/*   ORXONOX - the hottest 3D action shooter ever to exist
 *                    > www.orxonox.net <
 *
 *
 *   License notice:
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation; either version 2
 *   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 General Public License for more details.
 *
 *   You should have received a copy of the GNU 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.
 *
 *   Author:
 *      remartin
 *   Co-authors:
 *      ...
 *
 */

/*

    @file
    @author remartin
    @brief An asteroid which can be destroyed. Some smaller asteroids are created and a pickup spawns. 

HANDBUCH:
o Die Collision Shape kann nur im Konstruktor hinzugefügt werden. Die XML-Argumente werden aber erst nach dem Konstruktor gesetzt. 
  Darum wird hier beim ersten Aufruf der tick()-Methode via putStuff() ein komplett neuer Asteroid generiert und der alte zerstört. 
o im Level-File includes/pickups.oxi importieren. 

OFFEN/Weiterentwicklung: 
o @TODO Add resource pickups. 
--> data_extern/images/effects: PNG's für die Pickups
--> https://www.orxonox.net/jenkins/view/Management/job/orxonox_doxygen_trunk/javadoc/group___pickup.html

o Density doesn't add up to 1...
o Does collision damage work properly
o Add sound effect (crunching etc. ) (No sound in space...)
o Explosion parts

ANDERORTS VERÄNDERTE SACHEN: 
Pickup-Zeug: 
o PickupSpawner.h: Zugriffsrechte setPickupTemplateName() und setMaxSpawnedItems()
o PickupSpawner.h: In Tick() zwei Testbedingungen eingefügt.
o Pawn.h: Attribut acceptsPickups_ inklusive get/set. 

ERLEGTE FEHLER:
o Grössenabhängige Collision Shape -> putStuff-Methode, Werte noch nicht durchgesickert. 
o setHealth: maxHealth() des pawns setzen! 
o Asteroiden fressen Pickups: Argument in Pawn, Test darauf in Tick() von PickupSpawner. 
o i++ einfach ganz verhindern, ++i stattdessen. 
o Velocity didn-t get passed properly through the 2nd constructor. Used get/set instead. 
o Rand() geht bis zu riesigen Nummern! rnd() ist zwischen 0 und 1

NOTIZEN:
o SUPER
o Warnungsverhinderung anderswo: (void)pickedUp; // To avoid compiler warning.
o friend class Pickupable;



*/

#include "AsteroidMinable.h"

#include <algorithm>

#include "core/CoreIncludes.h"
#include "core/GameMode.h"
#include "core/XMLPort.h"
#include "util/Convert.h"
#include "util/Math.h"

#include "pickup/PickupSpawner.h"
#include "pickup/Pickup.h"

#include "objects/collisionshapes/SphereCollisionShape.h"
#include "graphics/Model.h"

namespace orxonox{

    RegisterClass(AsteroidMinable);

    // @brief Standard constructor
    AsteroidMinable::AsteroidMinable(Context* context) : Pawn(context){

        RegisterObject(AsteroidMinable);

        // Default Values:
        this->size = 1;
        this->dropStuff = true; 
        this->generateSmaller = true; 
        this->acceptsPickups_ = false; 

        this->setCollisionType(WorldEntity::CollisionType::Dynamic);
        this->enableCollisionCallback();

        // Old from Pawn
        this->registerVariables();

        this->initialised = false;
    }

    AsteroidMinable::~AsteroidMinable(){

    }

    void AsteroidMinable::setSize(float s)
    {
        this->size = s;
        this->health_ = 15*size;
        this->maxHealth_ = this->health_;
    }

    // @brief Helper method.
    void AsteroidMinable::putStuff(){

        // The radar is able to detect whether an asteroid contains resources....
        if(dropStuff){
            this->setRadarObjectColour(ColourValue(1.0f, 1.0f, 0.0f, 1.0f));
            this->setRadarObjectShape(RadarViewable::Shape::Dot);
        }else{
            // Somehow remove from radar? (all pawns get registered automatically... )
            this->setRadarObjectColour(ColourValue(0.663f, 0.663f, 0.663f, 1.0f));
            this->setRadarObjectShape(RadarViewable::Shape::Dot);
        }

        // Add Model, random one of the 6 shapes
        Model* hull = new Model(this->getContext());
        hull->setMeshSource("ast" + multi_cast<std::string>(1 + (int)rnd(0, 6)) + ".mesh");
        hull->setScale(this->size);
        this->attach(hull);

        // Collision shape
        SphereCollisionShape* cs = new SphereCollisionShape(this->getContext());
        cs->setRadius((this->size)*2); //OFFEN: Feinabstimmung der Radien. 
        this->attachCollisionShape(cs); 

        this->initialised=true; 
    }

    void AsteroidMinable::XMLPort(Element& xmlelement, XMLPort::Mode mode){

        SUPER(AsteroidMinable, XMLPort, xmlelement, mode); 

        XMLPortParam(AsteroidMinable, "size", setSize, getSize, xmlelement, mode);
        XMLPortParam(AsteroidMinable, "generateSmaller", setShattering, doesShatter, xmlelement, mode);
        XMLPortParam(AsteroidMinable, "dropStuff", setDropStuff, doesDropStuff, xmlelement, mode);

    }

    void AsteroidMinable::registerVariables(){

        registerVariable(this->size, VariableDirection::ToClient);
        registerVariable(this->generateSmaller, VariableDirection::ToClient);
        registerVariable(this->dropStuff, VariableDirection::ToClient); 
        registerVariable(this->initialised, VariableDirection::ToClient);

    }

    void AsteroidMinable::tick(float dt){

        if(!(this->initialised)){this->putStuff();} 

        if(this->health_ <=0){this->death();}

    }

    void AsteroidMinable::death(){ // @brief Überschreibt die Methode in Pawn

        // just copied that from somewhere else. 
        this->bAlive_ = false;
        this->destroyLater();
        this->setDestroyWhenPlayerLeft(false);
        // pawn -> addExplosionPart
        // this->goWithStyle();


        // Pickups which can be harvested. It's munition at the moment, could be changed/extended. 
        if(dropStuff){
            PickupSpawner* thingy = new PickupSpawner(this->getContext());

            std::string tname;
            if(this->size <= 5){
                tname = "smallmunitionpickup";
            }else if(this->size <= 20){
                tname = "mediummunitionpickup";
            }else{
                tname = "hugemunitionpickup";
            }
            thingy->setPickupTemplateName(tname);
            thingy->setPosition(this->getPosition());
            thingy->setMaxSpawnedItems(1); // Would be default anyways
            thingy->setRespawnTime(0.2f);
        }

        // Smaller Parts = 'Children'
        if(this->generateSmaller){this->spawnChildren();}

    }

// @brief If the option generateSmaller is enabled, individual fragments are added with this method. 
    void AsteroidMinable::spawnChildren(){

    if (this->size <=1){return;} // Absicherung trivialer Fall

    float massRem = (this->size-1); //some mass is lost
    int num = (int)roundf(rnd(massRem-1)) + 1; // random number of children, at least one
    if(num > 10){num = 10;} // no max function in C? 
    std::vector<float> masses(num); // Masses of the asteroids
    // orxout() << "SpawnChildren(): Passed basic stuff. num = " << num << "; massRem(total) = "<< massRem << endl;
    massRem = massRem-num; // mass must be at least one, add later.  

    // Randomnised spawning points for the new asteroids
    std::vector<float> phi(num);
    std::vector<float> theta(num);

    // Discusting C stuff -> use that to initialise dynamic array values to 0. 
    for(int twat = 0; twat<num; ++twat)
    {
        masses[twat] = 0.0f;
        phi[twat] = 0.0f;
        theta[twat] = 0.0f;
    }

    float piG = 3.1415927410125732421875; //pi; // Math.pi ist statisch oder so. 
    float d_p = 2*piG/num;
    float d_t = piG/num;
    float p = d_p/2.0f;
    float t = d_t/2.0f;
    // float phiOffset = rnd()*2*pi; // Added everywhere to become independent of the coordinate system?
    // float thetaOffset = rnd()*pi;
    float rScaling; // scale radius to prevent asteroids from touching. (distance=AsteroidRadius/tan(sector/2))

    if(num == 1 ){
        rScaling = 1; // avoid tan(90). Unused. 
    }else{

        rScaling = tan(t); 

        int pos; // insert at random position (linear probing) in array, to get some randomness.  
        for(int it = 0; it<num; ++it){

            pos = mod((int)(rnd((float)num)),num);
            while(phi[pos] != 0.0){// find empty spot in array
                pos = (int)mod(++pos, num);
            }
            phi[pos] = p + it*d_p;// set angle there

            pos = mod((int)(rnd((float)num)),num);
            while(theta[pos] != 0.0){
                pos = (int)mod(++pos, num);
            }
            theta[pos] = t + it*d_t;
        }
    }

    //orxout() << "SpawnChildren(): Phi: "; printArrayString(phi);
    //orxout() << "SpawnChildren(): Theta: "; printArrayString(theta);
    //orxout() << "SpawnChildren(): Passed angle stuff. " << endl;

    // Triangular, discrete probability "density" with max at the average value massRem/num. 50% chance to be below that. 
    if(massRem>0){
        int c = (int)massRem;
        std::vector<float> probDensity(c);

        int a = (int)roundf(massRem/num);
        int b = c-a;
        
        int z = 0;
        float dProbA = 1.0f/(a*a + 3.0f*a + 2.0f); // one 'probability unit' for discrete ramp function. Gauss stuff.
        for(z = 0; z<a; ++z){probDensity[z] = (z+1)*dProbA; } // rising part

        float dProbB = 1.0f/(b*b +3.0f*b + 2.0f);
        for(z = 0; z<b; ++z){probDensity[c-1-z] = (z+1)*dProbB;} // falling part
    
        // // Just for testing:
        // float sum = 0.0;
        // for(int globi = 0; globi<c; ++globi){
        //     orxout() << "pDensity at [" << globi << "] is: " << probDensity[globi] << endl;
        //     sum = sum+ probDensity[globi];
        // }
        // orxout() << "Sum of densities should b 1, it is: " << sum << endl;

        // Distributing the mass to individual asteroids
        int result; 
        float rVal; // between 0 and 1
        float probSum; // summing up until rval is reached. 
        for(int trav = 0; trav<num; ++trav){
            result = 0;
            rVal = rnd(); 
            probSum = probDensity[0]; 

            while(rVal>probSum && result<massRem){// Not yet found && there-s smth left to distribute (Incrementing inside!)
                if(result<(massRem-2)){probSum = probSum + probDensity[result+1];} // avoid logical/acess error
                ++result;
            }

            masses[trav] = 1.0f + result; // Fragments have mass of at least one.
            massRem = massRem-result;

        }
    }else{
        for(int schnaegg = 0; schnaegg<num; ++schnaegg){masses[schnaegg] = 1;}
    }

    // orxout() << "SpawnChildren(): Masses: "; printArrayString(masses);
    // orxout() << "SpawnChildren(): Passed mass stuff. " << endl;

    // Creating the 'chlidren':
    for(int fisch = 0; fisch<num; ++fisch){

        Vector3 pos = Vector3::ZERO; // Position offset
        if(num > 1){// not required if there-s just one child
            float r = masses[fisch]/rScaling;
            pos = Vector3(r*sin(theta[fisch])*cos(phi[fisch]), r*sin(theta[fisch])*sin(phi[fisch]), r*cos(theta[fisch])); // convert spheric coordinates to vector
        }
        
        AsteroidMinable* child = new AsteroidMinable(this->getContext());
        child->setSize(masses[fisch]);
        child->setPosition(this->getPosition() + pos);
        child->setVelocity(this->getVelocity());
        child->setDropStuff(this->dropStuff);
    }
    // orxout() << "Leaving spawnChildren() method. " << endl;
}

// @brief overloading that to prevent asteroids from taking damage from each other (domino effect etc. ) 
    void AsteroidMinable::hit(Pawn* originator, const Vector3& force, const btCollisionShape* cs, float damage, float healthdamage, float shielddamage){

        // orxout() << "AsteroidMining::Hit(Variante 1) Dings aufgerufen. " << endl; 
        if(orxonox_cast<AsteroidMinable*>(originator) || orxonox_cast<Pickup*>(originator)){return;}
        this->damage(damage, healthdamage, shielddamage, originator, cs);
        this->setVelocity(this->getVelocity() + force);

        // if (this->getGametype() && this->getGametype()->allowPawnHit(this, originator))// && (!this->getController() || !this->getController()->getGodMode()) )
        // {
        //     this->damage(damage, healthdamage, shielddamage, originator, cs);
        //     this->setVelocity(this->getVelocity() + force);
        // }
    }

// @brief overloading that to prevent asteroids from taking damage from each other (domino effect etc. ) 
    void AsteroidMinable::hit(Pawn* originator, btManifoldPoint& contactpoint, const btCollisionShape* cs, float damage, float healthdamage, float shielddamage){

        //orxout() << "AsteroidMining::Hit(Variante 2) Dings aufgerufen. " << endl;
        if(orxonox_cast<AsteroidMinable*>(originator) || orxonox_cast<Pickup*>(originator)){return;}
        this->damage(damage, healthdamage, shielddamage, originator, cs);

        // if (this->getGametype() && this->getGametype()->allowPawnHit(this, originator))// && (!this->getController() || !this->getController()->getGodMode()) )
        // {
        //     this->damage(damage, healthdamage, shielddamage, originator, cs);

        //     //if ( this->getController() )
        //     //    this->getController()->hit(originator, contactpoint, damage); // changed to damage, why shielddamage?
        // }
    }
}