using System;
using K4os.Compression.LZ4;

#if UNITY_5_3_OR_NEWER
using UnityEngine;
#endif

namespace CommonTools
{

	public static class LZ4Utility
	{
		public static (string, int) CompressString(string input)
		{
			byte[] inputBytes = System.Text.Encoding.UTF8.GetBytes(input);
			var encodedBytes = new byte[LZ4Codec.MaximumOutputSize(inputBytes.Length)];
			var encodedLength = LZ4Codec.Encode(
				inputBytes, 0, inputBytes.Length,
				encodedBytes, 0, encodedBytes.Length);
			var resultArray = new byte[encodedLength];
			Array.Copy(encodedBytes, 0, resultArray, 0, encodedLength);
			return (Convert.ToBase64String(resultArray), inputBytes.Length);
		}

		public static string DecompressString(string compressedInput, int encodedLength)
		{
			var source = Convert.FromBase64String(compressedInput);
			var decompressedBytes = new byte[encodedLength];
			var decoded = LZ4Codec.Decode(
				source, 0, source.Length,
				decompressedBytes, 0, decompressedBytes.Length);
#if UNITY_5_3_OR_NEWER
        if (decoded < 0)
            Debug.LogWarning("LZ4 Decompress function did not decompress.");
#endif
			return System.Text.Encoding.UTF8.GetString(decompressedBytes);
		}
	}

}