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

namespace Pilz.Gaming.Minecraft;

public static class Utils
{
    public static string GetUUID(string value)
    {
        using var md5 = MD5.Create();

        //extracted from the java code:
        //new GameProfile(UUID.nameUUIDFromBytes(("OfflinePlayer:" + name).getBytes(Charsets.UTF_8)), name));
        byte[] data = md5.ComputeHash(Encoding.ASCII.GetBytes(value));
        //set the version to 3 -> Name based md5 hash
        data[6] = Convert.ToByte(data[6] & 0x0f | 0x30);
        //IETF variant
        data[8] = Convert.ToByte(data[8] & 0x3f | 0x80);

        //example: 069a79f4-44e9-4726-a5be-fca90e38aaf5
        var striped = Convert.ToHexString(data);
        var components = new string[] {
            striped[..].Remove(8),
            striped[8..].Remove(4),
            striped[12..].Remove(4),
            striped[16..].Remove(4),
            striped[20..]
        };

        return string.Join('-', components).ToLower();
    }

    public static string GetPlayerUUID(string username, bool offlineMode)
    {
        using var md5 = MD5.Create();

        if (!offlineMode)
            throw new NotSupportedException("Getting player's online UUID via the Mojang API is not supported at this time.");

        return GetUUID("OfflinePlayer:" + username);
    }
}