package pl.wroc.pwr.image.converter;

import pl.wroc.pwr.IOperator1P;
import pl.wroc.pwr.image.IHSVImage;
import pl.wroc.pwr.image.IRGBImage;
import pl.wroc.pwr.image.model.HSVImage;

public class RGBtoHSVConverter implements IOperator1P<IHSVImage, IRGBImage> {
	/**
	 *
	 */
	private static final long serialVersionUID = 74546847291827861L;

	public IHSVImage apply(IRGBImage inputImage) {
		IHSVImage outputImage = new HSVImage( inputImage.getSize( ) );
		for ( int i = 0; i < inputImage.getRedChannel( ).getMaxIndex( ); i++ ) {
			float saturation;
			float hue;
			float brightness;
			float red = inputImage.getRedChannel( ).getValue( i );
			float green = inputImage.getGreenChannel( ).getValue( i );
			float blue = inputImage.getBlueChannel( ).getValue( i );

			float minVal = Math.min( red, Math.min( green, blue ) );
			brightness = Math.max( red, Math.max( green, blue ) );

			float delta = brightness - minVal;

			if ( brightness == 0.0f ) {
				saturation = 0;
			} else {
				saturation = delta / brightness;
			}

			if ( saturation == 0.0f ) {
				hue = 0;
			} else {
				if ( red == brightness ) {
					hue = ( 1.0f / 6.0f ) * ( green - blue ) / delta;
				} else {
					if ( green == brightness ) {
						hue = ( 2.0f / 6.0f ) + ( 1.0f / 6.0f ) * ( blue - red ) / delta;
					} else {
						hue = ( 4.0f / 6.0f ) + ( 1.0f / 6.0f ) * ( red - green ) / delta;
					}
				}
			}

			if ( hue < 0.0f ) {
				hue = hue + 1.0f;
			}

			outputImage.getHueChannel( ).setValue( i, hue );
			outputImage.getSaturationChannel( ).setValue( i, saturation );
			outputImage.getBrightnessChannel( ).setValue( i, brightness );
		}
		return outputImage;
	}
}