/* ====================================================================
   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.xssf.usermodel;

import static org.apache.poi.POIXMLTypeLoader.DEFAULT_XML_OPTIONS;

import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import javax.xml.namespace.QName;

import org.apache.poi.POIXMLDocumentPart;
import org.apache.poi.openxml4j.opc.PackagePart;
import org.apache.poi.ss.usermodel.Chart;
import org.apache.poi.ss.usermodel.charts.AxisPosition;
import org.apache.poi.ss.usermodel.charts.ChartAxis;
import org.apache.poi.ss.usermodel.charts.ChartAxisFactory;
import org.apache.poi.ss.usermodel.charts.ChartData;
import org.apache.poi.util.Internal;
import org.apache.poi.xssf.usermodel.charts.XSSFCategoryAxis;
import org.apache.poi.xssf.usermodel.charts.XSSFChartAxis;
import org.apache.poi.xssf.usermodel.charts.XSSFChartDataFactory;
import org.apache.poi.xssf.usermodel.charts.XSSFChartLegend;
import org.apache.poi.xssf.usermodel.charts.XSSFManualLayout;
import org.apache.poi.xssf.usermodel.charts.XSSFValueAxis;
import org.apache.xmlbeans.XmlException;
import org.apache.xmlbeans.XmlObject;
import org.apache.xmlbeans.XmlOptions;
import org.openxmlformats.schemas.drawingml.x2006.chart.CTCatAx;
import org.openxmlformats.schemas.drawingml.x2006.chart.CTChart;
import org.openxmlformats.schemas.drawingml.x2006.chart.CTChartSpace;
import org.openxmlformats.schemas.drawingml.x2006.chart.CTPageMargins;
import org.openxmlformats.schemas.drawingml.x2006.chart.CTPlotArea;
import org.openxmlformats.schemas.drawingml.x2006.chart.CTPrintSettings;
import org.openxmlformats.schemas.drawingml.x2006.chart.CTTitle;
import org.openxmlformats.schemas.drawingml.x2006.chart.CTTx;
import org.openxmlformats.schemas.drawingml.x2006.chart.CTValAx;
import org.openxmlformats.schemas.drawingml.x2006.chart.ChartSpaceDocument;
import org.openxmlformats.schemas.drawingml.x2006.main.CTRegularTextRun;
import org.openxmlformats.schemas.drawingml.x2006.main.CTTextBody;
import org.openxmlformats.schemas.drawingml.x2006.main.CTTextField;
import org.openxmlformats.schemas.drawingml.x2006.main.CTTextParagraph;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;

/**
 * Represents a SpreadsheetML Chart
 */
public final class XSSFChart extends POIXMLDocumentPart implements Chart, ChartAxisFactory {

	/**
	 * Parent graphic frame.
	 */
	private XSSFGraphicFrame frame;

	/**
	 * Root element of the SpreadsheetML Chart part
	 */
	private CTChartSpace chartSpace;
	/**
	 * The Chart within that
	 */
	private CTChart chart;

	List<XSSFChartAxis> axis = new ArrayList<XSSFChartAxis>();

	/**
	 * Create a new SpreadsheetML chart
	 */
	protected XSSFChart() {
		super();
		createChart();
	}

	/**
	 * Construct a SpreadsheetML chart from a package part.
	 *
	 * @param part the package part holding the chart data,
	 * the content type must be <code>application/vnd.openxmlformats-officedocument.drawingml.chart+xml</code>
	 * 
	 * @since POI 3.14-Beta1
	 */
	protected XSSFChart(PackagePart part) throws IOException, XmlException {
		super(part);

		chartSpace = ChartSpaceDocument.Factory.parse(part.getInputStream(), DEFAULT_XML_OPTIONS).getChartSpace(); 
		chart = chartSpace.getChart();
	}
	
	/**
	 * Construct a new CTChartSpace bean.
	 * By default, it's just an empty placeholder for chart objects.
	 *
	 * @return a new CTChartSpace bean
	 */
	private void createChart() {
		chartSpace = CTChartSpace.Factory.newInstance();
		chart = chartSpace.addNewChart();
		CTPlotArea plotArea = chart.addNewPlotArea();

		plotArea.addNewLayout();
		chart.addNewPlotVisOnly().setVal(true);

		CTPrintSettings printSettings = chartSpace.addNewPrintSettings();
		printSettings.addNewHeaderFooter();

		CTPageMargins pageMargins = printSettings.addNewPageMargins();
		pageMargins.setB(0.75);
		pageMargins.setL(0.70);
		pageMargins.setR(0.70);
		pageMargins.setT(0.75);
		pageMargins.setHeader(0.30);
		pageMargins.setFooter(0.30);
		printSettings.addNewPageSetup();
	}

	/**
	 * Return the underlying CTChartSpace bean, the root element of the SpreadsheetML Chart part.
	 *
	 * @return the underlying CTChartSpace bean
	 */
	@Internal
	public CTChartSpace getCTChartSpace(){
		return chartSpace;
	}

	/**
	 * Return the underlying CTChart bean, within the Chart Space
	 *
	 * @return the underlying CTChart bean
	 */
	@Internal
	public CTChart getCTChart(){
		return chart;
	}

	@Override
	protected void commit() throws IOException {
		XmlOptions xmlOptions = new XmlOptions(DEFAULT_XML_OPTIONS);

		/*
		   Saved chart space must have the following namespaces set:
		   <c:chartSpace
		      xmlns:c="http://schemas.openxmlformats.org/drawingml/2006/chart"
		      xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main"
		      xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships">
		 */
		xmlOptions.setSaveSyntheticDocumentElement(new QName(CTChartSpace.type.getName().getNamespaceURI(), "chartSpace", "c"));

		PackagePart part = getPackagePart();
		OutputStream out = part.getOutputStream();
		chartSpace.save(out, xmlOptions);
		out.close();
	}

	/**
	 * Returns the parent graphic frame.
	 * @return the graphic frame this chart belongs to
	 */
	public XSSFGraphicFrame getGraphicFrame() {
		return frame;
	}

	/**
	 * Sets the parent graphic frame.
	 */
	protected void setGraphicFrame(XSSFGraphicFrame frame) {
		this.frame = frame;
	}

	public XSSFChartDataFactory getChartDataFactory() {
		return XSSFChartDataFactory.getInstance();
	}

	public XSSFChart getChartAxisFactory() {
		return this;
	}

	public void plot(ChartData data, ChartAxis... chartAxis) {
		data.fillChart(this, chartAxis);
	}

	public XSSFValueAxis createValueAxis(AxisPosition pos) {
		long id = axis.size() + 1;
		XSSFValueAxis valueAxis = new XSSFValueAxis(this, id, pos);
		if (axis.size() == 1) {
			ChartAxis ax = axis.get(0);
			ax.crossAxis(valueAxis);
			valueAxis.crossAxis(ax);
		}
		axis.add(valueAxis);
		return valueAxis;
	}

	public XSSFCategoryAxis createCategoryAxis(AxisPosition pos) {
		long id = axis.size() + 1;
		XSSFCategoryAxis categoryAxis = new XSSFCategoryAxis(this, id, pos);
		if (axis.size() == 1) {
			ChartAxis ax = axis.get(0);
			ax.crossAxis(categoryAxis);
			categoryAxis.crossAxis(ax);
		}
		axis.add(categoryAxis);
		return categoryAxis;
	}

    public List<? extends XSSFChartAxis> getAxis() {
        if (axis.isEmpty() && hasAxis()) {
            parseAxis();
        }
        return axis;
    }
	
	public XSSFManualLayout getManualLayout() {
		return new XSSFManualLayout(this);
	}

	/**
	 * @return true if only visible cells will be present on the chart,
	 *         false otherwise
	 */
	public boolean isPlotOnlyVisibleCells() {
		return chart.getPlotVisOnly().getVal();
	}

	/**
	 * @param plotVisOnly a flag specifying if only visible cells should be
	 *        present on the chart
	 */
	public void setPlotOnlyVisibleCells(boolean plotVisOnly) {
		chart.getPlotVisOnly().setVal(plotVisOnly);
	}

	/**
	 * Returns the title, or null if none is set
	 */
	public XSSFRichTextString getTitle() {
		if(! chart.isSetTitle()) {
			return null;
		}

		// TODO Do properly
		CTTitle title = chart.getTitle();

		StringBuffer text = new StringBuffer();
		XmlObject[] t = title
			.selectPath("declare namespace a='"+XSSFDrawing.NAMESPACE_A+"' .//a:t");
		for (int m = 0; m < t.length; m++) {
			NodeList kids = t[m].getDomNode().getChildNodes();
			final int count = kids.getLength();
			for (int n = 0; n < count; n++) {
				Node kid = kids.item(n);
				if (kid instanceof Text) {
					text.append(kid.getNodeValue());
				}
			}
		}

		return new XSSFRichTextString(text.toString());
	}

	/**
	 * Sets the title text.
	 */
	public void setTitle(String newTitle) {
		CTTitle ctTitle;
		if (chart.isSetTitle()) {
			ctTitle = chart.getTitle();
		} else {
			ctTitle = chart.addNewTitle();
		}

		CTTx tx;
		if (ctTitle.isSetTx()) {
			tx = ctTitle.getTx();
		} else {
			tx = ctTitle.addNewTx();
		}

		if (tx.isSetStrRef()) {
			tx.unsetStrRef();
		}

		CTTextBody rich;
		if (tx.isSetRich()) {
			rich = tx.getRich();
		} else {
			rich = tx.addNewRich();
			rich.addNewBodyPr();  // body properties must exist (but can be empty)
		}

		CTTextParagraph para;
		if (rich.sizeOfPArray() > 0) {
			para = rich.getPArray(0);
		} else {
			para = rich.addNewP();
		}

		if (para.sizeOfRArray() > 0) {
			CTRegularTextRun run = para.getRArray(0);
			run.setT(newTitle);
		} else if (para.sizeOfFldArray() > 0) {
			CTTextField fld = para.getFldArray(0);
			fld.setT(newTitle);
		} else {
			CTRegularTextRun run = para.addNewR();
			run.setT(newTitle);
		}
	}

	public XSSFChartLegend getOrCreateLegend() {
		return new XSSFChartLegend(this);
	}

	public void deleteLegend() {
		if (chart.isSetLegend()) {
			chart.unsetLegend();
		}
	}

	private boolean hasAxis() {
		CTPlotArea ctPlotArea = chart.getPlotArea();
		int totalAxisCount =
			ctPlotArea.sizeOfValAxArray()  +
			ctPlotArea.sizeOfCatAxArray()  +
			ctPlotArea.sizeOfDateAxArray() +
			ctPlotArea.sizeOfSerAxArray();
		return totalAxisCount > 0;
	}

	private void parseAxis() {
		// TODO: add other axis types
		parseCategoryAxis();
		parseValueAxis();
	}

	private void parseCategoryAxis() {
		for (CTCatAx catAx : chart.getPlotArea().getCatAxArray()) {
			axis.add(new XSSFCategoryAxis(this, catAx));
		}
	}

	private void parseValueAxis() {
		for (CTValAx valAx : chart.getPlotArea().getValAxArray()) {
			axis.add(new XSSFValueAxis(this, valAx));
		}
	}

}