/**
 * 
 */
package jalview.renderer;

import jalview.api.AlignViewportI;
import jalview.datamodel.AlignmentAnnotation;
import jalview.datamodel.Annotation;
import jalview.datamodel.ColumnSelection;
import jalview.datamodel.ContactListI;
import jalview.datamodel.ContactRange;
import jalview.datamodel.HiddenColumns;
import jalview.renderer.api.AnnotationRowRendererI;

import java.awt.Color;
import java.awt.Graphics;

/**
 * @author jprocter
 *
 */
public class ContactMapRenderer implements AnnotationRowRendererI
{

  @Override
  public void renderRow(Graphics g, int charWidth, int charHeight,
          boolean hasHiddenColumns, AlignViewportI viewport, HiddenColumns hiddenColumns,
          ColumnSelection columnSelection, AlignmentAnnotation _aa,
          Annotation[] aa_annotations, int sRes, int eRes, float min,
          float max, int y)
  {
    if (sRes > aa_annotations.length)
    {
      return;
    }
    eRes = Math.min(eRes, aa_annotations.length);

    int x = 0, y2 = y;

    g.setColor(Color.pink);

    g.drawLine(x, y2, (eRes - sRes) * charWidth, y2);

    int column;
    int aaMax = aa_annotations.length - 1;
    while (x < eRes - sRes)
    {
      column = sRes + x;
      if (hasHiddenColumns)
      {
        column = hiddenColumns.visibleToAbsoluteColumn(column);
      }

      if (column > aaMax)
      {
        break;
      }

      if (aa_annotations[column] == null)
      {
        x++;
        continue;
      }
      if (_aa.sequenceRef != null)
      {
        // get the sequence position for the column
        column = _aa.sequenceRef.findPosition(column) - 1;
      }
      ContactListI contacts = viewport.getContactList(_aa, column);
      if (contacts == null)
      {
        return;
      }
      int contact_height = contacts.getContactHeight();
      // fractional number of contacts covering each pixel
      double contacts_per_pixel = ((double) contact_height)
              / ((double) _aa.graphHeight);

      int pixels_step;

      if (contacts_per_pixel >= 1)
      {
        // many contacts rendered per pixel
        pixels_step = 1;
      }
      else
      {
        // pixel height for each contact
        pixels_step = (int) Math
                .ceil(((double) _aa.graphHeight) / (double) contact_height);
      }

      int cstart = 0, cend;

      for (int ht = y2,
              eht = y2 - _aa.graphHeight; ht >= eht; ht -= pixels_step)
      {
        cstart = (int) Math.floor(((double) y2 - ht) * contacts_per_pixel);
        cend = (int) Math.min(contact_height,
                Math.ceil(cstart + contacts_per_pixel * pixels_step));

        // TODO show maximum colour for range - sort of done
        // also need a 'getMaxPosForRange(start,end)' to accurately render
        Color col = getColorForRange(min, max, contacts, cstart, cend);

        {
          g.setColor(col);
        }
        if (pixels_step > 1)
        {
          g.fillRect(x * charWidth, ht, charWidth, 1 + pixels_step);
        }
        else
        {
          g.drawLine(x * charWidth, ht, (x + 1) * charWidth, ht);
        }
      }
      x++;
    }

  }

  Color minColor = Color.white, maxColor = Color.magenta;

  Color shadeFor(float min, float max, float value)
  {
    return jalview.util.ColorUtils.getGraduatedColour(value, 0, minColor,
            max, maxColor);
  }

  public Color getColorForRange(float min, float max, ContactListI cl,
          int i, int j)
  {
    ContactRange cr = cl.getRangeFor(i, j);
    // average for moment - probably more interested in maxIntProj though
    return shadeFor(min, max, (float) cr.getMean());
  }

}