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

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

import org.apache.poi.ooxml.POIXMLDocumentPart;
import org.apache.poi.ooxml.POIXMLException;
import org.apache.poi.ooxml.POIXMLRelation;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.openxml4j.opc.PackagePart;
import org.apache.poi.util.IOUtils;
import org.apache.poi.util.Internal;
import org.apache.xmlbeans.XmlCursor;
import org.apache.xmlbeans.XmlObject;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTHdrFtr;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTP;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTRow;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTTbl;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTTc;

/**
 * Parent of XWPF headers and footers
 */
public abstract class XWPFHeaderFooter extends POIXMLDocumentPart implements IBody {
    List<XWPFParagraph> paragraphs = new ArrayList<>();
    List<XWPFTable> tables = new ArrayList<>();
    List<XWPFPictureData> pictures = new ArrayList<>();
    List<IBodyElement> bodyElements = new ArrayList<>();

    CTHdrFtr headerFooter;
    XWPFDocument document;

    XWPFHeaderFooter(XWPFDocument doc, CTHdrFtr hdrFtr) {
        if (doc == null) {
            throw new NullPointerException();
        }

        document = doc;
        headerFooter = hdrFtr;
        readHdrFtr();
    }

    protected XWPFHeaderFooter() {
        headerFooter = CTHdrFtr.Factory.newInstance();
        readHdrFtr();
    }

    /**
     * @since by POI 3.14-Beta1
     */
    public XWPFHeaderFooter(POIXMLDocumentPart parent, PackagePart part) {
        super(parent, part);
        this.document = (XWPFDocument) getParent();

        if (this.document == null) {
            throw new NullPointerException();
        }
    }

    @Override
    protected void onDocumentRead() throws IOException {
        for (POIXMLDocumentPart poixmlDocumentPart : getRelations()) {
            if (poixmlDocumentPart instanceof XWPFPictureData) {
                XWPFPictureData xwpfPicData = (XWPFPictureData) poixmlDocumentPart;
                pictures.add(xwpfPicData);
                document.registerPackagePictureData(xwpfPicData);
            }
        }
    }

    @Internal
    public CTHdrFtr _getHdrFtr() {
        return headerFooter;
    }

    @Override
    public List<IBodyElement> getBodyElements() {
        return Collections.unmodifiableList(bodyElements);
    }

    /**
     * Returns the paragraph(s) that holds
     * the text of the header or footer.
     * Normally there is only the one paragraph, but
     * there could be more in certain cases, or
     * a table.
     */
    @Override
    public List<XWPFParagraph> getParagraphs() {
        return Collections.unmodifiableList(paragraphs);
    }


    /**
     * Return the table(s) that holds the text
     * of the header or footer, for complex cases
     * where a paragraph isn't used.
     * Normally there's just one paragraph, but some
     * complex headers/footers have a table or two
     * in addition.
     */
    @Override
    public List<XWPFTable> getTables() throws ArrayIndexOutOfBoundsException {
        return Collections.unmodifiableList(tables);
    }


    /**
     * Returns the textual content of the header/footer,
     * by flattening out the text of its paragraph(s)
     */
    public String getText() {
        StringBuilder t = new StringBuilder(64);
        //TODO: simplify this to get ibody elements in order
        for (XWPFParagraph paragraph : paragraphs) {
            if (!paragraph.isEmpty()) {
                String text = paragraph.getText();
                if (text != null && text.length() > 0) {
                    t.append(text);
                    t.append('\n');
                }
            }
        }

        for (XWPFTable table : tables) {
            String text = table.getText();
            if (text != null && text.length() > 0) {
                t.append(text);
                t.append('\n');
            }
        }

        for (IBodyElement bodyElement : getBodyElements()) {
            if (bodyElement instanceof XWPFSDT) {
                t.append(((XWPFSDT) bodyElement).getContent().getText()).append('\n');
            }
        }
        return t.toString();
    }

    /**
     * set a new headerFooter
     */
    public void setHeaderFooter(CTHdrFtr headerFooter) {
        this.headerFooter = headerFooter;
        readHdrFtr();
    }

    /**
     * if there is a corresponding {@link XWPFTable} of the parameter ctTable in the tableList of this header
     * the method will return this table
     * if there is no corresponding {@link XWPFTable} the method will return null
     */
    @Override
    public XWPFTable getTable(CTTbl ctTable) {
        for (XWPFTable table : tables) {
            if (table == null)
                return null;
            if (table.getCTTbl().equals(ctTable))
                return table;
        }
        return null;
    }

    @Override
    public XWPFParagraph getParagraph(CTP p) {
        for (XWPFParagraph paragraph : paragraphs) {
            if (paragraph.getCTP().equals(p))
                return paragraph;
        }
        return null;
    }

    /**
     * Returns the paragraph that holds
     * the text of the header or footer.
     */
    @Override
    public XWPFParagraph getParagraphArray(int pos) {
        if(pos >= 0 && pos<paragraphs.size()){
            return paragraphs.get(pos);
        }
        return null;
    }

    /**
     * get a List of all Paragraphs
     *
     * @return a list of {@link XWPFParagraph}
     */
    public List<XWPFParagraph> getListParagraph() {
        return paragraphs;
    }

    public List<XWPFPictureData> getAllPictures() {
        return Collections.unmodifiableList(pictures);
    }

    /**
     * get all Pictures in this package
     *
     * @return all Pictures in this package
     */
    public List<XWPFPictureData> getAllPackagePictures() {
        return document.getAllPackagePictures();

    }

    /**
     * Adds a picture to the document.
     *
     * @param pictureData The picture data
     * @param format      The format of the picture.
     * @return the index to this picture (0 based), the added picture can be obtained from {@link #getAllPictures()} .
     * @throws InvalidFormatException If the format of the picture is not known.
     */
    public String addPictureData(byte[] pictureData, int format) throws InvalidFormatException {
        XWPFPictureData xwpfPicData = document.findPackagePictureData(pictureData, format);
        POIXMLRelation relDesc = XWPFPictureData.RELATIONS[format];

        if (xwpfPicData == null) {
            /* Part doesn't exist, create a new one */
            int idx = document.getNextPicNameNumber(format);
            xwpfPicData = (XWPFPictureData) createRelationship(relDesc, XWPFFactory.getInstance(), idx);
            /* write bytes to new part */
            PackagePart picDataPart = xwpfPicData.getPackagePart();
            try (OutputStream out = picDataPart.getOutputStream()) {
                out.write(pictureData);
            } catch (IOException e) {
                throw new POIXMLException(e);
            }

            document.registerPackagePictureData(xwpfPicData);
            pictures.add(xwpfPicData);
            return getRelationId(xwpfPicData);
        } else if (!getRelations().contains(xwpfPicData)) {
            /*
             * Part already existed, but was not related so far. Create
             * relationship to the already existing part and update
             * POIXMLDocumentPart data.
             */
            // TODO add support for TargetMode.EXTERNAL relations.
            RelationPart rp = addRelation(null, XWPFRelation.IMAGES, xwpfPicData);
            pictures.add(xwpfPicData);
            return rp.getRelationship().getId();
        } else {
            /* Part already existed, get relation id and return it */
            return getRelationId(xwpfPicData);
        }
    }

    /**
     * Adds a picture to the document.
     *
     * @param is     The stream to read image from
     * @param format The format of the picture.
     * @return the index to this picture (0 based), the added picture can be obtained from {@link #getAllPictures()} .
     * @throws InvalidFormatException If the format of the picture is not known.
     * @throws IOException If reading the picture-data from the stream fails.
     */
    public String addPictureData(InputStream is, int format) throws InvalidFormatException, IOException {
        byte[] data = IOUtils.toByteArray(is);
        return addPictureData(data, format);
    }

    /**
     * returns the PictureData by blipID
     *
     * @return XWPFPictureData of a specificID
     */
    public XWPFPictureData getPictureDataByID(String blipID) {
        POIXMLDocumentPart relatedPart = getRelationById(blipID);
        if (relatedPart != null && relatedPart instanceof XWPFPictureData) {
            return (XWPFPictureData) relatedPart;
        }
        return null;
    }

    /**
     * Adds a new paragraph at the end of the header or footer
     *
     * @return new {@link XWPFParagraph} object
     */
    public XWPFParagraph createParagraph() {
        XWPFParagraph paragraph = new XWPFParagraph(headerFooter.addNewP(), this);
        paragraphs.add(paragraph);
        bodyElements.add(paragraph);
        return paragraph;
    }

    /**
     * Adds a new table at the end of the header or footer
     *
     * @param rows - number of rows in the table
     * @param cols - number of columns in the table
     * @return new {@link XWPFTable} object
     */
    public XWPFTable createTable(int rows, int cols) {
        XWPFTable table = new XWPFTable(headerFooter.addNewTbl(), this, rows, cols);
        tables.add(table);
        bodyElements.add(table);
        return table;
    }

    /**
     * Removes a specific paragraph from this header / footer
     *
     * @param paragraph - {@link XWPFParagraph} object to remove
     */
    public void removeParagraph(XWPFParagraph paragraph) {
        if (paragraphs.contains(paragraph)) {
            CTP ctP = paragraph.getCTP();
            XmlCursor c = ctP.newCursor();
            c.removeXml();
            c.dispose();
            paragraphs.remove(paragraph);
            bodyElements.remove(paragraph);
        }
    }

    /**
     * Removes a specific table from this header / footer
     *
     * @param table - {@link XWPFTable} object to remove
     */
    public void removeTable(XWPFTable table) {
        if (tables.contains(table)) {
            CTTbl ctTbl = table.getCTTbl();
            XmlCursor c = ctTbl.newCursor();
            c.removeXml();
            c.dispose();
            tables.remove(table);
            bodyElements.remove(table);
        }
    }

    /**
     * Clears all paragraphs and tables from this header / footer
     */
    public void clearHeaderFooter() {
       XmlCursor c = headerFooter.newCursor();
       c.removeXmlContents();
       c.dispose();
       paragraphs.clear();
       tables.clear();
       bodyElements.clear();
    }

    /**
     * add a new paragraph at position of the cursor
     *
     * @return the inserted paragraph
     */
    @Override
    public XWPFParagraph insertNewParagraph(XmlCursor cursor) {
        if (isCursorInHdrF(cursor)) {
            String uri = CTP.type.getName().getNamespaceURI();
            String localPart = "p";
            cursor.beginElement(localPart, uri);
            cursor.toParent();
            CTP p = (CTP) cursor.getObject();
            XWPFParagraph newP = new XWPFParagraph(p, this);
            XmlObject o = null;
            while (!(o instanceof CTP) && (cursor.toPrevSibling())) {
                o = cursor.getObject();
            }
            if ((!(o instanceof CTP)) || o == p) {
                paragraphs.add(0, newP);
            } else {
                int pos = paragraphs.indexOf(getParagraph((CTP) o)) + 1;
                paragraphs.add(pos, newP);
            }
            int i = 0;
            XmlCursor p2 = p.newCursor();
            cursor.toCursor(p2);
            p2.dispose();
            while (cursor.toPrevSibling()) {
                o = cursor.getObject();
                if (o instanceof CTP || o instanceof CTTbl)
                    i++;
            }
            bodyElements.add(i, newP);
            p2 = p.newCursor();
            cursor.toCursor(p2);
            cursor.toEndToken();
            p2.dispose();
            return newP;
        }
        return null;
    }


    /**
     * @return the inserted table
     */
    @Override
    public XWPFTable insertNewTbl(final XmlCursor cursor) {
        if (isCursorInHdrF(cursor)) {
            String uri = CTTbl.type.getName().getNamespaceURI();
            String localPart = "tbl";
            cursor.beginElement(localPart, uri);
            cursor.toParent();
            CTTbl t = (CTTbl) cursor.getObject();
            XWPFTable newT = new XWPFTable(t, this);
            cursor.removeXmlContents();
            XmlObject o = null;
            while (!(o instanceof CTTbl) && (cursor.toPrevSibling())) {
                o = cursor.getObject();
            }
            if (!(o instanceof CTTbl)) {
                tables.add(0, newT);
            } else {
                int pos = tables.indexOf(getTable((CTTbl) o)) + 1;
                tables.add(pos, newT);
            }
            int i = 0;
            XmlCursor cursor2 = t.newCursor();
            while (cursor2.toPrevSibling()) {
                o = cursor2.getObject();
                if (o instanceof CTP || o instanceof CTTbl) {
                    i++;
                }
            }
            cursor2.dispose();
            bodyElements.add(i, newT);
            cursor2 = t.newCursor();
            cursor.toCursor(cursor2);
            cursor.toEndToken();
            cursor2.dispose();
            return newT;
        }
        return null;
    }

    /**
     * verifies that cursor is on the right position
     */
    private boolean isCursorInHdrF(XmlCursor cursor) {
        XmlCursor verify = cursor.newCursor();
        verify.toParent();
        boolean result = (verify.getObject() == this.headerFooter);
        verify.dispose();
        return result;
    }


    public POIXMLDocumentPart getOwner() {
        return this;
    }

    /**
     * Returns the table at position pos
     */
    @Override
    public XWPFTable getTableArray(int pos) {
        if (pos >= 0 && pos < tables.size()) {
            return tables.get(pos);
        }
        return null;
    }

    /**
     * inserts an existing XWPFTable to the arrays bodyElements and tables
     */
    @Override
    public void insertTable(int pos, XWPFTable table) {
        bodyElements.add(pos, table);
        int i = 0;
        for (CTTbl tbl : headerFooter.getTblArray()) {
            if (tbl == table.getCTTbl()) {
                break;
            }
            i++;
        }
        tables.add(i, table);

    }

    public void readHdrFtr() {
        bodyElements = new ArrayList<>();
        paragraphs = new ArrayList<>();
        tables = new ArrayList<>();
        // parse the document with cursor and add
        // the XmlObject to its lists
        XmlCursor cursor = headerFooter.newCursor();
        cursor.selectPath("./*");
        while (cursor.toNextSelection()) {
            XmlObject o = cursor.getObject();
            if (o instanceof CTP) {
                XWPFParagraph p = new XWPFParagraph((CTP) o, this);
                paragraphs.add(p);
                bodyElements.add(p);
            }
            if (o instanceof CTTbl) {
                XWPFTable t = new XWPFTable((CTTbl) o, this);
                tables.add(t);
                bodyElements.add(t);
            }
        }
        cursor.dispose();
    }

    /**
     * get the TableCell which belongs to the TableCell
     */
    @Override
    public XWPFTableCell getTableCell(CTTc cell) {
        XmlCursor cursor = cell.newCursor();
        cursor.toParent();
        XmlObject o = cursor.getObject();
        if (!(o instanceof CTRow)) {
            cursor.dispose();
            return null;
        }
        CTRow row = (CTRow) o;
        cursor.toParent();
        o = cursor.getObject();
        cursor.dispose();
        if (!(o instanceof CTTbl)) {
            return null;
        }
        CTTbl tbl = (CTTbl) o;
        XWPFTable table = getTable(tbl);
        if (table == null) {
            return null;
        }
        XWPFTableRow tableRow = table.getRow(row);
        return tableRow.getTableCell(cell);
    }

    @Override
    public XWPFDocument getXWPFDocument() {
        if (document != null) {
            return document;
        } else {
            return (XWPFDocument) getParent();
        }
    }

    public void setXWPFDocument(XWPFDocument doc) {
        document = doc;
    }

    /**
     * returns the Part, to which the body belongs, which you need for adding relationship to other parts
     */
    @Override
    public POIXMLDocumentPart getPart() {
        return this;
    }

    @Override
    protected void prepareForCommit() {
        // must contain at least an empty paragraph
        if (bodyElements.size() == 0) {
            createParagraph();
        }

        // Cells must contain at least an empty paragraph
        for (XWPFTable tbl : tables) {
            for (XWPFTableRow row : tbl.tableRows) {
                for (XWPFTableCell cell : row.getTableCells()) {
                    if (cell.getBodyElements().size() == 0) {
                        cell.addParagraph();
                    }
                }
            }
        }
        super.prepareForCommit();

    }
}