using System;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using Microsoft.Extensions.Options;

namespace _0_Framework.Application;

public class PasswordHasher : IPasswordHasher
{
    private const int SaltSize = 16; // 128 bit 
    private const int KeySize = 32; // 256 bit

    public PasswordHasher(IOptions<HashingOptions> options)
    {
        Options = options.Value;
    }

    private HashingOptions Options { get; }

    public string Hash(string password)
    {
        using var algorithm = new Rfc2898DeriveBytes(password, SaltSize, Options.Iterations, HashAlgorithmName.SHA256);
        var key = Convert.ToBase64String(algorithm.GetBytes(KeySize));
        var salt = Convert.ToBase64String(algorithm.Salt);

        return $"{Options.Iterations}.{salt}.{key}";
    }

    public (bool Verified, bool NeedsUpgrade) Check(string hash, string password)
    {
        var parts = hash.Split('.', 3);

        if (parts.Length != 3)
        {
            return (false, false);
        }

        var iterations = Convert.ToInt32(parts[0]);
        var salt = Convert.FromBase64String(parts[1]);
        var key = Convert.FromBase64String(parts[2]);

        var needsUpgrade = iterations != Options.Iterations;

        using var algorithm = new Rfc2898DeriveBytes(password, salt, iterations, HashAlgorithmName.SHA256);
        var keyToCheck = algorithm.GetBytes(KeySize);

        var verified = keyToCheck.SequenceEqual(key);

        return (verified, needsUpgrade);
    }

    #region Mahan

    public string SlugHasher(long slug)
    {
        try
        {
            var test = slug.ToString();
            UTF8Encoding encoder = new UTF8Encoding();

            byte[] hashedDataBytes = encoder.GetBytes(test);



            return Convert.ToBase64String(hashedDataBytes);
        }
        catch
        {
            return "";
        }
    }

    public long SlugDecrypt(string slug)
    {
        if (string.IsNullOrWhiteSpace(slug) || slug.Trim() == "0")
        {
            return 0;
        }
        try
        {
            byte[] bytes = Convert.FromBase64String(slug);

            string result = System.Text.Encoding.UTF8.GetString(bytes);

            return long.Parse(result);
        }
        catch
        {
            return -1;
        }

    }

    #endregion

}