/**
 * 
 */
package jalview.schemes;

import jalview.datamodel.SequenceFeature;

import java.awt.Color;

/**
 * Value and/or thresholded colour scale used for colouring by annotation and feature score
 * @author JimP
 *
 */
public class GraduatedColor
{
  int thresholdState = AnnotationColourGradient.NO_THRESHOLD; // or ABOVE_THRESHOLD or BELOW_THRESHOLD
  float lr,lg,lb,dr,dg,db;
  /**
   * linear scaling parameters, base, minimum colour threshold, range of linear scale from lower to upper
   */
  float base,range,thrsh;
  /**
   * when true, colour from u to u-d rather than u to u+d
   */
  boolean tolow=false;
  /**
   * construct a graduatedColor object from simple parameters
   * @param low
   * @param high
   * @param min
   * @param max
   * color low->high from min->max
   */
  public GraduatedColor(Color low,Color high, float min,float max)
  {
    thrsh = Float.NaN;
    tolow = min>=max;
    lr = low.getRed()/255f;
    lg = low.getGreen()/255f;
    lb = low.getBlue()/255f;
    dr = (high.getRed()/255f)-lr;
    dg = (high.getGreen()/255f)-lg;
    db = (high.getBlue()/255f)-lb;
    if (tolow)
    {
      base = max;
      range = min-max;
    } else {
      base = min;
      range = max-min;
    }
  }
  public GraduatedColor(GraduatedColor oldcs)
  {
    lr = oldcs.lr;
    lg = oldcs.lg;
    lb = oldcs.lb;
    dr = oldcs.dr;
    dg = oldcs.dg;
    db = oldcs.db;
    base = oldcs.base;
    range = oldcs.range;
    tolow = oldcs.tolow;
    thresholdState = oldcs.thresholdState;
    thrsh = oldcs.thrsh;
  }
  /**
   * make a new gradient from an old one with a different scale range
   * @param oldcs
   * @param min
   * @param max
   */
  public GraduatedColor(GraduatedColor oldcs, float min, float max)
  {
    this(oldcs);
    if (max<min)
    {
      base = max;
      range = min-max;
      tolow=true;
    } else {
      base = min;
      range = max-min;
      tolow=false;
    }
  }
  public Color getMinColor()
  {
    return new Color(lr,lg,lb);
  }
  public Color getMaxColor()
  {
    return new Color(lr+dr,lg+dg,lb+db);
  }
  public boolean getTolow()
  {
    return tolow;
  }
  public void setTolow(boolean tolower)
  {
    tolow = tolower;
  }
  public boolean isColored(SequenceFeature feature)
  {
    float val = feature.getScore();
    if (val==Float.NaN)
    {
      return true;
    }
    if (this.thresholdState==AnnotationColourGradient.NO_THRESHOLD)
    {
      return true;
    }
    if (this.thrsh==Float.NaN)
    {
      return true;
    }
    boolean rtn = thresholdState==AnnotationColourGradient.ABOVE_THRESHOLD;
    if (val<=thrsh)
    {
      return !rtn; //  ? !tolow : tolow;
    } else {
      return rtn; //  ? tolow : !tolow;
    }
  }
  public Color findColor(SequenceFeature feature)
  {     
    if (range==0.0)
    {
      return getMaxColor();
    }
    float scr = feature.getScore();
    if (scr==Float.NaN)
    {
      return getMinColor();
    }
    float scl = (scr-base)/range;
    if (tolow) { scl = -scl; }
    if (scl<0f) { scl = 0f; }
    if (scl>1f) { scl = 1f; }
    return new Color(lr+scl*dr,lg+scl*dg,lb+scl*db);
  }
  public void setThresh(float value)
  {
    thrsh = value;
  }
  public void setThreshType(int aboveThreshold)
  {
    thresholdState = aboveThreshold;
  }
  public int getThreshType()
  {
    return thresholdState;
  }
}