feat: add reminder system with user preferences support

src/bot/commands/task.ts

@@ -1,5 +1,6 @@
 import { sendMessage } from '../utils/messaging';
 import { createTask, assignTask, completeTask, getPendingTasks } from '../../services/taskService';
+import { setRemindersEnabled } from '../../services/userService';
 
 export function handleTaskCommand(body: string, sender: string, groupId: string, linkedGroups: Set<string>) {
   if (groupId && linkedGroups.has(groupId)) {
@@ -63,8 +64,17 @@ export function handleTaskCommand(body: string, sender: string, groupId: string,
           }).join('\n');
           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');
+          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, o /tarea mostrar.');
+        sendMessage(sender, 'Acción no reconocida. Usa /tarea nueva, /tarea asignar, /tarea completar, /tarea mostrar, o /tarea recordatorios.');
       }
     }
   }

src/services/reminderService.ts

@@ -0,0 +1,49 @@
+import { query } from '../database/db';
+import { sendMessage } from '../bot/utils/messaging';
+import { Task } from '../models/task';
+import { getUserPreferences } from './userService';
+
+export function getTasksNeedingReminders(): Task[] {
+  const now = new Date().toISOString();
+  const tasks = query(`
+    SELECT t.* 
+    FROM tasks t
+    JOIN user_preferences up ON t.assigned_to = up.phone_number
+    WHERE t.completed = FALSE 
+      AND (t.due_date IS NULL OR t.due_date > ?)
+      AND (t.last_reminder IS NULL OR t.last_reminder < datetime(?, '-1 day'))
+      AND up.reminders_enabled = TRUE
+  `, [now, now]);
+
+  // Also include tasks for users who haven't set preferences yet
+  const newUsersTasks = query(`
+    SELECT t.* 
+    FROM tasks t
+    LEFT JOIN user_preferences up ON t.assigned_to = up.phone_number
+    WHERE t.completed = FALSE 
+      AND (t.due_date IS NULL OR t.due_date > ?)
+      AND (t.last_reminder IS NULL OR t.last_reminder < datetime(?, '-1 day'))
+      AND up.phone_number IS NULL
+  `, [now, now]);
+
+  return [...tasks, ...newUsersTasks];
+}
+
+export async function sendTaskReminder(task: Task) {
+  if (!task.assignedTo) return;
+
+  const message = `🔔 Recordatorio de tarea:\n` +
+    `ID: ${task.id}\n` +
+    `Descripción: ${task.description}\n` +
+    (task.dueDate ? `Fecha límite: ${task.dueDate}\n` : '') +
+    `Creada: ${task.createdAt}\n\n` +
+    `Usa /tarea completar ${task.id} cuando la termines.`;
+
+  try {
+    await sendMessage(task.assignedTo, message);
+    // Update last reminder timestamp
+    query('UPDATE tasks SET last_reminder = CURRENT_TIMESTAMP WHERE id = ?', [task.id]);
+  } catch (error) {
+    console.error('Error sending reminder:', error);
+  }
+}