/*
   render/particlesystem.cc
   This file is part of the Osirion project and is distributed under
   the terms of the GNU General Public License version 2
*/

#include "render/gl.h"
#include "render/particlesystem.h"

namespace render {

ParticleSystem::ParticleSystem(const ParticleSystemScript *script, const core::Entity *entity, const model::Particles *modelclass)
{
	// constructor asserts that modelclass->parent == entity->model
	
	particlesystem_modelscale = 1.0f;
	
	particlesystem_entity = entity;
	
	if (modelclass) {
		particlesystem_location.assign(modelclass->location());
		particlesystem_axis.assign(modelclass->axis());
	}
	
	if (entity && entity->model() && entity->model()->radius()) {
		particlesystem_modelscale = entity->radius() / entity->model()->radius();
		particlesystem_location *= particlesystem_modelscale;
		
	}
	
	// add ParticleEjectors as defined by the ParticleSystemScript
	for (ParticleSystemScript::Ejectors::const_iterator it = script->ejectors().begin(); it != script->ejectors().end(); ++it) {
		ParticleEjector *ejector = 0;
		switch ((*it)->type()) {
			case ParticleEjector::Sprite:
				ejector = new ParticleEjectorSprite(*(*it));
				break;
				
			case ParticleEjector::Flare:
				ejector = new ParticleEjectorFlare(*(*it));
				break;
				
			case ParticleEjector::Trail:
				ejector = new ParticleEjectorTrail(*(*it));
				break;
				
			case ParticleEjector::Streak:
				ejector = new ParticleEjectorStreak(*(*it));
				break;
				
			default:
				break;
		}
		
		if (ejector) {
			// safety values
			if (!ejector->interval()) {
				ejector->set_interval(1000);
			}
			
			ejectors().push_back(ejector);
			
			if (entity) {
				if (ejector->entity()) {
					if (ejector->entity_second()) {
						for (size_t i = 0; i < 3; i++) {
							ejector->get_color()[i] = (entity->color()[i] + entity->color_second()[i]) * 0.5f;
						}
					} else {
						ejector->set_color(entity->color());
					}
				} else if (ejector->entity_second()) {
					ejector->set_color(entity->color_second());
				} else if (ejector->engine()) {
					if (entity->model()) {
						ejector->set_color(entity->model()->enginecolor());
					}
				}
			}
			
			if (modelclass) {
				// modelclass overrides script parameters
				if (modelclass->has_color()) {
					ejector->set_color(modelclass->color());
				}
				if (entity) {
					if (modelclass->entity()) {
						if (modelclass->entity_second()) {
							for (size_t i = 0; i < 3; i++) {
								ejector->get_color()[i] = (entity->color()[i] + entity->color_second()[i]) * 0.5f;
							}
						} else {
							ejector->set_color(entity->color());
						}
					} else if (modelclass->entity_second()) {
						ejector->set_color(entity->color_second());
					} else if (modelclass->engine()) {
						if (entity->model()) {
							ejector->set_color(entity->model()->enginecolor());
						}
					}
				}
			}
			
			if (entity && ejector->scaled()) {
				ejector->get_speed_vec() *= entity->radius();
				ejector->get_tailspeed_vec() *= entity->radius();
				ejector->get_radius_vec() *= entity->radius();
				ejector->set_acceleration(ejector->acceleration() * entity->radius());
			}
		}
	}
}

ParticleSystem::~ParticleSystem()
{
	for (Ejectors::iterator it = ejectors().begin(); it != ejectors().end(); ++it) {
		delete (*it);
		(*it) = 0;
	}
	ejectors().clear();
		
}

void ParticleSystem::clear()
{
	for (Ejectors::iterator it = ejectors().begin(); it != ejectors().end(); ++it) {
		(*it)->clear();
	}
}
void ParticleSystem::draw(const float seconds)
{
	// clear particles for docked entities
	if ( entity() && (entity()->type() == core::Entity::Controlable)) {
		const core::EntityControlable *controlable = static_cast<const core::EntityControlable *>(entity());
		if (controlable->state() == core::Entity::Docked) {
			clear();
			return;
		}
	}

	math::Vector3f current_location(entity() ? entity()->location() + (entity()->axis() * location()) : location());
	math::Axis current_axis(entity() ? entity()->axis() * axis() : axis());
	
	for (Ejectors::iterator it = ejectors().begin(); it != ejectors().end(); ++it) {
		
		ParticleEjector *ejector = (*it);
		
		if (entity()) {
			bool ejector_active = true;
			
			if (entity()->type() == core::Entity::Controlable) {
				const core::EntityControlable *controlable = static_cast<const core::EntityControlable *>(entity());
				
				if (ejector->impulse() || ejector->thrust()) {
					ejector_active = false;
				
					switch (controlable->state()) {
						case core::Entity::Impulse:
						case core::Entity::ImpulseInitiate:
							if (ejector->impulse() || ejector->thrust()) {
								ejector_active = true;
							}
							break;
							
						case core::Entity::Normal:
							if (ejector->thrust()) {
								if (controlable->thrust() > 0.0f) {
									ejector_active = true;
								}
							}
							break;
							
						default:
							ejector_active = false;
							break;
					}
					ejector->enable(ejector_active);
				}
			}
		}
		
		(*it)->frame(seconds, current_location, current_axis  * ejector->axis());

	}
}

}