using Amphora;
using System.Text;
using UnitTestSharp;

namespace Susurrus.UnitTests
{
    public class SoundFormatsTests : TestFixture
    {
        public static byte[] Text(string text)
        {
            return Encoding.ASCII.GetBytes(text);
        }

        public static byte[] Padded(byte[] start, int length)
        {
            byte[] returnMe = new byte[length];
            System.Array.Copy(start, returnMe, start.Length);
            return returnMe;
        }

        public static byte[] OggPageWith(byte[] firstPacket)
        {
            byte[] returnMe = new byte[28 + firstPacket.Length];
            System.Array.Copy(Text("OggS"), returnMe, 4);
            returnMe[26] = 1;
            returnMe[27] = (byte)firstPacket.Length;
            System.Array.Copy(firstPacket, 0, returnMe, 28, firstPacket.Length);
            return returnMe;
        }

        public static SoundFormat DetectAll(byte[] header)
        {
            return SoundFormats.Detect(new ByteView(header));
        }

        public class DetectTests : TestFixture
        {
            public void RiffWave_IsWav()
            {
                CheckEqual(SoundFormat.Wav, DetectAll(Text("RIFF\0\0\0\0WAVEfmt ")));
            }

            public void RifxWave_IsWav()
            {
                CheckEqual(SoundFormat.Wav, DetectAll(Text("RIFX\0\0\0\0WAVEfmt ")));
            }

            public void Rf64Wave_IsWav()
            {
                CheckEqual(SoundFormat.Wav, DetectAll(Text("RF64\0\0\0\0WAVEfmt ")));
            }

            public void RiffThatIsNotWave_IsUnknown()
            {
                CheckEqual(SoundFormat.Unknown, DetectAll(Text("RIFF\0\0\0\0AVI LIST")));
            }

            public void OggWhoseFirstPacketIsVorbis_IsOggVorbis()
            {
                byte[] packet = { 0x01, (byte)'v', (byte)'o', (byte)'r', (byte)'b', (byte)'i', (byte)'s' };

                CheckEqual(SoundFormat.OggVorbis, DetectAll(OggPageWith(packet)));
            }

            public void OggWhoseFirstPacketIsOpus_IsOggOpus()
            {
                CheckEqual(SoundFormat.OggOpus, DetectAll(OggPageWith(Text("OpusHead"))));
            }

            public void OggWhoseFirstPacketIsFlac_IsOggFlac()
            {
                byte[] packet = { 0x7F, (byte)'F', (byte)'L', (byte)'A', (byte)'C' };

                CheckEqual(SoundFormat.OggFlac, DetectAll(OggPageWith(packet)));
            }

            public void OggWhoseFirstPacketIsSpeex_IsOggSpeex()
            {
                CheckEqual(SoundFormat.OggSpeex, DetectAll(OggPageWith(Text("Speex   "))));
            }

            public void OggWhoseFirstPacketIsAnythingElse_IsOggOther()
            {
                CheckEqual(SoundFormat.OggOther, DetectAll(OggPageWith(Text("theora!!"))));
            }

            public void OggWithTooFewBytesToShowItsCodec_IsOggOther()
            {
                CheckEqual(SoundFormat.OggOther, DetectAll(Text("OggS")));
            }

            public void OnlyTheBytesInTheViewAreLookedAt()
            {
                byte[] opus = OggPageWith(Text("OpusHead"));

                CheckEqual(SoundFormat.OggOther, SoundFormats.Detect(new ByteView(opus, startIndex: 0, endIndex: 30)));
            }

            public void TheViewsStartIsTheStartOfTheFile()
            {
                byte[] padded = Padded(Text("xxxxRIFF\0\0\0\0WAVEfmt "), 40);
                ByteView window = new ByteView(padded, startIndex: 4, endIndex: 20);

                CheckEqual(SoundFormat.Wav, SoundFormats.Detect(window));
            }

            public void DefaultView_IsUnknown()
            {
                CheckEqual(SoundFormat.Unknown, SoundFormats.Detect(default(ByteView)));
            }

            public void FlacMarker_IsFlac()
            {
                CheckEqual(SoundFormat.Flac, DetectAll(Text("fLaC\0\0\0\"")));
            }

            public void FormAiff_IsAiff()
            {
                CheckEqual(SoundFormat.Aiff, DetectAll(Text("FORM\0\0\0\0AIFFCOMM")));
            }

            public void FormAifc_IsAiff()
            {
                CheckEqual(SoundFormat.Aiff, DetectAll(Text("FORM\0\0\0\0AIFCFVER")));
            }

            public void FormThatIsNotAiff_IsUnknown()
            {
                CheckEqual(SoundFormat.Unknown, DetectAll(Text("FORM\0\0\0\0ILBMBMHD")));
            }

            public void FtypAtOffsetFour_IsMp4()
            {
                CheckEqual(SoundFormat.Mp4, DetectAll(Text("\0\0\0 ftypM4A ")));
            }

            public void AsfHeaderGuid_IsWma()
            {
                byte[] guid = { 0x30, 0x26, 0xB2, 0x75, 0x8E, 0x66, 0xCF, 0x11, 0xA6, 0xD9, 0x00, 0xAA, 0x00, 0x62 };

                CheckEqual(SoundFormat.Wma, DetectAll(guid));
            }

            public void Id3Tag_IsMp3()
            {
                CheckEqual(SoundFormat.Mp3, DetectAll(Text("ID3\u0004\0\0\0\0")));
            }

            public void MpegOneLayerThreeFrame_IsMp3()
            {
                CheckEqual(SoundFormat.Mp3, DetectAll(new byte[] { 0xFF, 0xFB, 0x50, 0xC4 }));
            }

            public void MpegTwoLayerThreeFrame_IsMp3()
            {
                CheckEqual(SoundFormat.Mp3, DetectAll(new byte[] { 0xFF, 0xF3, 0x50, 0xC4 }));
            }

            public void MpegTwoPointFiveLayerThreeFrame_IsMp3()
            {
                CheckEqual(SoundFormat.Mp3, DetectAll(new byte[] { 0xFF, 0xE3, 0x50, 0xC4 }));
            }

            public void AdtsFrameWithoutProtection_IsAac()
            {
                CheckEqual(SoundFormat.Aac, DetectAll(new byte[] { 0xFF, 0xF1, 0x50, 0x80 }));
            }

            public void AdtsFrameWithProtection_IsAac()
            {
                CheckEqual(SoundFormat.Aac, DetectAll(new byte[] { 0xFF, 0xF9, 0x50, 0x80 }));
            }

            public void FrameSyncWithAReservedVersion_IsUnknown()
            {
                CheckEqual(SoundFormat.Unknown, DetectAll(new byte[] { 0xFF, 0xEB, 0x50, 0xC4 }));
            }

            public void FrameSyncWithLayerZeroThatIsNotAdts_IsUnknown()
            {
                CheckEqual(SoundFormat.Unknown, DetectAll(new byte[] { 0xFF, 0xE1, 0x50, 0xC4 }));
            }

            public void FirstByteOfASyncAlone_IsUnknown()
            {
                CheckEqual(SoundFormat.Unknown, DetectAll(new byte[] { 0xFF }));
            }

            public void ASecondByteWithoutTheSyncBits_IsUnknown()
            {
                CheckEqual(SoundFormat.Unknown, DetectAll(new byte[] { 0xFF, 0x1F, 0x50, 0xC4 }));
            }

            public void NoBytes_IsUnknown()
            {
                CheckEqual(SoundFormat.Unknown, DetectAll(new byte[0]));
            }
        }

        public class DescribeTests : TestFixture
        {
            public void NamesEachFormatInASentence()
            {
                CheckEqual("a WAV file", SoundFormats.Describe(SoundFormat.Wav));
                CheckEqual("an Ogg Vorbis file", SoundFormats.Describe(SoundFormat.OggVorbis));
                CheckEqual("an Ogg Opus file", SoundFormats.Describe(SoundFormat.OggOpus));
                CheckEqual("an Ogg FLAC file", SoundFormats.Describe(SoundFormat.OggFlac));
                CheckEqual("an Ogg Speex file", SoundFormats.Describe(SoundFormat.OggSpeex));
                CheckEqual("an Ogg file that doesn't hold Vorbis", SoundFormats.Describe(SoundFormat.OggOther));
                CheckEqual("an MP3 file", SoundFormats.Describe(SoundFormat.Mp3));
                CheckEqual("an AAC file", SoundFormats.Describe(SoundFormat.Aac));
                CheckEqual("a FLAC file", SoundFormats.Describe(SoundFormat.Flac));
                CheckEqual("an AIFF file", SoundFormats.Describe(SoundFormat.Aiff));
                CheckEqual("an MP4 or M4A file", SoundFormats.Describe(SoundFormat.Mp4));
                CheckEqual("a WMA or other ASF file", SoundFormats.Describe(SoundFormat.Wma));
            }

            public void Unknown_IsUnrecognized()
            {
                CheckEqual("an unrecognized format", SoundFormats.Describe(SoundFormat.Unknown));
            }
        }
    }
}