/* -*- mode: C; tab-width:8; c-basic-offset:8 -*-
 * vi:set ts=8:
 *
 * al_queue.c
 *
 * Stuff related to the management and use of buffer queue.
 *
 * FIXME: clean this mess up
 */

#include "al_siteconfig.h"

#include <AL/al.h>
#include <stdlib.h>
#include <string.h>

#include "al_config.h"
#include "al_buffer.h"
#include "al_debug.h"
#include "al_error.h"
#include "al_main.h"
#include "al_source.h"
#include "al_queue.h"
#include "al_types.h"
#include "al_mixer.h"

#include "alc/alc_context.h"

/*
 * alSourceQueueBuffers( ALuint sid, ALsizei numBuffers, ALuint *bids )
 *
 * Queue bids[0..numBuffers-1] to the source named sid, setting
 * AL_INVALID_VALUE if numBuffers < 0, or AL_INVALID_NAME if either sid or and
 * bid in bids[0..numBuffers-1] is not a valid buffer.
 */
void alSourceQueueBuffers( ALuint sid, ALsizei numBuffers, const ALuint *bids ) {
	AL_source *src;
	ALsizei i;

	if( numBuffers == 0) {
		/* with n == 0, we NOP */
		return;
	}

	if( numBuffers < 0) {
		_alDebug(ALD_SOURCE, __FILE__, __LINE__,
		      "alSourceQueueBuffers: illegal n value %d\n", numBuffers );

		_alcDCLockContext();
		_alDCSetError( AL_INVALID_VALUE );
		_alcDCUnlockContext();

		return;
	}

	_alLockMixBuf();
	SOURCELOCK();

	src = _alDCGetSource( sid );
	if( src == NULL ) {
		_alDCSetError( AL_INVALID_NAME );

		_alDebug(ALD_SOURCE, __FILE__, __LINE__,
		      "alSourceQueueBuffers: invalid sid %d\n", sid );

		SOURCEUNLOCK();
		_alUnlockMixBuf();

		return;
	}

	_alLockBuffer();

	/* make sure that bids are valid */
	for( i = 0; i < numBuffers; i++ ) {
		if( _alIsBuffer( bids[i] ) == AL_FALSE ) {
			/*
			 * we have an invalid bid.  bid 0 is okay but the
			 * rest are not.
			 */
			if( bids[i] != 0 ) {
				_alUnlockBuffer();

				_alDCSetError( AL_INVALID_NAME );

				SOURCEUNLOCK();
				_alUnlockMixBuf();

				return;
			}
		}
	}

	/* now, append the bids */
	for( i = 0; i < numBuffers; i++ ) {
		if( bids[i] != 0 ) {
			/*
			 * only append non-0 bids, because we don't
			 * need them anyway.
			 */
		  	_alSourceQueueAppend( src, bids[i] );
		}
	}

	/* we're done */

	_alUnlockBuffer();
	SOURCEUNLOCK();
	_alUnlockMixBuf();

	return;
}

/*
 * _alSourceQueueGetCurrentState( AL_source *src )
 *
 * Returns the current AL_sourcestate of the current queue entry for AL_source
 * *src.
 *
 * assumes locked sources
 */
AL_sourcestate *_alSourceQueueGetCurrentState( AL_source *src )
{
	int rind = src->bid_queue.read_index;

	/*
	 * This assert means we're querying a value with the read
	 * index beyond our size.
	 *
	 * Well, like a dumbass I made looping source queue specific.  Now I'm
	 * paying the price.  Okay, return return return.
	 */
	/* assert( rind < src->bid_queue.size ); */

	if(rind >= src->bid_queue.size)
	{
		return NULL;
	}

	return &src->bid_queue.queuestate[rind];
}

/*
 * _alSourceQueueInit( AL_source *src )
 *
 * Initialize an AL_source queue.
 *
 * assumes locked context
 */
void _alSourceQueueInit( AL_source *src ) {
	src->bid_queue.queue       = NULL;
	src->bid_queue.queuestate  = NULL;
	src->bid_queue.size        = 0;

	_alSourceQueueClear( src );

	return;
}

/*
 * _alSourceQueueClear( AL_source *src )
 *
 * Clears a source's queue, removing all entries.
 *
 * assumes locked context
 */
void _alSourceQueueClear( AL_source *src ) {
	ALuint bid;
	int i;

	for(i = 0; i < src->bid_queue.size; i++) {
		bid = src->bid_queue.queue[i];

		if(bid != 0) {
			/* bid 0 is a special name */
			_alBidRemoveQueueRef(bid, src->sid);
		}
	}

	src->bid_queue.read_index  = 0;
	src->bid_queue.write_index = 0;
	src->bid_queue.size        = 0;

	_alSourceQueueAppend(src, 0);

	return;
}

/*
 * _alSourceQueueAppend( AL_source *src, ALuint bid )
 *
 * Append bid to source's queue.
 *
 * assumes locked context
 */
void _alSourceQueueAppend( AL_source *src, ALuint bid ) {
	int size    = src->bid_queue.size;
	int newsize = size + 1;
	int windex  = src->bid_queue.write_index;
	void *temp;

	if(src->bid_queue.size > 0) {
		if(src->bid_queue.queue[windex] == 0) {
			/*
			 * special case.  bid == 0 is the "no bid"
			 * bid, which means that it's just a place
			 * holder to allow buffer specific source
			 * parameters to be set.
			 *
			 * Don't bother to resize, just overwrite.
			 */
			src->bid_queue.queue[windex] = bid;

			return;
		}
	}

	temp = realloc(src->bid_queue.queue,
		       newsize * sizeof *src->bid_queue.queue);
	if(temp == NULL) {
		return;
	}
	src->bid_queue.queue = temp;
	src->bid_queue.queue[size] = 0;

	temp = realloc(src->bid_queue.queuestate,
		       newsize * sizeof *src->bid_queue.queuestate);
	if(temp == NULL) {
		return;
	}
	src->bid_queue.queuestate = temp;

	/*
	 * If this is a "real" append operation, ie not bid == NONE,
	 * then increment the write index so that buffer specific
	 * source setting operations take place.
	 */
	if(bid != 0) {
		windex++;
		src->bid_queue.write_index++;
	}

	/*
	 * Initialize sourcestate flags.
	 */
	_alSourceStateInit(&src->bid_queue.queuestate[windex]);

	/*
	 * Set bid and new size.
	 */
	src->bid_queue.queue[windex] = bid;
	src->bid_queue.size = newsize;


	return;
}


/*
 * _alSourceQueueHead( AL_source *src, ALuint bid )
 *
 * Truncates a source's queue with a single entry of bid.
 *
 * assumes locked context
 */
void _alSourceQueueHead( AL_source *src, ALuint bid ) {
	_alSourceQueueClear( src );

	src->bid_queue.queue[0]    = bid;
	src->bid_queue.write_index = 0;
	src->bid_queue.read_index  = 0;
	src->bid_queue.size        = 1;

	return;
}

/*
 * alSourceUnqueueBuffers( ALuint sid, ALsizei n, ALuint *bids )
 *
 * Unqueues first occurance of each bid in bids[0..n-1] from source named sid.
 */
void alSourceUnqueueBuffers( ALuint sid, ALsizei n, ALuint *bids ) {
	_alLockMixBuf();
	_alcDCLockContext();

	_alSourceUnqueueBuffers( sid, n, bids );

	_alcDCUnlockContext();
	_alUnlockMixBuf();

	return;
}

/*
 * _alSourceStateInit( AL_sourcestate *srcstate )
 *
 * Initialize an AL_sourcestate object to the default settings.
 */
void _alSourceStateInit( AL_sourcestate *srcstate ) {
	srcstate->flags = ALQ_NONE;

	return;
}

/*
 * _alSourceUnqueueBuffers( ALuint sid, ALsizei n, ALuint *bids )
 *
 * Non locking version of alSourceUnqueueBuffers.
 *
 * assumes locked context
 */
void _alSourceUnqueueBuffers(ALuint sid, ALsizei n, ALuint *bids ) {
	AL_source *src;
	ALuint *tempqueue;
	AL_sourcestate *tempstate;
	int newsize;
	int i;

	if(n == 0) {
		/* legal nop */
		return;
	}

	if(n < 0) {
		/* bad n */
		_alDCSetError( AL_INVALID_VALUE );

		_alDebug(ALD_SOURCE, __FILE__, __LINE__,
			"alSourceUnqueueBuffers: invalid numBuffers %d", n );

		return;
	}

	src = _alDCGetSource( sid );
	if(src == NULL) {
		_alDCSetError(AL_INVALID_NAME);
		return;
	}

	if(n > src->bid_queue.read_index) {
		/* User has requested too many buffers unqueued */
		_alDCSetError( AL_INVALID_VALUE );

		_alDebug(ALD_SOURCE, __FILE__, __LINE__,
			"alSourceUnqueueBuffers: invalid numBuffers %d", n );

		return;
	}

	/* make sure queue is valid */
	for( i = 0; i < n; i++ )
	{
		if(!_alIsBuffer(src->bid_queue.queue[i]))
		{
			_alDCSetError( AL_INVALID_NAME );
			_alDebug(ALD_SOURCE, __FILE__, __LINE__,
				"alSourceUnqueueBuffers: invalid buffer name %d",
				n );

			return;
		}
	}

	/* copy queue into bids */
	newsize = src->bid_queue.size - n;

	for( i = 0; i < n; i++ )
	{
		_alBidRemoveQueueRef( src->bid_queue.queue[i], src->sid );
		_alBidRemoveCurrentRef( src->bid_queue.queue[i], src->sid );
	}

	/* resize */
	tempqueue = malloc(newsize * sizeof *tempqueue);
	tempstate = malloc(newsize * sizeof *tempstate);

	assert( tempqueue );
	assert( tempstate );

	if((tempqueue == NULL) || (tempstate == NULL))
	{
		/*
		 * since newsize is less than our current size,
		 * we really shouldn't bomb out here, but should
		 * instead just set the deleted bids to 0 or something[
		 */
		_alDCSetError(AL_OUT_OF_MEMORY);
		_alDebug(ALD_SOURCE, __FILE__, __LINE__,
			"alSourceUnqueueBuffers: unable to allocate memory" );

		return;
	}

	/* okay, we've succedded, so copy the bids for return */
	memcpy( bids, src->bid_queue.queue, n * sizeof *bids );

	/* copy the new queue and state */
	memcpy( tempqueue,
		&src->bid_queue.queue[n], newsize * sizeof *tempqueue );
	memcpy( tempstate,
		&src->bid_queue.queuestate[n], newsize * sizeof *tempstate );

	/*
	 * read_index now points to the wrong bid, so subtract by
	 * old size - newsize.
	 */
	src->bid_queue.read_index -= (src->bid_queue.size - newsize);

	/*
	 * write_indesx too
	 */
	src->bid_queue.write_index -= (src->bid_queue.size - newsize);

	free( src->bid_queue.queue );
	free( src->bid_queue.queuestate );

	src->bid_queue.queue      = tempqueue;
	src->bid_queue.queuestate = tempstate;
	src->bid_queue.size       = newsize;

	return;
}