using MeetUp.Data;
using MeetUp.Data.Models;
using System;
using System.Collections.Generic;
using System.Data.Entity.Validation;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace MeetUp.Services
{
    public class UserService
    {
        //private readonly MeetUpDbContext db;

        public UserService()
        {
            //this.db = new MeetUpDbContext();
        }

        public bool Create(string email, string password, string fullname, string description="")
        {
            using (var db = new MeetUpDbContext())
            {
                var mailExists = db.Users.Any(u => u.Email == email);

                if(mailExists)
                {
                    return false;
                }

                var user = new User
                {
                    Email = email,
                    Password = this.HashPassword(password, email),
                    FullName = fullname,
                    Description = description,
                    Sex = 1,
                    CityId = 1,
                };

                db.Users.Add(user);

                try
                {
                    db.SaveChanges();
                } catch(DbEntityValidationException ex)
                {
                    foreach (var entityValidationErrors in ex.EntityValidationErrors)
                    {
                        foreach (var validationError in entityValidationErrors.ValidationErrors)
                        {
                            System.Diagnostics.Debug.WriteLine("Property: " + validationError.PropertyName + " Error: " + validationError.ErrorMessage);
                        }
                    }
                }


                return true;
            }
        }

        public bool Login(string email, string password)
        {
            using (var db = new MeetUpDbContext())
            {
                var hashedPass = this.HashPassword(password, email);

                var user = db.Users.Where(u => u.Email == email && u.Password == hashedPass);

                if (user == null)
                {
                    return false;
                }

                return true;
            }
        }

        public List<User> All()
        {
            using (var db = new MeetUpDbContext())
            {
                return db.Users.ToList();
            }
        }

        public string HashPassword(string password, string salt)
        {
            using (var sha1 = new SHA1Managed())
            {
                return BitConverter.ToString(sha1.ComputeHash(Encoding.UTF8.GetBytes(password + salt)));
            }
        }

        public void DeleteUser(int id)
        {
            MeetUpDbContext ctx = new MeetUpDbContext();
            var user = new User { Id = id };
            ctx.Users.Attach(user);
            ctx.Users.Remove(user);
            ctx.SaveChanges();

        }

        public void EditUser()
        {
            MeetUpDbContext ctx = new MeetUpDbContext();
            User user = ctx.Users.Create();
            user.Id = 4;
            ctx.Users.Attach(user);

            user.FullName = "darko";

            ctx.SaveChanges();
        }

        public List<User> getUsers()
        {
            List<User> allUsers = new List<User>();

            using (var context = new MeetUpDbContext())
            {
                var users = from u in context.Users select u;

                foreach (User u in users)
                {
                    allUsers.Add(u);
                }

            }

            return allUsers;
        }

        public User GetUserById(int id)
        {
            User user = new User();

            using (var context = new MeetUpDbContext())
            {
                user = (from u in context.Users where u.Id == id select u).First();

            }

            return user;
        }

        public void updateUser(int id, string fullName, string email, string description, string password)
        {
            using (var context = new MeetUpDbContext())
            {
                var user = context.Users.SingleOrDefault(u => u.Id == id);
                if(user != null)
                {
                    user.FullName = fullName;
                    user.Description = description;
                    user.Email = email;
                    user.Password = this.HashPassword(password, email);

                    context.SaveChanges();
                }

            }
        }

    }
}