/* vim: set ts=4 sts=4 sw=4 noet : */
#include<stdlib.h>
#include<math.h>
#include "general.h"
#include "vertex.h"
#include "bond.h"
#include "triangle.h"
#include "vesicle.h"
#include "energy.h"
#include "timestep.h"
#include "cell.h"
#include "io.h"
#include<stdio.h>
#include "vertexmove.h"
#include <string.h>
#include "constvol.h"
#include "plugins.h"

ts_bool single_verticle_timestep(ts_vesicle *vesicle,ts_vertex *vtx,ts_double *rn){
    ts_uint i;
    ts_bool retval; 
    ts_uint cellidx; 
    ts_double delta_energy, oenergy,dstretchenergy=0.0;
    ts_double costheta,sintheta,phi,r;
	//This will hold all the information of vtx and its neighbours
    ts_vertex backupvtx[20]; // *constvol_vtx_moved=NULL, *constvol_vtx_backup=NULL;
    memcpy((void *)&backupvtx[0],(void *)vtx,sizeof(ts_vertex));

    //random move in a sphere with radius stepsize:
    r=vesicle->stepsize*rn[0];
    phi=rn[1]*2*M_PI;
    costheta=2*rn[2]-1;
    sintheta=sqrt(1-pow(costheta,2));
    vtx->x=vtx->x+r*sintheta*cos(phi);
    vtx->y=vtx->y+r*sintheta*sin(phi);
    vtx->z=vtx->z+r*costheta;


/* Entry point for plugin vm_hard_constraint() function */
	vesicle->plist->pointer=vesicle->plist->chain->vm_hard_constraint;
	while(vesicle->plist->pointer!=NULL){
		retval = vesicle->plist->pointer->plugin->function->vm_hard_constraint(vesicle,vtx, &backupvtx[0]);
		if(retval==TS_FAIL){
			vtx=memcpy((void *)vtx,(void *)&backupvtx[0],sizeof(ts_vertex));
			return TS_FAIL;
		}
		vesicle->plist->pointer=vesicle->plist->pointer->next;
	}
/* End of vm_hard_constraint() */

/* Backuping the neighbours */ 
	for(i=0;i<vtx->neigh_no;i++){
	memcpy((void *)&backupvtx[i+1],(void *)vtx->neigh[i],sizeof(ts_vertex));
	}

/* Entry point for plugin vm_energy_before_prepare() */

	vesicle->plist->pointer=vesicle->plist->chain->vm_energy_before_prepare;
	while(vesicle->plist->pointer!=NULL){
		vesicle->plist->pointer->plugin->function->vm_energy_before_prepare(vesicle, vtx);
		vesicle->plist->pointer=vesicle->plist->pointer->next;
	}
/* End of vm_energy_before_prepare() */

	//stretching energy 1 of 3
	if(vesicle->tape->stretchswitch==1){
		for(i=0;i<vtx->tristar_no;i++) dstretchenergy-=vtx->tristar[i]->energy;
	}
    delta_energy=0;

//update the normals of triangles that share bead i.
    for(i=0;i<vtx->tristar_no;i++) triangle_normal_vector(vtx->tristar[i]);
	oenergy=vtx->energy;
    energy_vertex(vtx);
    delta_energy=vtx->xk*(vtx->energy - oenergy);
    //the same is done for neighbouring vertices
    for(i=0;i<vtx->neigh_no;i++){
        oenergy=vtx->neigh[i]->energy;
        energy_vertex(vtx->neigh[i]);
        delta_energy+=vtx->neigh[i]->xk*(vtx->neigh[i]->energy-oenergy);
    }


/* Entry point for plugin vm_energy_after_execute() */

	vesicle->plist->pointer=vesicle->plist->chain->vm_energy_after_execute;
	while(vesicle->plist->pointer!=NULL){
		delta_energy+=vesicle->plist->pointer->plugin->function->vm_energy_after_execute(vesicle, vtx, backupvtx);
		vesicle->plist->pointer=vesicle->plist->pointer->next;
	}


/* Vertices with spontaneous curvature may have spontaneous force perpendicular to the surface of the vesicle. additional delta energy is calculated in this function */
	delta_energy+=direct_force_energy(vesicle,vtx,backupvtx);

	//stretching energy 2 of 3
	if(vesicle->tape->stretchswitch==1){
		for(i=0;i<vtx->tristar_no;i++){ 
			stretchenergy(vesicle, vtx->tristar[i]);
			dstretchenergy+=vtx->tristar[i]->energy;
			}
	}

	delta_energy+=dstretchenergy;	
		
/* No poly-bond energy for now!
	if(vtx->grafted_poly!=NULL){
		delta_energy+=
			(pow(sqrt(vtx_distance_sq(vtx, vtx->grafted_poly->vlist->vtx[0])-1),2)-
			pow(sqrt(vtx_distance_sq(&backupvtx[0], vtx->grafted_poly->vlist->vtx[0])-1),2)) *vtx->grafted_poly->k;
	}
*/


/* Entry point for plugin vm_before_montecarlo_constraint() function */
	vesicle->plist->pointer=vesicle->plist->chain->vm_before_montecarlo_constraint;
	while(vesicle->plist->pointer!=NULL){
		retval = vesicle->plist->pointer->plugin->function->vm_before_montecarlo_constraint(vesicle,vtx, &backupvtx[0]);
		if(retval==TS_FAIL){
			vtx=memcpy((void *)vtx,(void *)&backupvtx[0],sizeof(ts_vertex));
			for(i=0;i<vtx->neigh_no;i++){
				vtx->neigh[i]=memcpy((void *)vtx->neigh[i],(void *)&backupvtx[i+1],sizeof(ts_vertex));
				}
			for(i=0;i<vtx->tristar_no;i++) triangle_normal_vector(vtx->tristar[i]); 
			return TS_FAIL;
		}
		vesicle->plist->pointer=vesicle->plist->pointer->next;
	}
/* End of vm_before_montecarlo_constraint() */





//   fprintf(stderr, "DE=%f\n",delta_energy);
    //MONTE CARLOOOOOOOO
    if(delta_energy>=0){
#ifdef TS_DOUBLE_DOUBLE
        if(exp(-delta_energy)< drand48())
#endif
#ifdef TS_DOUBLE_FLOAT
        if(expf(-delta_energy)< (ts_float)drand48())
#endif
#ifdef TS_DOUBLE_LONGDOUBLE
        if(expl(-delta_energy)< (ts_ldouble)drand48())
#endif
    {
/*************************************************** MC step rejected **************************************************************/
	vtx=memcpy((void *)vtx,(void *)&backupvtx[0],sizeof(ts_vertex));
	for(i=0;i<vtx->neigh_no;i++){
		vtx->neigh[i]=memcpy((void *)vtx->neigh[i],(void *)&backupvtx[i+1],sizeof(ts_vertex));
	}
	
	//update the normals of triangles that share bead i.
	for(i=0;i<vtx->tristar_no;i++) triangle_normal_vector(vtx->tristar[i]);

	//stretching energy 3 of 3
	if(vesicle->tape->stretchswitch==1){
		for(i=0;i<vtx->tristar_no;i++){ 
			stretchenergy(vesicle,vtx->tristar[i]);
			}
	}



/* Entry point for plugin vm_before_montecarlo_constraint() function */
	vesicle->plist->pointer=vesicle->plist->chain->vm_new_state_rejected;
	while(vesicle->plist->pointer!=NULL){
		vesicle->plist->pointer->plugin->function->vm_new_state_rejected(vesicle,vtx, &backupvtx[0]);
		vesicle->plist->pointer=vesicle->plist->pointer->next;
	}
/* End of vm_before_montecarlo_constraint() */


    return TS_FAIL; 
    }
}
/*************************************************** MC step accepted **************************************************************/
	cellidx=vertex_self_avoidance(vesicle, vtx);
	if(vtx->cell!=vesicle->clist->cell[cellidx]){
		retval=cell_add_vertex(vesicle->clist->cell[cellidx],vtx);
		if(retval==TS_SUCCESS) cell_remove_vertex(backupvtx[0].cell,vtx);	
	}

/* Entry point for plugin vm_before_montecarlo_constraint() function */
	vesicle->plist->pointer=vesicle->plist->chain->vm_new_state_accepted;
	while(vesicle->plist->pointer!=NULL){
		vesicle->plist->pointer->plugin->function->vm_new_state_accepted(vesicle,vtx, &backupvtx[0]);
		vesicle->plist->pointer=vesicle->plist->pointer->next;
	}
/* End of vm_before_montecarlo_constraint() */

    return TS_SUCCESS;
}





ts_bool single_poly_vertex_move(ts_vesicle *vesicle,ts_poly *poly,ts_vertex *vtx,ts_double *rn){
	ts_uint i;
	ts_bool retval; 
	ts_uint cellidx; 
//	ts_double delta_energy;
	ts_double costheta,sintheta,phi,r;
	ts_double dist;
	//This will hold all the information of vtx and its neighbours
	ts_vertex backupvtx;
//	ts_bond backupbond[2];
	memcpy((void *)&backupvtx,(void *)vtx,sizeof(ts_vertex));

	//random move in a sphere with radius stepsize:
	r=vesicle->stepsize*rn[0];
	phi=rn[1]*2*M_PI;
	costheta=2*rn[2]-1;
	sintheta=sqrt(1-pow(costheta,2));
	vtx->x=vtx->x+r*sintheta*cos(phi);
	vtx->y=vtx->y+r*sintheta*sin(phi);
	vtx->z=vtx->z+r*costheta;


	//distance with neighbours check
	for(i=0;i<vtx->neigh_no;i++){
		dist=vtx_distance_sq(vtx,vtx->neigh[i]);
		if(dist<1.0 || dist>vesicle->dmax) {
			vtx=memcpy((void *)vtx,(void *)&backupvtx,sizeof(ts_vertex));
			return TS_FAIL;
		}
	}

// Distance with grafted vesicle-vertex check:	
	if(vtx==poly->vlist->vtx[0]){
		dist=vtx_distance_sq(vtx,poly->grafted_vtx);
        if(dist<1.0 || dist>vesicle->dmax) {
		vtx=memcpy((void *)vtx,(void *)&backupvtx,sizeof(ts_vertex));
		return TS_FAIL;
		}
	}


	//self avoidance check with distant vertices
	cellidx=vertex_self_avoidance(vesicle, vtx);
	//check occupation number
	retval=cell_occupation_number_and_internal_proximity(vesicle->clist,cellidx,vtx);
	
	if(retval==TS_FAIL){
		vtx=memcpy((void *)vtx,(void *)&backupvtx,sizeof(ts_vertex));
        return TS_FAIL;
	} 


	//if all the tests are successful, then energy for vtx and neighbours is calculated
/* Energy ignored for now!
	delta_energy=0;
	for(i=0;i<vtx->bond_no;i++){
		memcpy((void *)&backupbond[i],(void *)vtx->bond[i],sizeof(ts_bond));

		vtx->bond[i]->bond_length=sqrt(vtx_distance_sq(vtx->bond[i]->vtx1,vtx->bond[i]->vtx2));
		bond_energy(vtx->bond[i],poly);
		delta_energy+= vtx->bond[i]->energy - backupbond[i].energy;
	}

	if(vtx==poly->vlist->vtx[0]){
		delta_energy+=
			(pow(sqrt(vtx_distance_sq(vtx, poly->grafted_vtx)-1),2)-
			pow(sqrt(vtx_distance_sq(&backupvtx, poly->grafted_vtx)-1),2)) *poly->k;
		
	}


	if(delta_energy>=0){
#ifdef TS_DOUBLE_DOUBLE
        if(exp(-delta_energy)< drand48() )
#endif
#ifdef TS_DOUBLE_FLOAT
        if(expf(-delta_energy)< (ts_float)drand48())
#endif
#ifdef TS_DOUBLE_LONGDOUBLE
        if(expl(-delta_energy)< (ts_ldouble)drand48())
#endif
    	{
	//not accepted, reverting changes
	vtx=memcpy((void *)vtx,(void *)&backupvtx,sizeof(ts_vertex));
	for(i=0;i<vtx->bond_no;i++){
	vtx->bond[i]=memcpy((void *)vtx->bond[i],(void *)&backupbond[i],sizeof(ts_bond));
	}

    return TS_FAIL; 
	}
	}
*/
		
//	oldcellidx=vertex_self_avoidance(vesicle, &backupvtx[0]);
	if(vtx->cell!=vesicle->clist->cell[cellidx]){
		retval=cell_add_vertex(vesicle->clist->cell[cellidx],vtx);
//		if(retval==TS_SUCCESS) cell_remove_vertex(vesicle->clist->cell[oldcellidx],vtx);
		if(retval==TS_SUCCESS) cell_remove_vertex(backupvtx.cell,vtx);	
	}
//	if(oldcellidx);
    //END MONTE CARLOOOOOOO
    return TS_SUCCESS;
}




ts_bool single_filament_vertex_move(ts_vesicle *vesicle,ts_poly *poly,ts_vertex *vtx,ts_double *rn){
	ts_uint i;
	ts_bool retval; 
	ts_uint cellidx; 
	ts_double delta_energy;
	ts_double costheta,sintheta,phi,r;
	ts_double dist[2];
	//This will hold all the information of vtx and its neighbours
	ts_vertex backupvtx,backupneigh[2];
	ts_bond backupbond[2];

	//backup vertex:		
	memcpy((void *)&backupvtx,(void *)vtx,sizeof(ts_vertex));

	//random move in a sphere with radius stepsize:
	r=vesicle->stepsize*rn[0];
	phi=rn[1]*2*M_PI;
	costheta=2*rn[2]-1;
	sintheta=sqrt(1-pow(costheta,2));
	vtx->x=vtx->x+r*sintheta*cos(phi);
	vtx->y=vtx->y+r*sintheta*sin(phi);
	vtx->z=vtx->z+r*costheta;


	//distance with neighbours check
	for(i=0;i<vtx->bond_no;i++){
		dist[i]=vtx_distance_sq(vtx->bond[i]->vtx1,vtx->bond[i]->vtx2);
		if(dist[i]<1.0 || dist[i]>vesicle->dmax) {
			vtx=memcpy((void *)vtx,(void *)&backupvtx,sizeof(ts_vertex));
			return TS_FAIL;
		}
	}

// TODO: Maybe faster if checks only nucleus-neighboring cells
// Nucleus penetration check:
	if (vtx->x*vtx->x + vtx->y*vtx->y + vtx->z*vtx->z < vesicle->R_nucleus){
		vtx=memcpy((void *)vtx,(void *)&backupvtx,sizeof(ts_vertex));
		return TS_FAIL;
	}


	//self avoidance check with distant vertices
	cellidx=vertex_self_avoidance(vesicle, vtx);
	//check occupation number
	retval=cell_occupation_number_and_internal_proximity(vesicle->clist,cellidx,vtx);
	if(retval==TS_FAIL){
		vtx=memcpy((void *)vtx,(void *)&backupvtx,sizeof(ts_vertex));
        return TS_FAIL;
	} 

	//backup bonds
	for(i=0;i<vtx->bond_no;i++){
		memcpy(&backupbond[i],vtx->bond[i], sizeof(ts_bond));
		vtx->bond[i]->bond_length=sqrt(dist[i]);
		bond_vector(vtx->bond[i]);
	}

	//backup neighboring vertices:
	for(i=0;i<vtx->neigh_no;i++){
		memcpy(&backupneigh[i],vtx->neigh[i], sizeof(ts_vertex));
	}
	
	//if all the tests are successful, then energy for vtx and neighbours is calculated
	delta_energy=0;
	
	if(vtx->bond_no == 2){
		vtx->energy = -(vtx->bond[0]->x*vtx->bond[1]->x + vtx->bond[0]->y*vtx->bond[1]->y + vtx->bond[0]->z*vtx->bond[1]->z)/vtx->bond[0]->bond_length/vtx->bond[1]->bond_length;
		delta_energy += vtx->energy - backupvtx.energy;
	}

	for(i=0;i<vtx->neigh_no;i++){
		if(vtx->neigh[i]->bond_no == 2){
			vtx->neigh[i]->energy = -(vtx->neigh[i]->bond[0]->x*vtx->neigh[i]->bond[1]->x + vtx->neigh[i]->bond[0]->y*vtx->neigh[i]->bond[1]->y + vtx->neigh[i]->bond[0]->z*vtx->neigh[i]->bond[1]->z)/vtx->neigh[i]->bond[0]->bond_length/vtx->neigh[i]->bond[1]->bond_length;
			delta_energy += vtx->neigh[i]->energy - backupneigh[i].energy;
		}
	}

	// poly->k is filament persistence length (in units l_min)
	delta_energy *= poly->k;

	if(delta_energy>=0){
#ifdef TS_DOUBLE_DOUBLE
        if(exp(-delta_energy)< drand48() )
#endif
#ifdef TS_DOUBLE_FLOAT
        if(expf(-delta_energy)< (ts_float)drand48())
#endif
#ifdef TS_DOUBLE_LONGDOUBLE
        if(expl(-delta_energy)< (ts_ldouble)drand48())
#endif
    	{
	//not accepted, reverting changes
	vtx=memcpy((void *)vtx,(void *)&backupvtx,sizeof(ts_vertex));
	for(i=0;i<vtx->neigh_no;i++){
		memcpy(vtx->neigh[i],&backupneigh[i],sizeof(ts_vertex));
	}
	for(i=0;i<vtx->bond_no;i++){
		vtx->bond[i]=memcpy((void *)vtx->bond[i],(void *)&backupbond[i],sizeof(ts_bond));
	}

    return TS_FAIL; 
	}
	}
	
	
//	oldcellidx=vertex_self_avoidance(vesicle, &backupvtx[0]);
	if(vtx->cell!=vesicle->clist->cell[cellidx]){
		retval=cell_add_vertex(vesicle->clist->cell[cellidx],vtx);
//		if(retval==TS_SUCCESS) cell_remove_vertex(vesicle->clist->cell[oldcellidx],vtx);
		if(retval==TS_SUCCESS) cell_remove_vertex(backupvtx.cell,vtx);	
	}
//	if(oldcellidx);
    //END MONTE CARLOOOOOOO
    return TS_SUCCESS;
}