/*
    Project:    Email Chess
    Author:     Matti Kantola
                maza@ee.oulu.fi
                http://www.angelfire.com/nd/maza
    
    Description:
                Chess game where moves are exchanged using email.
                This is the main program and logic.

    History:    26.7.2000   wrote initial version
                27.7.2000   wrote rest, first release
                2.8.2000    more features
*/

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

public class Chess extends Applet implements MouseListener, ActionListener, ItemListener
{
    String num="87654321";
    String chr="ABCDEFGH";

    final int RW=50,RH=50;
    final Color WCOLOR=Color.lightGray,BCOLOR=Color.gray;

    String move=null;

    Piece[] white;
    Piece[] black;

    VerLayout vl;

    TextField tfme;
    TextField tfopp;
    TextField tfemail;
    Label lmove;
    Button bmove;
    Button brot;
    TextArea ta;
    Choice chprom;
        
    Image wpawn;
    Image wrook;    
    Image wknight;
    Image wbishop;
    Image wqueen;
    Image wking;
        
    Image bpawn;
    Image brook;
    Image bknight;
    Image bbishop;
    Image bqueen;
    Image bking;

    Image[] wbimages;

    boolean rotate=false;

    int lastmove=-1;
    int srcx=-1,srcy=-1;
    
    public void start()
    {
        URL u=getCodeBase();

        white=new Piece[16];
        black=new Piece[16];

        wpawn=getImage(u,"images/wpawn.gif");
        wrook=getImage(u,"images/wrook.gif");
        wknight=getImage(u,"images/wknight.gif");
        wbishop=getImage(u,"images/wbishop.gif");
        wqueen=getImage(u,"images/wqueen.gif");
        wking=getImage(u,"images/wking.gif");
        
        bpawn=getImage(u,"images/bpawn.gif");
        brook=getImage(u,"images/brook.gif");
        bknight=getImage(u,"images/bknight.gif");
        bbishop=getImage(u,"images/bbishop.gif");
        bqueen=getImage(u,"images/bqueen.gif");
        bking=getImage(u,"images/bking.gif");

        wbimages=new Image[12];
        wbimages[0]=wpawn;
        wbimages[1]=wknight;
        wbimages[2]=wbishop;
        wbimages[3]=wrook;
        wbimages[4]=wqueen;
        wbimages[5]=wking;
        wbimages[6]=bpawn;
        wbimages[7]=bknight;
        wbimages[8]=bbishop;
        wbimages[9]=brook;
        wbimages[10]=bqueen;
        wbimages[11]=bking;

        white[0]=new Piece(0,7,Piece.WHITE,wrook,"R");
        white[1]=new Piece(1,7,Piece.WHITE,wknight,"N");
        white[2]=new Piece(2,7,Piece.WHITE,wbishop,"B");
        white[3]=new Piece(3,7,Piece.WHITE,wqueen,"Q");
        white[4]=new Piece(4,7,Piece.WHITE,wking,"K");
        white[5]=new Piece(5,7,Piece.WHITE,wbishop,"B");
        white[6]=new Piece(6,7,Piece.WHITE,wknight,"N");
        white[7]=new Piece(7,7,Piece.WHITE,wrook,"R");
        white[8]=new Piece(0,6,Piece.WHITE,wpawn,"P");
        white[9]=new Piece(1,6,Piece.WHITE,wpawn,"P");
        white[10]=new Piece(2,6,Piece.WHITE,wpawn,"P");
        white[11]=new Piece(3,6,Piece.WHITE,wpawn,"P");
        white[12]=new Piece(4,6,Piece.WHITE,wpawn,"P");
        white[13]=new Piece(5,6,Piece.WHITE,wpawn,"P");
        white[14]=new Piece(6,6,Piece.WHITE,wpawn,"P");
        white[15]=new Piece(7,6,Piece.WHITE,wpawn,"P");

        black[0]=new Piece(0,0,Piece.BLACK,brook,"r");
        black[1]=new Piece(1,0,Piece.BLACK,bknight,"n");
        black[2]=new Piece(2,0,Piece.BLACK,bbishop,"b");
        black[3]=new Piece(3,0,Piece.BLACK,bqueen,"q");
        black[4]=new Piece(4,0,Piece.BLACK,bking,"k");
        black[5]=new Piece(5,0,Piece.BLACK,bbishop,"b");
        black[6]=new Piece(6,0,Piece.BLACK,bknight,"n");
        black[7]=new Piece(7,0,Piece.BLACK,brook,"r");
        black[8]=new Piece(0,1,Piece.BLACK,bpawn,"p");
        black[9]=new Piece(1,1,Piece.BLACK,bpawn,"p");
        black[10]=new Piece(2,1,Piece.BLACK,bpawn,"p");
        black[11]=new Piece(3,1,Piece.BLACK,bpawn,"p");
        black[12]=new Piece(4,1,Piece.BLACK,bpawn,"p");
        black[13]=new Piece(5,1,Piece.BLACK,bpawn,"p");
        black[14]=new Piece(6,1,Piece.BLACK,bpawn,"p");
        black[15]=new Piece(7,1,Piece.BLACK,bpawn,"p");
    
        vl=new VerLayout(430,100,22,20);
        setLayout(vl);

        tfme=new TextField();
        tfopp=new TextField();
        tfemail=new TextField();
        bmove=new Button("Send move");
        brot=new Button("Rotate board");
        Button bin=new Button("Input board");
        Button bout=new Button("Output board");
        lmove=new Label();

        chprom=new Choice();
        chprom.add("Pawn");
        chprom.add("Knight");
        chprom.add("Bishop");
        chprom.add("Rook");
        chprom.add("Queen");
        chprom.add("King");

        ta=new TextArea("",8,8,TextArea.SCROLLBARS_NONE);
        vl.setSize(ta,100,100);

        bmove.setActionCommand("0");
        brot.setActionCommand("1");
        bin.setActionCommand("2");
        bout.setActionCommand("3");
        
        bmove.addActionListener(this);
        brot.addActionListener(this);
        bin.addActionListener(this);
        bout.addActionListener(this);
        chprom.addItemListener(this);

        add(new Label("Your name"));
        add(tfme);
        add(new Label("Opponent name"));
        add(tfopp);
        add(new Label("Opponent email"));
        add(tfemail);
        add(new Label("Current move"));
        add(lmove);
        add(bmove);
        add(brot);
        add(bout);
        add(bin);
        add(ta);
        add(new Label("Promote to"));
        add(chprom);

        addMouseListener(this);
    }

    public void paint(Graphics g)
    {
        int x,y;
        Color col;

        for(y=0;y<8;y++)
        {
            for(x=0;x<8;x++)
            {
                col=((x&1)^(y&1))==1?BCOLOR:WCOLOR;
                g.setColor(col);
                g.fillRect(x*RW,y*RH,RW,RH);
            }
        
            g.setColor(Color.black);
            g.drawString(""+num.charAt(y),8*RW+8,y*RH+(RH/2));
            g.drawString(""+chr.charAt(y),y*RW+(RW/2),8*RH+12);
        }
        
        for(int i=0;i<16;i++)
        {
            drawPiece(g,white[i]);
            drawPiece(g,black[i]);
        }

        if(srcx!=-1)
        {
            g.setColor(Color.red);
            g.drawRect(srcx*RW,srcy*RH,RW-1,RH-1);
            g.drawRect(srcx*RW+1,srcy*RH+1,RW-3,RH-3);
        }
    }

    public void drawPiece(Graphics g,Piece p)
    {
        Color col;

        if(p.alive)
        {
            col=((p.x&1)^(p.y&1))==1?BCOLOR:WCOLOR;
            g.drawImage(p.image,p.x*RW,p.y*RH,col,this);
        }
    }

    public boolean move(int ox,int oy,int nx,int ny)
    {
        Piece src,dst;

        src=findAt(ox,oy);
        dst=findAt(nx,ny);

        if(src!=null)
        {
            if(dst!=null)
            {
                if(src.type==dst.type)
                {
                    return false;
                }

                dst.alive=false;
            }

            src.x=nx;
            src.y=ny;
       
            return true;
        }

        return false;
    }

    public Piece findAt(int x,int y)
    {
        for(int i=0;i<16;i++)
        {
            if(white[i].isAt(x,y))
            {
                return white[i];
            }

            if(black[i].isAt(x,y))
            {
                return black[i];
            }
        }
    
        return null;
    }

    public void rotate180()
    {
        Piece[] p;

        if(rotate) rotate=false;
            else rotate=true;

        p=new Piece[64];

        for(int i=0;i<64;i++)
        {
            p[i]=findAt(i%8,i/8);
        }
        
        for(int i=0;i<64;i++)
        {
            if(p[i]!=null)
            {
                p[i].x=7-i%8;
                p[i].y=7-i/8;
            }
        }

        if(rotate)
        {
            num="12345678";
            chr="HGFEDCBA";
        }
        else
        {
            num="87654321";
            chr="ABCDEFGH";
        }

        repaint();
    }

    public void mousePressed(MouseEvent e)
    {
        if( (e.getX()>8*RW) || (e.getY()>8*RH) ) return;
        
        int oldx=-1,oldy=-1;
        int newmove=-1;

        if(srcx!=-1)
        {
            oldx=srcx;
            oldy=srcy;
        }

        srcx=e.getX()/RW;
        srcy=e.getY()/RH;

        repaint(srcx*RW,srcy*RH,RW,RH);

        if(oldx!=-1)
        {
            if((srcx==oldx) && (srcy==oldy))
            {
                srcx=-1;
            }
            else 
            {
                Piece p=findAt(oldx,oldy);
                if(p!=null) newmove=p.type;

                if(move(oldx,oldy,srcx,srcy))
                {
                    if( (move==null) || (newmove!=lastmove) )
                    {
                        move="";
                    }

                    lastmove=newmove;

                    move+=  ""+chr.charAt(oldx)+num.charAt(oldy)+"-"+
                            chr.charAt(srcx)+num.charAt(srcy)+" ";
                    
                    lmove.setText(  ""+chr.charAt(oldx)+num.charAt(oldy)+"-"+
                                    chr.charAt(srcx)+num.charAt(srcy));
                    
                    srcx=-1;
                }
            }

            repaint(oldx*RW,oldy*RH,RW,RH);
        }
    } 
    
    public void mouseEntered(MouseEvent e){} 
    public void mouseExited(MouseEvent e){} 
    public void mouseClicked(MouseEvent e){} 
    public void mouseReleased(MouseEvent e){}

    public void itemStateChanged(ItemEvent e)
    {
        if(e.getItemSelectable() instanceof Choice)
        {
            Choice c=(Choice)e.getItemSelectable();

            Piece p=findAt(srcx,srcy);

            if(p!=null)
            {
                p.image=wbimages[p.type*6+c.getSelectedIndex()];
                repaint(srcx*RW,srcy*RH,RW,RH);
            }
        }
    }

    public void actionPerformed(ActionEvent e)
    {
        switch(e.getActionCommand().charAt(0))
        {
            case '0':
                if(move!=null)
                {
                    try{
                        URL u=new URL(  "mailto:"+tfemail.getText()+"?Subject="+
                                        "Game "+tfme.getText()+" vs "+tfopp.getText()+" "+
                                        move);
                        getAppletContext().showDocument(u);
                        move=null;
                    } catch(Exception ee){}

                    srcx=-1;
                }
                break;
                        
            case '1':
                rotate180();
                break;

            case '2':
                if(rotate) rotate180();

                BoardIO.setup(ta.getText(),white,black);
                repaint();
                break;

            case '3':
                if(rotate) rotate180();
                
                Piece[] p=new Piece[64];

                for(int i=0;i<64;i++)
                {
                    p[i]=findAt(i%8,i/8);
                }

                try{
                    URL u=new URL(  "mailto:"+tfemail.getText()+"?Subject="+
                                    "Game "+tfme.getText()+" vs "+tfopp.getText()+" board situation&Body="+
                                    BoardIO.getSetup(p));
                    getAppletContext().showDocument(u);
                } catch(Exception ee){}
                break;
        }
    }
}