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/*=============================================================================
	Interleaver.cpp
	
=============================================================================*/

#include "CAAudioFile.h"
#include "CAXException.h"
#include <unistd.h>
#include "CAChannelLayouts.h"
#include "CAFilePathUtils.h"

static void usage()
{
	fprintf(stderr,
			"Usage:\n"
			"%s [option...] input_file... -o output_file\n\n"
			"Options: (may appear before or after arguments)\n"
			"    { -l | --channellayout } layout_tag\n"
			"        layout_tag: name of a constant from CoreAudioTypes.h\n"
			"          (prefix \"kAudioChannelLayoutTag_\" may be omitted)\n",
			getprogname()
			);
	exit(1);
}


void	Interleave(int nInputs, const char *infilenames[], const char *outfilename, const CAAudioChannelLayout *layout)
{
	const UInt32 kBufferSizeFrames = 0x8000;
	const UInt32 kBufferSizeBytes = kBufferSizeFrames * sizeof(Float32);
	class FileAndBuffer : public CAAudioFile {
	public:
		FileAndBuffer() : mBuf(NULL), mPtrs(NULL) { }
		~FileAndBuffer() { delete mBuf; delete mPtrs; }
		
		CABufferList *	mBuf;
		CABufferList *	mPtrs;
	};
	FileAndBuffer *infiles = new FileAndBuffer[nInputs], *file;
	FileAndBuffer outfile;
	int i;
	UInt32 outputChannels = 0;
	double sampleRate = 0.;
	UInt32 maxBitDepth = 0;
	CAStreamBasicDescription clientFormat;
	bool outFileCreated = false;
	
	try {
		// set up input files
		for (i = 0; i < nInputs; ++i) {
			file = &infiles[i];
			file->Open(infilenames[i]);
			const CAStreamBasicDescription &fmt = file->GetFileDataFormat();
			//fmt.PrintFormat(stdout, "", "input file");
			XThrowIf(fmt.mFormatID != kAudioFormatLinearPCM, -1, "input files must be PCM");
			outputChannels += fmt.mChannelsPerFrame;
			if (sampleRate == 0.)
				sampleRate = fmt.mSampleRate;
			else
				XThrowIf(fmt.mSampleRate != sampleRate, -1, "input files must have the same sample rate");
			if (fmt.mBitsPerChannel > maxBitDepth)
				maxBitDepth = fmt.mBitsPerChannel;
			clientFormat.mSampleRate = sampleRate;
			clientFormat.SetCanonical(fmt.mChannelsPerFrame, false);	// deinterleaved
			file->SetClientFormat(clientFormat, NULL);
			file->mBuf = CABufferList::New("readbuf", clientFormat);
			file->mBuf->AllocateBuffers(kBufferSizeBytes);
			file->mPtrs = CABufferList::New("readptrs", clientFormat);
			//clientFormat.PrintFormat(stdout, "", "input client");
		}
		
		if (layout != NULL) {
			if (AudioChannelLayoutTag_GetNumberOfChannels(layout->Tag()) != outputChannels) {
				fprintf(stderr, "Channel layout tag '%s' is inappropriate for %lu channels of audio -- aborting\n", 
					CAChannelLayouts::ConstantToString(layout->Tag()), outputChannels);
				exit(2);
			}
		}

		// prepare output file format
		CAStreamBasicDescription outfmt;
		outfmt.mSampleRate = sampleRate;
		outfmt.mFormatID = kAudioFormatLinearPCM;
		outfmt.mFormatFlags = kLinearPCMFormatFlagIsBigEndian | kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked;
		outfmt.mBitsPerChannel = maxBitDepth;
		outfmt.mChannelsPerFrame = outputChannels;
		outfmt.mBytesPerPacket = outfmt.mBytesPerFrame = outputChannels * (maxBitDepth >> 3);
		outfmt.mFramesPerPacket = 1;
		//outfmt.PrintFormat(stdout, "", "output file");
		
		unlink(outfilename);
		FSRef parentDir;
		CFStringRef outName;
		XThrowIfError(PosixPathToParentFSRefAndName(outfilename, parentDir, outName), "Couldn't locate output directory");
		outfile.CreateNew(parentDir, outName, kAudioFileAIFFType, outfmt, layout ? &layout->Layout() : NULL);
		outFileCreated = true;
		
		// create the output file and buffers
		clientFormat.mSampleRate = sampleRate;
		clientFormat.SetCanonical(outputChannels, false);
		outfile.SetClientFormat(clientFormat, NULL);
		//clientFormat.PrintFormat(stdout, "", "output client");

		outfile.mPtrs = CABufferList::New("writeptrs", clientFormat);

		AudioBufferList &writebufs = outfile.mPtrs->GetModifiableBufferList();
		int outbuf = 0;
		for (i = 0; i < nInputs; ++i) {
			file = &infiles[i];
			const CABufferList *bl = file->mBuf;
			const AudioBufferList &readbufs = bl->GetBufferList();
			memcpy(&writebufs.mBuffers[outbuf], &readbufs.mBuffers[0], 
				readbufs.mNumberBuffers * sizeof(AudioBuffer));
			outbuf += readbufs.mNumberBuffers;
		}
		
		while (true) {
			UInt32 maxFramesRead = 0;
			UInt32 nframes;
			for (i = 0; i < nInputs; ++i) {
				file = &infiles[i];
				file->mPtrs->SetFrom(file->mBuf);
				nframes = kBufferSizeFrames;
				AudioBufferList &readbufs = file->mPtrs->GetModifiableBufferList();
				file->Read(nframes, &readbufs);
				//CAShowAudioBufferList(&readbufs, 8, 0);
				if (nframes > maxFramesRead)
					maxFramesRead = nframes;
				if (nframes < kBufferSizeFrames)
					file->mPtrs->PadWithZeroes(kBufferSizeBytes);
			}
			if (maxFramesRead == 0)
				break;

			if (maxFramesRead < kBufferSizeFrames)
				outfile.mPtrs->SetNumBytes(maxFramesRead * sizeof(Float32));
			//CAShowAudioBufferList(&writebufs, 8, 0);
			outfile.Write(maxFramesRead, &writebufs);
			if (maxFramesRead < kBufferSizeFrames)
				break;
		}
	}
	catch (...) {
		if (outFileCreated)
			unlink(outfilename);
		delete[] infiles;
		throw;
	}
	outfile.Close();
	// input files are closed from destructors
	delete[] infiles;
}

static void	MissingArgument()
{
	fprintf(stderr, "missing argument\n\n");
	usage();
}

int	main(int argc, const char *argv[])
{
	int nins = 0;
	static const int MAX_INPUT_FILES = 32;
	const char *infiles[MAX_INPUT_FILES];
	const char *outfile = NULL;
	UInt32 layoutTag = 0;

	for (int i = 1; i < argc; ++i) {
		const char *arg = argv[i];
		if (arg[0] != '-') {
			if (nins >= MAX_INPUT_FILES) {
				fprintf(stderr, "too many input files\n\n");
				usage();
			}
			infiles[nins++] = arg;
		} else {
			arg += 1;
			if (arg[0] == 'o') {
				if (++i == argc) MissingArgument();
				outfile = argv[i];
			} else if (arg[0] == 'l' || !strcmp(arg, "-channellayout")) {
				if (++i == argc) MissingArgument();
				layoutTag = CAChannelLayouts::StringToConstant(argv[i]);
				if (layoutTag == CAChannelLayouts::kInvalidTag) {
					fprintf(stderr, "unknown channel layout tag: %s\n\n", argv[i]);
					usage();
				}
			} else {
				fprintf(stderr, "unknown argument: %s\n\n", arg - 1);
				usage();
			}
		}
	}
	
	if (nins < 2 || outfile == NULL)
		usage();
	
	try {
		if (layoutTag != 0) {
			CAAudioChannelLayout layout = CAAudioChannelLayout(layoutTag);
			Interleave(nins, infiles, outfile, &layout);
		} else
			Interleave(nins, infiles, outfile, NULL);
	}
	catch (CAXException &e) {
		char buf[256];
		fprintf(stderr, "Error: %s (%s)\n", e.mOperation, CAXException::FormatError(buf, e.mError));
		return 1;
	}
	catch (...) {
		fprintf(stderr, "An unknown error occurred\n");
		return 1;
	}
	return 0;
}