using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Tokens;
using System;
using System.Collections.Generic;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Security.Claims;
using System.Text;
using UnivateProperties_API.Context;
using UnivateProperties_API.Helpers;
using UnivateProperties_API.Model.Users;

namespace UnivateProperties_API.Repository.Users
{
    public class UserRepository : IRepository<User>
    {
        private readonly DataContext _dbContext;

        public UserRepository(DataContext dbContext)
        {
            _dbContext = dbContext;
        }

        public List<User> Get(Func<User, bool> where)
        {
            return _dbContext.Users.Where(where).ToList();
        }

        public List<User> GetAll()
        {
            return _dbContext.Users.ToList();
        }

        public User GetDetailed(Func<User, bool> first)
        {
            var item = _dbContext.Users.FirstOrDefault(first);
            UserRepository account = new UserRepository(_dbContext);
            item = GetDetailedObject(item, account);
            return item;
        }

        private User GetDetailedObject(User item, UserRepository repo)
        {
            item = repo.GetDetailed(x => x.Id == item.Id);
            return item;
        }

        public void Insert(User item)
        {
            _dbContext.Add(item);
            Save();
        }

        public void Insert(IEnumerable<User> item)
        {
            _dbContext.Add(item);
            Save();
        }

        public void Remove(User item)
        {
            var i = _dbContext.Users.Find(item);
            _dbContext.Users.Remove(i);
            Save();
        }

        public void Remove(IEnumerable<User> items)
        {
            foreach (var item in items)
            {
                User i = _dbContext.Users.Find(item);
                _dbContext.Users.Remove(i);
            }
            Save();
        }

        public void RemoveAtId(int item)
        {
            var i = _dbContext.Users.Find(item);
            _dbContext.Users.Remove(i);
            Save();
        }

        //public void Update(User item)
        //{
        //    _dbContext.Entry(item).State = EntityState.Modified;
        //    Save();
        //}

        public void Update(User userParam)
        {
            var user = _dbContext.Users.Find(userParam.Id);

            if (user == null)
                throw new AppException("User not found");

            if (userParam.Username != user.Username)
            {
                // username has changed so check if the new username is already taken
                if (_dbContext.Users.Any(x => x.Username == userParam.Username))
                    throw new AppException("Username " + userParam.Username + " is already taken");
            }

            // update user properties
            user.Username = userParam.Username;

            // update password if it was entered
            if (!string.IsNullOrWhiteSpace(userParam.PasswordHash.ToString()))
            {
                byte[] passwordHash, passwordSalt;
                CreatePasswordHash(userParam.PasswordHash.ToString(), out passwordHash, out passwordSalt);

                user.PasswordHash = passwordHash;
                user.PasswordSalt = passwordSalt;
            }

            _dbContext.Users.Update(user);
            _dbContext.SaveChanges();
        }

        private static void CreatePasswordHash(string password, out byte[] passwordHash, out byte[] passwordSalt)
        {
            if (password == null) throw new ArgumentNullException("password");
            if (string.IsNullOrWhiteSpace(password)) throw new ArgumentException("Value cannot be empty or whitespace only string.", "password");

            using (var hmac = new System.Security.Cryptography.HMACSHA512())
            {
                passwordSalt = hmac.Key;
                passwordHash = hmac.ComputeHash(System.Text.Encoding.UTF8.GetBytes(password));
            }
        }

        public void Save()
        {
            _dbContext.SaveChanges();
        }

        public List<User> GetDetailedAll()
        {
            throw new NotImplementedException();
        }
    }
}