using System;
using System.Collections.ObjectModel;
using System.Data.Entity;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Input;
using To_DoList.Commands;
using To_DoList.Contracts;
using To_DoList.Models;
using To_DoList.Services;
using To_DoList.Views;

namespace To_DoList.ViewModels
{
    public class TaskViewModel: BaseViewModel, IObserver
    {
        private readonly IDataService _dataService = DataService.GetInstance();

        private Models.Task _selectedTask;
        private Models.Category _selectedCategory;

        public TaskViewModel()
        {
            _dataService.AddObserver(this);

            var tasks = _dataService.GetObjects<Models.Task>();
            var categories = _dataService.GetObjects<Models.Category>();

            Tasks = new ObservableCollection<Models.Task>(tasks);
            Categories = new ObservableCollection<Models.Category>(categories);

            RemoveActivityCommand = new RelayCommand(RemoveTask_Executed, RemoveTask_CanExecute);
        }

        public ObservableCollection<Models.Task> Tasks { get; set; }
        public ObservableCollection<Models.Category> Categories { get; set; }

        public ICommand RemoveActivityCommand { get; set; }

        public Models.Task SelectedTask
        {
            get { return _selectedTask; }
            set
            {
                _selectedTask = value;
                OnPropertyChanged("SelectedTask");
            }
        }

        public Models.Category SelectedCategory
        {
            get { return _selectedCategory; }
            set
            {
                _selectedCategory = value;
                OnPropertyChanged("SelectedCategory");
            }
        }

        public void Update(Type t)
        {
            var tasks = _dataService.GetObjects<Models.Task>();
            var categories = _dataService.GetObjects<Models.Category>();

            Tasks.Clear();
            Categories.Clear();

            foreach (var task in tasks)
            {
                Tasks.Add(task);
            }

            foreach (var category in categories)
            {
                Categories.Add(category);
            }
        }

        private bool RemoveTask_CanExecute(object sender)
        {
            return SelectedTask != null;
        }

        private void RemoveTask_Executed(object sender)
        {
            _dataService.Delete(SelectedTask);
        }
    }
}