using System;
using System.Collections.ObjectModel;
using Caliburn;
using Caliburn.Actions;
using Caliburn.Events.Brokering;

namespace Samples.TodoListModule
{
    public class TodoListPresenter
    {
        private ObservableCollection<Todo> _todos;
        public ObservableCollection<Todo> Todos
        {
            get
            {
                if (_todos == null)
                    _todos = new ObservableCollection<Todo>();

                return _todos;
            }
        }

        public ActionCommand MarkAllDoneCommand
        {
            get { return new ActionCommand(this, MarkAllDone, (x) => _todos.Count > 0); }
        }

        public void MarkAllDone(object parameter)
        {
            foreach (Todo todo in _todos)
            {
                todo.IsDone = true;
            }
        }

        public void New()
        {
            Edit(new Todo());
        }

        public void Edit(Todo todo)
        {
            TodoPresenter presenter = DI.Resolve<TodoPresenter>();
            presenter.Todo = todo;

            OnAddPresenterRequested(presenter);
        }

        [Subscribe("event://Module/Todo/Save")]
        public void Save(Todo todo)
        {
            if (!_todos.Contains(todo))
            {
                todo.Id = Guid.NewGuid();
                _todos.Add(todo);
            }
        }

        [Subscribe("event://Module/Todo/Delete")]
        public void Delete(Todo todo)
        {
            _todos.Remove(todo);
        }

        [Publish("event://Shell/Presenter/AddRequested")]
        public event Action<TodoPresenter> AddPresenterRequested;

        protected virtual void OnAddPresenterRequested(TodoPresenter presenter)
        {
            if (AddPresenterRequested != null)
                AddPresenterRequested(presenter);
        }
    }
}