using System;
using System.Security.Cryptography;
using System.Text;

using TextSender_API.Models;
using TextSender_API.Repositories;

namespace TextSender_API.Controllers;

public class PasswordVerification
{
    #region Fiends
    private UsersRepository? _userRepo;
    private SaltRepository? _saltRepo;
    private int _keySize = 64;
    private int _iterations = 350000;
    #endregion

    #region Constructors
    public PasswordVerification()
    {
    }

    public PasswordVerification(UsersRepository userRepo, SaltRepository saltRepo)
    {
        this._userRepo = userRepo;
        this._saltRepo = saltRepo;
    }
    #endregion

    #region Methods
    public bool VerifyPassword(User user, string password)
    {
        var salt = this._saltRepo.Retrieve(user.Id);
        var hashedPassword = this.HashPassword(user, salt, password);

        return hashedPassword.Equals(user.Password);
    }
    public Salt CreateSalt(User user)
    {
        var salt = new Salt();
        salt.Key = RandomNumberGenerator.GetBytes(this._keySize);

        return salt;
    }

    public string HashPassword(User user, Salt salt, string password = "")
    {
        var hashAlgorithm = HashAlgorithmName.SHA512;
        var dbHashedPassword = user.Password;

        if (!string.IsNullOrEmpty(password))
        {
            user.Password = password;
        }

        var hash = Rfc2898DeriveBytes.Pbkdf2(
            Encoding.UTF8.GetBytes(user.Password!),
            salt.Key!,
            this._iterations,
            hashAlgorithm,
            this._keySize);

        user.Password = dbHashedPassword;

        return Convert.ToHexString(hash);
    }
    #endregion
}