using System.ComponentModel;
using ClaudeDo.Data.Models;
using ClaudeDo.Data.Repositories;
using ClaudeDo.Worker.Hub;
using ModelContextProtocol.Server;
using TaskStatus = ClaudeDo.Data.Models.TaskStatus;

namespace ClaudeDo.Worker.Planning;

public sealed record ChildTaskDto(string TaskId, string Title, string? Description, string Status, IReadOnlyList<string> Tags);
public sealed record CreatedChildDto(string TaskId, string Status);

[McpServerToolType]
public sealed class PlanningMcpService
{
    private readonly TaskRepository _tasks;
    private readonly PlanningMcpContextAccessor _contextAccessor;
    private readonly HubBroadcaster _broadcaster;

    public PlanningMcpService(
        TaskRepository tasks,
        PlanningMcpContextAccessor contextAccessor,
        HubBroadcaster broadcaster)
    {
        _tasks = tasks;
        _contextAccessor = contextAccessor;
        _broadcaster = broadcaster;
    }

    private Task BroadcastTaskUpdatedAsync(string taskId, CancellationToken ct)
        => _broadcaster.TaskUpdated(taskId);

    [McpServerTool, Description("Create a new draft child task under the current planning session's parent task.")]
    public async Task<CreatedChildDto> CreateChildTask(
        string title,
        string? description,
        IReadOnlyList<string>? tags,
        string? commitType,
        CancellationToken cancellationToken)
    {
        var ctx = _contextAccessor.Current;
        var child = await _tasks.CreateChildAsync(ctx.ParentTaskId, title, description, tags, commitType, cancellationToken);
        await BroadcastTaskUpdatedAsync(ctx.ParentTaskId, cancellationToken);
        return new CreatedChildDto(child.Id, "Draft");
    }

    [McpServerTool, Description("List all child tasks under the current planning session's parent task.")]
    public async Task<IReadOnlyList<ChildTaskDto>> ListChildTasks(
        CancellationToken cancellationToken)
    {
        var ctx = _contextAccessor.Current;
        var children = await _tasks.GetChildrenAsync(ctx.ParentTaskId, cancellationToken);
        var list = new List<ChildTaskDto>(children.Count);
        foreach (var c in children)
        {
            var tagList = await _tasks.GetTagsAsync(c.Id, cancellationToken);
            list.Add(new ChildTaskDto(c.Id, c.Title, c.Description, c.Status.ToString(), tagList.Select(t => t.Name).ToList()));
        }
        return list;
    }

    [McpServerTool, Description("Update an existing draft child task. Only Draft tasks may be modified.")]
    public async Task<ChildTaskDto> UpdateChildTask(
        string taskId,
        string? title,
        string? description,
        IReadOnlyList<string>? tags,
        string? commitType,
        CancellationToken cancellationToken)
    {
        var ctx = _contextAccessor.Current;
        var child = await _tasks.GetByIdAsync(taskId, cancellationToken)
            ?? throw new InvalidOperationException($"Task {taskId} not found.");
        if (child.ParentTaskId != ctx.ParentTaskId)
            throw new InvalidOperationException("Task is not a child of this planning session.");
        if (child.Status != TaskStatus.Draft)
            throw new InvalidOperationException("Cannot modify a finalized task.");

        if (title is not null) child.Title = title;
        if (description is not null) child.Description = description;
        if (commitType is not null) child.CommitType = commitType;
        await _tasks.UpdateAsync(child, cancellationToken);

        var reload = (await _tasks.GetByIdAsync(taskId, cancellationToken))!;
        var tagList = await _tasks.GetTagsAsync(reload.Id, cancellationToken);
        await BroadcastTaskUpdatedAsync(ctx.ParentTaskId, cancellationToken);
        return new ChildTaskDto(reload.Id, reload.Title, reload.Description, reload.Status.ToString(), tagList.Select(t => t.Name).ToList());
    }

    [McpServerTool, Description("Delete a draft child task. Only Draft tasks may be deleted.")]
    public async Task DeleteChildTask(
        string taskId,
        CancellationToken cancellationToken)
    {
        var ctx = _contextAccessor.Current;
        var child = await _tasks.GetByIdAsync(taskId, cancellationToken)
            ?? throw new InvalidOperationException($"Task {taskId} not found.");
        if (child.ParentTaskId != ctx.ParentTaskId)
            throw new InvalidOperationException("Task is not a child of this planning session.");
        if (child.Status != TaskStatus.Draft)
            throw new InvalidOperationException("Cannot delete a finalized task.");

        await _tasks.DeleteAsync(taskId, cancellationToken);
        await BroadcastTaskUpdatedAsync(ctx.ParentTaskId, cancellationToken);
    }

    [McpServerTool, Description("Update the title and/or description of the parent planning task itself.")]
    public async Task UpdatePlanningTask(
        string? title,
        string? description,
        CancellationToken cancellationToken)
    {
        var ctx = _contextAccessor.Current;
        await _tasks.UpdatePlanningTaskAsync(ctx.ParentTaskId, title, description, cancellationToken);
        await BroadcastTaskUpdatedAsync(ctx.ParentTaskId, cancellationToken);
    }

    [McpServerTool, Description("Finalize the planning session, promoting all draft child tasks to queued or manual status.")]
    public async Task<int> Finalize(
        bool queueAgentTasks,
        CancellationToken cancellationToken)
    {
        var ctx = _contextAccessor.Current;
        var count = await _tasks.FinalizePlanningAsync(ctx.ParentTaskId, queueAgentTasks, cancellationToken);
        await BroadcastTaskUpdatedAsync(ctx.ParentTaskId, cancellationToken);
        return count;
    }
}