using System.IO.Compression;

namespace HyperbolicDownloaderApi.FileProcessing;

internal static class FileCompressor
{
    public static void CompressFile(string inputFilePath, string compressedFilePath)
    {
        using FileStream originalFileStream = File.Open(inputFilePath, FileMode.Open);
        using FileStream compressedFileStream = File.Create(compressedFilePath);
        using GZipStream? compressor = new GZipStream(compressedFileStream, CompressionMode.Compress);
        originalFileStream.CopyTo(compressor);
    }

    public static void DecompressFile(string compressedFilePath, string outputFilePath)
    {
        using FileStream compressedFileStream = File.Open(compressedFilePath, FileMode.Open);
        using FileStream outputFileStream = File.Create(outputFilePath);
        using GZipStream? decompressor = new GZipStream(compressedFileStream, CompressionMode.Decompress);
        decompressor.CopyTo(outputFileStream);
    }

    public static IEnumerable<byte[]> ReadChunks(string path, int chunkSize)
    {
        byte[] buffer = new byte[chunkSize];
        using FileStream fs = File.Open(path, FileMode.Open, FileAccess.Read, FileShare.Read);
        using BufferedStream bs = new BufferedStream(fs);
        while (bs.Read(buffer, 0, chunkSize) != 0)
        {
            yield return buffer;
        }
    }
}