/** applet No. 1012
 *
 * gas particles in glass 2d network
 * doorways distribution in glass network - fictive temperature
 * - fast kinetic Monte-Carlo simulation
 *
 * Created by Ikeuchi Mitsuru on September 09 2006.
 * Copyright (c) 2006 Ikeuchi Mitsuru. All rights reserved.
 *
 * ver 0.0.1   2006.09.09  created
 * ver 0.0.2   2007.06.07  improved code
 *
 */

import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class fictiveTemp2dKMC extends Applet
  implements ItemListener, ActionListener, AdjustmentListener, Runnable {

  // ------------------------------------ preset field -----------

  Thread th = null; // for run()-paint() thread

 // for event
  Choice ch_view;
  Button bt_reset, bt_restart, bt_startStop;
  Scrollbar sc_door, sc_qq1, sc_qq2, sc_qq3, sc_kT;

  // for off-paint buffer
  Dimension dim;
  Image imgOff,imgOffInit;
  Graphics gOff,gOffInit;

  // KMC
  double t = 0.0;
  double dt = 1.0;

  int resetSW = 0;
  int restartSW = 0;
  int started = 1;
  int changeFlag = 1;

  double kT = 0.025;
  double doorwayRatio = 0.5;
  double totalRate = 1.0e15;

  int NNx = 64;
  int NNy = 64;
  int NNa = 2000;
  int NNlayer = 10;
  int NNN = 20000;

  int lattice[][] = new int[NNx][NNy];
  int doorwayKind[][][] = new int[NNx][NNy][4];
  int atom[][] = new int[NNN][2];
  double transition[] = new double[NNN*4];
  double transitionAtom[] = new double[NNN];
  double rate[] = new double[8];
  double activationEnergy[] = { 1000.0, 0.40, 0.30, 0.20 };

  int doorKindInfo[][] = new int[2][4];

  // display
  int dispWidth = 630;
  int dispHeight = 420;
  int sleepTime = 50;
  int dispMode = 0;


  // ------------------------------ applet main thread -----------

  public void init() {

    resize(dispWidth,dispHeight);
    setBackground(Color.white);

    dim = getSize();
    imgOffInit = createImage(dim.width,dim.height);
    gOffInit = imgOffInit.getGraphics();

    imgOff = createImage(dim.width,dim.height);
    gOff = imgOff.getGraphics();

    ch_view = new Choice();
    ch_view.add("gas");
    ch_view.add("easy way");
    ch_view.addItemListener(this);
    ch_view.select("gas");

    bt_reset= new Button("reset");
    bt_reset.addActionListener(this);

    bt_restart = new Button("restart");
    bt_restart.addActionListener(this); 

    bt_startStop= new Button("start/stop");
    bt_startStop.addActionListener(this); 

    sc_door= new Scrollbar(Scrollbar.HORIZONTAL,50,10,0,110);
    sc_door.addAdjustmentListener(this);

    sc_qq1= new Scrollbar(Scrollbar.HORIZONTAL,40,10,30,60);
    sc_qq1.addAdjustmentListener(this);

    sc_qq2= new Scrollbar(Scrollbar.HORIZONTAL,30,10,20,50);
    sc_qq2.addAdjustmentListener(this);

    sc_qq3= new Scrollbar(Scrollbar.HORIZONTAL,20,10,10,40);
    sc_qq3.addAdjustmentListener(this);

    sc_kT= new Scrollbar(Scrollbar.HORIZONTAL,25,10,20,110);
    sc_kT.addAdjustmentListener(this);

    setLayout(new BorderLayout());
    Panel pnl = new Panel();
    pnl.setLayout(new GridLayout(2,6,5,0));
    //pnl.add(new Label("  "));
    pnl.add(bt_reset);
    pnl.add(bt_restart);
    pnl.add(bt_startStop);
    pnl.add(new Label("  "));
    pnl.add(new Label("    temp"));
    pnl.add(new Label("    view"));

    pnl.add(sc_door);
    pnl.add(sc_qq1);
    pnl.add(sc_qq2);
    pnl.add(sc_qq3);
    pnl.add(sc_kT);
    pnl.add(ch_view);
    add(pnl,"North");

    setInitialCondition();
  }

  public void start() {
    if (th == null) {
      th = new Thread(this);
      th.start();
    }
  }

  public void stop() {
    if (th != null) th = null;
  }


  // ---------------------------------- event listener -----------

  public void itemStateChanged(ItemEvent ev){
    if (ev.getSource() == ch_view) {
      dispMode = ch_view.getSelectedIndex();
      setoffImageInit(dispMode);
    }
  }

  public void actionPerformed(ActionEvent ev){
    if (ev.getSource() == bt_reset){ 
      resetSW = 1;
    } else if (ev.getSource() == bt_restart){ 
      restartSW = 1;
    } else if (ev.getSource() == bt_startStop){
      if (started==0) {
        started = 1;
      } else {
        started = 0;
      }
    }
  }

  public void adjustmentValueChanged(AdjustmentEvent ev){
    if (ev.getSource() == sc_door) { 
      doorwayRatio = 0.01*sc_door.getValue();
      resetSW = 1;
    } else if (ev.getSource() == sc_qq1) { 
      activationEnergy[1] = 0.01*(double)(sc_qq1.getValue());
      changeFlag = 1;
    } else if (ev.getSource() == sc_qq2) { 
      activationEnergy[2] = 0.01*(double)(sc_qq2.getValue());
      changeFlag = 1;
    } else if (ev.getSource() == sc_qq3) { 
      activationEnergy[3] = 0.01*(double)(sc_qq3.getValue());
      changeFlag = 1;
    } else if (ev.getSource() == sc_kT) { 
      kT = 0.001*(double)(sc_kT.getValue());
      changeFlag = 1;
    }
  }



  // ========================= run() - paint() loop ==============

  public void run() {
    while (th != null) {
      timeEvolution();
      offPaint();
      repaint();
      try {
        Thread.sleep(sleepTime);
      } catch (InterruptedException e) { }
    }
  }

  public void update(Graphics g) {
    paint(g);
  }

  public void paint(Graphics g) {
    g.drawImage(imgOff,0,0,this);
  }


  // ---------------------------------------- offPaint -----------

  private void setoffImageInit(int mode) {
    int gx,gy,sz;

    gx = 30; gy = 90; sz = 5;
    gOffInit.setColor(Color.white);
    gOffInit.fillRect(0,0,dim.width,dim.height);

    if (mode==0) {
      dispInitDoorway(gx, gy, sz);
    } else if (mode==1) {
      dispInitDoorway(gx, gy, sz);
      dispInitEasyway(gx, gy, sz);
    }
  }

  private void offPaint() {
    int gx,gy,sz,gbx,k;
    double col;

    gx = 30; gy = 90; sz = 5;
    gOff.drawImage(imgOffInit,0,0,this);

    if (dispMode==0) {
      dispLattice(gx, gy, sz);

    } else if (dispMode==1) {
      dispLattice(gx, gy, sz);

    } else if (dispMode==2) {
      ;

    }

    gOff.setColor(Color.black);
    gOff.drawString("doorRatio="+(int)(doorwayRatio*100+0.5)/100.0+" ",dispWidth/6*0+10,70);
    col = colorOf(1);
    gOff.setColor(Color.getHSBColor((float)col,0.8f,0.8f));
    gOff.drawString("Q1="+(int)(activationEnergy[1]*100.0+0.5)/100.0+" eV",dispWidth/6*1+10,70);
    col = colorOf(2);
    gOff.setColor(Color.getHSBColor((float)col,0.8f,0.8f));
    gOff.drawString("Q2="+(int)(activationEnergy[2]*100.0+0.5)/100.0+" eV",dispWidth/6*2+10,70);
    col = colorOf(3);
    gOff.setColor(Color.getHSBColor((float)col,0.8f,0.8f));
    gOff.drawString("Q3="+(int)(activationEnergy[3]*100.0+0.5)/100.0+" eV",dispWidth/6*3+10,70);

    gOff.setColor(Color.black);
    gOff.drawString("kT="+(int)(kT*1000+0.5)/1000.0+" eV",dispWidth/6*4+10,70);
    gOff.drawString("  ="+(int)(kT*11600+0.5)+" K",dispWidth/6*4+10,90);

    gbx = 400;
    gOff.setColor(Color.blue);
    gOff.drawString("t="+(int)(t*1e11+0.5)/100.0+" ns",gbx,120);
    //gOff.drawString("No. of gas="+numberOfgasatom()+"",gbx,140);
    gOff.drawString("No. of gas="+NNa+"",gbx,140);

    gOff.setColor(Color.black);
    gOff.drawString("hopping counts / No. of door",gbx,200);
    for (k=1;k<4;k++) {
      col = colorOf(k);
      gOff.setColor(Color.getHSBColor((float)col,0.8f,0.8f));
      gOff.drawString("Q"+k+"="+doorKindInfo[1][k]+"",gbx,200+20*k);
      gOff.drawString(" / "+doorKindInfo[0][k]+"",gbx+100,200+20*k);
    }
  }


  // ------------------------------------ plot methods -----------

  private void dispLattice(int gx, int gy, int span) {
    int i,j,ir;
    double col;

    gOff.setColor(Color.getHSBColor(0.6f,0.9f,0.9f));
    ir = span-2;
    for(i=0;i<NNx;i++) {
      for(j=0;j<NNy;j++) {
        if (lattice[i][j]>=0) {
          gOff.fillOval(gx+span*i+1,gy+span*j+1, ir, ir);
        }
      }
    }
  }

  private double colorOf(int knd) {
    double col;

    if (knd==0) {
      col = 0.01;
    } else if (knd==1) {
      col = 0.05;
    } else if (knd==2) {
      col = 0.15;
    } else if (knd==3) {
      col = 0.33;
    } else {
      col = 0.85;
    }
    return (col);
  }

  //

  private void dispInitDoorway(int gx, int gy, int span) {
    int i,j,knd;
    double col;

    for(i=0;i<NNx;i++) {
      for(j=0;j<NNy;j++) {
        knd = doorwayKind[i][j][2];
        col = colorOf(knd);
        gOffInit.setColor(Color.getHSBColor((float)col,0.8f,0.8f));

        gOffInit.drawLine(gx+span*i,gy+span*j+span, gx+span*i+span-1, gy+span*j+span);

        knd = doorwayKind[i][j][0];
        col = colorOf(knd);
        gOffInit.setColor(Color.getHSBColor((float)col,0.8f,0.8f));
        gOffInit.drawLine(gx+span*(i+1),gy+span*j, gx+span*(i+1), gy+span*j+span-1);
      }
    }

    i=0;
      for(j=0;j<NNy;j++) {
        knd = doorwayKind[i][j][1];
        col = colorOf(knd);
        gOffInit.setColor(Color.getHSBColor((float)col,0.8f,0.8f));
        gOffInit.drawLine(gx,gy+span*j, gx, gy+span*j+span-1);
      }

    for(i=0;i<NNx;i++) {
      j=0;
        knd = doorwayKind[i][j][3];
        col = colorOf(knd);
        gOffInit.setColor(Color.getHSBColor((float)col,0.8f,0.8f));
        gOffInit.drawLine(gx+span*i,gy, gx+span*i+span-1, gy);
    }
  }

  private void dispInitEasyway(int gx, int gy, int span) {
    int i,j,ir,k,knd;
    double col;

    ir = span-1;
    for(i=0;i<NNx;i++) {
      for(j=0;j<NNy;j++) {
        knd = -1;
        for(k=0;k<4;k++) {
          if (doorwayKind[i][j][k]>knd) knd = doorwayKind[i][j][k];
        }
        col = colorOf(knd);
        gOffInit.setColor(Color.getHSBColor((float)col,0.2f,0.8f));
        gOffInit.fillRect(gx+span*i+1,gy+span*j+1, ir, ir);
      }
    }
  }



  // ================ kinetic Monte-Carlo Method 2D ==============

  //  set initial condition

  private void setInitialCondition() {
    int ia;

    t = 0.0;

    setDoorwayKind();
    initLattice();
    NNa = setGasAtom();

    setAllTransition();
    changeFlag = 0;

    setDoorKindInfo();
    setoffImageInit(dispMode);
  }

  private void initLattice() {
    int i,j;

    for(i=0;i<NNx;i++) {
      for(j=0;j<NNy;j++) {
        lattice[i][j] = -1;
      }
    }
  }

  private int setGasAtom() {
    int i,j,ia,nx;

    nx = NNlayer;
    ia = 0;
    for(i=0;i<nx;i++) {
      for(j=0;j<NNy;j++) {
        atom[ia][0] = i; atom[ia][1] = j;
        lattice[i][j] = ia;
        ia += 1;
      }
    }
    return ( ia );
  }

  private void setDoorwayKind() {
    int i,j,ik;
    double r,r1,r2;

    for(i=0;i<NNx;i++) {
      for(j=0;j<NNy;j++) {
        doorwayKind[i][j][0] = 0;
        doorwayKind[i][j][1] = 0;
        doorwayKind[i][j][2] = 0;
        doorwayKind[i][j][3] = 0;
      }
    }

	r1 = doorwayRatio/(1.0 + 2.0*doorwayRatio);
    r2 = (1.0+doorwayRatio)/(1.0 + 2.0*doorwayRatio);
    for(i=0;i<NNx;i++) {
      for(j=0;j<NNy;j++) {
	    r = Math.random();
		if (r<r1) {
		  ik = 1;
		} else if (r<r2) {
		  ik = 2;
		} else {
		  ik = 3;
		}
        doorwayKind[i][j][0] = ik;
        doorwayKind[(i+1)%NNx][j][1] = doorwayKind[i][j][0];

	    r = Math.random();
		if (r<r1) {
		  ik = 1;
		} else if (r<r2) {
		  ik = 2;
		} else {
		  ik = 3;
		}
        doorwayKind[i][j][2] = ik;
        doorwayKind[i][(j+1)%NNy][3] = doorwayKind[i][j][2];
      }
    }

    i=0;
      for(j=0;j<NNy;j++) {
        doorwayKind[i][j][1] = 0;
      }

    i=NNx-1;
      for(j=0;j<NNy;j++) {
        doorwayKind[i][j][0] = 0;
      }
  }


  // ---------------------------------- time evolution -----------

  private void timeEvolution() {

    if (resetSW==1) {
      setInitialCondition();
      resetSW = 0;
      started = 1;
    }

    if (restartSW==1) {
      t = 0.0;
      initLattice();
      NNa = setGasAtom();

      setAllTransition();
      setDoorKindInfo();
      changeFlag = 0;
      restartSW = 0;
      started = 1;
    }

    if (started==1) {
      timeStep();
    }
  }

  private void timeStep() {
    int i,nn;
    double deltat;

    nn = NNa/10+1; if (nn>1000) nn = 1000;

    for(i=0;i<nn;i++) {
      deltat = kmcStep();
      t = t + deltat;
    }
    correctTotalRate();
  }

  private void correctTotalRate() {
    int i;
    double s;

    s = 0.0;
    for(i=0;i<NNa;i++) {
      s += transitionAtom[i];
    }
    totalRate = s;
  }

  private double kmcStep() {
    int i,ip;
    double rsum,r;

    if (changeFlag==1) {
      totalRate = setAllTransition();
      changeFlag = 0;
    }

    ip = selectTransion(totalRate);
    setMoveDoorKindInfo(ip);
    move(ip);

    r = (1.0-1.0e-12)*Math.random()+1.0e-12;
    return(-Math.log(r)/totalRate);
  }

  // set transition , and calc. sum of transition

  private double setAllTransition() {
    int ia;
    double rsum;

    rsum = 0.0;
    for(ia=0;ia<NNa;ia++) {
      rsum += setTransition(ia);
    }
    return (rsum);
  }

  private double setTransition(int ia) {
    int i,j,nb;

    i = atom[ia][0]; j = atom[ia][1];

    if (lattice[(i+1)%NNx][j]>=0) {
      transition[ia*4+0] = 0.0;
    } else {
      transition[ia*4+0] = transition(i,j,0);
    }

    if (lattice[(i-1+NNx)%NNx][j]>=0) {
      transition[ia*4+1] = 0.0;
    } else {
      transition[ia*4+1] = transition(i,j,1);
    }

    if (lattice[i][(j+1)%NNy]>=0) {
      transition[ia*4+2] = 0.0;
    } else {
      transition[ia*4+2] = transition(i,j,2);
    }

    if (lattice[i][(j-1+NNy)%NNy]>=0) {
      transition[ia*4+3] = 0.0;
    } else {
      transition[ia*4+3] = transition(i,j,3);
    }

    transitionAtom[ia] = transition[ia*4+0]+transition[ia*4+1]+transition[ia*4+2]+transition[ia*4+3];
    return (transitionAtom[ia]);
  }

  private double transition(int i, int j, int dir) {
    return( transitionRate(activationEnergy[doorwayKind[i][j][dir]]) );
  }

  private double transitionRate(double energy) {
    double h,nue0;

    h = 6.626e-34;
    nue0 = kT*1.602e-19/h;

    return( nue0*Math.exp(-energy/kT) );
  }

  // select transion

  private int selectTransion(double rsum) {
    int ia,iap;
    double rnd;

    rnd = rsum*Math.random();

    for (ia=0; ia<NNa; ia++) {
      rnd -= transitionAtom[ia];
      if (rnd<0.0) {
        rnd += transitionAtom[ia];
        for (iap=0; iap<4; iap++) {
          rnd -= transition[ia*4+iap];
          if (rnd<0.0) return (ia*4+iap);
        }
        return(ia*4+3);
      }
    }
    return((NNa-1)*4+3);
  }

  // move (update adatom[][],lattice[][])

  private void move(int ip) {
    int ia,id,i0,j0,i,j;
    double rs0,rs1;

    if (transition[ip]>0.0) {
      ia = ip/4;
      id = ip%4;
      i = atom[ia][0]; j = atom[ia][1];

      lattice[i][j] = -1;
      if (id==0) i = (i+1)%NNx;
      if (id==1) i = (i-1+NNx)%NNx;
      if (id==2) j = (j+1)%NNy;
      if (id==3) j = (j-1+NNy)%NNy;
      atom[ia][0] = i; atom[ia][1] = j;
      lattice[i][j] = ia;

      rs0 = rateAround(i,j);
      rs1 = setRateAround(i,j);
      totalRate = totalRate - rs0 + rs1;
    }
  }

  private double setRateAround(int i0, int j0) {
    int i,j,ii,jj;
    double srate;

    srate = 0.0;
    for (i=i0-2; i<=i0+2; i++) {
      ii = (i+NNx)%NNx;
      for (j=j0-2; j<=j0+2; j++) {
        jj =  (j+NNy)%NNy;
        if (lattice[ii][jj]>=0) {
          srate += setTransition(lattice[ii][jj]);
        }
      }
    }
    return ( srate );
  }

  private double rateAround(int i0, int j0) {
    int i,j,ii,jj;
    double srate;

    srate = 0.0;
    for (i=i0-2; i<=i0+2; i++) {
      ii = (i+NNx)%NNx;
      for (j=j0-2; j<=j0+2; j++) {
        jj =  (j+NNy)%NNy;
        if (lattice[ii][jj]>=0) {
          srate += transitionAtom[lattice[ii][jj]];
        }
      }
    }
    return ( srate );
  }

  // --------------------------------------- utilities -----------

  private int numberOfAtom() {
    int i,j,n;

    n = 0;
    for(i=0;i<NNx;i++) {
      for(j=0;j<NNy;j++) {
        if (lattice[i][j]>=0) n += 1;
      }
    }
    return(n);
  }

  private void setDoorKindInfo() {
    int i,j,knd,id;

    for(knd=0;knd<4;knd++) {
      doorKindInfo[0][knd] = 0;
      doorKindInfo[1][knd] = 0;
    }

    for(i=0;i<NNx;i++) {
      for(j=0;j<NNy;j++) {
        for(id=0;id<4;id++) {
          knd = doorwayKind[i][j][id];
          doorKindInfo[0][knd] += 1;
        }
      }
    }
  }

  private void setMoveDoorKindInfo(int ip) {
    int ia,id,i,j,knd;

    ia = ip/4;
    id = ip%4;
    i = atom[ia][0]; j = atom[ia][1];

    knd = doorwayKind[i][j][id];
    doorKindInfo[1][knd] += 1;
  }

}


/* ----- kinetic Monte-Carlo algorithm -----
 * ( or the Bortz-Kalos-Liebowitz (BKL) algorithm )
 *
 * i-th transition rate in the system : ri
 * total transition rate : RN = sum(ri, {i=1,2,...,N})
 *
 * 1) t = 0
 *
 * 2) select i : randomly (proportional to ri/RN)
 *  calculate R(i) = sum(rj, {j=1,2,...,i})
 *  get a uniform random number u in [0,1]
 *  find i  R(i-1) < u RN <= R(i)
 *
 * 3) execute i-th transition
 *
 * 4) update the time
 *  get a uniform random numner u in (0,1]
 *  dt = -log(u)/R
 *  t = t + dt
 *
 * 5) goto 2)
 *
 * ----------
 *
 * transion rate k
 *  k = nue0*exp(-dE/kT)
 *  nue0 = kT/h , h: Plank constant
 *
 */