/*************************************************************************/
/*  event_queue.cpp                                                      */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* 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 "event_queue.h"


Error EventQueue::push_call(uint32_t p_instance_ID, const StringName& p_method, VARIANT_ARG_DECLARE) {

	uint8_t room_needed=sizeof(Event);
	int args=0;
	if (p_arg5.get_type()!=Variant::NIL)
		args=5;
	else if (p_arg4.get_type()!=Variant::NIL)
		args=4;
	else if (p_arg3.get_type()!=Variant::NIL)
		args=3;
	else if (p_arg2.get_type()!=Variant::NIL)
		args=2;
	else if (p_arg1.get_type()!=Variant::NIL)
		args=1;
	else 
		args=0;
		
	room_needed+=sizeof(Variant)*args;
		
	ERR_FAIL_COND_V( (buffer_end+room_needed) >= buffer_size , ERR_OUT_OF_MEMORY );
	Event * ev = memnew_placement( &event_buffer[ buffer_end ], Event );
	ev->args=args;
	ev->instance_ID=p_instance_ID;
	ev->method=p_method;
	
	buffer_end+=sizeof(Event);
	
	if (args==1) {
	
		Variant * v = memnew_placement( &event_buffer[ buffer_end ], Variant );
		buffer_end+=sizeof(Variant);
		*v=p_arg1;
	} else if (args==2) {
	
		Variant * v = memnew_placement( &event_buffer[ buffer_end ], Variant );
		buffer_end+=sizeof(Variant);
		*v=p_arg2;
	} else if (args==3) {
	
		Variant * v = memnew_placement( &event_buffer[ buffer_end ], Variant );
		buffer_end+=sizeof(Variant);
		*v=p_arg3;
		
	} else if (args==4) {
	
		Variant * v = memnew_placement( &event_buffer[ buffer_end ], Variant );
		buffer_end+=sizeof(Variant);
		*v=p_arg4;
	} else if (args==5) {
	
		Variant * v = memnew_placement( &event_buffer[ buffer_end ], Variant );
		buffer_end+=sizeof(Variant);
		*v=p_arg5;
	}
	
	if (buffer_max_used>buffer_end);
		buffer_max_used=buffer_end;
		
	return OK;
}

void EventQueue::flush_events() {

	uint32_t read_pos=0;
	
	while (read_pos < buffer_end ) {
	
		Event *event = (Event*)&event_buffer[ read_pos ];
		Variant *args= (Variant*)(event+1);
		Object *obj = ObjectDB::get_instance(event->instance_ID);
					
		if (obj) {		
			// events don't expect a return value
			obj->call( event->method, 
				(event->args>=1) ? args[0] : Variant(),
				(event->args>=2) ? args[1] : Variant(),
				(event->args>=3) ? args[2] : Variant(),
				(event->args>=4) ? args[3] : Variant(),
				(event->args>=5) ? args[4] : Variant() );
		}
		
		if (event->args>=1) args[0].~Variant();
		if (event->args>=2) args[1].~Variant();
		if (event->args>=3) args[2].~Variant();
		if (event->args>=4) args[3].~Variant();
		if (event->args>=5) args[4].~Variant();
		event->~Event();
		
		read_pos+=sizeof(Event)+sizeof(Variant)*event->args;
	}
	
	buffer_end=0; // reset buffer
}

EventQueue::EventQueue(uint32_t p_buffer_size) {

	
	buffer_end=0;
	buffer_max_used=0;
	buffer_size=p_buffer_size;
	event_buffer = memnew_arr( uint8_t, buffer_size );
	
}
EventQueue::~EventQueue() {

	uint32_t read_pos=0;
	
	while (read_pos < buffer_end ) {
	
		Event *event = (Event*)&event_buffer[ read_pos ];
		Variant *args= (Variant*)(event+1);
		for (int i=0;i<event->args;i++)
			args[i].~Variant();
		event->~Event();
		
		read_pos+=sizeof(Event)+sizeof(Variant)*event->args;
	}
	
	memdelete_arr(event_buffer);
	event_buffer=NULL;
}