using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Entity;
using Shared;

namespace Contextlib
{
    public class DbUsersManager : IUserService<Users>
    {
        private WTFContext _context;
        private GenericRepository<Users> _repo;

        public DbUsersManager( WTFContext context )
        {
            _context = context ?? throw new ArgumentNullException(nameof(context), "Database context cannot be null.");
            _repo = new GenericRepository<Users>(_context);
        }

        public async Task AddUser(Users user)
        {
            if (user == null) {
                throw new ArgumentNullException(nameof(user), "user cannot be null.");
            }
            _repo.Insert(user);
            await _context.SaveChangesAsync();
        }

        public async Task<int> CountUser()
        {
            return _repo.Count();
        }

        public async Task<bool> ExistEmail(string email)
        {
            IQueryable<Users> users = _context.users.Where(u=>u.Email == email);
            return users != null;
        }

        public async Task<bool> ExistUsername(string username)
        {
            IQueryable<Users> users = _context.users.Where(u => u.UserName == username);
            return users != null;
        }

        public async Task<PaginationResult<Users>> GetAllUser()
        {
            List<Users> users = _repo.GetItems(0,_repo.Count(),[nameof(Users.Images)]).ToList();
            return new PaginationResult<Users>(users.Count,0,users.Count,users);
        }

        public async Task<string> GetHashPassword(string username)
        {
            Users? user = _context.users.Where(u=>u.UserName == username).FirstOrDefault();
            if (user != null)
            {
                return "";
            }
            return user.Password;
        }

        public async Task<int> GetLastUserId()
        {
            PaginationResult<Users> users = await GetAllUser();
            int lastUserId = 0;
            foreach (Users user in users.items)
            {
                if (user.Id >= lastUserId)
                {
                    lastUserId = user.Id + 1;
                }
            }
            return lastUserId;
        }

        public async Task<PaginationResult<Users>> GetSomeUser(int index, int pageSize)
        {
            List<Users> users = _repo.GetItems(index, pageSize, [nameof(Users.Images)]).ToList();
            return new PaginationResult<Users>(users.Count, index, pageSize, users);
        }

        public async Task<Users> GetUserByEmail(string email)
        {
            var user = _repo.GetItems(item => item.Email == email, 0, 1, [nameof(Character.Images)]).FirstOrDefault();

            if (user == null)
            {
                throw new KeyNotFoundException($"Error : No user found with the email: {email}.");
            }

            return user;
        }

        public async Task<Users> GetUserById(int id)
        {
            Users? user =_repo.GetById(id, item => item.Id == id, nameof(Users.Images));
            if (user == null)
            {
                throw new KeyNotFoundException($"Error : No users found with the ID: {id}.");
            }
            return user;
        }

        public async Task<Users> GetUserByUsername(string username)
        {
            var user = _repo.GetItems(item => item.UserName == username, 0, 1, [nameof(Character.Images)]).FirstOrDefault();

            if (user == null)
            {
                throw new KeyNotFoundException($"Error : No user found with the name: {username}.");
            }

            return user;
        }

        public async Task RemoveUser(Users user)
        {
            _repo.Delete(user);
            await _context.SaveChangesAsync();
        }

        public async Task SetAdminRole(bool isAdmin)
        {
            throw new NotImplementedException();
        }

        public async Task<Users> UpdateUser(int userId, Users user)
        {
            Users? u = _repo.GetById(userId);
            if (u != null)
            {
                bool change = false;
                if (user.IdImage != 0)
                {
                    u.IdImage = user.IdImage;
                    change = true;
                }
                if (user.UserName != null)
                {
                    u.UserName = user.UserName;
                    change = true;
                }
                if (user.Email != null)
                {
                    u.Email = user.Email;
                    change = true;
                }
                if (user.Password != null)
                {
                    u.Password = user.Password;
                    change = true;
                }
                _repo.Update(u);
                if (change)_context.SaveChanges();
            }
            return u;
        }
    }
}