//! \file       AudioOGG.cs
//! \date       Fri Nov 07 00:32:15 2014
//! \brief      NVorbis wrapper for GameRes.
//
// Copyright (C) 2014 by morkt
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//

using System;
using System.ComponentModel.Composition;
using System.IO;
using System.Linq;
using NVorbis;

namespace GameRes.Formats
{
    public class OggInput : SoundInput
    {
        VorbisReader    m_reader;

        public override long Position
        {
            get
            {
                return (long)(m_reader.DecodedTime.TotalSeconds * m_reader.SampleRate * m_reader.Channels * sizeof(float));
            }
            set
            {
                if (value < 0 || value > Length) throw new ArgumentOutOfRangeException("value");

                m_reader.DecodedTime = TimeSpan.FromSeconds((double)value / m_reader.SampleRate / m_reader.Channels / sizeof(float));
            }
        }

        public override bool CanSeek { get { return Source.CanSeek; } }

        public override int SourceBitrate
        {
            get { return m_reader.NominalBitrate; }
        }

        public override string SourceFormat { get { return "ogg"; } }

        public OggInput (Stream file) : base (file)
        {
            m_reader = new VorbisReader (Source, false);
            var format = new GameRes.WaveFormat();
            format.FormatTag                = 3; // WAVE_FORMAT_IEEE_FLOAT
            format.Channels                 = (ushort)m_reader.Channels;
            format.SamplesPerSecond         = (uint)m_reader.SampleRate;
            format.BitsPerSample            = 32;
            format.BlockAlign               = (ushort)(4 * format.Channels);
            format.AverageBytesPerSecond    = format.SamplesPerSecond * format.BlockAlign;
            this.Format = format;
            this.PcmSize = (long)(m_reader.TotalTime.TotalSeconds * format.SamplesPerSecond * format.Channels * sizeof(float));
        }

        public override void Reset ()
        {
            m_reader.DecodedTime = TimeSpan.FromSeconds (0);
        }

        // This buffer can be static because it can only be used by 1 instance per thread
        [ThreadStatic]
        static float[] _conversionBuffer = null;

        public override int Read(byte[] buffer, int offset, int count)
        {
            // adjust count so it is in floats instead of bytes
            count /= sizeof(float);

            // make sure we don't have an odd count
            count -= count % m_reader.Channels;

            // get the buffer, creating a new one if none exists or the existing one is too small
            var cb = _conversionBuffer ?? (_conversionBuffer = new float[count]);
            if (cb.Length < count)
            {
                cb = (_conversionBuffer = new float[count]);
            }

            // let ReadSamples(float[], int, int) do the actual reading; adjust count back to bytes
            int cnt = m_reader.ReadSamples (cb, 0, count) * sizeof(float);

            // move the data back to the request buffer
            Buffer.BlockCopy (cb, 0, buffer, offset, cnt);

            // done!
            return cnt;
        }

        #region IDisposable Members
        bool _ogg_disposed = false;
        protected override void Dispose (bool disposing)
        {
            if (!_ogg_disposed)
            {
                if (disposing)
                {
                    m_reader.Dispose();
                }
                _ogg_disposed = true;
                base.Dispose (disposing);
            }
        }
        #endregion
    }

    [Export(typeof(AudioFormat))]
    public class OggAudio : AudioFormat
    {
        public override string         Tag { get { return "OGG"; } }
        public override string Description { get { return "Ogg/Vorbis audio format"; } }
        public override uint     Signature { get { return 0x5367674f; } } // 'OggS'
        public override bool      CanWrite { get { return false; } }

        public override SoundInput TryOpen (IBinaryStream file)
        {
            return new OggInput (file.AsStream);
        }

        public static AudioFormat Instance { get { return s_OggFormat.Value; } }

        static readonly ResourceInstance<AudioFormat> s_OggFormat = new ResourceInstance<AudioFormat> ("OGG");
    }
}
