/*
  Copyright (c) 2013 Alex Diener
  
  This software is provided 'as-is', without any express or implied
  warranty. In no event will the authors be held liable for any damages
  arising from the use of this software.
  
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
  
  Alex Diener adiener@sacredsoftware.net
*/

#include "vorbisaudioio/VorbisAudioStream.h"
#include "vorbisaudioio/VorbisAudioIOPrivate.h"
#include "vorbis/codec.h"
#include <string.h>

#define stemobject_implementation VorbisAudioStream
stemobject_vtable_begin();
stemobject_vtable_entry(dispose);
stemobject_vtable_entry(read);
stemobject_vtable_entry(seek);
stemobject_vtable_end();

VorbisAudioStream * VorbisAudioStream_createWithFile(const char * filePath) {
	stemobject_create_implementation(initWithFile, filePath)
}

VorbisAudioStream * VorbisAudioStream_createWithData(void * data, size_t length, bool takeOwnership) {
	stemobject_create_implementation(initWithData, data, length, takeOwnership)
}

static void sharedInit(VorbisAudioStream * self) {
	call_super(init, self, 2, 1, 44100);
	
	self->dataOwned = false;
	self->fileOwned = false;
	self->currentSection = 0;
	self->frameCount = 0;
}

static bool sharedGetInfo(VorbisAudioStream * self) {
	vorbis_info * info;
	
	info = ov_info(&self->vorbisFile, -1);
	if (info == NULL) {
#ifdef DEBUG
		fprintf(stderr, "Error: ov_info returned NULL\n");
#endif
		return false;
	}
	self->bytesPerSample = 2;
	self->channelCount = info->channels;
	self->sampleRate = info->rate;
	self->frameCount = ov_pcm_total(&self->vorbisFile, -1) * self->channelCount;
	return true;
}

bool VorbisAudioStream_initWithFile(VorbisAudioStream * self, const char * filePath) {
	int status;
	
	sharedInit(self);
	status = ov_fopen(filePath, &self->vorbisFile);
	if (status != 0) {
#ifdef DEBUG
		fprintf(stderr, "Error: ov_fopen returned %d\n", status);
#endif
		VorbisAudioStream_dispose(self);
		return false;
	}
	self->fileOwned = true;
	if (!sharedGetInfo(self)) {
		VorbisAudioStream_dispose(self);
		return false;
	}
	return true;
}

bool VorbisAudioStream_initWithData(VorbisAudioStream * self, void * data, size_t length, bool takeOwnership) {
	ov_callbacks callbacks;
	int status;
	
	sharedInit(self);
	
	self->readContext = memreadContextInit(data, length);
	self->dataOwned = takeOwnership;
	
	callbacks.read_func = VorbisAudioIO_memreadFunc;
	callbacks.seek_func = VorbisAudioIO_memseekFunc;
	callbacks.close_func = NULL;
	callbacks.tell_func = VorbisAudioIO_memtellFunc;
	status = ov_open_callbacks(&self->readContext, &self->vorbisFile, NULL, 0, callbacks);
	if (status != 0) {
#ifdef DEBUG
		fprintf(stderr, "Error: ov_open_callbacks returned %d\n", status);
#endif
		VorbisAudioStream_dispose(self);
		return false;
	}
	self->fileOwned = true;
	if (!sharedGetInfo(self)) {
		VorbisAudioStream_dispose(self);
		return false;
	}
	return true;
}

void VorbisAudioStream_dispose(VorbisAudioStream * self) {
	if (self->fileOwned) {
		ov_clear(&self->vorbisFile);
	}
	if (self->dataOwned) {
		free((void *) self->readContext.data);
	}
	call_super(dispose, self);
}

AudioFrameIndex VorbisAudioStream_read(VorbisAudioStream * self, AudioFrameIndex frameCount, void * outBuffer, bool loop) {
	long readResult;
	long bytesRead = 0;
	
	while (bytesRead < (long) (frameCount * self->channelCount)) {
		readResult = ov_read(&self->vorbisFile, outBuffer + bytesRead, frameCount * self->channelCount - bytesRead, OV_READ_ENDIANNESS, 2, 1, &self->currentSection);
		if (readResult == 0) {
			if (loop) {
				ov_pcm_seek(&self->vorbisFile, 0);
			} else {
				break;
			}
		} else if (readResult < 0) {
#ifdef DEBUG
			fprintf(stderr, "Error: ov_read returned %ld\n", readResult);
#endif
			break;
		}
		bytesRead += readResult;
	}
	return bytesRead / self->channelCount;
}

void VorbisAudioStream_seek(VorbisAudioStream * self, AudioFrameIndex offset, int whence) {
	switch (whence) {
		case SEEK_CUR:
			offset += ov_pcm_tell(&self->vorbisFile);
			break;
			
		case SEEK_END:
			offset += self->frameCount;
			break;
	}
	ov_pcm_seek(&self->vorbisFile, offset);
}