/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>

This program 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 program 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 program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "particles.h"
#include <cmath>
#include "client.h"
#include "collision.h"
#include "client/clientevent.h"
#include "client/renderingengine.h"
#include "util/numeric.h"
#include "light.h"
#include "environment.h"
#include "clientmap.h"
#include "mapnode.h"
#include "nodedef.h"
#include "client.h"
#include "settings.h"

/*
	Utility
*/

v3f random_v3f(v3f min, v3f max)
{
	return v3f( rand()/(float)RAND_MAX*(max.X-min.X)+min.X,
			rand()/(float)RAND_MAX*(max.Y-min.Y)+min.Y,
			rand()/(float)RAND_MAX*(max.Z-min.Z)+min.Z);
}

Particle::Particle(
	IGameDef *gamedef,
	LocalPlayer *player,
	ClientEnvironment *env,
	v3f pos,
	v3f velocity,
	v3f acceleration,
	float expirationtime,
	float size,
	bool collisiondetection,
	bool collision_removal,
	bool object_collision,
	bool vertical,
	video::ITexture *texture,
	v2f texpos,
	v2f texsize,
	const struct TileAnimationParams &anim,
	u8 glow,
	video::SColor color
):
	scene::ISceneNode(RenderingEngine::get_scene_manager()->getRootSceneNode(),
		RenderingEngine::get_scene_manager())
{
	// Misc
	m_gamedef = gamedef;
	m_env = env;

	// Texture
	m_material.setFlag(video::EMF_LIGHTING, false);
	m_material.setFlag(video::EMF_BACK_FACE_CULLING, false);
	m_material.setFlag(video::EMF_BILINEAR_FILTER, false);
	m_material.setFlag(video::EMF_FOG_ENABLE, true);
	m_material.MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
	m_material.setTexture(0, texture);
	m_texpos = texpos;
	m_texsize = texsize;
	m_animation = anim;

	// Color
	m_base_color = color;
	m_color = color;

	// Particle related
	m_pos = pos;
	m_velocity = velocity;
	m_acceleration = acceleration;
	m_expiration = expirationtime;
	m_player = player;
	m_size = size;
	m_collisiondetection = collisiondetection;
	m_collision_removal = collision_removal;
	m_object_collision = object_collision;
	m_vertical = vertical;
	m_glow = glow;

	// Irrlicht stuff
	m_collisionbox = aabb3f
			(-size/2,-size/2,-size/2,size/2,size/2,size/2);
	this->setAutomaticCulling(scene::EAC_OFF);

	// Init lighting
	updateLight();

	// Init model
	updateVertices();
}

void Particle::OnRegisterSceneNode()
{
	if (IsVisible)
		SceneManager->registerNodeForRendering(this, scene::ESNRP_TRANSPARENT_EFFECT);

	ISceneNode::OnRegisterSceneNode();
}

void Particle::render()
{
	video::IVideoDriver* driver = SceneManager->getVideoDriver();
	driver->setMaterial(m_material);
	driver->setTransform(video::ETS_WORLD, AbsoluteTransformation);

	u16 indices[] = {0,1,2, 2,3,0};
	driver->drawVertexPrimitiveList(m_vertices, 4,
			indices, 2, video::EVT_STANDARD,
			scene::EPT_TRIANGLES, video::EIT_16BIT);
}

void Particle::step(float dtime)
{
	m_time += dtime;
	if (m_collisiondetection) {
		aabb3f box = m_collisionbox;
		v3f p_pos = m_pos * BS;
		v3f p_velocity = m_velocity * BS;
		collisionMoveResult r = collisionMoveSimple(m_env, m_gamedef, BS * 0.5f,
			box, 0.0f, dtime, &p_pos, &p_velocity, m_acceleration * BS, nullptr,
			m_object_collision);
		if (m_collision_removal && r.collides) {
			// force expiration of the particle
			m_expiration = -1.0;
		} else {
			m_pos = p_pos / BS;
			m_velocity = p_velocity / BS;
		}
	} else {
		m_velocity += m_acceleration * dtime;
		m_pos += m_velocity * dtime;
	}
	if (m_animation.type != TAT_NONE) {
		m_animation_time += dtime;
		int frame_length_i, frame_count;
		m_animation.determineParams(
				m_material.getTexture(0)->getSize(),
				&frame_count, &frame_length_i, NULL);
		float frame_length = frame_length_i / 1000.0;
		while (m_animation_time > frame_length) {
			m_animation_frame++;
			m_animation_time -= frame_length;
		}
	}

	// Update lighting
	updateLight();

	// Update model
	updateVertices();
}

void Particle::updateLight()
{
	u8 light = 0;
	bool pos_ok;

	v3s16 p = v3s16(
		floor(m_pos.X+0.5),
		floor(m_pos.Y+0.5),
		floor(m_pos.Z+0.5)
	);
	MapNode n = m_env->getClientMap().getNodeNoEx(p, &pos_ok);
	if (pos_ok)
		light = n.getLightBlend(m_env->getDayNightRatio(), m_gamedef->ndef());
	else
		light = blend_light(m_env->getDayNightRatio(), LIGHT_SUN, 0);

	u8 m_light = decode_light(light + m_glow);
	m_color.set(255,
		m_light * m_base_color.getRed() / 255,
		m_light * m_base_color.getGreen() / 255,
		m_light * m_base_color.getBlue() / 255);
}

void Particle::updateVertices()
{
	f32 tx0, tx1, ty0, ty1;

	if (m_animation.type != TAT_NONE) {
		const v2u32 texsize = m_material.getTexture(0)->getSize();
		v2f texcoord, framesize_f;
		v2u32 framesize;
		texcoord = m_animation.getTextureCoords(texsize, m_animation_frame);
		m_animation.determineParams(texsize, NULL, NULL, &framesize);
		framesize_f = v2f(framesize.X / (float) texsize.X, framesize.Y / (float) texsize.Y);

		tx0 = m_texpos.X + texcoord.X;
		tx1 = m_texpos.X + texcoord.X + framesize_f.X * m_texsize.X;
		ty0 = m_texpos.Y + texcoord.Y;
		ty1 = m_texpos.Y + texcoord.Y + framesize_f.Y * m_texsize.Y;
	} else {
		tx0 = m_texpos.X;
		tx1 = m_texpos.X + m_texsize.X;
		ty0 = m_texpos.Y;
		ty1 = m_texpos.Y + m_texsize.Y;
	}

	m_vertices[0] = video::S3DVertex(-m_size / 2, -m_size / 2,
		0, 0, 0, 0, m_color, tx0, ty1);
	m_vertices[1] = video::S3DVertex(m_size / 2, -m_size / 2,
		0, 0, 0, 0, m_color, tx1, ty1);
	m_vertices[2] = video::S3DVertex(m_size / 2, m_size / 2,
		0, 0, 0, 0, m_color, tx1, ty0);
	m_vertices[3] = video::S3DVertex(-m_size / 2, m_size / 2,
		0, 0, 0, 0, m_color, tx0, ty0);

	v3s16 camera_offset = m_env->getCameraOffset();
	for (video::S3DVertex &vertex : m_vertices) {
		if (m_vertical) {
			v3f ppos = m_player->getPosition()/BS;
			vertex.Pos.rotateXZBy(std::atan2(ppos.Z - m_pos.Z, ppos.X - m_pos.X) /
				core::DEGTORAD + 90);
		} else {
			vertex.Pos.rotateYZBy(m_player->getPitch());
			vertex.Pos.rotateXZBy(m_player->getYaw());
		}
		m_box.addInternalPoint(vertex.Pos);
		vertex.Pos += m_pos*BS - intToFloat(camera_offset, BS);
	}
}

/*
	ParticleSpawner
*/

ParticleSpawner::ParticleSpawner(
	IGameDef *gamedef,
	LocalPlayer *player,
	u16 amount,
	float time,
	v3f minpos, v3f maxpos,
	v3f minvel, v3f maxvel,
	v3f minacc, v3f maxacc,
	float minexptime, float maxexptime,
	float minsize, float maxsize,
	bool collisiondetection,
	bool collision_removal,
	bool object_collision,
	u16 attached_id,
	bool vertical,
	video::ITexture *texture,
	u32 id,
	const struct TileAnimationParams &anim,
	u8 glow,
	ParticleManager *p_manager
):
	m_particlemanager(p_manager)
{
	m_gamedef = gamedef;
	m_player = player;
	m_amount = amount;
	m_spawntime = time;
	m_minpos = minpos;
	m_maxpos = maxpos;
	m_minvel = minvel;
	m_maxvel = maxvel;
	m_minacc = minacc;
	m_maxacc = maxacc;
	m_minexptime = minexptime;
	m_maxexptime = maxexptime;
	m_minsize = minsize;
	m_maxsize = maxsize;
	m_collisiondetection = collisiondetection;
	m_collision_removal = collision_removal;
	m_object_collision = object_collision;
	m_attached_id = attached_id;
	m_vertical = vertical;
	m_texture = texture;
	m_time = 0;
	m_animation = anim;
	m_glow = glow;

	for (u16 i = 0; i<=m_amount; i++)
	{
		float spawntime = (float)rand()/(float)RAND_MAX*m_spawntime;
		m_spawntimes.push_back(spawntime);
	}
}

void ParticleSpawner::spawnParticle(ClientEnvironment *env, float radius,
	bool is_attached, const v3f &attached_pos, float attached_yaw)
{
	v3f ppos = m_player->getPosition() / BS;
	v3f pos = random_v3f(m_minpos, m_maxpos);

	// Need to apply this first or the following check
	// will be wrong for attached spawners
	if (is_attached) {
		pos.rotateXZBy(attached_yaw);
		pos += attached_pos;
	}

	if (pos.getDistanceFrom(ppos) > radius)
		return;

	v3f vel = random_v3f(m_minvel, m_maxvel);
	v3f acc = random_v3f(m_minacc, m_maxacc);

	if (is_attached) {
		// Apply attachment yaw
		vel.rotateXZBy(attached_yaw);
		acc.rotateXZBy(attached_yaw);
	}

	float exptime = rand() / (float)RAND_MAX
			* (m_maxexptime - m_minexptime)
			+ m_minexptime;
	float size = rand() / (float)RAND_MAX
			* (m_maxsize - m_minsize)
			+ m_minsize;

	m_particlemanager->addParticle(new Particle(
		m_gamedef,
		m_player,
		env,
		pos,
		vel,
		acc,
		exptime,
		size,
		m_collisiondetection,
		m_collision_removal,
		m_object_collision,
		m_vertical,
		m_texture,
		v2f(0.0, 0.0),
		v2f(1.0, 1.0),
		m_animation,
		m_glow
	));
}

void ParticleSpawner::step(float dtime, ClientEnvironment* env)
{
	m_time += dtime;

	static thread_local const float radius =
			g_settings->getS16("max_block_send_distance") * MAP_BLOCKSIZE;

	bool unloaded = false;
	bool is_attached = false;
	v3f attached_pos = v3f(0,0,0);
	float attached_yaw = 0;
	if (m_attached_id != 0) {
		if (ClientActiveObject *attached = env->getActiveObject(m_attached_id)) {
			attached_pos = attached->getPosition() / BS;
			attached_yaw = attached->getYaw();
			is_attached = true;
		} else {
			unloaded = true;
		}
	}

	if (m_spawntime != 0) {
		// Spawner exists for a predefined timespan
		for (std::vector<float>::iterator i = m_spawntimes.begin();
				i != m_spawntimes.end();) {
			if ((*i) <= m_time && m_amount > 0) {
				m_amount--;

				// Pretend to, but don't actually spawn a particle if it is
				// attached to an unloaded object or distant from player.
				if (!unloaded)
					spawnParticle(env, radius, is_attached, attached_pos, attached_yaw);

				i = m_spawntimes.erase(i);
			} else {
				++i;
			}
		}
	} else {
		// Spawner exists for an infinity timespan, spawn on a per-second base

		// Skip this step if attached to an unloaded object
		if (unloaded)
			return;

		for (int i = 0; i <= m_amount; i++) {
			if (rand() / (float)RAND_MAX < dtime)
				spawnParticle(env, radius, is_attached, attached_pos, attached_yaw);
		}
	}
}


ParticleManager::ParticleManager(ClientEnvironment* env) :
	m_env(env)
{}

ParticleManager::~ParticleManager()
{
	clearAll();
}

void ParticleManager::step(float dtime)
{
	stepParticles (dtime);
	stepSpawners (dtime);
}

void ParticleManager::stepSpawners (float dtime)
{
	MutexAutoLock lock(m_spawner_list_lock);
	for (std::map<u32, ParticleSpawner*>::iterator i =
			m_particle_spawners.begin();
			i != m_particle_spawners.end();)
	{
		if (i->second->get_expired())
		{
			delete i->second;
			m_particle_spawners.erase(i++);
		}
		else
		{
			i->second->step(dtime, m_env);
			++i;
		}
	}
}

void ParticleManager::stepParticles (float dtime)
{
	MutexAutoLock lock(m_particle_list_lock);
	for(std::vector<Particle*>::iterator i = m_particles.begin();
			i != m_particles.end();)
	{
		if ((*i)->get_expired())
		{
			(*i)->remove();
			delete *i;
			i = m_particles.erase(i);
		}
		else
		{
			(*i)->step(dtime);
			++i;
		}
	}
}

void ParticleManager::clearAll ()
{
	MutexAutoLock lock(m_spawner_list_lock);
	MutexAutoLock lock2(m_particle_list_lock);
	for(std::map<u32, ParticleSpawner*>::iterator i =
			m_particle_spawners.begin();
			i != m_particle_spawners.end();)
	{
		delete i->second;
		m_particle_spawners.erase(i++);
	}

	for(std::vector<Particle*>::iterator i =
			m_particles.begin();
			i != m_particles.end();)
	{
		(*i)->remove();
		delete *i;
		i = m_particles.erase(i);
	}
}

void ParticleManager::handleParticleEvent(ClientEvent *event, Client *client,
	LocalPlayer *player)
{
	switch (event->type) {
		case CE_DELETE_PARTICLESPAWNER: {
			MutexAutoLock lock(m_spawner_list_lock);
			if (m_particle_spawners.find(event->delete_particlespawner.id) !=
					m_particle_spawners.end()) {
				delete m_particle_spawners.find(event->delete_particlespawner.id)->second;
				m_particle_spawners.erase(event->delete_particlespawner.id);
			}
			// no allocated memory in delete event
			break;
		}
		case CE_ADD_PARTICLESPAWNER: {
			{
				MutexAutoLock lock(m_spawner_list_lock);
				if (m_particle_spawners.find(event->add_particlespawner.id) !=
						m_particle_spawners.end()) {
					delete m_particle_spawners.find(event->add_particlespawner.id)->second;
					m_particle_spawners.erase(event->add_particlespawner.id);
				}
			}

			video::ITexture *texture =
				client->tsrc()->getTextureForMesh(*(event->add_particlespawner.texture));

			ParticleSpawner *toadd = new ParticleSpawner(client, player,
					event->add_particlespawner.amount,
					event->add_particlespawner.spawntime,
					*event->add_particlespawner.minpos,
					*event->add_particlespawner.maxpos,
					*event->add_particlespawner.minvel,
					*event->add_particlespawner.maxvel,
					*event->add_particlespawner.minacc,
					*event->add_particlespawner.maxacc,
					event->add_particlespawner.minexptime,
					event->add_particlespawner.maxexptime,
					event->add_particlespawner.minsize,
					event->add_particlespawner.maxsize,
					event->add_particlespawner.collisiondetection,
					event->add_particlespawner.collision_removal,
					event->add_particlespawner.object_collision,
					event->add_particlespawner.attached_id,
					event->add_particlespawner.vertical,
					texture,
					event->add_particlespawner.id,
					event->add_particlespawner.animation,
					event->add_particlespawner.glow,
					this);

			/* delete allocated content of event */
			delete event->add_particlespawner.minpos;
			delete event->add_particlespawner.maxpos;
			delete event->add_particlespawner.minvel;
			delete event->add_particlespawner.maxvel;
			delete event->add_particlespawner.minacc;
			delete event->add_particlespawner.texture;
			delete event->add_particlespawner.maxacc;

			{
				MutexAutoLock lock(m_spawner_list_lock);
				m_particle_spawners.insert(
						std::pair<u32, ParticleSpawner*>(
								event->add_particlespawner.id,
								toadd));
			}
			break;
		}
		case CE_SPAWN_PARTICLE: {
			video::ITexture *texture =
				client->tsrc()->getTextureForMesh(*(event->spawn_particle.texture));

			Particle *toadd = new Particle(client, player, m_env,
					*event->spawn_particle.pos,
					*event->spawn_particle.vel,
					*event->spawn_particle.acc,
					event->spawn_particle.expirationtime,
					event->spawn_particle.size,
					event->spawn_particle.collisiondetection,
					event->spawn_particle.collision_removal,
					event->spawn_particle.object_collision,
					event->spawn_particle.vertical,
					texture,
					v2f(0.0, 0.0),
					v2f(1.0, 1.0),
					event->spawn_particle.animation,
					event->spawn_particle.glow);

			addParticle(toadd);

			delete event->spawn_particle.pos;
			delete event->spawn_particle.vel;
			delete event->spawn_particle.acc;
			delete event->spawn_particle.texture;

			break;
		}
		default: break;
	}
}

// The final burst of particles when a node is finally dug, *not* particles
// spawned during the digging of a node.

void ParticleManager::addDiggingParticles(IGameDef* gamedef,
	LocalPlayer *player, v3s16 pos, const MapNode &n, const ContentFeatures &f)
{
	// No particles for "airlike" nodes
	if (f.drawtype == NDT_AIRLIKE)
		return;

	for (u16 j = 0; j < 16; j++) {
		addNodeParticle(gamedef, player, pos, n, f);
	}
}

// During the digging of a node particles are spawned individually by this
// function, called from Game::handleDigging() in game.cpp.

void ParticleManager::addNodeParticle(IGameDef* gamedef,
	LocalPlayer *player, v3s16 pos, const MapNode &n, const ContentFeatures &f)
{
	// No particles for "airlike" nodes
	if (f.drawtype == NDT_AIRLIKE)
		return;

	// Texture
	u8 texid = myrand_range(0, 5);
	const TileLayer &tile = f.tiles[texid].layers[0];
	video::ITexture *texture;
	struct TileAnimationParams anim;
	anim.type = TAT_NONE;

	// Only use first frame of animated texture
	if (tile.material_flags & MATERIAL_FLAG_ANIMATION)
		texture = (*tile.frames)[0].texture;
	else
		texture = tile.texture;

	float size = (rand() % 8) / 64.0f;
	float visual_size = BS * size;
	if (tile.scale)
		size /= tile.scale;
	v2f texsize(size * 2.0f, size * 2.0f);
	v2f texpos;
	texpos.X = (rand() % 64) / 64.0f - texsize.X;
	texpos.Y = (rand() % 64) / 64.0f - texsize.Y;

	// Physics
	v3f velocity(
		(rand() % 150) / 50.0f - 1.5f,
		(rand() % 150) / 50.0f,
		(rand() % 150) / 50.0f - 1.5f
	);
	v3f acceleration(
		0.0f,
		-player->movement_gravity * player->physics_override_gravity / BS,
		0.0f
	);
	v3f particlepos = v3f(
		(f32)pos.X + (rand() % 100) / 200.0f - 0.25f,
		(f32)pos.Y + (rand() % 100) / 200.0f - 0.25f,
		(f32)pos.Z + (rand() % 100) / 200.0f - 0.25f
	);

	video::SColor color;
	if (tile.has_color)
		color = tile.color;
	else
		n.getColor(f, &color);

	Particle* toadd = new Particle(
		gamedef,
		player,
		m_env,
		particlepos,
		velocity,
		acceleration,
		(rand() % 100) / 100.0f, // expiration time
		visual_size,
		true,
		false,
		false,
		false,
		texture,
		texpos,
		texsize,
		anim,
		0,
		color);

	addParticle(toadd);
}

void ParticleManager::addParticle(Particle* toadd)
{
	MutexAutoLock lock(m_particle_list_lock);
	m_particles.push_back(toadd);
}
