function tasksApp() {
  return {
    newTask: '',
    filter: 'all',
    tasks: [],
    
    init() {
      const saved = localStorage.getItem('tasks');
      if (saved) {
        try {
          this.tasks = JSON.parse(saved);
        } catch (e) {
          console.error('Failed to load tasks:', e);
          this.tasks = [];
        }
      }
    },
    
    addTask() {
      if (this.newTask.trim() === '') return;
      
      this.tasks.push({
        id: Date.now(),
        text: this.newTask.trim(),
        completed: false,
        createdAt: new Date().toISOString()
      });
      
      this.newTask = '';
      this.save();
    },
    
    toggleTask(id) {
      const task = this.tasks.find(t => t.id === id);
      if (task) {
        task.completed = !task.completed;
        this.save();
      }
    },
    
    deleteTask(id) {
      this.tasks = this.tasks.filter(t => t.id !== id);
      this.save();
    },
    
    clearCompleted() {
      this.tasks = this.tasks.filter(t => !t.completed);
      this.save();
    },
    
    save() {
      try {
        localStorage.setItem('tasks', JSON.stringify(this.tasks));
      } catch (e) {
        console.error('Failed to save tasks:', e);
      }
    },
    
    get filteredTasks() {
      if (this.filter === 'active') {
        return this.tasks.filter(t => !t.completed);
      }
      if (this.filter === 'completed') {
        return this.tasks.filter(t => t.completed);
      }
      return this.tasks;
    },
    
    get activeTasks() {
      return this.tasks.filter(t => !t.completed).length;
    },
    
    get completedTasks() {
      return this.tasks.filter(t => t.completed).length;
    }
  };
}