#include"root.h"
#include"node.h"
#include"mesh.h"
#include"particleEmitter.h"
#include"light.h"
#include"text.h"
#include"material.h"
#include"matrix.h"
#include<glm.hpp>
#include<glm/gtc/matrix_inverse.hpp>

using namespace std;
using namespace glm;

namespace vb01{
	Node::Node(Vector3 pos, Quaternion orientation, Vector3 scale,string name){
		this->pos=pos;
		this->scale=scale;
		this->orientation=orientation;
		this->name=name;
		globalAxis[0]=Vector3::VEC_I;
		globalAxis[1]=Vector3::VEC_J;
		globalAxis[2]=Vector3::VEC_K;
	}

	Node::~Node(){
		for(Mesh *m : meshes)
			delete m;
		for(Light *l : lights)
			delete l;
		for(ParticleEmitter *p : emitters)
			delete p;
		for(Text *t : texts)
			delete t;
		for(Node *c : children){
			//dettachChild(c);
			delete c;
		}
	}

	void Node::update(){
		if(visible){
			for(Light *l : lights)
				l->update();
			for(Mesh *m : meshes)
				m->update();
			for(Text *t : texts)
				t->update();
			for(Node *c : children)
				c->update();
			for(ParticleEmitter *p : emitters)
				p->update();
		}
	}

	void Node::attachChild(Node *child){
		child->setParent(this);
		children.push_back(child);
		child->updateAxis();
	}

	void Node::dettachChild(Node *child){
		child->setParent(nullptr);
		int id=-1;
		for(int i=0;i<children.size();i++)
			if(children[i]==child){
				id=i;
				break;
			}
		if(id!=-1)
			children.erase(children.begin()+id);
	}

	void Node::attachMesh(Mesh *mesh){
		meshes.push_back(mesh);
		mesh->setNode(this);
	}

	void Node::attachParticleEmitter(ParticleEmitter *emitter){
		emitters.push_back(emitter);
		emitter->setNode(this);
	}

	void Node::addLight(Light *light){
		Root::getSingleton()->numLights++;
		lights.push_back(light);	
		light->setNode(this);
		updateShaders();
	}

	void Node::removeLight(int id){
		Root::getSingleton()->numLights--;
		Light *light=lights[id];
		light->setNode(nullptr);
		lights.erase(lights.begin()+id);
		updateShaders();
	}

	void Node::addText(Text *text){
		texts.push_back(text);
		text->setNode(this);	
	}

	void Node::lookAt(Vector3 newDir, Vector3 newUp, Node *node){
		adjustDir(newDir, node);
		adjustUp(newUp, node);
	}

	void Node::lookAt(Vector3 newDir, Node *node){
		adjustDir(newDir, node);
	}

	void Node::adjustDir(Vector3 newDir, Node *node){
		Vector3 parAxis[]{
			node->getGlobalAxis(0),
			node->getGlobalAxis(1),
			node->getGlobalAxis(2)
		};
		newDir=(parAxis[0]*newDir.x+parAxis[1]*newDir.y+parAxis[2]*newDir.z).norm();

		float angle=globalAxis[2].getAngleBetween(newDir);
		Vector3 rotAxis=globalAxis[2].cross(newDir).norm();
		if(rotAxis==Vector3::VEC_ZERO)
			rotAxis=globalAxis[1];

		Quaternion oldRot = node->localToGlobalOrientation(orientation);
		Quaternion newRot = node->globalToLocalOrientation(Quaternion(angle,rotAxis));
		setOrientation(newRot*oldRot);
	}

	void Node::adjustUp(Vector3 newUp, Node *node){
		Vector3 parAxis[]{
			node->getGlobalAxis(0),
			node->getGlobalAxis(1),
			node->getGlobalAxis(2)
		};
		newUp=(parAxis[0]*newUp.x+parAxis[1]*newUp.y+parAxis[2]*newUp.z).norm();

		mat3 mat;
		mat[0][0]=globalAxis[0].x;
		mat[1][0]=globalAxis[0].y;
		mat[2][0]=globalAxis[0].z;
		mat[0][1]=globalAxis[1].x;
		mat[1][1]=globalAxis[1].y;
		mat[2][1]=globalAxis[1].z;
		mat[0][2]=globalAxis[2].x;
		mat[1][2]=globalAxis[2].y;
		mat[2][2]=globalAxis[2].z;
		mat=inverse(mat);

		vec3 nu=vec3(newUp.x,newUp.y,newUp.z)*mat;
		newUp=(globalAxis[0]*nu.x+globalAxis[1]*nu.y).norm();
		float angle=globalAxis[1].getAngleBetween(newUp);

		Quaternion oldRot = node->localToGlobalOrientation(orientation);
		Quaternion newRot = node->globalToLocalOrientation(Quaternion(angle*(nu.x<0?1:-1),globalAxis[2]));
		setOrientation(newRot*oldRot);
	}

	void Node::getDescendants(Node *node, vector<Node*> &descendants){
		for(int i=0;i<node->getNumChildren();i++){
			if(node->getChild(i)->getNumChildren()>0)
				getDescendants(node->getChild(i),descendants);
			else
				descendants.push_back(node->getChild(i));
		}
	}

	vector<Node*> Node::getAncestors(Node *node, Node *topAncestor){
		vector<Node*> ancestors;
		Node *parent = node;
		if(!topAncestor)
			topAncestor = Root::getSingleton()->getRootNode();

		while(parent){
			ancestors.push_back(parent);
			if(parent == topAncestor)
				break;
			parent = parent->getParent();
		}
		return ancestors;
	}

	void Node::updateAxis(){
		Vector3 parGlobalAxis[3]{
			parent->getGlobalAxis(0),
			parent->getGlobalAxis(1),
			parent->getGlobalAxis(2)
		};

		float rotAngle = orientation.getAngle();
		Vector3 rotAxis = orientation.getAxis();
		Vector3 newAxis = (parGlobalAxis[0] * rotAxis.x + parGlobalAxis[1] * rotAxis.y + parGlobalAxis[2] * rotAxis.z).norm();
		Quaternion rotQuat=Quaternion(rotAngle, newAxis);

		for(int i = 0; i < 3; i++)
			globalAxis[i] = (rotQuat * parGlobalAxis[i]).norm();
		for(Node *ch : children)
			ch->updateAxis();
	}

	Vector3 Node::localToGlobalPosition(Vector3 localPos){
		vector<Node*> ancestors = getAncestors(this);
		Vector3 origin = Vector3::VEC_ZERO;
		
		while(!ancestors.empty()){
	        int id=ancestors.size()-1;
	        Node *par=ancestors[id]->getParent();
	        Vector3 parAxis[]={
		        par?par->getGlobalAxis(0):Vector3::VEC_I,
		        par?par->getGlobalAxis(1):Vector3::VEC_J,
		        par?par->getGlobalAxis(2):Vector3::VEC_K
	        };
	        Vector3 p=ancestors[id]->getPosition();
	        origin=origin+parAxis[0]*p.x+parAxis[1]*p.y+parAxis[2]*p.z;
	        ancestors.pop_back();
        }

		return origin + globalAxis[0] * localPos.x + globalAxis[1] * localPos.y + globalAxis[2] * localPos.z;
	}

	Vector3 Node::globalToLocalPosition(Vector3 globalPos){
		Vector3 currentGlobalPos = localToGlobalPosition(Vector3::VEC_ZERO);

		mat3 mat;
		mat[0][0]=globalAxis[0].x;
		mat[1][0]=globalAxis[0].y;
		mat[2][0]=globalAxis[0].z;
		mat[0][1]=globalAxis[1].x;
		mat[1][1]=globalAxis[1].y;
		mat[2][1]=globalAxis[1].z;
		mat[0][2]=globalAxis[2].x;
		mat[1][2]=globalAxis[2].y;
		mat[2][2]=globalAxis[2].z;
		mat=inverse(mat);

		vec3 local = vec3(globalPos.x - currentGlobalPos.x, globalPos.y - currentGlobalPos.y, globalPos.z - currentGlobalPos.z) * mat;
		return Vector3(local.x, local.y, local.z);
	}

	Quaternion Node::adjustRot(vector<Node*> ancestors, Quaternion adjustableRot, bool localToGlobal){
		Quaternion rOrigin = adjustableRot;

		while(!ancestors.empty()){
			int id = localToGlobal ? 0 : ancestors.size() - 1;

			float angle = ancestors[id]->getOrientation().getAngle();
			Vector3 axis = ancestors[id]->getOrientation().getAxis();

			Quaternion o;
			if(localToGlobal){
				Node *par = ancestors[id]->getParent();
				Vector3 parAxis[]{
					par?par->getGlobalAxis(0):Vector3::VEC_I,
					par?par->getGlobalAxis(1):Vector3::VEC_J,
					par?par->getGlobalAxis(2):Vector3::VEC_K
				};

				axis = (parAxis[0] * axis.x + parAxis[1] * axis.y + parAxis[2] * axis.z).norm();

				o = Quaternion(angle, axis);
				rOrigin = rOrigin * o;
				ancestors.erase(ancestors.begin());
			}
			else{
				o = Quaternion(angle, axis).conj();
				rOrigin = rOrigin * o;
				ancestors.pop_back();
			}

		}

		return rOrigin;
	}

	Quaternion Node::localToGlobalOrientation(Quaternion localRot){
		vector<Node*> ancestors = getAncestors(this);

		Quaternion origin = adjustRot(ancestors, Quaternion::QUAT_W, true);

		return localRot * origin;
	}

	Quaternion Node::globalToLocalOrientation(Quaternion globalRot){
		vector<Node*> ancestors = getAncestors(this);
		
		Quaternion origin = adjustRot(ancestors, globalRot, false);

		return origin;
	}

	void Node::updateShaders(){
		Root *root=Root::getSingleton();
		Node *rootNode=Root::getSingleton()->getRootNode();
		vector<Node*> descendants;
		rootNode->getDescendants(rootNode,descendants);
		descendants.push_back(rootNode);
		for(Node *n : descendants){
			vector<Mesh*> meshes=n->getMeshes();
			for(Mesh *m : meshes){
				Material *mat=m->getMaterial();
				string str="const int numLights="+to_string(root->numLights>0?root->numLights:1)+";";

				if(mat){
					//mat->getShader()->editShader(true,'=',';',str);
					mat->getShader()->editShader(Shader::FRAGMENT_SHADER,1,str);
				}
			}
		}
	}

	void Node::setOrientation(Quaternion q){
		this->orientation=q;
		updateAxis();
	}
}