using Gitea.Model;
using System;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text.RegularExpressions;

namespace SPTInstaller.Aki.Helper
{
    public static class FileHashHelper
    {
        public static string GetGiteaReleaseHash(Release release)
        {
            var regex = Regex.Match(release.Body, @"Release Hash: (?<hash>\S+)");

            if (regex.Success)
            {
                return regex.Groups["hash"].Value;
            }

            return null;
        }

        public static bool CheckHash(FileInfo file, string expectedHash)
        {
            using (MD5 md5Service = MD5.Create())
            using (var sourceStream = file.OpenRead())
            {
                byte[] sourceHash = md5Service.ComputeHash(sourceStream);
                byte[] expectedHashBytes = Convert.FromBase64String(expectedHash);

                bool matched = Enumerable.SequenceEqual(sourceHash, expectedHashBytes);

                return matched;
            }
        }
    }
}