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;

// Switching lists must drop the previous list's selection; reloading the SAME list (worker
// refresh / reconnect) must keep it, so a live update never yanks the detail pane away.
public class TasksIslandListSwitchSelectionTests : IDisposable
{
    private readonly string _dbPath;

    public TasksIslandListSwitchSelectionTests()
    {
        _dbPath = Path.Combine(Path.GetTempPath(), $"claudedo_ui_listswitch_{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 async Task SeedTwoListsAsync()
    {
        await using var db = NewContext();
        db.Lists.Add(new ListEntity { Id = "L1", Name = "Work", CreatedAt = DateTime.UtcNow });
        db.Lists.Add(new ListEntity { Id = "L2", Name = "Home", CreatedAt = DateTime.UtcNow });
        db.Tasks.Add(new TaskEntity
        {
            Id = "T1", ListId = "L1", Title = "Task one",
            Status = TaskStatus.Idle, CreatedAt = DateTime.UtcNow, SortOrder = 0,
        });
        db.Tasks.Add(new TaskEntity
        {
            Id = "T2", ListId = "L2", Title = "Task two",
            Status = TaskStatus.Idle, CreatedAt = DateTime.UtcNow, SortOrder = 0,
        });
        await db.SaveChangesAsync();
    }

    private static ListNavItemViewModel Nav(string listId, string name) =>
        new() { Id = $"user:{listId}", Name = name, Kind = ListKind.User };

    [Fact]
    public async Task LoadForList_OtherList_ClearsSelectedTask_AndRaisesSelectionChanged()
    {
        await SeedTwoListsAsync();
        var vm = new TasksIslandViewModel(new TestDbFactory(NewContext), worker: null);

        vm.LoadForList(Nav("L1", "Work"));
        Assert.True(await vm.SelectByIdAsync("T1"));

        var selectionChanges = 0;
        vm.SelectionChanged += (_, _) => selectionChanges++;

        vm.LoadForList(Nav("L2", "Home"));
        if (vm.LoadTask is { } load) await load;

        Assert.Null(vm.SelectedTask);
        Assert.Equal(1, selectionChanges);
    }

    [Fact]
    public async Task LoadForList_NullList_ClearsSelectedTask()
    {
        await SeedTwoListsAsync();
        var vm = new TasksIslandViewModel(new TestDbFactory(NewContext), worker: null);

        vm.LoadForList(Nav("L1", "Work"));
        Assert.True(await vm.SelectByIdAsync("T1"));

        vm.LoadForList(null);

        Assert.Null(vm.SelectedTask);
    }

    [Fact]
    public async Task LoadForList_SameList_KeepsSelectedTask()
    {
        await SeedTwoListsAsync();
        var vm = new TasksIslandViewModel(new TestDbFactory(NewContext), worker: null);

        vm.LoadForList(Nav("L1", "Work"));
        Assert.True(await vm.SelectByIdAsync("T1"));

        vm.LoadForList(Nav("L1", "Work"));
        if (vm.LoadTask is { } load) await load;

        Assert.Equal("T1", vm.SelectedTask?.Id);
    }
}