/*
 * producer_consumer.c -- produce as a consumer of an encapsulated producer
 * Copyright (C) 2008-2020 Meltytech, LLC
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <framework/mlt.h>

#define CONSUMER_PROPERTIES_PREFIX "consumer."
#define PRODUCER_PROPERTIES_PREFIX "producer."

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

struct context_s {
	mlt_producer self;
	mlt_producer producer;
	mlt_consumer consumer;
	mlt_profile profile;
	int64_t audio_counter;
	mlt_position audio_position;
};
typedef struct context_s *context; 


static int get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
{
	context cx = mlt_frame_pop_service( frame );
	mlt_frame nested_frame = mlt_frame_pop_service( frame );

	*width = cx->profile->width;
	*height = cx->profile->height;

	int result = mlt_frame_get_image( nested_frame, image, format, width, height, writable );

	// Allocate the image
	int size = mlt_image_format_size( *format, *width, *height, NULL );
	uint8_t *new_image = mlt_pool_alloc( size );

	// Update the frame
	mlt_properties properties = mlt_frame_properties( frame );
	mlt_frame_set_image( frame, new_image, size, mlt_pool_release );
	memcpy( new_image, *image, size );
	mlt_properties_set( properties, "progressive", mlt_properties_get( MLT_FRAME_PROPERTIES(nested_frame), "progressive" ) );
	*image = new_image;
	
	// Copy the alpha channel
	uint8_t *alpha = mlt_properties_get_data( MLT_FRAME_PROPERTIES( nested_frame ), "alpha", &size );
	if ( alpha && size > 0 )
	{
		new_image = mlt_pool_alloc( size );
		memcpy( new_image, alpha, size );
		mlt_frame_set_alpha( frame, new_image, size, mlt_pool_release );
	}

	return result;
}

static int get_audio( mlt_frame frame, void **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
{
	context cx = mlt_frame_pop_audio( frame );
	mlt_frame nested_frame = mlt_frame_pop_audio( frame );
	int result = 0;

	// if not repeating last frame
	if ( mlt_frame_get_position( nested_frame ) != cx->audio_position )
	{
		double fps = mlt_profile_fps( cx->profile );
		if ( mlt_producer_get_fps( cx->self ) < fps ) {
			fps = mlt_producer_get_fps( cx->self );
			mlt_properties_set_double( MLT_FRAME_PROPERTIES(nested_frame), "producer_consumer_fps", fps );
		}
		*samples = mlt_audio_calculate_frame_samples( fps, *frequency, cx->audio_counter++ );
		result = mlt_frame_get_audio( nested_frame, buffer, format, frequency, channels, samples );
		int size = mlt_audio_format_size( *format, *samples, *channels );
		int16_t *new_buffer = mlt_pool_alloc( size );

		mlt_frame_set_audio( frame, new_buffer, *format, size, mlt_pool_release );
		memcpy( new_buffer, *buffer, size );
		*buffer = new_buffer;
		cx->audio_position = mlt_frame_get_position( nested_frame );
	}
	else
	{
		// otherwise return no samples
		*samples = 0;
	}

	return result;
}

static void property_changed( mlt_properties owner, mlt_consumer self, char *name )
{
	mlt_properties properties = MLT_PRODUCER_PROPERTIES(self);
	context cx = mlt_properties_get_data( properties, "context", NULL );

	if ( !cx )
		return;

	if ( name == strstr( name, CONSUMER_PROPERTIES_PREFIX ) )
		mlt_properties_set(MLT_CONSUMER_PROPERTIES( cx->consumer ), name + strlen( CONSUMER_PROPERTIES_PREFIX ),
			mlt_properties_get( properties, name ));

	if ( name == strstr( name, PRODUCER_PROPERTIES_PREFIX ) )
		mlt_properties_set(MLT_PRODUCER_PROPERTIES( cx->producer ), name + strlen( PRODUCER_PROPERTIES_PREFIX ),
			mlt_properties_get( properties, name ));
}

static int get_frame( mlt_producer self, mlt_frame_ptr frame, int index )
{
	mlt_properties properties = MLT_PRODUCER_PROPERTIES(self);
	context cx = mlt_properties_get_data( properties, "context", NULL );

	if ( !cx )
	{
		// Allocate and initialize our context
		cx = mlt_pool_alloc( sizeof( struct context_s ) );
		memset( cx, 0, sizeof( *cx ) );
		mlt_properties_set_data( properties, "context", cx, 0, mlt_pool_release, NULL );
		cx->self = self;
		char *profile_name = mlt_properties_get( properties, "profile" );
		if ( !profile_name )
			profile_name = mlt_properties_get( properties, "mlt_profile" );
		mlt_profile profile = mlt_service_profile( MLT_PRODUCER_SERVICE( self ) );

		if ( profile_name )
		{
			cx->profile = mlt_profile_init( profile_name );
			cx->profile->is_explicit = 1;
		}
		else
		{
			cx->profile = mlt_profile_clone( profile );
			cx->profile->is_explicit = 0;
		}

		// Encapsulate a real producer for the resource
		cx->producer = mlt_factory_producer( cx->profile, NULL,
			mlt_properties_get( properties, "resource" ) );
		if ( ( profile_name && !strcmp( profile_name, "auto" ) ) ||
			mlt_properties_get_int( properties, "autoprofile" ) )
		{
			mlt_profile_from_producer( cx->profile, cx->producer );
			mlt_producer_close( cx->producer );
			cx->producer = mlt_factory_producer( cx->profile, NULL,	mlt_properties_get( properties, "resource" ) );
		}

		// Since we control the seeking, prevent it from seeking on its own
		mlt_producer_set_speed( cx->producer, 0 );
		cx->audio_position = -1;

		// We will encapsulate a consumer
		cx->consumer = mlt_consumer_new( cx->profile );
		// Do not use _pass_list on real_time so that it defaults to 0 in the absence of
		// an explicit real_time property.
		mlt_properties_set_int( MLT_CONSUMER_PROPERTIES( cx->consumer ), "real_time",
			mlt_properties_get_int( properties, "real_time" ) );
		mlt_properties_pass_list( MLT_CONSUMER_PROPERTIES( cx->consumer ), properties,
			"buffer, prefill, deinterlace_method, rescale" );

		mlt_properties_pass( MLT_CONSUMER_PROPERTIES( cx->consumer ), properties, CONSUMER_PROPERTIES_PREFIX );
		mlt_properties_pass( MLT_PRODUCER_PROPERTIES( cx->producer ), properties, PRODUCER_PROPERTIES_PREFIX );
		mlt_events_listen( properties, self, "property-changed", ( mlt_listener )property_changed );

		// Connect it all together
		mlt_consumer_connect( cx->consumer, MLT_PRODUCER_SERVICE( cx->producer ) );
		mlt_consumer_start( cx->consumer );
	}

	// Generate a frame
	*frame = mlt_frame_init( MLT_PRODUCER_SERVICE( self ) );
	if ( *frame )
	{
		// Seek the producer to the correct place
		// Calculate our positions
		double actual_position = (double) mlt_producer_frame( self );
		if ( mlt_producer_get_speed( self ) != 0 )
			actual_position *= mlt_producer_get_speed( self );
		mlt_position need_first = floor( actual_position );
		mlt_producer_seek( cx->producer,
			lrint( need_first * mlt_profile_fps( cx->profile ) / mlt_producer_get_fps( self ) ) );

		// Get the nested frame
		mlt_frame nested_frame = mlt_consumer_rt_frame( cx->consumer );

		// Stack the producer and our methods on the nested frame
		mlt_frame_push_service( *frame, nested_frame );
		mlt_frame_push_service( *frame, cx );
		mlt_frame_push_get_image( *frame, get_image );
		mlt_frame_push_audio( *frame, nested_frame );
		mlt_frame_push_audio( *frame, cx );
		mlt_frame_push_audio( *frame, get_audio );
		
		// Give the returned frame temporal identity
		mlt_frame_set_position( *frame, mlt_producer_position( self ) );
		
		// Store the nested frame on the produced frame for destruction
		mlt_properties frame_props = MLT_FRAME_PROPERTIES( *frame );
		mlt_properties_set_data( frame_props, "_producer_consumer.frame", nested_frame, 0, (mlt_destructor) mlt_frame_close, NULL );

		// Inform the normalizers about our video properties
		mlt_properties_set_double( frame_props, "aspect_ratio", mlt_profile_sar( cx->profile ) );
		mlt_properties_set_int( frame_props, "width", cx->profile->width );
		mlt_properties_set_int( frame_props, "height", cx->profile->height );
		mlt_properties_set_int( frame_props, "meta.media.width", cx->profile->width );
		mlt_properties_set_int( frame_props, "meta.media.height", cx->profile->height );
		mlt_properties_set_int( frame_props, "progressive", cx->profile->progressive );
	}

	// Calculate the next timecode
	mlt_producer_prepare_next( self );

	return 0;
}

static void producer_close( mlt_producer self )
{
	context cx = mlt_properties_get_data( MLT_PRODUCER_PROPERTIES( self ), "context", NULL );
	
	// Shut down all the encapsulated services
	if ( cx )
	{
		mlt_consumer_stop( cx->consumer );
		mlt_consumer_close( cx->consumer );
		mlt_producer_close( cx->producer );
		mlt_profile_close( cx->profile );
	}
	
	self->close = NULL;
	mlt_producer_close( self );
	free( self );
}

mlt_producer producer_consumer_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
{
	mlt_producer self = mlt_producer_new( profile );

	// Encapsulate the real producer
	mlt_profile temp_profile = mlt_profile_clone( profile );
	temp_profile->is_explicit = 0;
	mlt_producer real_producer = mlt_factory_producer( temp_profile, NULL, arg );

	if ( self && real_producer )
	{
		// Override some producer methods
		self->close = ( mlt_destructor )producer_close;
		self->get_frame = get_frame;
		
		// Get the properties of this producer
		mlt_properties properties = MLT_PRODUCER_PROPERTIES( self );
		mlt_properties_set( properties, "resource", arg );
		mlt_properties_pass_list( properties, MLT_PRODUCER_PROPERTIES( real_producer ), "out, length" );

		// Done with the producer - will re-open later when we have the profile property
		mlt_producer_close( real_producer );
	}
	else
	{
		if ( self )
			mlt_producer_close( self );
		if ( real_producer )
			mlt_producer_close( real_producer );

		self = NULL;
	}
	mlt_profile_close( temp_profile );
	return self;
}