package org.simantics.district.network.ui;

import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;

import org.simantics.g2d.participant.TransformUtil;
import org.simantics.maps.MapScalingTransform;
import org.simantics.scenegraph.utils.GeometryUtils;
import org.simantics.utils.page.MarginUtils;
import org.simantics.utils.page.MarginUtils.Margins;

public class DistrictTransformUtil extends TransformUtil {

    @Override
    public void fitArea(Rectangle2D controlArea, Rectangle2D diagramArea, Margins margins) {
        if (margins == null) {
            MarginUtils.Margin margin = MarginUtils.marginOf(0, 0, 0);
            margins = new MarginUtils.Margins(margin, margin, margin, margin);
        }
        org.simantics.scenegraph.utils.GeometryUtils.expandRectangle(diagramArea, -1);
        diagramArea = GeometryUtils.expandRectangle(diagramArea,
                margins.top.diagramAbsolute,
                margins.bottom.diagramAbsolute,
                margins.left.diagramAbsolute,
                margins.right.diagramAbsolute);
        controlArea = GeometryUtils.expandRectangle(controlArea,
                -margins.top.controlAbsolute    - margins.top.controlRelative * controlArea.getHeight(),
                -margins.bottom.controlAbsolute - margins.bottom.controlRelative * controlArea.getHeight(),
                -margins.left.controlAbsolute   - margins.left.controlRelative * controlArea.getWidth(),
                -margins.right.controlAbsolute  - margins.right.controlRelative * controlArea.getWidth());

        double controlAspectRatio = controlArea.getWidth() / controlArea.getHeight();
        double canvasAspectRatio  = diagramArea.getWidth() / diagramArea.getHeight();
        // Control is really wide => center canvas horizontally, match vertically
        double scale = 1.0;
        double tx = 0.0;
        double ty = 0.0;
        if (controlAspectRatio>canvasAspectRatio)
        {
            scale = controlArea.getHeight() / diagramArea.getHeight();
        } else
            // Control is really tall => center canvas vertically, match horizontally
        {
            scale = controlArea.getWidth() / diagramArea.getWidth();
        }
        AffineTransform current = getTransform();
        double currentX = current.getScaleX();
        double targetX = scale;
        double toBeX = currentX;
        if (targetX > 0) {
            // let's check that targetX zoomLevel is between 0-20
            AffineTransform tar = new AffineTransform();
            tar.scale(targetX, targetX);
            int tarZoomLevel = MapScalingTransform.zoomLevel(tar);
            if (tarZoomLevel < 20 && tarZoomLevel > 0) {
                toBeX = Math.pow(2.0, tarZoomLevel);
            }
            else {
                toBeX = targetX;
            }
            
            if (controlAspectRatio>canvasAspectRatio) {
                tx = ( controlArea.getWidth() - diagramArea.getWidth() * toBeX ) / 2;
                ty = diagramArea.getHeight() * (targetX - toBeX) / 2;
            }
            else {
                ty = ( controlArea.getHeight() - diagramArea.getHeight() * toBeX ) / 2;
                tx = diagramArea.getWidth() * (targetX - toBeX) / 2;
            }
            
            AffineTransform at = new AffineTransform();
            at.translate(tx, ty);
            at.translate(controlArea.getMinX(), controlArea.getMinY());
            at.scale(toBeX, toBeX);
            at.translate(-diagramArea.getMinX(), -diagramArea.getMinY());
            setTransform(at);
        } else {
            // negative, how, no can do?
            
        }
    }
}