using System.Linq;
using ClaudeDo.Data;
using ClaudeDo.Data.Models;
using ClaudeDo.Ui.ViewModels.Modals;
using Microsoft.EntityFrameworkCore;
using Xunit;
using TaskStatus = ClaudeDo.Data.Models.TaskStatus;

namespace ClaudeDo.Ui.Tests.ViewModels;

public class MergeHelperSelectionModalViewModelTests : IDisposable
{
    private readonly string _dbPath;

    public MergeHelperSelectionModalViewModelTests()
    {
        _dbPath = Path.Combine(Path.GetTempPath(), $"claudedo_mh_test_{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 MergeHelperSelectionModalViewModel BuildVm()
        => new(new TestDbFactory(NewContext));

    private async Task SeedAllStatusesAsync()
    {
        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 });
        var order = 0;
        void Add(string id, string listId, TaskStatus status) =>
            db.Tasks.Add(new TaskEntity
            {
                Id = id, ListId = listId, Title = $"task {id}",
                Status = status, CreatedAt = DateTime.UtcNow, SortOrder = order++,
            });

        Add("t-idle", "L1", TaskStatus.Idle);
        Add("t-queued", "L1", TaskStatus.Queued);
        Add("t-running", "L1", TaskStatus.Running);
        Add("t-review", "L1", TaskStatus.WaitingForReview);
        Add("t-children", "L1", TaskStatus.WaitingForChildren);
        Add("t-failed", "L1", TaskStatus.Failed);
        Add("t-done", "L1", TaskStatus.Done);
        Add("t-cancelled", "L1", TaskStatus.Cancelled);
        Add("t-other-list", "L2", TaskStatus.Idle);
        await db.SaveChangesAsync();
    }

    [Fact]
    public async Task Load_ExcludesTerminalStatuses_AndTicksActionableByDefault()
    {
        await SeedAllStatusesAsync();
        var vm = BuildVm();
        vm.Configure("L1", "Work");
        await vm.LoadAsync();

        Assert.DoesNotContain(vm.Tasks, t => t.Id is "t-done" or "t-cancelled");
        Assert.DoesNotContain(vm.Tasks, t => t.Id == "t-other-list");
        Assert.Equal(6, vm.Tasks.Count);

        Assert.True(vm.Tasks.Single(t => t.Id == "t-idle").IsSelected);
        Assert.True(vm.Tasks.Single(t => t.Id == "t-queued").IsSelected);
        Assert.True(vm.Tasks.Single(t => t.Id == "t-review").IsSelected);
        Assert.True(vm.Tasks.Single(t => t.Id == "t-failed").IsSelected);
        Assert.False(vm.Tasks.Single(t => t.Id == "t-running").IsSelected);
        Assert.False(vm.Tasks.Single(t => t.Id == "t-children").IsSelected);
    }

    [Fact]
    public async Task Load_PerListScope_FiltersToThatList()
    {
        await SeedAllStatusesAsync();
        var vm = BuildVm();
        vm.Configure("L2", "Home");
        await vm.LoadAsync();

        Assert.Single(vm.Tasks);
        Assert.Equal("t-other-list", vm.Tasks[0].Id);
        Assert.Contains("Home", vm.ScopeLabel);
    }

    [Fact]
    public async Task CanConfirm_FollowsRowSelection()
    {
        await SeedAllStatusesAsync();
        var vm = BuildVm();
        vm.Configure("L1", "Work");
        await vm.LoadAsync();

        Assert.True(vm.CanConfirm);

        vm.SelectNoneCommand.Execute(null);
        Assert.False(vm.CanConfirm);
        Assert.All(vm.Tasks, t => Assert.False(t.IsSelected));

        vm.Tasks[0].IsSelected = true;      // single row re-enables via PropertyChanged hook
        Assert.True(vm.CanConfirm);

        vm.SelectAllCommand.Execute(null);
        Assert.All(vm.Tasks, t => Assert.True(t.IsSelected));
    }

    [Fact]
    public async Task Confirm_ReturnsSelectedIds_InRowOrder()
    {
        await SeedAllStatusesAsync();
        var vm = BuildVm();
        vm.Configure("L1", "Work");
        await vm.LoadAsync();

        vm.SelectNoneCommand.Execute(null);
        vm.Tasks.Single(t => t.Id == "t-review").IsSelected = true;
        vm.Tasks.Single(t => t.Id == "t-idle").IsSelected = true;

        var closed = false;
        vm.CloseAction = () => closed = true;
        vm.ConfirmCommand.Execute(null);

        var result = await vm.Result.Task;
        Assert.NotNull(result);
        // Row order (SortOrder): t-idle was seeded before t-review.
        Assert.Equal(new[] { "t-idle", "t-review" }, result);
        Assert.True(closed);
    }

    [Fact]
    public async Task Cancel_ReturnsNull()
    {
        await SeedAllStatusesAsync();
        var vm = BuildVm();
        vm.Configure("L1", "Work");
        await vm.LoadAsync();

        var closed = false;
        vm.CloseAction = () => closed = true;
        vm.CancelCommand.Execute(null);

        Assert.Null(await vm.Result.Task);
        Assert.True(closed);
    }

    [Fact]
    public async Task Load_NoCandidates_HasTasksFalse_CannotConfirm()
    {
        await using (var db = NewContext())
        {
            db.Lists.Add(new ListEntity { Id = "L1", Name = "Work", CreatedAt = DateTime.UtcNow });
            db.Tasks.Add(new TaskEntity { Id = "t-done", ListId = "L1", Title = "done", Status = TaskStatus.Done, CreatedAt = DateTime.UtcNow });
            await db.SaveChangesAsync();
        }

        var vm = BuildVm();
        vm.Configure("L1", "Work");
        await vm.LoadAsync();

        Assert.False(vm.HasTasks);
        Assert.False(vm.CanConfirm);
    }
}