import java.awt.*;

public class Graph extends Canvas {

private boolean debug = false;  // debugging mode

private Substance substance;   // current substance
private int id;                // id of the substance

private Rectangle bounds;     // defines the whole graph panel 
private Rectangle gpanel;      // defines ONLY the graph area
private boolean loaded;
private boolean mode;   //true for save mode and false otherwise

private Font title_font;  //font for graph title
private Font TPfont;     // font for axis labels
private Font H1font;     // font for heading
private Font scale_font; // font for scale
private FontMetrics fm;
private int between = 2;   // distance between two current rectangles

private Point origin;   // point where two axis intersect
private int offtop = 35;
private int offbottom = 40;
private int offleft = 50;
private int offright = 20;

private Increment current; // current state of path on the graph
private State current_state; 
private Path[] path;         // path of increments

private Image image;
private Graphics offg;


public Graph(Substance _substance) {
  substance = _substance;
  id = substance.getID();
  current_state = substance.getState(substance.getXRange().x,substance.getYRange().x);
  loaded = false;
  path = new Path[3];
  mode = false; // default not to save path
  title_font = new Font("TimesRoman", Font.PLAIN, 18);
  TPfont = new Font("TimesRoman", Font.ITALIC+Font.BOLD, 14);
  scale_font = new Font("TimesRoman", Font.PLAIN, 12);
}


public void setSubstance(Substance _substance) {
   substance = _substance;
   id = substance.getID();
   
   if(!mode) {
      resetEverything();
   }
   else {
      current = path[id].last();
      setState();
      resetScreen();
   }
}

private void resetEverything() {
   resetCurrent();
   setState();
   current.setColor(current_state.getColor());
   path[id] = new Path(current);
   resetScreen();
}



private void setState() {
  State new_state = substance.getState(calculateTP().x, calculateTP().y); 
  if(current_state != new_state) {
     current_state = new_state;
  }
}

public State getState() { return current_state; }



public int getTemperature() { return calculateTP().x; }
public int getPressure()    { return calculateTP().y; }



public void reset() { 
   resetEverything();  
}


public void clear() { 
   path[id].clear(); 
   resetScreen();
}


public void reveal() {
  int width = gpanel.width/(current.width+between);
  int height = gpanel.height/(current.height+between);
  boolean right = true;

  resetEverything();

  for(int i=0; i<height; i++) {
     for(int j=0; j<width; j++) { 
         if(right) moveRight();
         else moveLeft();
     }
     right = !right;
     moveUp();
  }
}


public void setSaveMode(boolean _mode) {
   mode = _mode;
}

//-------------------------------------------------------
private void resetScreen() {
  Graphics g = this.getGraphics();
  paint(g);
  g.dispose();
}



//---------------------------------------------------------------
public boolean keyDown(Event evt, int key) {
        if(key == Event.UP) moveUp();
   else if(key == Event.DOWN) moveDown();
   else if(key == Event.LEFT) moveLeft();
   else if(key == Event.RIGHT) moveRight();
   return super.keyDown(evt, key);
}


/*
   current rectangle is erased by drawing some other color over it
   new white rectangle is drawn in update
*/
private void move() {
   setState();
   current.setColor(current_state.getColor());
   path[id].append(current);
   repaint();
}


public void moveUp() {
   if(current.y  > gpanel.y + current.height + between) {
      eraseCurrent();
      int x = current.x;
      int y =  current.y - current.height - between;
      int side = current.width;
      current = new Increment(Color.black, x, y, side, side);
      move();
   }
}

public void moveDown() {
   if(current.y+current.height < gpanel.y + gpanel.height) {
      eraseCurrent();
      int x = current.x;
      int y =  current.y + current.height + between;;
      int side = current.width;
      current = new Increment(Color.black, x, y, side, side);
      move();
   }
}

public void moveLeft() {
   if(current.x > gpanel.x) {
      eraseCurrent();
      int x = current.x - current.width - between;;
      int y = current.y; 
      int side = current.width;
      current = new Increment(Color.black, x, y, side, side);
      move();
   }
}

public void moveRight() {
   if(current.x + current.width + between < gpanel.x + gpanel.width) {
      eraseCurrent();
      int x = current.x + current.width + between;;
      int y =  current.y;
      int side = current.width;
      current = new Increment(Color.black, x, y, side, side);
      move();
   }
}
//----------------------------------------------------------------------
private void drawCurrent(Graphics g) {  
   g.setColor(Color.white);  // draw current using white color
   g.fillRect(current.x,current.y,current.width,current.height);
}
 
private void eraseCurrent() {
   Graphics g = getGraphics();
   current.draw(g);      // draw current using its own color
   g.dispose();
}

private void resetCurrent() {
   current = new Increment(current_state.getColor(),origin.x,origin.y-4,4,4);
}
      
//--------------------------------------------------------
private Point calculateTP() {
   if(current==null) {
      return new Point(substance.getXRange().x,substance.getYRange().x);
   }
   int x = current.x - gpanel.x;
   int y = gpanel.height - (current.y - gpanel.y);
   int tlength = substance.getXRange().y - substance.getXRange().x;
   int plength = substance.getYRange().y - substance.getYRange().x;

   int temperature = x*tlength/gpanel.width + substance.getXRange().x;
   int pressure    = y*plength/gpanel.height + substance.getYRange().x;
   return new Point(temperature, pressure);
}


//-------------------------------------------------------
public void paint(Graphics g) {
   if(!loaded) { setLayout(); loaded = true; }
   
   drawGraphBG(g);
   drawSubstanceName(g);
   drawAxis(g);
   drawScale(g);
   drawPressureLabel(g);
   drawTemperatureLabel(g);

   path[id].draw(g);
   
   g.setColor(Color.gray);
   g.drawLine(bounds.x, bounds.y+bounds.height-1, 
              bounds.x+bounds.width,bounds.y+bounds.height-1);
   
   update(g);
}

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


//------------------- Paint background ---------------------
private void drawGraphBG(Graphics g) {
   g.setColor(Color.black);
   g.fill3DRect(bounds.x,bounds.y,bounds.width,bounds.height, true);
}

private void drawAxis(Graphics g) {   
   //Engraved.draw3DLine(g, origin.x-2, origin.y, gpanel.x-2, gpanel.y, true);
   //Engraved.draw3DLine(g, origin.x, origin.y+1, gpanel.x+gpanel.width, 
   //                    gpanel.y+gpanel.height+1, false);
   g.setColor(Color.green);
   g.drawLine(origin.x-2, origin.y, gpanel.x-2, gpanel.y);
   g.drawLine(origin.x, origin.y+1, gpanel.x+gpanel.width, 
                       gpanel.y+gpanel.height+1);
}
      

private void drawScale(Graphics g) {
   int x, y;
   g.setColor(Color.white);
   g.setFont(scale_font);
   fm = g.getFontMetrics(scale_font);
   int[] xpoints = substance.getXPoints();
   int[] ypoints = substance.getYPoints();
   int width = substance.getXRange().y-substance.getXRange().x;
   int height = substance.getYRange().y-substance.getYRange().x;
   int off = 4;
   // horizontal 
   y = origin.y+2;
   for(int i=0; i<xpoints.length; i++) {
      x = origin.x + (gpanel.width*(xpoints[i]-substance.getXRange().x))/width-2;
      String s = Integer.toString(xpoints[i]);
          
      //Engraved.draw3DLine(g, x, y+off, x, y-off, false);
      //Engraved.draw3DString(g, s, x-fm.stringWidth(s)/2, origin.y+17, false);      
      g.setColor(Color.green);
      g.drawLine(x, y+off, x, y-off);
      g.drawString(s, x-fm.stringWidth(s)/2, origin.y+17);
   }
   // vertical
   x = origin.x - 2;
   for(int i=0; i<ypoints.length; i++) {
      y = 1+origin.y - (gpanel.height*(ypoints[i]-substance.getYRange().x))/height;
      String s = Integer.toString(ypoints[i]);
      //Engraved.draw3DString(g, s, x-fm.stringWidth(s)-5, y+fm.getHeight()/2-2,false); 
      //Engraved.draw3DLine(g, x-off, y, x+off, y, false);
      g.setColor(Color.green);
      g.drawString(s, x-fm.stringWidth(s)-5, y+fm.getHeight()/2-2); 
      g.drawLine(x-off, y, x+off, y);
   }
}

private void drawPressureLabel(Graphics g) {
   g.setFont(TPfont);
   fm = g.getFontMetrics(TPfont);
   String p = "PRESSURE kbars";
   int x = bounds.x + 10;
   int y = gpanel.y;
   for(int i=0; i<p.length(); i++) {
      String s = String.valueOf(p.charAt(i));
      y += fm.getHeight() - 2;
      g.setColor(Color.blue);
      g.drawString(s, x, y);
      //Engraved.draw3DString(g, s, x, y, false);
   }
}

private void drawTemperatureLabel(Graphics g) {
   g.setFont(TPfont);
   fm = g.getFontMetrics(TPfont);
   String s = "TEMPERATURE (C)";
   int x = (gpanel.x+gpanel.width) - fm.stringWidth(s)-40;
   int y = (bounds.y+bounds.height) - 10;
   //Engraved.draw3DString(g, s, x, y, false);
   g.setColor(Color.blue);
   g.drawString(s, x, y);
}

private void drawSubstanceName(Graphics g) {
   g.setFont(title_font);
   fm = g.getFontMetrics(title_font);
   String s = substance.getName();
   //set Rectangle
   int _offleft = 25;  // for string position inside rectangle
   int _offtop =  2;   // same
   int x = bounds.x + (bounds.width - fm.stringWidth(s))/2 - _offleft;
   int y = bounds.y+5;
   int width = fm.stringWidth(s) + 2*_offleft;
   int height = fm.getHeight() + 2*_offtop;
   Rectangle r = new Rectangle(x, y, width, height);
   g.setColor(Color.lightGray);
   g.fill3DRect(r.x, r.y, r.width, r.height, true);

   // set String inside rectangle
   x = r.x + _offleft;
   y = r.y + r.height - _offtop - 5;
   
   Engraved.draw3DString(g, s, x, y, true);
   //Engraved.draw3DRect(g, r.x, r.y, r.width, r.height, true);
}


//------------------------------------------------------------------

private void setLayout() {
   bounds = new Rectangle(0,0,size().width, size().height);
   gpanel = new Rectangle(bounds.x+offleft, bounds.y+offtop, 
                          bounds.width-(offleft+offright),
                          bounds.height-(offtop+offbottom));
   origin = new Point(gpanel.x, gpanel.y+gpanel.height);
   current = new Increment(current_state.getColor(),origin.x,origin.y-4,4,4);
   for(int i=0; i<3; i++) {
      path[i] = new Path(current);
   }
}

//---------------------DEBUG-----------------------------
private void dbi(String s) {
   if(debug) System.out.println(s);
}

}