import java.awt.*;
import java.applet.*;
import java.util.Random;

public class Puzzle extends Applet
{
	int picturewidth;
	int pictureheight;
	int xpieces;
	int ypieces;
	int piecewidth;
	int pieceheight;
	int offscreenwidth;
	int offscreenheight;
	Color backgroundcolor;
	
	Piece piece[];
	Image pictureimage;
	Image offscreenimage;
	Graphics offscreen;
	boolean loaded;
	boolean pieceisfloating;
	int cursorxinpiece;
	int cursoryinpiece;
	int groupcount;
	int joincount;
	
	public void init()
	{
		try{
		// イメージローディング
		loaded = false;
		pictureimage = getImage(getCodeBase(), getParameter("picture"));
		// パラメータ読み込み
		xpieces = Integer.parseInt(getParameter("xpieces"));
		ypieces = Integer.parseInt(getParameter("ypieces"));
		offscreenwidth = this.size().width;
		offscreenheight = this.size().height;
		backgroundcolor = new Color(
		 Integer.parseInt(getParameter("bgcolorR")),
		 Integer.parseInt(getParameter("bgcolorG")),
		 Integer.parseInt(getParameter("bgcolorB")));
		// ピース配列作成
		piece = new Piece[xpieces*ypieces];
		// オフスクリーンの作成
		offscreenimage = createImage(offscreenwidth, offscreenheight);
		offscreen = offscreenimage.getGraphics();
		if(offscreen.drawImage(pictureimage, 0, 0, this) == true)
			makepieces();
		}catch(Exception e){e.printStackTrace(System.out);}
	}
	public boolean imageUpdate(Image img, int infoflags, int x, int y, int width, int height)
	{
		// 読み込み完了しているか確認
		if((infoflags & ALLBITS) == ALLBITS)
		{
			makepieces();
			return false;
		}
		else
			return true;
	}
	
	private void makepieces()
	{
		try{
		picturewidth = pictureimage.getWidth(null);
		pictureheight = pictureimage.getHeight(null);
		piecewidth = picturewidth/xpieces;
		pieceheight = pictureheight/ypieces;
		Random rnd = new Random();
		for(int i = 0; i < xpieces; i++)
		 for(int j = 0; j < ypieces; j++)
		{
			int k = j*xpieces+i;
			piece[k] = new Piece();
			piece[k].group = -1;
			piece[k].pxpos = i;
			piece[k].pypos = j;
			piece[k].left = (int)(rnd.nextDouble()*(offscreenwidth-piecewidth));
			piece[k].top = (int)(rnd.nextDouble()*(offscreenheight-pieceheight));
			piece[k].image = createImage(piecewidth, pieceheight);
			piece[k].image.getGraphics().drawImage(pictureimage, -piecewidth*i, -pieceheight*j, null);
		}
		pieceisfloating = false;
		groupcount = 0;
		joincount = 0;
		// 読み込み完了フラグon
		loaded = true;
		repaint();
		}catch(Exception e){e.printStackTrace(System.out);}
	}
	
	public void update(Graphics g)
	{
		if(loaded)
		{
			// オフスクリーン消去
			offscreen.setColor(backgroundcolor);
			offscreen.fillRect(0, 0, offscreenwidth, offscreenheight);
			// ピース描画、後ろの番号のピースを先に描く
			for(int i = xpieces*ypieces-1; i >= 0; i--)
			{
				offscreen.drawImage(piece[i].image, piece[i].left, piece[i].top, null);
				//debug offscreen.setColor(Color.red);
				//debug offscreen.drawString("("+piece[i].pxpos+","+piece[i].pypos+")", piece[i].left, piece[i].top);
				//debug offscreen.setColor(Color.white);
				//debug offscreen.drawString(Integer.toString(i), piece[i].left, piece[i].top+10);
				//debug offscreen.setColor(Color.yellow);
				//debug offscreen.drawString(Integer.toString(piece[i].group), piece[i].left, piece[i].top+20);
			}
		}
		paint(g);
	}
	
	public void paint(Graphics g)
	{
		g.drawImage(offscreenimage, 0, 0, null);
	}
	
	public boolean mouseDown(Event e, int x, int y)
	{
		try{
		for(int i = 0; i < xpieces*ypieces; i++)
			if((piece[i].left < x)&&(x < piece[i].left+piecewidth)&&
			 (piece[i].top < y)&&(y < piece[i].top+pieceheight))
			{
				// 選択ピースを最前面（０番ピース）に移動
				Piece tmppiece;
				tmppiece = piece[i];
				for(int j = i; j > 0; j--)
					piece[j] = piece[j-1];
				piece[0] = tmppiece;
				// ピースフローティングon、カーソル位置保存
				pieceisfloating = true;
				cursorxinpiece = x-piece[0].left;
				cursoryinpiece = y-piece[0].top;
				repaint();
				break;
			}
		}catch(Exception ex){ex.printStackTrace(System.out);}
		return true;
	}
	
	public boolean mouseDrag(Event e, int x, int y)
	{
		if(pieceisfloating)
		{
			// フロートピースをカーソル位置に移動
			piece[0].left = x-cursorxinpiece;
			piece[0].top = y-cursoryinpiece;
			// 他のピースとつながってグループになっている場合、それらも移動
			if(piece[0].group != -1)
			{
				int ox = piece[0].left-piece[0].pxpos*piecewidth;
				int oy = piece[0].top-piece[0].pypos*pieceheight;
				for(int i = 1; i<xpieces*ypieces; i++)
					if(piece[i].group == piece[0].group)
					{
						piece[i].left = ox+piece[i].pxpos*piecewidth;
						piece[i].top = oy+piece[i].pypos*pieceheight;
					}
			}
			repaint();
		}
		return true;
	}
	
	public boolean mouseUp(Event e, int x, int y)
	{
		if(pieceisfloating)
		{
			for(int l = 0; l < xpieces*ypieces; l++)
			 if(piece[l].group == piece[l].group)
			{
				for(int i = 1; i < xpieces*ypieces; i++)
				 if((piece[l].group == -1)||(piece[i].group != piece[l].group))
				{
					for(int j = 0; j < 4; j++)
					{
						int px = 0, py = 0;
						switch(j)
						{
							// 左、上、右、下
							case 0:
								if((piece[l].pxpos-1 == piece[i].pxpos)&&(piece[l].pypos == piece[i].pypos))
								{
									px = piece[i].left+piecewidth;
									py = piece[i].top;
									break;
								}
								else
									continue;
							case 1:
								if((piece[l].pxpos == piece[i].pxpos)&&(piece[l].pypos-1 == piece[i].pypos))
								{
									px = piece[i].left;
									py = piece[i].top+pieceheight;
									break;
								}
								else
									continue;
							case 2:
								if((piece[l].pxpos+1 == piece[i].pxpos)&&(piece[l].pypos == piece[i].pypos))
								{
									px = piece[i].left-piecewidth;
									py = piece[i].top;
									break;
								}
								else
									continue;
							case 3:
								if((piece[l].pxpos == piece[i].pxpos)&&(piece[l].pypos+1 == piece[i].pypos))
								{
									px = piece[i].left;
									py = piece[i].top-pieceheight;
									break;
								}
								else
									continue;
						}
						if(Math.pow(px-piece[l].left, 2)+Math.pow(py-piece[l].top, 2) < 100)
						{
							//debug System.out.println("joined--");
							//debug System.out.println("piece[l]:"+piece[l].toString());
							//debug System.out.println("piece["+i+"]:"+piece[i].toString());
							if(piece[l].group == -1)
							{
								if(piece[i].group == -1)
								{
									piece[i].group = groupcount;
									piece[l].group = groupcount;
									groupcount++;
								}
								else
									piece[l].group = piece[i].group;
							}
							else
							{
								if(piece[i].group == -1)
									piece[i].group = piece[l].group;
								else
								{
									int piecegroup = piece[i].group;
									for(int k = 0; k<xpieces*ypieces; k++)
										if(piece[k].group == piecegroup)
											piece[k].group = piece[l].group;
								}
							}
							joincount++;
						}
					}
				}
			}
			// グループになったピースの位置をあわせる
			if(piece[0].group != -1)
			{
				int ox = piece[0].left-piece[0].pxpos*piecewidth;
				int oy = piece[0].top-piece[0].pypos*pieceheight;
				for(int i = 1; i<xpieces*ypieces; i++)
				if(piece[i].group == piece[0].group)
				{
					piece[i].left = ox+piece[i].pxpos*piecewidth;
					piece[i].top = oy+piece[i].pypos*pieceheight;
				}
			}
			// フローティング解除
			pieceisfloating = false;
			repaint();
			// 完成していたらメッセージ
			if(joincount == xpieces*ypieces-1)
				showStatus("complete.");
			//debug System.out.println("joincount=" + joincount);
		}
		return true;
	}
}