/*
 * Visit to: http://w...content-available-to-author-only...x.com
 */

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Data.SqlClient;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Windows;
using System.Data.Entity;
using WPF_CRUD_EFCodeFirst_Simple.Annotations;
using WPF_CRUD_EFCodeFirst_Simple.Models;

namespace WPF_CRUD_EFCodeFirst_Simple
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window, INotifyPropertyChanged
    {
        public MainWindow()
        {
            InitializeComponent();
            DataContext = this;
        }

        private readonly ManagerDbContext _context = new ManagerDbContext();

        #region CRUD Implementing

        private IEnumerable<Departments> _departmentses;
        public ObservableCollection<Departments> Departmentses
        {
            get
            {
                return 
                    new ObservableCollection<Departments>(_context.Departmentses);
            }
            set
            {
                _departmentses = value;
                OnPropertyChanged("Departmentses");
            }
        }

        private IEnumerable<Employee> _employee;

        public IEnumerable<Employee> Employees
        {
            get
            {
                return 
                    new ObservableCollection<Employee>(_context.Employees.Include(e => e.Departments));
            }
            set
            {
                _employee = value;
                OnPropertyChanged("Employees");
            }
        }

        private Employee _currentSelectedEmployee;
        public Employee CurrentSelectedEmployee
        {
            get
            {
                return _currentSelectedEmployee;
            }
            set
            {
                _currentSelectedEmployee = value;
                OnPropertyChanged("CurrentSelectedEmployee");
            }
        }

        private void AddNewEmployee(Employee employee)
        {
            _context.Employees.Add(employee);
            _context.SaveChanges();
        }

        private void UpdateCurrentEmployee(Employee employee)
        {
            var employeeToUpdate = _context.Employees.SingleOrDefault
                    (x => x.Id == employee.Id);
            if (employeeToUpdate != null)
            {
                employeeToUpdate.FirstName = employee.FirstName;
                employeeToUpdate.LastName = employee.LastName;
                employeeToUpdate.Birthday = employee.Birthday;
                employeeToUpdate.DepId = employee.DepId;
            }
            _context.SaveChanges();
        }

        private void DeleteCurrentEmployee(Employee employee)
        {
            var employeeToDelete = _context.Employees.SingleOrDefault
                    (x => x.Id == employee.Id);
            _context.Employees.Remove(employeeToDelete);
            _context.SaveChanges();
        }
        #endregion

        #region INotifyPropertyChanged Implementing

        public event PropertyChangedEventHandler PropertyChanged;

        [NotifyPropertyChangedInvocator]
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
        }

        #endregion
        
        #region Event Handlers

        private bool insert = false;
        /// <summary>
        /// Clear Form
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void BtnInsert_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                if (DtpkBirthday.SelectedDate != null && CbbDepartment.SelectedValue != null)
                    AddNewEmployee(new Employee
                    {
                        FirstName = TxtFirstName.Text,
                        LastName = TxtLastName.Text,
                        Birthday = (DateTime)DtpkBirthday.SelectedDate,
                        DepId = (int)CbbDepartment.SelectedValue
                    });
                DataGrid1.ItemsSource = Employees;  // Refresh
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            
            //TxtId.Clear();
            //TxtFirstName.Clear();
            //TxtLastName.Clear();
            //DtpkBirthday.SelectedDate = DateTime.Now;
            //CbbDepartment.ClearValue(ComboBox.SelectedItemProperty);
        }

        /// <summary>
        /// Change a Employee Object
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void BtnEdit_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                UpdateCurrentEmployee(CurrentSelectedEmployee);
            }
            catch (SqlException ex)
            {
                MessageBox.Show(ex.Message);
            } 
        }

        /// <summary>
        /// Delete Employee Object
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void BtnDelete_Click(object sender, RoutedEventArgs e)
        {
            var status = MessageBox.Show("Bạn có muốn xóa Nhân Viên này không?", "Cảnh Báo", MessageBoxButton.YesNo, MessageBoxImage.Question);
            if (status == MessageBoxResult.No) return;
            //ELSE
            DeleteCurrentEmployee(CurrentSelectedEmployee);
            DataGrid1.ItemsSource = Employees; // Refresh
        }

        /// <summary>
        /// Close Form
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void BtnExit_Click(object sender, RoutedEventArgs e)
        {
            Close();
        }
        #endregion

        
    }
}