using ClaudeDo.Data;
using ClaudeDo.Data.Models;
using ClaudeDo.Ui.ViewModels.Islands;
using Microsoft.EntityFrameworkCore;
using TaskStatus = ClaudeDo.Data.Models.TaskStatus;

namespace ClaudeDo.Ui.Tests.ViewModels;

// OnWorkerTaskUpdated falls back to a full LoadForList reload for a planning parent (or any task
// with children) because the delta path can't recompute the child-derived flags on its own. That
// reload used to hand back brand new TaskRowViewModel instances, orphaning SelectedTask (and the
// DetailsIslandViewModel bound to it) on a live status change. See TaskUpdated_FullReload_* below.
public class TasksIslandFullReloadSelectionTests : IDisposable
{
    private readonly string _dbPath;

    public TasksIslandFullReloadSelectionTests()
    {
        _dbPath = Path.Combine(Path.GetTempPath(), $"claudedo_ui_fullreload_{Guid.NewGuid():N}.db");
        using var ctx = NewContext();
        ctx.Database.EnsureCreated();
    }

    public void Dispose()
    {
        try { File.Delete(_dbPath); } catch { }
        try { File.Delete(_dbPath + "-wal"); } catch { }
        try { File.Delete(_dbPath + "-shm"); } catch { }
    }

    private ClaudeDoDbContext NewContext()
    {
        var opts = new DbContextOptionsBuilder<ClaudeDoDbContext>()
            .UseSqlite($"Data Source={_dbPath}")
            .Options;
        return new ClaudeDoDbContext(opts);
    }

    private sealed class TestDbFactory : IDbContextFactory<ClaudeDoDbContext>
    {
        private readonly Func<ClaudeDoDbContext> _create;
        public TestDbFactory(Func<ClaudeDoDbContext> create) => _create = create;
        public ClaudeDoDbContext CreateDbContext() => _create();
    }

    private sealed class FakeWorker : StubWorkerClient
    {
    }

    private async Task SeedPlanningParentWithChildAsync()
    {
        await using var db = NewContext();
        db.Lists.Add(new ListEntity { Id = "L1", Name = "Work", CreatedAt = DateTime.UtcNow });
        db.Tasks.Add(new TaskEntity
        {
            Id = "P1", ListId = "L1", Title = "Parent",
            Status = TaskStatus.WaitingForChildren, PlanningPhase = PlanningPhase.Finalized,
            CreatedAt = DateTime.UtcNow, SortOrder = 0,
        });
        db.Tasks.Add(new TaskEntity
        {
            Id = "C1", ListId = "L1", ParentTaskId = "P1", Title = "Child",
            Status = TaskStatus.Running, CreatedAt = DateTime.UtcNow, SortOrder = 1,
        });
        await db.SaveChangesAsync();
    }

    [Fact]
    public async Task TaskUpdated_FullReload_KeepsSameSelectedInstance()
    {
        await SeedPlanningParentWithChildAsync();

        var worker = new FakeWorker();
        var vm = new TasksIslandViewModel(new TestDbFactory(NewContext), worker);
        vm.LoadForList(new ListNavItemViewModel { Id = "user:L1", Name = "Work", Kind = ListKind.User });
        if (vm.LoadTask is { } lt) await lt;

        Assert.True(await vm.SelectByIdAsync("P1"));
        var selectedBefore = vm.SelectedTask;
        Assert.NotNull(selectedBefore);

        // Child finishes, which flips the parent's status — the broadcast lands for the parent's
        // id and (being a planning parent) takes the full-reload branch of OnWorkerTaskUpdated.
        await using (var db = NewContext())
        {
            (await db.Tasks.FirstAsync(t => t.Id == "C1")).Status = TaskStatus.Done;
            (await db.Tasks.FirstAsync(t => t.Id == "P1")).Status = TaskStatus.WaitingForReview;
            await db.SaveChangesAsync();
        }
        worker.RaiseTaskUpdated("P1");

        var deadline = DateTime.UtcNow.AddSeconds(3);
        while (DateTime.UtcNow < deadline && vm.SelectedTask?.Status != TaskStatus.WaitingForReview)
            await Task.Delay(25);

        // The reload must not have replaced the row: SelectedTask still points at the same
        // instance, it just got mutated in place — so the detail pane stays bound and current.
        Assert.Same(selectedBefore, vm.SelectedTask);
        Assert.Equal(TaskStatus.WaitingForReview, vm.SelectedTask!.Status);
        Assert.Same(vm.SelectedTask, vm.Items.First(r => r.Id == "P1"));
    }
}