using System;
using System.Collections.Generic;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace LightlessSync.Utils;

public static class Crypto
{
#pragma warning disable SYSLIB0021 // Type or member is obsolete

    private static readonly Dictionary<(string, ushort), string> _hashListPlayersSHA256 = new();
    private static readonly Dictionary<string, string> _hashListSHA256 = new(StringComparer.Ordinal);
    private static readonly SHA256CryptoServiceProvider _sha256CryptoProvider = new();

    public static string GetFileHash(this string filePath)
    {
        using SHA1 sha1 = SHA1.Create();
        using FileStream stream = File.Open(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite | FileShare.Delete);
        return BitConverter.ToString(sha1.ComputeHash(stream)).Replace("-", "", StringComparison.Ordinal);
    }

    public static string GetHash256(this (string, ushort) playerToHash)
    {
        if (_hashListPlayersSHA256.TryGetValue(playerToHash, out var hash))
            return hash;

        return _hashListPlayersSHA256[playerToHash] =
            BitConverter.ToString(_sha256CryptoProvider.ComputeHash(Encoding.UTF8.GetBytes(playerToHash.Item1 + playerToHash.Item2.ToString()))).Replace("-", "", StringComparison.Ordinal);
    }

    public static string GetHash256(this string stringToHash)
    {
        return GetOrComputeHashSHA256(stringToHash);
    }

    private static string GetOrComputeHashSHA256(string stringToCompute)
    {
        if (_hashListSHA256.TryGetValue(stringToCompute, out var hash))
            return hash;

        return _hashListSHA256[stringToCompute] =
            BitConverter.ToString(_sha256CryptoProvider.ComputeHash(Encoding.UTF8.GetBytes(stringToCompute))).Replace("-", "", StringComparison.Ordinal);
    }
#pragma warning restore SYSLIB0021 // Type or member is obsolete
}