package ch09.section09;

import example.About;
import java.util.Random;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.MIDlet;

public class Board
    extends Canvas
    implements CommandListener {
  MIDlet midlet;
  Display dpy;
  Options options;
//初始化一個長度為15的字符串
  String letters = "RATEYOURMINDPAL";
  Font font;
  Piece blankp;
  Piece[] all;
  Piece[][] grid;
  Random rand;
//定義坐標
  int gridx;
  int gridy;

//定義長寬
  int gridw;
  int gridh;

//定義單元格區域
  int cellw;
  int cellh;
  int cellyoff;
  int cellxoff;

//定義功能按鈕
  static final int CMD_ABOUT = 0;
  static final int CMD_EXIT = 1;
  static final int CMD_OPTIONS = 2;
  static final int CMD_RESET = 3;
  static final int CMD_START = 4;
  static final int CMD_UNLOCK = 5;
  static final int CMD_ZLAST = 6;
  Command cmd[];
//聲明變量
  static final int INITIALIZED = 0;
  static final int PLAYING = 1;
  static final int WON = 2;
  int gameState;
  boolean cheated;
  void D(String s) {
    System.out.println(s);
  }

  class Piece {
    String label;
    boolean inv;
    int serial;

//單元格初始化坐標
    int ix, iy;

//單元格當前坐標
    int x, y;
    Piece(String str, int ser, int nx, int ny, boolean v) {
      label = str;
      serial = ser;
      x = ix = nx;
      y = iy = ny;
      inv = v;
    }

    void setLocation(int nx, int ny) {
      x = nx;
      y = ny;
    }

    boolean isHome() {
      return (x == ix) && (y == iy);
    }

    void goHome() {
      setGrid(this, ix, iy);
    }

    //設置背景色為白色
    void paint(Graphics g) {
      int px = x * cellw;
      int py = y * cellh;
      if (label != null) {
        if (inv) {
          //邊框為黑色
          g.setColor(0);
          g.setFont(font);
          g.drawRect(px, py, cellw - 2, cellh - 2);
          g.drawString(label, px + cellxoff, py + cellyoff,
                       Graphics.TOP | Graphics.LEFT);
        }
        else {
          //空白框
          g.setColor(0);
          g.fillRect(px, py, cellw - 1, cellh - 1);
          g.setColor(0xFFFFFF);
          g.setFont(font);
          g.drawString(label, px + cellxoff, py + cellyoff,
                       Graphics.TOP | Graphics.LEFT);
        }
      }
    }
  }

  class BoardCommand
      extends Command {
    int tag;
    BoardCommand(String label, int type, int pri, int tag_) {
      super(label, type, pri);
      tag = tag_;
    }
  }

  void setGrid(Piece p, int x, int y) {
    grid[x][y] = p;
    p.setLocation(x, y);
  }

//移動單元格
  void moveBlank(int swapx, int swapy) {
    setGrid(grid[swapx][swapy], blankp.x, blankp.y);
    setGrid(blankp, swapx, swapy);
  }

  void swap(int x1, int y1, int x2, int y2) {
    Piece t = grid[x1][y1];
    setGrid(grid[x2][y2], x1, y1);
    setGrid(t, x2, y2);
  }

  boolean isSolved() {
    for (int i = 0; i < gridh; i++) {
      for (int j = 0; j < gridw; j++) {
        if (!grid[j][i].isHome()) {
          return false;
        }
      }
    }
    return true;
  }

//獲取一個取值范圍在[0..n]之間的一個整數
  int randRange(int n) {
    int r = rand.nextInt() % n;
    if (r < 0) {
      r += n;
    }
    return r;
  }

  void randomize_by_moving() {
    int dx, dy, v;
    for (int i = 0; i < 100; i++) {
      dx = dy = 0;
      v = (rand.nextInt() & 2) - 1; // 1 or -1
      if ( (rand.nextInt() & 1) == 0) {
        dx = v;
      }
      else {
        dy = v;
      }
      if (blankp.x + dx < 0) {
        dx = 1;
      }
      if (blankp.x + dx == gridw) {
        dx = -1;
      }
      if (blankp.y + dy < 0) {
        dy = 1;
      }
      if (blankp.y + dy == gridh) {
        dy = -1;
      }
      moveBlank(blankp.x + dx, blankp.y + dy);
    }
    //移動至右下角
    while (blankp.x != gridw - 1) {
      moveBlank(blankp.x + 1, blankp.y);
    }
    while (blankp.y != gridh - 1) {
      moveBlank(blankp.x, blankp.y + 1);
    }
  }

  void shuffle() {
    int limit = gridw * gridh - 1;
    Piece ta[] = new Piece[limit];
    Piece temp;
    System.arraycopy(all, 0, ta, 0, limit);
    for (int i = 0; i < limit; i++) {
      int j = randRange(limit);
      temp = ta[j];
      ta[j] = ta[i];
      ta[i] = temp;
    }
    for (int i = 0; i < limit; i++) {
      setGrid(ta[i], i / gridw, i % gridw);
    }
    setGrid(blankp, gridw - 1, gridh - 1);
  }

  void randomize(boolean hard) {
    shuffle();
    int ra, rb;
    int x, y;
    if (hard) {
      ra = 7;
      rb = 0;
    }
    else {
      ra = 0;
      rb = 7;
    }
    x = rand.nextInt() & 1;
    y = rand.nextInt() & 1;
    if (x == 1 && y == 1) {
      x = 2;
      y = 0;
    }
    swap(x, y, all[ra].x, all[ra].y);
    swap( (rand.nextInt() & 1) + 1, 3, all[rb].x, all[rb].y);
    if ( (displacement() & 1) == 1) {
      swap(1, 3, 2, 3);
    }
  }

//計算匹配數，空白格必須在右下角
  int displacement() {
    boolean temp[] = new boolean[gridw * gridh - 1];
    int n = 0;
    for (int i = 0; i < gridh; i++) {
      for (int j = 0; j < gridw; j++) {
        Piece p = grid[j][i];
        if (p == blankp) {
          continue;
        }
        temp[p.serial] = true;
        for (int k = 0; k < p.serial; k++) {
          if (!temp[k]) {
            n++;
          }
        }
      }
    }
    return n;
  }

  void resetGrid() {
    Piece temp[] = new Piece[gridw * gridh];
    int k = 0;
    for (int i = 0; i < gridw; i++) {
      for (int j = 0; j < gridh; j++) {
        temp[k++] = grid[i][j];
      }
    }
    for (k = 0; k < temp.length; k++) {
      temp[k].goHome();
    }
  }

  void rearrangeFunnily(boolean hard) {
    resetGrid();
    if (hard) {
      //難級別
      swap(0, 0, 3, 1);
      swap(2, 2, 3, 2);
      swap(3, 2, 0, 3);
      swap(0, 3, 2, 3);
    }
    else {
      //易級別
      swap(2, 2, 3, 2);
      swap(3, 2, 0, 3);
    }
  }

  void setState(int ns) {
    gameState = ns;
    switch (gameState) {
      case INITIALIZED:
        addCommand(cmd[CMD_ABOUT]);
        removeCommand(cmd[CMD_RESET]);
        addCommand(cmd[CMD_START]);
        addCommand(cmd[CMD_UNLOCK]);
        addCommand(cmd[CMD_EXIT]);
        addCommand(cmd[CMD_OPTIONS]);
        break;
      case PLAYING:
        addCommand(cmd[CMD_ABOUT]);
        addCommand(cmd[CMD_RESET]);
        removeCommand(cmd[CMD_START]);
        removeCommand(cmd[CMD_UNLOCK]);
        addCommand(cmd[CMD_EXIT]);
        addCommand(cmd[CMD_OPTIONS]);
        break;
      case WON:
        addCommand(cmd[CMD_ABOUT]);
        removeCommand(cmd[CMD_RESET]);
        addCommand(cmd[CMD_START]);
        addCommand(cmd[CMD_UNLOCK]);
        addCommand(cmd[CMD_EXIT]);
        addCommand(cmd[CMD_OPTIONS]);
        break;
    }
  }

  public Board(MIDlet midlet_) {
    int i;
    midlet = midlet_;
    dpy = Display.getDisplay(midlet);
    gridw = 4;
    gridh = 4;
    font = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_PLAIN, Font.SIZE_MEDIUM);
    cellw = font.charWidth('M') + 7;
    cellh = font.getHeight() + 1;
    cellxoff = 3;
    cellyoff = 0;
    gridx = (getWidth() - (gridw * cellw) + 1) / 2;
    gridy = 10;
    cheated = false;
    rand = new Random();
    //創建單元格數組
    grid = new Piece[gridw][];
    for (i = 0; i < gridw; i++) {
      grid[i] = new Piece[gridh];
    }
    all = new Piece[gridw * gridh];
    for (i = 0; i < (gridw * gridh) - 1; i++) {
      int x = i % gridw;
      int y = i / gridw;
      String s = letters.substring(i, i + 1);
      grid[x][y] =
          all[i] =
          new Piece(s, i, x, y, i < (gridw * gridh / 2));
    }
    //生成空白格
    blankp = new Piece(null, gridw * gridh - 1, gridw - 1, gridh - 1, false);
    grid[gridw - 1][gridh - 1] = blankp;
    all[gridw * gridh - 1] = blankp;
    //設置命令按鈕
    cmd = new Command[CMD_ZLAST];
    cmd[CMD_ABOUT] = new BoardCommand("About", Command.HELP, 5, CMD_ABOUT);
    cmd[CMD_EXIT] = new BoardCommand("Exit", Command.EXIT, 6, CMD_EXIT);
    cmd[CMD_OPTIONS] = ew BoardCommand("Options", Command.SCREEN, 3,
                                       CMD_OPTIONS);
    cmd[CMD_RESET] = new BoardCommand("Reset", Command.SCREEN, 1, CMD_RESET);
    cmd[CMD_START] = new BoardCommand("Start", Command.SCREEN, 1, CMD_START);
    cmd[CMD_UNLOCK] = new BoardCommand("Unlock", Command.SCREEN, 4, CMD_UNLOCK);
    //設置監聽器
    setCommandListener(this);
    //設置選項窗體
    options = new Options(dpy, this);
    //設置初始狀態
    setState(INITIALIZED);
  }

  public void commandAction(Command c, Displayable d) {
    switch ( ( (BoardCommand) c).tag) {
      case CMD_ABOUT:
        About.showAbout(Display.getDisplay(midlet));
        break;
      case CMD_EXIT:
        midlet.notifyDestroyed();
        break;
      case CMD_OPTIONS:
        dpy.setCurrent(options);
        break;
      case CMD_RESET:
        cheated = false;
        resetGrid();
        setState(INITIALIZED);
        repaint();
        break;
      case CMD_START:
        cheated = false;
        if (options.funny) {
          rearrangeFunnily(options.hard);
        }
        else {
          randomize(options.hard);
        }
        setState(PLAYING);
        repaint();
        break;
      case CMD_UNLOCK:
        cheated = true;
        setState(PLAYING);
        repaint();
        break;
    }
  }

  public void showNotify() {
  }

  public void hideNotify() {
  }

  public void paint(Graphics g) {
    g.setColor(0xFFFFFF);
    g.fillRect(0, 0, getWidth(), getHeight());
    g.translate(gridx, gridy);
    g.setColor(0);
    g.drawRect( -2, -2, gridw * cellw + 2, gridh * cellh + 2);
    for (int j = 0; j < gridw; j++) {
      for (int k = 0; k < gridh; k++) {
        grid[j][k].paint(g);
      }
    }
    if (gameState == WON) {
      g.translate( -g.getTranslateX(), -g.getTranslateY());
      g.setColor(0);
      g.setFont(Font.getDefaultFont());
      g.drawString(
          (cheated ? "CHEATER!" : "YOU WIN!"),
          getWidth() / 2,
          getHeight() - 1,
          Graphics.BOTTOM | Graphics.HCENTER);
    }
  }

  public void keyPressed(int code) {
    if (gameState != PLAYING) {
      return;
    }
    int game = getGameAction(code);
    int swapx = blankp.x;
    int swapy = blankp.y;
    int direction = (options.reversed ? -1 : 1);
    switch (game) {
      case Canvas.UP:
        swapy += direction;
        break;
      case Canvas.DOWN:
        swapy -= direction;
        break;
      case Canvas.LEFT:
        swapx += direction;
        break;
      case Canvas.RIGHT:
        swapx -= direction;
        break;
      default:
        return;
    }
    if (swapx < 0 || swapx >= gridw ||
        swapy < 0 || swapy >= gridh) {
      return;
    }
    moveBlank(swapx, swapy);
    repaint();
    if (isSolved()) {
      setState(WON);
    }
  }
}