTaskAsync(listId, TaskStatus.Queued);
        await queue.RunNow(task.Id);

        var result = await sut.GetQueueState(CancellationToken.None);

        var slot = Assert.Single(result.ActiveSlots);
        Assert.Equal("override", slot.Slot);
        Assert.Equal(task.Id, slot.TaskId);

        tcs.SetResult(new RunResult { ExitCode = 0, ResultMarkdown = "ok" });
    }

    [Fact]
    public async Task GetQueueState_WaitingTaskIds_OrderedBySortOrderThenCreatedAt_AndFiltersIneligible()
    {
        var listId = await SeedListAsync();
        var (_, sut) = CreateSut();

        var second = await SeedTaskAsync(listId, TaskStatus.Queued, sortOrder: 1, createdAt: DateTime.UtcNow);
        var first = await SeedTaskAsync(listId, TaskStatus.Queued, sortOrder: 0, createdAt: DateTime.UtcNow.AddMinutes(1));
        await SeedTaskAsync(listId, TaskStatus.Queued, sortOrder: 2, isManual: true);
        await SeedTaskAsync(listId, TaskStatus.Queued, sortOrder: 3, blockedByTaskId: first.Id);
        await SeedTaskAsync(listId, TaskStatus.Queued, sortOrder: 4, scheduledFor: DateTime.UtcNow.AddHours(1));
        await SeedTaskAsync(listId, TaskStatus.Running, sortOrder: -1);

        var result = await sut.GetQueueState(CancellationToken.None);

        Assert.Equal(new[] { first.Id, second.Id }, result.WaitingTaskIds);
    }
}