using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.BL;
using Tango.BL.Entities;
using Tango.Core;
using Tango.PPC.Common.Authentication;

namespace Tango.PPC.UI.Authentication
{
    /// <summary>
    /// Represents the default PPC authentication provider.
    /// </summary>
    /// <seealso cref="Tango.Core.ExtendedObject" />
    /// <seealso cref="Tango.PPC.Common.Authentication.IAuthenticationProvider" />
    public class DefaultAuthenticationProvider : ExtendedObject, IAuthenticationProvider
    {
        /// <summary>
        /// Occurs when the current logged-in user has changed.
        /// </summary>
        public event EventHandler<User> CurrentUserChanged;

        private User _currentUser;
        /// <summary>
        /// Gets the current logged-in user.
        /// </summary>
        public User CurrentUser
        {
            get { return _currentUser; }
            private set
            {
                _currentUser = value;
                RaisePropertyChangedAuto();
            }
        }

        /// <summary>
        /// Performs a user login by the specified email and password.
        /// </summary>
        /// <param name="email">The email.</param>
        /// <param name="password">The password.</param>
        /// <returns></returns>
        public User Login(string email, string password)
        {
            CurrentUser = ObservablesEntitiesAdapter.Instance.Users.SingleOrDefault(x => x.Email.ToLower() == email && x.Password == password);
            CurrentUserChanged?.Invoke(this, CurrentUser);
            return CurrentUser;
        }

        /// <summary>
        /// Logs-out the current logged-in user.
        /// </summary>
        public void Logout()
        {
            CurrentUser = null;
            CurrentUserChanged?.Invoke(this, CurrentUser);
        }
    }
}