//  Copyright (c) 2007-2008 Fredrik Mellbin
//
//  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.

#include "ffmpegsource.h"

int FFMatroskaSource::GetTrackIndex(int Index, unsigned char ATrackType, IScriptEnvironment *Env) {
	if (Index == -1)
		for (unsigned int i = 0; i < mkv_GetNumTracks(MF); i++)
			if (mkv_GetTrackInfo(MF, i)->Type == ATrackType) {
				Index = i;
				break;
			}

	if (Index == -1)
		Env->ThrowError("FFmpegSource: No %s track found", (ATrackType & TT_VIDEO) ? "video" : "audio");
	if (Index <= -2)
		return -2;

	if (Index >= (int)mkv_GetNumTracks(MF))
		Env->ThrowError("FFmpegSource: Invalid %s track number", (ATrackType & TT_VIDEO) ? "video" : "audio");

	TrackInfo *TI = mkv_GetTrackInfo(MF, Index);

	if (TI->Type != ATrackType)
		Env->ThrowError("FFmpegSource: Selected track is not %s", (ATrackType & TT_VIDEO) ? "video" : "audio");

	return Index;
}

FFMatroskaSource::FFMatroskaSource(const char *ASource, int AVideoTrack, int AAudioTrack, const char *ATimecodes,
	bool AVCache, const char *AVideoCache, const char *AAudioCache, const char *APPString,
	int AQuality, int AThreads, IScriptEnvironment* Env) {

	CurrentFrame = 0;
	int VideoTrack;
	int AudioTrack;
	unsigned int TrackMask = ~0;
	AVCodecContext *AudioCodecContext = NULL;
	AVCodec *AudioCodec = NULL;
	VideoCodecContext = NULL;
	AVCodec *VideoCodec = NULL;
	TrackInfo *VideoTI = NULL;
	BufferSize = 0;
	Buffer = NULL;
	VideoCS = NULL;
	AudioCS = NULL;

	memset(&ST,0,sizeof(ST));
	ST.base.read = (int (__cdecl *)(InputStream *,ulonglong,void *,int))StdIoRead;
	ST.base.scan = (longlong (__cdecl *)(InputStream *,ulonglong,unsigned int))StdIoScan;
	ST.base.getcachesize = (unsigned int (__cdecl *)(InputStream *))StdIoGetCacheSize;
	ST.base.geterror = (const char *(__cdecl *)(InputStream *))StdIoGetLastError;
	ST.base.memalloc = (void *(__cdecl *)(InputStream *,size_t))StdIoMalloc;
	ST.base.memrealloc = (void *(__cdecl *)(InputStream *,void *,size_t))StdIoRealloc;
	ST.base.memfree = (void (__cdecl *)(InputStream *,void *)) StdIoFree;
	ST.base.progress = (int (__cdecl *)(InputStream *,ulonglong,ulonglong))StdIoProgress;

	ST.fp = fopen(ASource, "rb");
	if (ST.fp == NULL)
		Env->ThrowError("FFmpegSource: Can't open '%s': %s", ASource, strerror(errno));

	setvbuf(ST.fp, NULL, _IOFBF, CACHESIZE);

	MF = mkv_OpenEx(&ST.base, 0, 0, ErrorMessage, sizeof(ErrorMessage));
	if (MF == NULL) {
		fclose(ST.fp);
		Env->ThrowError("FFmpegSource: Can't parse Matroska file: %s", ErrorMessage);
	}

	VideoTrack = GetTrackIndex(AVideoTrack, TT_VIDEO, Env);
	AudioTrack = GetTrackIndex(AAudioTrack, TT_AUDIO, Env);

	bool VCacheIsValid = true;
	bool ACacheIsValid = true;

	if (VideoTrack >= 0) {
		VCacheIsValid = LoadFrameInfoFromFile(AVideoCache, ASource, VideoTrack);

		VideoTI = mkv_GetTrackInfo(MF, VideoTrack);

		if (VideoTI->CompEnabled) {
			VideoCS = cs_Create(MF, VideoTrack, ErrorMessage, sizeof(ErrorMessage));
			if (VideoCS == NULL)
				Env->ThrowError("FFmpegSource: Can't create decompressor: %s", ErrorMessage);
		}

		VideoCodecContext = avcodec_alloc_context();
		VideoCodecContext->extradata = (uint8_t *)VideoTI->CodecPrivate;
		VideoCodecContext->extradata_size = VideoTI->CodecPrivateSize;
		VideoCodecContext->thread_count = AThreads;

		VideoCodec = avcodec_find_decoder(MatroskaToFFCodecID(VideoTI));
		if (VideoCodec == NULL)
			Env->ThrowError("FFmpegSource: Video codec not found");

		if (avcodec_open(VideoCodecContext, VideoCodec) < 0)
			Env->ThrowError("FFmpegSource: Could not open video codec");

		// Fix for mpeg2 and other formats where decoding a frame is necessary to get information about the stream
		if (VideoCodecContext->pix_fmt == PIX_FMT_NONE || VideoCodecContext->width == 0 || VideoCodecContext->height == 0) {
			mkv_SetTrackMask(MF, ~(1 << VideoTrack));
			int64_t Dummy;
			DecodeNextFrame(DecodeFrame, &Dummy, Env);
			mkv_Seek(MF, 0, MKVF_SEEK_TO_PREV_KEYFRAME);
		}

		VI.image_type = VideoInfo::IT_TFF;
		VI.width = VideoCodecContext->width;
		VI.height = VideoCodecContext->height;;
		VI.fps_denominator = 1;
		VI.fps_numerator = 30;

		if (VI.width <= 0 || VI.height <= 0)
			Env->ThrowError("FFmpegSource: Codec returned zero size video");

		SetOutputFormat(VideoCodecContext->pix_fmt, Env);
		InitPP(VI.width, VI.height, APPString, AQuality, VideoCodecContext->pix_fmt, Env);

		if (!VCacheIsValid)
			TrackMask &= ~(1 << VideoTrack);
	}

	if (AudioTrack >= 0) {
		TrackInfo *AudioTI = mkv_GetTrackInfo(MF, AudioTrack);

		if (AudioTI->CompEnabled) {
			AudioCS = cs_Create(MF, AudioTrack, ErrorMessage, sizeof(ErrorMessage));
			if (AudioCS == NULL)
				Env->ThrowError("FFmpegSource: Can't create decompressor: %s", ErrorMessage);
		}

		AudioCodecContext = avcodec_alloc_context();
		AudioCodecContext->extradata = (uint8_t *)AudioTI->CodecPrivate;
		AudioCodecContext->extradata_size = AudioTI->CodecPrivateSize;

		AudioCodec = avcodec_find_decoder(MatroskaToFFCodecID(AudioTI));
		if (AudioCodec == NULL)
			Env->ThrowError("FFmpegSource: Audio codec not found");

		if (avcodec_open(AudioCodecContext, AudioCodec) < 0)
			Env->ThrowError("FFmpegSource: Could not open audio codec");

		// Fix for ac3 and other codecs where decoding a block of audio is required to get information about it
		if (AudioCodecContext->channels == 0 || AudioCodecContext->sample_rate == 0) {
			mkv_SetTrackMask(MF, ~(1 << AudioTrack));
			uint64_t StartTime, EndTime, FilePos;
			unsigned int Track, FrameFlags, FrameSize;
			mkv_ReadFrame(MF, 0, &Track, &StartTime, &EndTime, &FilePos, &FrameSize, &FrameFlags);

			int Size = ReadFrame(FilePos, FrameSize, AudioCS, Env);
			uint8_t *Data = Buffer;

			while (Size > 0) {
				int TempOutputBufSize = AVCODEC_MAX_AUDIO_FRAME_SIZE;
				int Ret = avcodec_decode_audio2(AudioCodecContext, (int16_t *)DecodingBuffer, &TempOutputBufSize, Data, Size);
				if (Ret < 0)
					Env->ThrowError("FFmpegSource: Audio decoding error");

				Size -= Ret;
				Data += Ret;
			}

			mkv_Seek(MF, 0, MKVF_SEEK_TO_PREV_KEYFRAME);
		}

		VI.nchannels = AudioCodecContext->channels;
		VI.audio_samples_per_second = AudioCodecContext->sample_rate;

		switch (AudioCodecContext->sample_fmt) {
			case SAMPLE_FMT_U8: VI.sample_type = SAMPLE_INT8; break;
			case SAMPLE_FMT_S16: VI.sample_type = SAMPLE_INT16; break;
			case SAMPLE_FMT_S24: VI.sample_type = SAMPLE_INT24; break;
			case SAMPLE_FMT_S32: VI.sample_type = SAMPLE_INT32; break;
			case SAMPLE_FMT_FLT: VI.sample_type = SAMPLE_FLOAT; break;
			default:
				Env->ThrowError("FFmpegSource: Unsupported/unknown sample format");
		}

		ACacheIsValid = OpenAudioCache(AAudioCache, ASource, AudioTrack, Env);
		if (!ACacheIsValid)
			TrackMask &= ~(1 << AudioTrack);
	}

	mkv_SetTrackMask(MF, TrackMask);

	// Needs to be indexed?
	if (!ACacheIsValid || !VCacheIsValid) {
		FILE *RawCache = NULL;
		if (!ACacheIsValid)
			AudioCacheType = acRaw;	

		switch (AudioCacheType) {
			case acRaw: RawCache = NewRawCacheWriter(AAudioCache, ASource, AudioTrack, Env); break;
		}

		uint64_t StartTime, EndTime, FilePos;
		unsigned int Track, FrameFlags, FrameSize;

		while (mkv_ReadFrame(MF, 0, &Track, &StartTime, &EndTime, &FilePos, &FrameSize, &FrameFlags) == 0)
			if (Track == VideoTrack && !VCacheIsValid) {
				Frames.push_back(FrameInfo(StartTime, (FrameFlags & FRAME_KF) != 0));
				VI.num_frames++;
			} else if (Track == AudioTrack && !ACacheIsValid) {
				int Size = ReadFrame(FilePos, FrameSize, AudioCS, Env);
				uint8_t *Data = Buffer;

				while (Size > 0) {
					int TempOutputBufSize = AVCODEC_MAX_AUDIO_FRAME_SIZE;
					int Ret = avcodec_decode_audio2(AudioCodecContext, (int16_t *)DecodingBuffer, &TempOutputBufSize, Data, Size);
					if (Ret < 0)
						Env->ThrowError("FFmpegSource: Audio decoding error");

					int DecodedSamples = (int)VI.AudioSamplesFromBytes(TempOutputBufSize);

					Size -= Ret;
					Data += Ret;
					VI.num_audio_samples += DecodedSamples;

					if (AudioCacheType == acRaw) {
						fwrite(DecodingBuffer, 1, TempOutputBufSize, RawCache);
					}
				}
			}

		if (!ACacheIsValid) {
			switch (AudioCacheType) {
				case acRaw: CloseRawCacheWriter(RawCache); break;
			}

			ACacheIsValid = OpenAudioCache(AAudioCache, ASource, AudioTrack, Env);
			if (!ACacheIsValid)
				Env->ThrowError("FFmpegSource: Failed to open newly created audio cache for reading");
		}

		if (VideoTrack >= 0 && VI.num_frames == 0)
			Env->ThrowError("FFmpegSource: Video track contains no frames");

		if (AudioTrack >= 0 && VI.num_audio_samples == 0)
			Env->ThrowError("FFmpegSource: Audio track contains no samples");

		if (VideoTrack >= 0)
			mkv_Seek(MF, Frames.front().DTS, MKVF_SEEK_TO_PREV_KEYFRAME);

		if (AVCache && !VCacheIsValid)
			if (!SaveFrameInfoToFile(AVideoCache, ASource, VideoTrack))
				Env->ThrowError("FFmpegSource: Failed to write video cache info");
	}

	if (AudioTrack >= 0) {
		avcodec_close(AudioCodecContext);
		av_free(AudioCodecContext);
	}

	if (VideoTrack >= 0) {
		mkv_SetTrackMask(MF, ~(1 << VideoTrack));

		// Calculate the average framerate
		if (Frames.size() >= 2) {
			double DTSDiff = (double)(Frames.back().DTS - Frames.front().DTS);
			VI.fps_denominator = (unsigned int)(DTSDiff * mkv_TruncFloat(VideoTI->TimecodeScale) / (double)1000 / (double)(VI.num_frames - 1) + 0.5);
			VI.fps_numerator = 1000000; 
		}

		if (!SaveTimecodesToFile(ATimecodes, mkv_TruncFloat(VideoTI->TimecodeScale), 1000000))
			Env->ThrowError("FFmpegSource: Failed to write timecodes");

		// Set AR variables
		int ffsar_num = VideoTI->AV.Video.DisplayWidth * VideoTI->AV.Video.PixelHeight;
		int ffsar_den = VideoTI->AV.Video.DisplayHeight * VideoTI->AV.Video.PixelWidth;
		Env->SetVar("FFSAR_NUM", ffsar_num);
		Env->SetVar("FFSAR_DEN", ffsar_den);
		Env->SetVar("FFSAR", ffsar_num / (double)ffsar_den);

		// Set crop variables
		Env->SetVar("FFCROP_LEFT", (int)VideoTI->AV.Video.CropL);
		Env->SetVar("FFCROP_RIGHT", (int)VideoTI->AV.Video.CropR);
		Env->SetVar("FFCROP_TOP", (int)VideoTI->AV.Video.CropT);
		Env->SetVar("FFCROP_BOTTOM", (int)VideoTI->AV.Video.CropB);
	}
}

FFMatroskaSource::~FFMatroskaSource() {
	free(Buffer);
	mkv_Close(MF);
	fclose(ST.fp);
	if (VideoCodecContext)
		avcodec_close(VideoCodecContext);
	av_free(VideoCodecContext);
}

int FFMatroskaSource::ReadFrame(uint64_t AFilePos, unsigned int AFrameSize, CompressedStream *ACS, IScriptEnvironment *Env) {
	if (ACS) {
		char CSBuffer[4096];

		unsigned int DecompressedFrameSize = 0;

		cs_NextFrame(ACS, AFilePos, AFrameSize);

		for (;;) {
			int ReadBytes = cs_ReadData(ACS, CSBuffer, sizeof(CSBuffer));
			if (ReadBytes < 0)
				Env->ThrowError("FFmpegSource: Error decompressing data: %s", cs_GetLastError(ACS));
			if (ReadBytes == 0) {
				return DecompressedFrameSize;
			}

			if (BufferSize < DecompressedFrameSize + ReadBytes) {
				BufferSize = AFrameSize;
				Buffer = (uint8_t *)realloc(Buffer, BufferSize);
				if (Buffer == NULL) 
					Env->ThrowError("FFmpegSource: Out of memory");
			}

			memcpy(Buffer + DecompressedFrameSize, CSBuffer, ReadBytes);
			DecompressedFrameSize += ReadBytes;
		}
	} else {
		if (_fseeki64(ST.fp, AFilePos, SEEK_SET))
			Env->ThrowError("FFmpegSource: fseek(): %s", strerror(errno));

		if (BufferSize < AFrameSize) {
			BufferSize = AFrameSize;
			Buffer = (uint8_t *)realloc(Buffer, BufferSize);
			if (Buffer == NULL) 
				Env->ThrowError("FFmpegSource: Out of memory");
		}

		size_t ReadBytes = fread(Buffer, 1, AFrameSize, ST.fp);
		if (ReadBytes != AFrameSize) {
			if (ReadBytes == 0) {
				if (feof(ST.fp))
					Env->ThrowError("FFmpegSource: Unexpected EOF while reading frame");
				else
					Env->ThrowError("FFmpegSource: Error reading frame: %s", strerror(errno));
			} else
				Env->ThrowError("FFmpegSource: Short read while reading frame");
			Env->ThrowError("FFmpegSource: Unknown read error");
		}

		return AFrameSize;
	}

	return 0;
}

int FFMatroskaSource::DecodeNextFrame(AVFrame *AFrame, int64_t *AFirstStartTime, IScriptEnvironment* Env) {
	int FrameFinished = 0;
	int Ret = -1;
	*AFirstStartTime = -1;

	uint64_t StartTime, EndTime, FilePos;
	unsigned int Track, FrameFlags, FrameSize;
	
	while (mkv_ReadFrame(MF, 0, &Track, &StartTime, &EndTime, &FilePos, &FrameSize, &FrameFlags) == 0) {
		if (*AFirstStartTime < 0)
			*AFirstStartTime = StartTime;
		FrameSize = ReadFrame(FilePos, FrameSize, VideoCS, Env);
		Ret = avcodec_decode_video(VideoCodecContext, AFrame, &FrameFinished, Buffer, FrameSize);

		if (FrameFinished)
			goto Done;
	}

	// Flush the last frames
	if (VideoCodecContext->has_b_frames)
		Ret = avcodec_decode_video(VideoCodecContext, AFrame, &FrameFinished, NULL, 0);

	if (!FrameFinished)
		goto Error;

Error:
Done:
	return Ret;
}

PVideoFrame FFMatroskaSource::GetFrame(int n, IScriptEnvironment* Env) {
	if (LastFrameNum == n)
		return LastFrame;

	bool HasSeeked = false;

	if (n < CurrentFrame || FindClosestKeyFrame(n) > CurrentFrame) {
		mkv_Seek(MF, Frames[n].DTS, MKVF_SEEK_TO_PREV_KEYFRAME);
		avcodec_flush_buffers(VideoCodecContext);
		HasSeeked = true;
	}

	do {
		int64_t StartTime;
		int Ret = DecodeNextFrame(DecodeFrame, &StartTime, Env);

		if (HasSeeked) {
			HasSeeked = false;

			if (StartTime < 0 || (CurrentFrame = FrameFromDTS(StartTime)) < 0)
				Env->ThrowError("FFmpegSource: Frame accurate seeking is not possible in this file");
		}

		CurrentFrame++;
	} while (CurrentFrame <= n);

	LastFrame = OutputFrame(DecodeFrame, Env);
	LastFrameNum = n;
	return LastFrame;
}