#include "boardwidget.h"
#include <QMouseEvent>
#include <QPainter>

/*类静态数据成员定义*/
const QSize BoardWidget::WIDGET_SIZE(430, 430);
const QSize BoardWidget::CELL_SIZE(25, 25);
const QPoint BoardWidget::START_POS(40, 40);
const QPoint BoardWidget::ROW_NUM_START(15, 45);
const QPoint BoardWidget::CLU_NUM_START(39, 25);
const int BoardWidget::BOARD_WIDTH;
const int BoardWidget::BOARD_HEIGHT;
const int BoardWidget::NO_PIECE;
const int BoardWidget::WHITE_PIECE;
const int BoardWidget::BLACK_PIECE;
const bool BoardWidget::WHITE_PLAYER;
const bool BoardWidget::BLACK_PLAYER;

BoardWidget::BoardWidget(QWidget *parent) : QWidget(parent) {
  setFixedSize(WIDGET_SIZE);
  setMouseTracking(true);

  initBoard();
}

void BoardWidget::paintEvent(QPaintEvent *event) {
  QPainter painter(this);
  painter.fillRect(0, 0, width(), height(), Qt::gray); //背景颜色

  for (int i = 0; i < BOARD_WIDTH; i++) {
    painter.drawText(CLU_NUM_START + QPoint(i * CELL_SIZE.width(), 0),
                     QString::number(i + 1));
  }
  for (int i = 0; i < BOARD_HEIGHT; i++) {
    painter.drawText(ROW_NUM_START + QPoint(0, i * CELL_SIZE.height()),
                     QString::number(i + 1));
  }

  for (int i = 0; i < BOARD_WIDTH - 1; i++) //绘制棋盘格子
  {
    for (int j = 0; j < BOARD_HEIGHT - 1; j++) {
      painter.drawRect(QRect(
          START_POS + QPoint(i * CELL_SIZE.width(), j * CELL_SIZE.height()),
          CELL_SIZE));
    }
  }

  painter.setPen(Qt::red); //落子提示
  QPoint poses[12] = {trackPos + QPoint(0, 8),   trackPos,
                      trackPos + QPoint(8, 0),   trackPos + QPoint(17, 0),
                      trackPos + QPoint(25, 0),  trackPos + QPoint(25, 8),
                      trackPos + QPoint(25, 17), trackPos + QPoint(25, 25),
                      trackPos + QPoint(17, 25), trackPos + QPoint(8, 25),
                      trackPos + QPoint(0, 25),  trackPos + QPoint(0, 17)};
  painter.drawPolyline(poses, 3);
  painter.drawPolyline(poses + 3, 3);
  painter.drawPolyline(poses + 6, 3);
  painter.drawPolyline(poses + 9, 3);

  painter.setPen(Qt::NoPen);
  for (int i = 0; i < BOARD_WIDTH; i++) //绘制棋子
  {
    for (int j = 0; j < BOARD_HEIGHT; j++) {
      if (board[i][j] != NO_PIECE) {
        QColor color = (board[i][j] == WHITE_PIECE) ? Qt::white : Qt::black;
        painter.setBrush(QBrush(color));
        painter.drawEllipse(
            START_POS.x() - CELL_SIZE.width() / 2 + i * CELL_SIZE.width(),
            START_POS.y() - CELL_SIZE.height() / 2 + j * CELL_SIZE.height(),
            CELL_SIZE.width(), CELL_SIZE.height());
      }
    }
  }

  painter.setPen(Qt::red);
  if (lastPos.x() != -1) {
    QPoint drawPos = START_POS + QPoint(lastPos.x() * CELL_SIZE.width(),
                                        lastPos.y() * CELL_SIZE.height());
    painter.drawLine(drawPos + QPoint(0, 5), drawPos + QPoint(0, -5));
    painter.drawLine(drawPos + QPoint(5, 0), drawPos + QPoint(-5, 0));
  }

  for (QPoint pos : winPoses) {
    QPoint drawPos = START_POS + QPoint(pos.x() * CELL_SIZE.width(),
                                        pos.y() * CELL_SIZE.height());
    painter.drawLine(drawPos + QPoint(0, 5), drawPos + QPoint(0, -5));
    painter.drawLine(drawPos + QPoint(5, 0), drawPos + QPoint(-5, 0));
  }
}

void BoardWidget::mouseReleaseEvent(QMouseEvent *event) {
  if (!endGame) {
    QPoint pos = event->pos() - START_POS;
    int x = pos.x();
    int y = pos.y();
    int pieceX = x / CELL_SIZE.width();
    int pieceY = y / CELL_SIZE.height();
    int offsetX = x % CELL_SIZE.width();
    int offsetY = y % CELL_SIZE.height();
    if (offsetX > CELL_SIZE.width() / 2) {
      pieceX++;
    }
    if (offsetY > CELL_SIZE.height() / 2) {
      pieceY++;
    }
    downPiece(pieceX, pieceY);
  }
}

void BoardWidget::mouseMoveEvent(QMouseEvent *event) {
  QPoint pos = event->pos() - START_POS +
               QPoint(CELL_SIZE.width() / 2, CELL_SIZE.height() / 2);
  int x = pos.x();
  int y = pos.y();
  //超过范围
  if (x < 0 || x >= CELL_SIZE.width() * BOARD_WIDTH || y < 0 ||
      y >= CELL_SIZE.height() * BOARD_HEIGHT) {
    return;
  }
  int offsetX = x % CELL_SIZE.width();
  int offsetY = y % CELL_SIZE.height();
  setTrackPos(QPoint(x - offsetX, y - offsetY) + START_POS -
              QPoint(CELL_SIZE.width() / 2, CELL_SIZE.height() / 2));
}

void BoardWidget::initBoard() {
  for (int i = 0; i < BOARD_WIDTH; i++) {
    for (int j = 0; j < BOARD_HEIGHT; j++) {
      board[i][j] = NO_PIECE;
    }
  }
  trackPos = QPoint(28, 28);
  lastPos = QPoint(-1, -1);
  endGame = false;
  winPoses.clear();
  nextPlayer = BLACK_PLAYER;
}

void BoardWidget::downPiece(int x, int y) {
  if (x >= 0 && x < BOARD_WIDTH && y >= 0 && y < BOARD_HEIGHT &&
      board[x][y] == NO_PIECE) {
    board[x][y] = (nextPlayer == WHITE_PLAYER) ? WHITE_PIECE : BLACK_PIECE;
    nextPlayer = !nextPlayer;
    lastPos = QPoint(x, y);
    checkWinner();
    update();
  }
}

void BoardWidget::checkWinner() {
  bool fullPieces = true;
  for (int i = 0; i < BOARD_WIDTH; i++) {
    for (int j = 0; j < BOARD_HEIGHT; j++) {
      if (board[i][j] == NO_PIECE) {
        fullPieces = false;
      }
      if (board[i][j] != NO_PIECE && isFivePieceFrom(i, j)) {
        bool winner =
            (board[i][j] == WHITE_PIECE) ? WHITE_PLAYER : BLACK_PLAYER;
        endGame = true;
        emit gameOver(winner);
      }
    }
  }
  if (fullPieces) {
    endGame = true;
    emit gameOver(2); //代表和棋
  }
}

bool BoardWidget::isFivePieceFrom(int x, int y) {
  return isVFivePieceFrom(x, y) || isHFivePieceFrom(x, y) ||
         isFSFivePieceFrom(x, y) || isBSFivePieceFrom(x, y);
}

bool BoardWidget::isVFivePieceFrom(int x, int y) {
  int piece = board[x][y];
  for (int i = 1; i < 5; i++) {
    if (y + i >= BOARD_HEIGHT || board[x][y + i] != piece) {
      return false;
    }
  }
  winPoses.clear();
  for (int i = 0; i < 5; i++) {
    winPoses.append(QPoint(x, y + i));
  }
  return true;
}

bool BoardWidget::isHFivePieceFrom(int x, int y) {
  int piece = board[x][y];
  for (int i = 1; i < 5; i++) {
    if (x + i >= BOARD_WIDTH || board[x + i][y] != piece) {
      return false;
    }
  }
  winPoses.clear();
  for (int i = 0; i < 5; i++) {
    winPoses.append(QPoint(x + i, y));
  }
  return true;
}

bool BoardWidget::isFSFivePieceFrom(int x, int y) {
  int piece = board[x][y];
  for (int i = 1; i < 5; i++) {
    if (x + i >= BOARD_WIDTH || y - i < 0 || board[x + i][y - i] != piece) {
      return false;
    }
  }
  winPoses.clear();
  for (int i = 0; i < 5; i++) {
    winPoses.append(QPoint(x + i, y - i));
  }
  return true;
}

bool BoardWidget::isBSFivePieceFrom(int x, int y) {
  int piece = board[x][y];
  for (int i = 1; i < 5; i++) {
    if (x + i >= BOARD_WIDTH || y + i >= BOARD_HEIGHT ||
        board[x + i][y + i] != piece) {
      return false;
    }
  }
  winPoses.clear();
  for (int i = 0; i < 5; i++) {
    winPoses.append(QPoint(x + i, y + i));
  }
  return true;
}

void BoardWidget::setTrackPos(const QPoint &value) {
  trackPos = value;
  update();
}