/**

 * @author Rodrigo

 * https://gist.github.com/roooodcastro/6325153

 */

sclass GraphPanel extends JPanel {

  int width = 800;

  int heigth = 400;

  int padding = 25;

  int labelPadding = 25;

  Color lineColor = new Color(44, 102, 230, 180);

  Color pointColor = new Color(100, 100, 100, 180);

  Color gridColor = new Color(200, 200, 200, 200);

  static final Stroke GRAPH_STROKE = new BasicStroke(2f);

  int pointWidth = 4;

  int numberYDivisions = 10;

  List<Double> scores;

  public GraphPanel(List<Double> scores) {

      this.scores = scores;

  }

  @Override

  protected void paintComponent(Graphics g) {

      super.paintComponent(g);

      Graphics2D g2 = (Graphics2D) g;

      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

      double xScale = ((double) getWidth() - (2 * padding) - labelPadding) / (scores.size() - 1);

      double yScale = ((double) getHeight() - 2 * padding - labelPadding) / (getMaxScore() - getMinScore());

      List<Point> graphPoints = new ArrayList<>();

      for (int i = 0; i < scores.size(); i++) {

          int x1 = (int) (i * xScale + padding + labelPadding);

          int y1 = (int) ((getMaxScore() - scores.get(i)) * yScale + padding);

          graphPoints.add(new Point(x1, y1));

      }

      // draw white background

      g2.setColor(Color.WHITE);

      g2.fillRect(padding + labelPadding, padding, getWidth() - (2 * padding) - labelPadding, getHeight() - 2 * padding - labelPadding);

      g2.setColor(Color.BLACK);

      // create hatch marks and grid lines for y axis.

      for (int i = 0; i < numberYDivisions + 1; i++) {

          int x0 = padding + labelPadding;

          int x1 = pointWidth + padding + labelPadding;

          int y0 = getHeight() - ((i * (getHeight() - padding * 2 - labelPadding)) / numberYDivisions + padding + labelPadding);

          int y1 = y0;

          if (scores.size() > 0) {

              g2.setColor(gridColor);

              g2.drawLine(padding + labelPadding + 1 + pointWidth, y0, getWidth() - padding, y1);

              g2.setColor(Color.BLACK);

              String yLabel = ((int) ((getMinScore() + (getMaxScore() - getMinScore()) * ((i * 1.0) / numberYDivisions)) * 100)) / 100.0 + "";

              FontMetrics metrics = g2.getFontMetrics();

              int labelWidth = metrics.stringWidth(yLabel);

              g2.drawString(yLabel, x0 - labelWidth - 5, y0 + (metrics.getHeight() / 2) - 3);

          }

          g2.drawLine(x0, y0, x1, y1);

      }

      // and for x axis

      for (int i = 0; i < scores.size(); i++) {

          if (scores.size() > 1) {

              int x0 = i * (getWidth() - padding * 2 - labelPadding) / (scores.size() - 1) + padding + labelPadding;

              int x1 = x0;

              int y0 = getHeight() - padding - labelPadding;

              int y1 = y0 - pointWidth;

              if ((i % ((int) ((scores.size() / 20.0)) + 1)) == 0) {

                  g2.setColor(gridColor);

                  g2.drawLine(x0, getHeight() - padding - labelPadding - 1 - pointWidth, x1, padding);

                  g2.setColor(Color.BLACK);

                  String xLabel = i + "";

                  FontMetrics metrics = g2.getFontMetrics();

                  int labelWidth = metrics.stringWidth(xLabel);

                  g2.drawString(xLabel, x0 - labelWidth / 2, y0 + metrics.getHeight() + 3);

              }

              g2.drawLine(x0, y0, x1, y1);

          }

      }

      // create x and y axes 

      g2.drawLine(padding + labelPadding, getHeight() - padding - labelPadding, padding + labelPadding, padding);

      g2.drawLine(padding + labelPadding, getHeight() - padding - labelPadding, getWidth() - padding, getHeight() - padding - labelPadding);

      Stroke oldStroke = g2.getStroke();

      g2.setColor(lineColor);

      g2.setStroke(GRAPH_STROKE);

      for (int i = 0; i < graphPoints.size() - 1; i++) {

          int x1 = graphPoints.get(i).x;

          int y1 = graphPoints.get(i).y;

          int x2 = graphPoints.get(i + 1).x;

          int y2 = graphPoints.get(i + 1).y;

          g2.drawLine(x1, y1, x2, y2);

      }

      g2.setStroke(oldStroke);

      g2.setColor(pointColor);

      for (int i = 0; i < graphPoints.size(); i++) {

          int x = graphPoints.get(i).x - pointWidth / 2;

          int y = graphPoints.get(i).y - pointWidth / 2;

          int ovalW = pointWidth;

          int ovalH = pointWidth;

          g2.fillOval(x, y, ovalW, ovalH);

      }

  }

//    @Override

//    public Dimension getPreferredSize() {

//        return new Dimension(width, heigth);

//    }

  double getMinScore() {

      double minScore = Double.MAX_VALUE;

      for (Double score : scores) {

          minScore = Math.min(minScore, score);

      }

      return minScore;

  }

  double getMaxScore() {

      double maxScore = Double.MIN_VALUE;

      for (Double score : scores) {

          maxScore = Math.max(maxScore, score);

      }

      return maxScore;

  }

  public void setScores(List<Double> scores) {

      this.scores = scores;

      invalidate();

      repaint();

  }

  public List<Double> getScores() { return scores; }

}