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

namespace ClaudeDo.Worker.External;

public sealed record HandoffListHandlerResult(bool Requested, string TaskId, int SurvivingCount);

[McpServerToolType]
public sealed class HandoffMcpTools
{
    private readonly TaskRepository _tasks;
    private readonly HubBroadcaster _broadcaster;

    public HandoffMcpTools(TaskRepository tasks, HubBroadcaster broadcaster)
    {
        _tasks = tasks;
        _broadcaster = broadcaster;
    }

    [McpServerTool, Description(
        "Call at the end of Phase 2 of the list handler (\"Let Claude handle it\") to hand this run off " +
        "to a fresh ConPTY session that carries out Phases 3-5, without dragging along this session's " +
        "dedupe/rewrite context. Reuses the SAME handler task -- no new task is created, and " +
        "HandlerBaseCommit is untouched. The current tile stays open; you must end your own turn " +
        "immediately after calling this.")]
    public async Task<HandoffListHandlerResult> HandoffListHandler(
        [Description("This session's own handler task id.")] string taskId,
        [Description("The tasks that made it past dedupe, in the order to run them.")] IReadOnlyList<string> survivingTaskIds,
        CancellationToken cancellationToken)
    {
        if (survivingTaskIds.Count == 0)
            throw new InvalidOperationException("survivingTaskIds must contain at least one task id.");

        _ = await _tasks.GetByIdAsync(taskId, cancellationToken)
            ?? throw new InvalidOperationException($"Task {taskId} not found.");

        foreach (var id in survivingTaskIds)
            _ = await _tasks.GetByIdAsync(id, cancellationToken)
                ?? throw new InvalidOperationException($"Task {id} not found.");

        await _broadcaster.HandoffRequested(taskId, survivingTaskIds);
        return new HandoffListHandlerResult(true, taskId, survivingTaskIds.Count);
    }
}