using StbVorbisSharp;

namespace DaggerFramework.Resources
{
    public class SoundLoader : IResourceLoader
    {
        public IEnumerable<string> SupportedExtensions => new string[]
        {
            "ogg"
        };

        public Type ResourceType => typeof(Sound);

        public Resource Load(string path)
        {
            Vorbis vorbis;
            Sound result;

            var fileBuffer = File.ReadAllBytes(path);
            vorbis = Vorbis.FromMemory(fileBuffer);

            vorbis.SubmitBuffer();

            if (vorbis.Decoded == 0)
            {
                vorbis.Restart();
                vorbis.SubmitBuffer();
            }

            var audioShort = vorbis.SongBuffer;
            int length = vorbis.Decoded * vorbis.Channels;
            byte[] audioData = new byte[length * 2];

            for (int i = 0; i < length; i++)
            {
                if (i * 2 >= audioData.Length) break;

                var b1 = (byte)(audioShort[i] >> 8);
                var b2 = (byte)(audioShort[i] & 256);

                audioData[i * 2] = b2;
                audioData[i * 2 + 1] = b1;
            }

            result = new Sound(path, audioData);
            result.Format = (SoundFormat)vorbis.Channels - 1;
            result.SampleRate = vorbis.SampleRate;
            result.BufferSize = length;

            vorbis.Dispose();
            return result;
        }
    }
}