/*
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 "constants.h"
#include "debug.h"
#include "main.h" // For g_profiler and g_settings
#include "settings.h"
#include "tile.h"
#include "gamedef.h"
#include "collision.h"
#include <stdlib.h>
#include "util/numeric.h"
#include "light.h"
#include "environment.h"
#include "clientmap.h"
#include "mapnode.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);
}

std::vector<Particle*> all_particles;
std::map<u32, ParticleSpawner*> all_particlespawners;

Particle::Particle(
	IGameDef *gamedef,
	scene::ISceneManager* smgr,
	LocalPlayer *player,
	ClientEnvironment &env,
	v3f pos,
	v3f velocity,
	v3f acceleration,
	float expirationtime,
	float size,
	bool collisiondetection,
	video::ITexture *texture,
	v2f texpos,
	v2f texsize
):
	scene::ISceneNode(smgr->getRootSceneNode(), smgr)
{
	// Misc
	m_gamedef = gamedef;

	// 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;


	// Particle related
	m_pos = pos;
	m_velocity = velocity;
	m_acceleration = acceleration;
	m_expiration = expirationtime;
	m_time = 0;
	m_player = player;
	m_size = size;
	m_collisiondetection = collisiondetection;

	// Irrlicht stuff
	m_collisionbox = core::aabbox3d<f32>
			(-size/2,-size/2,-size/2,size/2,size/2,size/2);
	this->setAutomaticCulling(scene::EAC_OFF);

	// Init lighting
	updateLight(env);

	// Init model
	updateVertices();

	all_particles.push_back(this);
}

Particle::~Particle()
{
}

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

	ISceneNode::OnRegisterSceneNode();
}

void Particle::render()
{
	// TODO: Render particles in front of water and the selectionbox

	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, ClientEnvironment &env)
{
	m_time += dtime;
	if (m_collisiondetection)
	{
		core::aabbox3d<f32> box = m_collisionbox;
		v3f p_pos = m_pos*BS;
		v3f p_velocity = m_velocity*BS;
		v3f p_acceleration = m_acceleration*BS;
		collisionMoveSimple(&env, m_gamedef,
			BS*0.5, box,
			0, dtime,
			p_pos, p_velocity, p_acceleration);
		m_pos = p_pos/BS;
		m_velocity = p_velocity/BS;
		m_acceleration = p_acceleration/BS;
	}
	else
	{
		m_velocity += m_acceleration * dtime;
		m_pos += m_velocity * dtime;
	}

	// Update lighting
	updateLight(env);

	// Update model
	updateVertices();
}

void Particle::updateLight(ClientEnvironment &env)
{
	u8 light = 0;
	try{
		v3s16 p = v3s16(
			floor(m_pos.X+0.5),
			floor(m_pos.Y+0.5),
			floor(m_pos.Z+0.5)
		);
		MapNode n = env.getClientMap().getNode(p);
		light = n.getLightBlend(env.getDayNightRatio(), m_gamedef->ndef());
	}
	catch(InvalidPositionException &e){
		light = blend_light(env.getDayNightRatio(), LIGHT_SUN, 0);
	}
	m_light = decode_light(light);
}

void Particle::updateVertices()
{
	video::SColor c(255, m_light, m_light, m_light);
	f32 tx0 = m_texpos.X;
	f32 tx1 = m_texpos.X + m_texsize.X;
	f32 ty0 = m_texpos.Y;
	f32 ty1 = m_texpos.Y + m_texsize.Y;

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

	for(u16 i=0; i<4; i++)
	{
		m_vertices[i].Pos.rotateYZBy(m_player->getPitch());
		m_vertices[i].Pos.rotateXZBy(m_player->getYaw());
		m_box.addInternalPoint(m_vertices[i].Pos);
		m_vertices[i].Pos += m_pos*BS;
	}
}


/*
	Helpers
*/


void allparticles_step (float dtime, ClientEnvironment &env)
{
	for(std::vector<Particle*>::iterator i = all_particles.begin();
			i != all_particles.end();)
	{
		if ((*i)->get_expired())
		{
			(*i)->remove();
			delete *i;
			all_particles.erase(i);
		}
		else
		{
			(*i)->step(dtime, env);
			i++;
		}
	}
}

void addDiggingParticles(IGameDef* gamedef, scene::ISceneManager* smgr,
		LocalPlayer *player, ClientEnvironment &env, v3s16 pos,
		const TileSpec tiles[])
{
	for (u16 j = 0; j < 32; j++) // set the amount of particles here
	{
		addNodeParticle(gamedef, smgr, player, env, pos, tiles);
	}
}

void addPunchingParticles(IGameDef* gamedef, scene::ISceneManager* smgr,
		LocalPlayer *player, ClientEnvironment &env,
		v3s16 pos, const TileSpec tiles[])
{
	addNodeParticle(gamedef, smgr, player, env, pos, tiles);
}

// add a particle of a node
// used by digging and punching particles
void addNodeParticle(IGameDef* gamedef, scene::ISceneManager* smgr,
		LocalPlayer *player, ClientEnvironment &env, v3s16 pos,
		const TileSpec tiles[])
{
	// Texture
	u8 texid = myrand_range(0,5);
	video::ITexture *texture = tiles[texid].texture;

	// Only use first frame of animated texture
	f32 ymax = 1;
	if(tiles[texid].material_flags & MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES)
		ymax /= tiles[texid].animation_frame_count;

	float size = rand()%64/512.;
	float visual_size = BS*size;
	v2f texsize(size*2, ymax*size*2);
	v2f texpos;
	texpos.X = ((rand()%64)/64.-texsize.X);
	texpos.Y = ymax*((rand()%64)/64.-texsize.Y);

	// Physics
	v3f velocity(	(rand()%100/50.-1)/1.5,
			rand()%100/35.,
			(rand()%100/50.-1)/1.5);

	v3f acceleration(0,-9,0);
	v3f particlepos = v3f(
		(f32)pos.X+rand()%100/200.-0.25,
		(f32)pos.Y+rand()%100/200.-0.25,
		(f32)pos.Z+rand()%100/200.-0.25
	);

	new Particle(
		gamedef,
		smgr,
		player,
		env,
		particlepos,
		velocity,
		acceleration,
		rand()%100/100., // expiration time
		visual_size,
		true,
		texture,
		texpos,
		texsize);
}

/*
	ParticleSpawner
*/

ParticleSpawner::ParticleSpawner(IGameDef* gamedef, scene::ISceneManager *smgr, 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, video::ITexture *texture, u32 id)
{
	m_gamedef = gamedef;
	m_smgr = smgr;
	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_texture = texture;
	m_time = 0;

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

	all_particlespawners.insert(std::pair<u32, ParticleSpawner*>(id, this));
}

ParticleSpawner::~ParticleSpawner() {}

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

	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--;

				v3f pos = random_v3f(m_minpos, m_maxpos);
				v3f vel = random_v3f(m_minvel, m_maxvel);
				v3f acc = random_v3f(m_minacc, m_maxacc);
				float exptime = rand()/(float)RAND_MAX
						*(m_maxexptime-m_minexptime)
						+m_minexptime;
				float size = rand()/(float)RAND_MAX
						*(m_maxsize-m_minsize)
						+m_minsize;

				new Particle(
					m_gamedef,
					m_smgr,
					m_player,
					env,
					pos,
					vel,
					acc,
					exptime,
					size,
					m_collisiondetection,
					m_texture,
					v2f(0.0, 0.0),
					v2f(1.0, 1.0));
				m_spawntimes.erase(i);
			}
			else
			{
				i++;
			}
		}
	}
	else // Spawner exists for an infinity timespan, spawn on a per-second base
	{
		for (int i = 0; i <= m_amount; i++)
		{
			if (rand()/(float)RAND_MAX < dtime)
			{
				v3f pos = random_v3f(m_minpos, m_maxpos);
				v3f vel = random_v3f(m_minvel, m_maxvel);
				v3f acc = random_v3f(m_minacc, m_maxacc);
				float exptime = rand()/(float)RAND_MAX
						*(m_maxexptime-m_minexptime)
						+m_minexptime;
				float size = rand()/(float)RAND_MAX
						*(m_maxsize-m_minsize)
						+m_minsize;

				new Particle(
					m_gamedef,
					m_smgr,
					m_player,
					env,
					pos,
					vel,
					acc,
					exptime,
					size,
					m_collisiondetection,
					m_texture,
					v2f(0.0, 0.0),
					v2f(1.0, 1.0));
			}
		}
	}
}

void allparticlespawners_step (float dtime, ClientEnvironment &env)
{
	for(std::map<u32, ParticleSpawner*>::iterator i = 
			all_particlespawners.begin();
			i != all_particlespawners.end();)
	{
		if (i->second->get_expired())
		{
			delete i->second;
			all_particlespawners.erase(i++);
		}
		else
		{
			i->second->step(dtime, env);
			i++;
		}
	}
}

void delete_particlespawner (u32 id)
{
	if (all_particlespawners.find(id) != all_particlespawners.end())
	{
		delete all_particlespawners.find(id)->second;
		all_particlespawners.erase(id);
	}
}

void clear_particles ()
{
	for(std::map<u32, ParticleSpawner*>::iterator i =
			all_particlespawners.begin();
			i != all_particlespawners.end();)
	{
		delete i->second;
		all_particlespawners.erase(i++);
	}

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