using System.Text;
using ClaudeDo.Data;
using ClaudeDo.Data.Models;
using ClaudeDo.Data.Repositories;
using ClaudeDo.Worker.External;
using ClaudeDo.Worker.Hub;
using ClaudeDo.Worker.Tests.Infrastructure;
using TaskStatus = ClaudeDo.Data.Models.TaskStatus;

namespace ClaudeDo.Worker.Tests.External;

public sealed class AttachmentMcpToolsTests : IDisposable
{
    private readonly DbFixture _db = new();
    private readonly ClaudeDoDbContext _ctx;
    private readonly TaskRepository _tasks;
    private readonly ListRepository _lists;
    private readonly TaskAttachmentRepository _attachments;
    private readonly string _storeRoot;
    private readonly AttachmentStore _store;

    public AttachmentMcpToolsTests()
    {
        _ctx = _db.CreateContext();
        _tasks = new TaskRepository(_ctx);
        _lists = new ListRepository(_ctx);
        _attachments = new TaskAttachmentRepository(_ctx);
        _storeRoot = Path.Combine(Path.GetTempPath(), $"att_test_{Guid.NewGuid():N}");
        _store = new AttachmentStore(_storeRoot);
    }

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

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

    private async Task<TaskEntity> SeedTaskAsync(string listId, TaskStatus status = TaskStatus.Idle)
    {
        var task = new TaskEntity
        {
            Id = Guid.NewGuid().ToString(),
            ListId = listId,
            Title = "t",
            Status = status,
            CreatedAt = DateTime.UtcNow,
            CommitType = "chore",
        };
        await _tasks.AddAsync(task);
        return task;
    }

    private AttachmentMcpTools BuildSut()
    {
        var hubCtx = new CapturingHubContext();
        var broadcaster = new HubBroadcaster(hubCtx);
        return new AttachmentMcpTools(_tasks, _attachments, _store, broadcaster);
    }

    [Fact]
    public async Task Add_textContent_writes_file_and_db_row()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId);
        var sut = BuildSut();

        var dto = await sut.AddTaskAttachment(task.Id, "plan.md", textContent: "# Hello", ct: CancellationToken.None);

        // File on disk
        var filePath = Path.Combine(_storeRoot, task.Id, "plan.md");
        Assert.True(File.Exists(filePath));
        Assert.Equal("# Hello", await File.ReadAllTextAsync(filePath));

        // DB row
        await using var vCtx = _db.CreateContext();
        var row = await new TaskAttachmentRepository(vCtx).GetAsync(task.Id, "plan.md");
        Assert.NotNull(row);
        Assert.Equal(Encoding.UTF8.GetByteCount("# Hello"), row!.ByteSize);
        Assert.Equal(dto.ByteSize, row.ByteSize);
        Assert.Equal("plan.md", dto.FileName);
    }

    [Fact]
    public async Task Add_base64Content_writes_file_and_db_row()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId);
        var sut = BuildSut();

        var original = new byte[] { 1, 2, 3, 4, 5 };
        var b64 = Convert.ToBase64String(original);

        var dto = await sut.AddTaskAttachment(task.Id, "data.bin", base64Content: b64, ct: CancellationToken.None);

        var filePath = Path.Combine(_storeRoot, task.Id, "data.bin");
        Assert.True(File.Exists(filePath));
        Assert.Equal(original, await File.ReadAllBytesAsync(filePath));
        Assert.Equal(5, dto.ByteSize);
    }

    [Fact]
    public async Task List_returns_added_items()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId);
        var sut = BuildSut();

        await sut.AddTaskAttachment(task.Id, "a.txt", textContent: "a", ct: CancellationToken.None);
        await sut.AddTaskAttachment(task.Id, "b.txt", textContent: "bb", ct: CancellationToken.None);

        var list = await sut.ListTaskAttachments(task.Id);

        Assert.Equal(2, list.Count);
        Assert.Contains(list, d => d.FileName == "a.txt");
        Assert.Contains(list, d => d.FileName == "b.txt");
    }

    [Fact]
    public async Task Remove_deletes_file_and_row()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId);
        var sut = BuildSut();

        await sut.AddTaskAttachment(task.Id, "remove.txt", textContent: "x", ct: CancellationToken.None);
        var filePath = Path.Combine(_storeRoot, task.Id, "remove.txt");
        Assert.True(File.Exists(filePath));

        await sut.RemoveTaskAttachment(task.Id, "remove.txt");

        Assert.False(File.Exists(filePath));
        await using var vCtx = _db.CreateContext();
        var row = await new TaskAttachmentRepository(vCtx).GetAsync(task.Id, "remove.txt");
        Assert.Null(row);
    }

    [Fact]
    public async Task Add_missing_task_throws()
    {
        var sut = BuildSut();

        await Assert.ThrowsAsync<InvalidOperationException>(
            () => sut.AddTaskAttachment("no-such-id", "f.txt", textContent: "x", ct: CancellationToken.None));
    }

    [Fact]
    public async Task Add_running_task_throws()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId, TaskStatus.Running);
        var sut = BuildSut();

        await Assert.ThrowsAsync<InvalidOperationException>(
            () => sut.AddTaskAttachment(task.Id, "f.txt", textContent: "x", ct: CancellationToken.None));
    }

    [Fact]
    public async Task Add_neither_content_throws()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId);
        var sut = BuildSut();

        await Assert.ThrowsAsync<InvalidOperationException>(
            () => sut.AddTaskAttachment(task.Id, "f.txt", ct: CancellationToken.None));
    }

    [Fact]
    public async Task Add_both_content_throws()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId);
        var sut = BuildSut();

        await Assert.ThrowsAsync<InvalidOperationException>(
            () => sut.AddTaskAttachment(task.Id, "f.txt", textContent: "x", base64Content: "eA==", ct: CancellationToken.None));
    }

    [Fact]
    public async Task Add_invalid_base64_throws()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId);
        var sut = BuildSut();

        await Assert.ThrowsAsync<InvalidOperationException>(
            () => sut.AddTaskAttachment(task.Id, "f.bin", base64Content: "!!!not-base64!!!", ct: CancellationToken.None));
    }

    [Fact]
    public async Task Readd_same_fileName_overwrites_one_row_updated_size()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId);
        var sut = BuildSut();

        await sut.AddTaskAttachment(task.Id, "plan.md", textContent: "short", ct: CancellationToken.None);
        await sut.AddTaskAttachment(task.Id, "plan.md", textContent: "much longer content here", ct: CancellationToken.None);

        // Only one row in DB
        await using var vCtx = _db.CreateContext();
        var rows = await new TaskAttachmentRepository(vCtx).ListByTaskIdAsync(task.Id);
        Assert.Single(rows);

        // Updated size
        var expected = Encoding.UTF8.GetByteCount("much longer content here");
        Assert.Equal(expected, rows[0].ByteSize);
    }

    [Fact]
    public async Task Remove_running_task_throws()
    {
        var listId = await SeedListAsync();
        var task = await SeedTaskAsync(listId, TaskStatus.Running);
        var sut = BuildSut();

        await Assert.ThrowsAsync<InvalidOperationException>(
            () => sut.RemoveTaskAttachment(task.Id, "f.txt"));
    }
}