package org.herac.tuxguitar.gui.tools.custom.tuner;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.herac.tuxguitar.gui.editors.TGPainter;

/**
 * @author Nikola Kolarovic <johnny47ns@yahoo.com>
 * 
 */
public class TGTunerRoughWidget extends Composite {

  private static final int MIN_HEIGHT = 25;
  static String[] TONESSTRING = { "C", "C#", "D", "D#", "E", "F", "F#", "G",
      "G#", "A", "A#", "B" };
  private final int boundaryHeight = 16;

  protected Composite composite = null;
  protected float currentFrequency = 0;
  private final int endAb = 20;
  private final int markerHeight = 12;
  private final int markerWidth = 4;
  /** constants for drawing */
  private final int startA = 20;

  public TGTunerRoughWidget(Composite parent) {
    super(parent, SWT.NONE);
    this.init();
  }

  /**
   * formula which gets fine tone position (on scale 0-240) in fact, it's
   * inverse formula of inverse of TGTuner::getNoteFrequency()
   */
  protected int getTone(float frequency) {
    float midiTone = (float) (45 + 12 * (Math.log(frequency / 110) / Math
        .log(2)));
    return Math.round(20 * (midiTone % 12));
  }

  public void init() {
    this.setLayout(new GridLayout(1, true));
    this.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
    ((GridData) this.getLayoutData()).widthHint = 600;

    this.composite = new Composite(this, SWT.BORDER | SWT.DOUBLE_BUFFERED);
    this.composite.setBackground(this.getDisplay().getSystemColor(
        SWT.COLOR_WHITE));
    this.composite.addPaintListener(new PaintListener() {
      public void paintControl(PaintEvent e) {
        TGPainter painter = new TGPainter(e.gc);
        TGTunerRoughWidget.this.paintWidget(painter);
      }

    });
    GridData data = new GridData(SWT.FILL, SWT.FILL, true, true);
    data.minimumHeight = MIN_HEIGHT;
    data.grabExcessHorizontalSpace = true;
    this.composite.setLayoutData(data);

  }

  private void paintWidget(TGPainter painter) {

    Point compositeSize = this.composite.getSize();

    // lines and tones
    painter.setForeground(getDisplay().getSystemColor(SWT.COLOR_BLACK));
    painter.initPath();
    painter.moveTo(this.startA, compositeSize.y / 2);
    painter.lineTo(compositeSize.x - this.endAb, compositeSize.y / 2);
    painter.closePath();
    int increment = (int) Math
        .round((compositeSize.x - this.startA - this.endAb) / 12.0);
    int currentTone = 0;
    for (int i = this.startA; i < compositeSize.x + 1 - this.endAb; i += increment) {
      painter.initPath();
      painter.moveTo(i, compositeSize.y / 2 - this.boundaryHeight / 2);
      painter.lineTo(i, compositeSize.y / 2 + this.boundaryHeight / 2);
      painter.closePath();
      painter.drawString(TONESSTRING[currentTone % 12], i, compositeSize.y / 2
          - this.boundaryHeight / 2 - 20);
      currentTone++;
    }

    // marker
    if (this.currentFrequency > 0) {
      painter.setForeground(getDisplay().getSystemColor(SWT.COLOR_BLUE));
      painter.initPath();
      int markerPos = this.markerWidth
          / 2
          + this.startA
          + (int) Math
              .round(((compositeSize.x - this.startA - this.endAb) / 240.0)
                  * (this.getTone(this.currentFrequency)));
      painter.moveTo(markerPos, compositeSize.y / 2 - this.markerHeight / 2);
      painter.setLineWidth(this.markerWidth);
      painter.lineTo(markerPos, compositeSize.y / 2 + this.markerHeight / 2);
      painter.closePath();
    }

  }

  public void redraw() {
    super.redraw();
    this.composite.redraw();
  }

  public void setCurrentFrequency(double currentFrequency) {
    this.currentFrequency = (float) currentFrequency;
    this.redraw();
  }

}