/*
 *  ====================================================================
 *    Licensed to the Apache Software Foundation (ASF) under one or more
 *    contributor license agreements.  See the NOTICE file distributed with
 *    this work for additional information regarding copyright ownership.
 *    The ASF licenses this file to You under the Apache License, Version 2.0
 *    (the "License"); you may not use this file except in compliance with
 *    the License.  You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 * ====================================================================
 */

package org.apache.poi.xslf.usermodel;

import java.awt.geom.AffineTransform;
import java.awt.geom.Path2D;
import java.awt.geom.PathIterator;
import java.awt.geom.Rectangle2D;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.poi.ooxml.util.POIXMLUnits;
import org.apache.poi.sl.draw.geom.CustomGeometry;
import org.apache.poi.sl.usermodel.FreeformShape;
import org.apache.poi.util.Beta;
import org.apache.poi.util.Units;
import org.apache.poi.xslf.draw.geom.XSLFCustomGeometry;
import org.apache.xmlbeans.XmlCursor;
import org.apache.xmlbeans.XmlObject;
import org.openxmlformats.schemas.drawingml.x2006.main.CTAdjPoint2D;
import org.openxmlformats.schemas.drawingml.x2006.main.CTCustomGeometry2D;
import org.openxmlformats.schemas.drawingml.x2006.main.CTGeomRect;
import org.openxmlformats.schemas.drawingml.x2006.main.CTNonVisualDrawingProps;
import org.openxmlformats.schemas.drawingml.x2006.main.CTPath2D;
import org.openxmlformats.schemas.drawingml.x2006.main.CTPath2DClose;
import org.openxmlformats.schemas.drawingml.x2006.main.CTPath2DCubicBezierTo;
import org.openxmlformats.schemas.drawingml.x2006.main.CTPath2DLineTo;
import org.openxmlformats.schemas.drawingml.x2006.main.CTPath2DMoveTo;
import org.openxmlformats.schemas.drawingml.x2006.main.CTPath2DQuadBezierTo;
import org.openxmlformats.schemas.drawingml.x2006.main.CTShapeProperties;
import org.openxmlformats.schemas.drawingml.x2006.main.CTTransform2D;
import org.openxmlformats.schemas.presentationml.x2006.main.CTShape;
import org.openxmlformats.schemas.presentationml.x2006.main.CTShapeNonVisual;

/**
 * Represents a custom geometric shape.
 * This shape will consist of a series of lines and curves described within a creation path.
 */
@Beta
public class XSLFFreeformShape extends XSLFAutoShape
    implements FreeformShape<XSLFShape,XSLFTextParagraph> {

    private static final Logger LOG = LogManager.getLogger(XSLFFreeformShape.class);

    /*package*/ XSLFFreeformShape(CTShape shape, XSLFSheet sheet) {
        super(shape, sheet);
    }

    @Override
    public int setPath(final Path2D path) {
        final CTPath2D ctPath = CTPath2D.Factory.newInstance();

        final Rectangle2D bounds = path.getBounds2D();
        final int x0 = Units.toEMU(bounds.getX());
        final int y0 = Units.toEMU(bounds.getY());
        final PathIterator it = path.getPathIterator(new AffineTransform());
        int numPoints = 0;
        ctPath.setH(Units.toEMU(bounds.getHeight()));
        ctPath.setW(Units.toEMU(bounds.getWidth()));

        final double[] vals = new double[6];
        while (!it.isDone()) {
            final int type = it.currentSegment(vals);
            final CTAdjPoint2D[] points;
            switch (type) {
                case PathIterator.SEG_MOVETO:
                    points = addMoveTo(ctPath);
                    break;
                case PathIterator.SEG_LINETO:
                    points = addLineTo(ctPath);
                    break;
                case PathIterator.SEG_QUADTO:
                    points = addQuadBezierTo(ctPath);
                    break;
                case PathIterator.SEG_CUBICTO:
                    points = addCubicBezierTo(ctPath);
                    break;
                case PathIterator.SEG_CLOSE:
                    points = addClosePath(ctPath);
                    break;
                default: {
                    throw new IllegalStateException("Unrecognized path segment type: " + type);
                }
            }

            int i=0;
            for (final CTAdjPoint2D point : points) {
                point.setX(Units.toEMU(vals[i++])-x0);
                point.setY(Units.toEMU(vals[i++])-y0);
            }

            numPoints += Math.max(points.length, 1);
            it.next();
        }

        XmlObject xo = getShapeProperties();
        if (!(xo instanceof CTShapeProperties)) {
            return -1;
        }

        ((CTShapeProperties)xo).getCustGeom().getPathLst().setPathArray(new CTPath2D[]{ctPath});
        setAnchor(bounds);
        return numPoints;
    }

    /**
     * @return definition of the shape geometry
     */
    @Override
    public CustomGeometry getGeometry() {
        final XmlObject xo = getShapeProperties();
        if (!(xo instanceof CTShapeProperties)) {
            return null;
        }

        return XSLFCustomGeometry.convertCustomGeometry(((CTShapeProperties)xo).getCustGeom());
    }

    @Override
    public Path2D.Double getPath() {
        final Path2D.Double path = new Path2D.Double();

        final XmlObject xo = getShapeProperties();
        if (!(xo instanceof CTShapeProperties)) {
            return null;
        }

        final CTCustomGeometry2D geom = ((CTShapeProperties)xo).getCustGeom();
        for(CTPath2D spPath : geom.getPathLst().getPathArray()) {
            try (XmlCursor cursor = spPath.newCursor()) {
                if (cursor.toFirstChild()) {
                    do {
                        final XmlObject ch = cursor.getObject();
                        if (ch instanceof CTPath2DMoveTo) {
                            addMoveTo(path, (CTPath2DMoveTo)ch);
                        } else if (ch instanceof CTPath2DLineTo) {
                            addLineTo(path, (CTPath2DLineTo)ch);
                        } else if (ch instanceof CTPath2DQuadBezierTo) {
                            addQuadBezierTo(path, (CTPath2DQuadBezierTo)ch);
                        } else if (ch instanceof CTPath2DCubicBezierTo) {
                            addCubicBezierTo(path, (CTPath2DCubicBezierTo)ch);
                        } else if (ch instanceof CTPath2DClose) {
                            addClosePath(path);
                        } else {
                            LOG.atWarn().log("can't handle path of type {}", xo.getClass());
                        }
                    } while (cursor.toNextSibling());
                }
            }
        }

        // the created path starts at (x=0, y=0).
        // this used to scale each path element to the path bounding box,
        // but now the dimensions/relations are kept as-is
        final AffineTransform at = new AffineTransform();

        final CTTransform2D xfrm = getXfrm(false);
        final Rectangle2D xfrm2d = new Rectangle2D.Double
                (POIXMLUnits.parseLength(xfrm.getOff().xgetX()), POIXMLUnits.parseLength(xfrm.getOff().xgetY()), xfrm.getExt().getCx(), xfrm.getExt().getCy());

        final Rectangle2D bounds = getAnchor();
        at.translate(bounds.getX()+bounds.getCenterX(), bounds.getY()+bounds.getCenterY());
        at.scale(1./Units.EMU_PER_POINT, 1./Units.EMU_PER_POINT);
        at.translate(-xfrm2d.getCenterX(), -xfrm2d.getCenterY());
        return new Path2D.Double(at.createTransformedShape(path));
    }

    private static CTAdjPoint2D[] addMoveTo(final CTPath2D path) {
        return new CTAdjPoint2D[]{path.addNewMoveTo().addNewPt()};
    }

    private static void addMoveTo(final Path2D path, final CTPath2DMoveTo xo) {
        final CTAdjPoint2D pt = xo.getPt();
        path.moveTo((Long)pt.getX(), (Long)pt.getY());
    }

    private static CTAdjPoint2D[] addLineTo(final CTPath2D path) {
        return new CTAdjPoint2D[]{path.addNewLnTo().addNewPt()};
    }

    private static void addLineTo(final Path2D path, final CTPath2DLineTo xo) {
        final CTAdjPoint2D pt = xo.getPt();
        path.lineTo((Long)pt.getX(), (Long)pt.getY());
    }

    private static CTAdjPoint2D[] addQuadBezierTo(final CTPath2D path) {
        final CTPath2DQuadBezierTo bez = path.addNewQuadBezTo();
        return new CTAdjPoint2D[]{ bez.addNewPt(), bez.addNewPt() };
    }

    private static void addQuadBezierTo(final Path2D path, final CTPath2DQuadBezierTo xo) {
        final CTAdjPoint2D pt1 = xo.getPtArray(0);
        final CTAdjPoint2D pt2 = xo.getPtArray(1);
        path.quadTo((Long)pt1.getX(), (Long)pt1.getY(),
                (Long)pt2.getX(), (Long)pt2.getY());
    }

    private static CTAdjPoint2D[] addCubicBezierTo(final CTPath2D path) {
        final CTPath2DCubicBezierTo bez = path.addNewCubicBezTo();
        return new CTAdjPoint2D[]{ bez.addNewPt(), bez.addNewPt(), bez.addNewPt() };
    }

    private static void addCubicBezierTo(final Path2D path, final CTPath2DCubicBezierTo xo) {
        final CTAdjPoint2D pt1 = xo.getPtArray(0);
        final CTAdjPoint2D pt2 = xo.getPtArray(1);
        final CTAdjPoint2D pt3 = xo.getPtArray(2);
        path.curveTo((Long)pt1.getX(), (Long)pt1.getY(),
                (Long)pt2.getX(), (Long)pt2.getY(),
                (Long)pt3.getX(), (Long)pt3.getY());
    }

    private static CTAdjPoint2D[] addClosePath(final CTPath2D path) {
        path.addNewClose();
        return new CTAdjPoint2D[0];
    }

    private static void addClosePath(final Path2D path) {
        path.closePath();
    }

    /**
     * @param shapeId 1-based shapeId
     */
    static CTShape prototype(int shapeId) {
        CTShape ct = CTShape.Factory.newInstance();
        CTShapeNonVisual nvSpPr = ct.addNewNvSpPr();
        CTNonVisualDrawingProps cnv = nvSpPr.addNewCNvPr();
        cnv.setName("Freeform " + shapeId);
        cnv.setId(shapeId);
        nvSpPr.addNewCNvSpPr();
        nvSpPr.addNewNvPr();
        CTShapeProperties spPr = ct.addNewSpPr();
        CTCustomGeometry2D geom = spPr.addNewCustGeom();
        geom.addNewAvLst();
        geom.addNewGdLst();
        geom.addNewAhLst();
        geom.addNewCxnLst();
        CTGeomRect rect = geom.addNewRect();
        rect.setR("r");
        rect.setB("b");
        rect.setT("t");
        rect.setL("l");
        geom.addNewPathLst();
        return ct;
    }
}