/* ====================================================================
   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.xwpf.extractor;

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

import org.apache.poi.POIXMLDocument;
import org.apache.poi.POIXMLTextExtractor;
import org.apache.poi.openxml4j.exceptions.OpenXML4JException;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.xwpf.model.XWPFCommentsDecorator;
import org.apache.poi.xwpf.model.XWPFHeaderFooterPolicy;
import org.apache.poi.xwpf.usermodel.IBodyElement;
import org.apache.poi.xwpf.usermodel.ICell;
import org.apache.poi.xwpf.usermodel.IRunElement;
import org.apache.poi.xwpf.usermodel.XWPFDocument;
import org.apache.poi.xwpf.usermodel.XWPFHyperlink;
import org.apache.poi.xwpf.usermodel.XWPFHyperlinkRun;
import org.apache.poi.xwpf.usermodel.XWPFParagraph;
import org.apache.poi.xwpf.usermodel.XWPFRelation;
import org.apache.poi.xwpf.usermodel.XWPFSDT;
import org.apache.poi.xwpf.usermodel.XWPFSDTCell;
import org.apache.poi.xwpf.usermodel.XWPFTable;
import org.apache.poi.xwpf.usermodel.XWPFTableCell;
import org.apache.poi.xwpf.usermodel.XWPFTableRow;
import org.apache.xmlbeans.XmlException;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTSectPr;

/**
 * Helper class to extract text from an OOXML Word file
 */
public class XWPFWordExtractor extends POIXMLTextExtractor {
    public static final XWPFRelation[] SUPPORTED_TYPES = {
            XWPFRelation.DOCUMENT, XWPFRelation.TEMPLATE,
            XWPFRelation.MACRO_DOCUMENT,
            XWPFRelation.MACRO_TEMPLATE_DOCUMENT
    };

    private XWPFDocument document;
    private boolean fetchHyperlinks = false;

    public XWPFWordExtractor(OPCPackage container) throws XmlException, OpenXML4JException, IOException {
        this(new XWPFDocument(container));
    }

    public XWPFWordExtractor(XWPFDocument document) {
        super(document);
        this.document = document;
    }

    public static void main(String[] args) throws Exception {
        if (args.length < 1) {
            System.err.println("Use:");
            System.err.println("  XWPFWordExtractor <filename.docx>");
            System.exit(1);
        }
        POIXMLTextExtractor extractor =
                new XWPFWordExtractor(POIXMLDocument.openPackage(
                        args[0]
                ));
        System.out.println(extractor.getText());
        extractor.close();
    }

    /**
     * Should we also fetch the hyperlinks, when fetching
     * the text content? Default is to only output the
     * hyperlink label, and not the contents
     */
    public void setFetchHyperlinks(boolean fetch) {
        fetchHyperlinks = fetch;
    }

    public String getText() {
        StringBuffer text = new StringBuffer();
        XWPFHeaderFooterPolicy hfPolicy = document.getHeaderFooterPolicy();

        // Start out with all headers
        extractHeaders(text, hfPolicy);

        // Process all body elements
        for (IBodyElement e : document.getBodyElements()) {
            appendBodyElementText(text, e);
            text.append('\n');
        }

        // Finish up with all the footers
        extractFooters(text, hfPolicy);

        return text.toString();
    }

    public void appendBodyElementText(StringBuffer text, IBodyElement e) {
        if (e instanceof XWPFParagraph) {
            appendParagraphText(text, (XWPFParagraph) e);
        } else if (e instanceof XWPFTable) {
            appendTableText(text, (XWPFTable) e);
        } else if (e instanceof XWPFSDT) {
            text.append(((XWPFSDT) e).getContent().getText());
        }
    }

    public void appendParagraphText(StringBuffer text, XWPFParagraph paragraph) {
        CTSectPr ctSectPr = null;
        if (paragraph.getCTP().getPPr() != null) {
            ctSectPr = paragraph.getCTP().getPPr().getSectPr();
        }

        XWPFHeaderFooterPolicy headerFooterPolicy = null;

        if (ctSectPr != null) {
            headerFooterPolicy = new XWPFHeaderFooterPolicy(document, ctSectPr);
            extractHeaders(text, headerFooterPolicy);
        }


        for (IRunElement run : paragraph.getRuns()) {
            text.append(run.toString());
            if (run instanceof XWPFHyperlinkRun && fetchHyperlinks) {
                XWPFHyperlink link = ((XWPFHyperlinkRun) run).getHyperlink(document);
                if (link != null)
                    text.append(" <").append(link.getURL()).append(">");
            }
        }

        // Add comments
        XWPFCommentsDecorator decorator = new XWPFCommentsDecorator(paragraph, null);
        String commentText = decorator.getCommentText();
        if (commentText.length() > 0) {
            text.append(commentText).append('\n');
        }

        // Do endnotes and footnotes
        String footnameText = paragraph.getFootnoteText();
        if (footnameText != null && footnameText.length() > 0) {
            text.append(footnameText).append('\n');
        }

        if (ctSectPr != null) {
            extractFooters(text, headerFooterPolicy);
        }
    }

    private void appendTableText(StringBuffer text, XWPFTable table) {
        //this works recursively to pull embedded tables from tables
        for (XWPFTableRow row : table.getRows()) {
            List<ICell> cells = row.getTableICells();
            for (int i = 0; i < cells.size(); i++) {
                ICell cell = cells.get(i);
                if (cell instanceof XWPFTableCell) {
                    text.append(((XWPFTableCell) cell).getTextRecursively());
                } else if (cell instanceof XWPFSDTCell) {
                    text.append(((XWPFSDTCell) cell).getContent().getText());
                }
                if (i < cells.size() - 1) {
                    text.append("\t");
                }
            }
            text.append('\n');
        }
    }

    private void extractFooters(StringBuffer text, XWPFHeaderFooterPolicy hfPolicy) {
        if (hfPolicy == null) return;

        if (hfPolicy.getFirstPageFooter() != null) {
            text.append(hfPolicy.getFirstPageFooter().getText());
        }
        if (hfPolicy.getEvenPageFooter() != null) {
            text.append(hfPolicy.getEvenPageFooter().getText());
        }
        if (hfPolicy.getDefaultFooter() != null) {
            text.append(hfPolicy.getDefaultFooter().getText());
        }
    }

    private void extractHeaders(StringBuffer text, XWPFHeaderFooterPolicy hfPolicy) {
        if (hfPolicy == null) return;

        if (hfPolicy.getFirstPageHeader() != null) {
            text.append(hfPolicy.getFirstPageHeader().getText());
        }
        if (hfPolicy.getEvenPageHeader() != null) {
            text.append(hfPolicy.getEvenPageHeader().getText());
        }
        if (hfPolicy.getDefaultHeader() != null) {
            text.append(hfPolicy.getDefaultHeader().getText());
        }
    }
}