import { sendMessage } from '../utils/messaging';
import { createTask, assignTask, completeTask, getPendingTasks } from '../../services/taskService';
import { setRemindersEnabled } from '../../services/userService';

function formatTaskList(tasks: any[]) {
  if (tasks.length === 0) {
    return 'No tienes tareas pendientes.';
  }
  
  return tasks.map((task) => {
    return `- Tarea ${task.id}: ${task.description}${task.dueDate ? ` (para el ${task.dueDate})` : ''}`;
  }).join('\n');
}

export function handleTaskCommand(body: string, sender: string, groupId: string, linkedGroups: Set<string>) {
  if (groupId && linkedGroups.has(groupId)) {
    if (body.startsWith('/tarea')) {
      const command = body.replace('/tarea', '').trim();
      const [action, ...args] = command.split(' ');
      const description = args.join(' ');

      // Extract WhatsApp mention (format: @<phone_number>)
      const assignedUserMatch = description.match(/@\d+/);
      const assignedUser = assignedUserMatch ? assignedUserMatch[0] : null;
      
      // Validate phone number format
      if (assignedUser && !/^@\d{8,}$/.test(assignedUser)) {
        sendMessage(sender, 'Formato de mención inválido. Usa @ seguido del número de teléfono');
        return;
      }

      const dueDateMatch = description.match(/\d{4}-\d{2}-\d{2}/);
      const dueDate = dueDateMatch ? dueDateMatch[0] : null;

      const cleanDescription = description
        .replace(/@\w+/g, '')
        .replace(/\d{4}-\d{2}-\d{2}/g, '')
        .trim();

      if (!action || action === 'mostrar') {
        // Handle bare /tarea or /tarea mostrar
        const user = `@${sender.split('@')[0]}`; // Default to the sender
        const tasks = getPendingTasks(user);

        if (tasks.length === 0) {
          sendMessage(sender, 'No tienes tareas pendientes.');
        } else {
          const taskList = formatTaskList(tasks);
          sendMessage(sender, `Tus tareas pendientes:\n${taskList}`);
        }
      } else if (action === 'nueva') {
        try {
          const finalAssignedUser = assignedUser || `@${sender.split('@')[0]}`;
          const task = createTask(sender, {
            description: cleanDescription,
            assignedTo: finalAssignedUser,
            dueDate: dueDate || undefined
          });
          
          let message = `✅ Tarea creada:\nID: ${task.id}\nDescripción: ${task.description}`;
          if (task.assignedTo) message += `\nAsignada a: ${task.assignedTo}`;
          if (task.dueDate) message += `\nFecha límite: ${task.dueDate}`;
          message += `\nCreada: ${task.createdAt}`;
          
          // Send confirmation privately to creator
          sendMessage(sender, message);
          // Also notify assignee if different from creator
          if (assignedUser && assignedUser !== `@${sender.split('@')[0]}`) {
            sendMessage(assignedUser, `📝 Se te ha asignado una nueva tarea:\n${message}`);
          }
        } catch (error) {
          console.error('Error creating task:', error);
          sendMessage(sender, `❌ Error al crear la tarea: ${error.message}`);
        }
      } else if (action === 'asignar') {
        try {
          const taskId = validateTaskId(args[0]);
          if (!assignedUser) {
            throw new Error('Debes mencionar a un usuario para asignar la tarea. Ejemplo: /tarea asignar 1 @12345678');
          }
          
          assignTask(taskId, assignedUser);
          // Send confirmation privately to the person who assigned
          sendMessage(sender, `✅ Tarea ${taskId} asignada a ${assignedUser}`);
          // Notify the new assignee privately
          sendMessage(assignedUser, `📝 Se te ha asignado la tarea ${taskId}`);
        } catch (error) {
          console.error('Error assigning task:', error);
          sendMessage(sender, `❌ Error al asignar tarea: ${error.message}`);
        }
      } else if (action === 'lista' || (!action && args.length === 1)) {
        // Handle both /tarea lista 14 and /tarea 14
        try {
          const taskId = validateTaskId(args[0]);
          const task = getTaskById(taskId);
          
          if (!task) {
            sendMessage(sender, `Tarea ${taskId} no encontrada`);
            return;
          }
          
          // Check if task is assigned to current user
          const currentUser = `@${sender.split('@')[0]}`;
          if (task.assignedTo !== currentUser) {
            sendMessage(sender, `No puedes completar la tarea ${taskId} porque no está asignada a ti`);
            return;
          }
          
          completeTask(taskId);
          // Send confirmation privately to the user who completed
          sendMessage(sender, `✅ Tarea ${taskId} completada: ${task.description}`);
          // Notify the task creator if different from completer
          if (task.createdBy && task.createdBy !== sender) {
            sendMessage(task.createdBy, `✅ Tarea ${taskId} completada por @${sender.split('@')[0]}: ${task.description}`);
          }
        } catch (error) {
          console.error('Error completing task:', error);
          sendMessage(sender, `❌ Error al completar tarea: ${error.message}`);
        }
      } else if (action === 'mostrar' || !action) {
        // Handle /tarea or /tarea mostrar
        const user = `@${sender.split('@')[0]}`; // Default to the sender
        const tasks = getPendingTasks(user);

        if (tasks.length === 0) {
          sendMessage(sender, 'No tienes tareas pendientes.');
        } else {
          const taskList = tasks.map((task) => {
            return `- Tarea ${task.id}: ${task.description}${task.dueDate ? ` (para el ${task.dueDate})` : ''}`;
          }).join('\n');
          // Always send task list privately
          sendMessage(sender, `Tus tareas pendientes:\n${taskList}`);
        }
      } else if (action === 'recordatorios') {
        const enable = args[0]?.toLowerCase();
        if (enable === 'on' || enable === 'off') {
          const phoneNumber = sender.split('@')[0];
          setRemindersEnabled(phoneNumber, enable === 'on');
          // Send reminder settings confirmation privately
          sendMessage(sender, `Recordatorios ${enable === 'on' ? 'activados' : 'desactivados'}`);
        } else {
          sendMessage(sender, 'Usa /tarea recordatorios on|off para gestionar tus recordatorios');
        }
      } else {
        sendMessage(sender, 'Acción no reconocida. Usa /tarea nueva, /tarea asignar, /tarea completar, /tarea mostrar, o /tarea recordatorios.');
      }
    }
  }
}