using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace IPA.Utilities
{
    public static class LoneFunctions
    {
        public static byte[] StringToByteArray(string hex)
        {
            int NumberChars = hex.Length;
            byte[] bytes = new byte[NumberChars / 2];
            for (int i = 0; i < NumberChars; i += 2)
                bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
            return bytes;
        }

        public static string ByteArrayToString(byte[] ba)
        {
            StringBuilder hex = new StringBuilder(ba.Length * 2);
            foreach (byte b in ba)
                hex.AppendFormat("{0:x2}", b);
            return hex.ToString();
        }

        // Copyright (c) 2008-2013 Hafthor Stefansson
        // Distributed under the MIT/X11 software license
        // Ref: http://www.opensource.org/licenses/mit-license.php.
        // From: https://stackoverflow.com/a/8808245/3117125
        public static unsafe bool UnsafeCompare(byte[] a1, byte[] a2)
        {
            if (a1 == a2) return true;
            if (a1 == null || a2 == null || a1.Length != a2.Length)
                return false;
            fixed (byte* p1 = a1, p2 = a2)
            {
                byte* x1 = p1, x2 = p2;
                int l = a1.Length;
                for (int i = 0; i < l / 8; i++, x1 += 8, x2 += 8)
                    if (*((long*)x1) != *((long*)x2)) return false;
                if ((l & 4) != 0) { if (*((int*)x1) != *((int*)x2)) return false; x1 += 4; x2 += 4; }
                if ((l & 2) != 0) { if (*((short*)x1) != *((short*)x2)) return false; x1 += 2; x2 += 2; }
                if ((l & 1) != 0) if (*((byte*)x1) != *((byte*)x2)) return false;
                return true;
            }
        }

        public static string GetRelativePath(string filespec, string folder)
        {
            Uri pathUri = new Uri(filespec);
            // Folders must end in a slash
            if (!folder.EndsWith(Path.DirectorySeparatorChar.ToString()))
            {
                folder += Path.DirectorySeparatorChar;
            }
            Uri folderUri = new Uri(folder);
            return Uri.UnescapeDataString(folderUri.MakeRelativeUri(pathUri).ToString().Replace('/', Path.DirectorySeparatorChar));
        }
    }
}