/* ====================================================================
   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.hslf.dev;

import java.io.BufferedWriter;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Arrays;

import org.apache.commons.io.output.UnsynchronizedByteArrayOutputStream;
import org.apache.poi.hslf.record.RecordTypes;
import org.apache.poi.hslf.usermodel.HSLFSlideShow;
import org.apache.poi.poifs.filesystem.DirectoryNode;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.util.IOUtils;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.LittleEndianConsts;

/**
 * Utility class which dumps raw contents of a ppt file into XML format
 */

public final class PPTXMLDump {
    private static final int HEADER_SIZE = 8; //size of the record header
    private static final int PICT_HEADER_SIZE = 25; //size of the picture header
    private static final String PICTURES_ENTRY = "Pictures";
    private static final String CR = System.getProperty("line.separator");

    private Writer out;
    private final byte[] docstream;
    private final byte[] pictstream;
    private final boolean hexHeader = true;

    public PPTXMLDump(File ppt) throws IOException {
        try (POIFSFileSystem fs = new POIFSFileSystem(ppt, true)) {
            docstream = readEntry(fs, HSLFSlideShow.POWERPOINT_DOCUMENT);
            pictstream = readEntry(fs, PICTURES_ENTRY);
        }
    }

    private static byte[] readEntry(POIFSFileSystem fs, String entry)
    throws IOException {
        DirectoryNode dn = fs.getRoot();
        if (!dn.hasEntryCaseInsensitive(entry)) {
            return null;
        }
        try (InputStream is = dn.createDocumentInputStream(entry);
            UnsynchronizedByteArrayOutputStream bos = UnsynchronizedByteArrayOutputStream.builder().get()) {
            IOUtils.copy(is, bos);
            return bos.toByteArray();
        }
    }

    /**
     * Dump the structure of the supplied PPT file into XML
     * @param outWriter {@code Writer} to write out
     * @throws java.io.IOException If writing to the writer fails
     */
    public void dump(Writer outWriter) throws IOException {
        this.out = outWriter;

        int padding = 0;
        write(out, "<Presentation>" + CR, padding);
        padding++;
        if (pictstream != null){
            write(out, "<Pictures>" + CR, padding);
            dumpPictures(pictstream, padding);
            write(out, "</Pictures>" + CR, padding);
        }
        //dump the structure of the powerpoint document
        write(out, "<PowerPointDocument>" + CR, padding);
        padding++;
        if(docstream != null) {
            dump(docstream, 0, docstream.length, padding);
        }
        padding--;
        write(out, "</PowerPointDocument>" + CR, padding);
        padding--;
        write(out, "</Presentation>", padding);
    }

    /**
     * Dump a part of the document stream into XML
     * @param data PPT binary data
     * @param offset offset from the beginning of the document
     * @param length of the document
     * @param padding used for formatting results
     * @throws java.io.IOException If writing out information fails
     */
    public void dump(byte[] data, int offset, int length, int padding) throws IOException {
        int pos = offset;
        while (pos <= (offset + length - HEADER_SIZE)){
            if (pos < 0) {
                break;
            }

            //read record header
            int info = LittleEndian.getUShort(data, pos);
            pos += LittleEndianConsts.SHORT_SIZE;
            int type = LittleEndian.getUShort(data, pos);
            pos += LittleEndianConsts.SHORT_SIZE;
            int size = (int)LittleEndian.getUInt(data, pos);
            pos += LittleEndianConsts.INT_SIZE;

            if (size < 0) {
                // stop processing of invalid header data
                continue;
            }

            //get name of the record by type
            String recname = RecordTypes.forTypeID(type).name();
            write(out, "<"+recname + " info=\""+info+"\" type=\""+type+"\" size=\""+size+"\" offset=\""+(pos-8)+"\"", padding);
            if (hexHeader){
                out.write(" header=\"");
                dump(out, data, pos-8, 8, 0, false);
                out.write("\"");
            }
            out.write(">" + CR);
            padding++;
            //this check works both for Escher and PowerPoint records
            boolean isContainer = (info & 0x000F) == 0x000F;
            if (isContainer) {
                //continue to dump child records
                dump(data, pos, size, padding);
            } else {
                //dump first 100 bytes of the atom data
                dump(out, data, pos, Math.min(size, data.length-pos), padding, true);
            }
            padding--;
            write(out, "</"+recname + ">" + CR, padding);

            pos += size;
        }
    }

    /**
     * Dumps the Pictures OLE stream into XML.
     *
     * @param data from the Pictures OLE data stream
     * @param padding How many leading blanks to add in the output
     * @throws java.io.IOException If writing out information fails
     */
    public void dumpPictures(byte[] data, int padding) throws IOException {
        int pos = 0;
        while (pos < data.length) {
            if(data.length - pos < PICT_HEADER_SIZE) {
                // corrupt file, cannot read header
                return;
            }
            byte[] header = Arrays.copyOfRange(data, pos, pos + PICT_HEADER_SIZE);
            int size = LittleEndian.getInt(header, 4) - 17;
            if(size < 0) {
                // corrupt file, negative image size
                return;
            }

            pos += PICT_HEADER_SIZE + size;

            padding++;
            write(out, "<picture size=\""+size+"\" type=\""+getPictureType(header)+"\">" + CR, padding);
            padding++;
            write(out, "<header>" + CR, padding);
            dump(out, header, 0, header.length, padding, true);
            write(out, "</header>" + CR, padding);
            write(out, "<imgdata>" + CR, padding);
            dump(out, data, 0, Math.min(size, 100), padding, true);
            write(out, "</imgdata>" + CR, padding);
            padding--;
            write(out, "</picture>" + CR, padding);
            padding--;
        }
    }

    public static void main(String[] args) throws Exception {
        if (args.length == 0){
            System.out.println(
                "Usage: PPTXMLDump (options) pptfile\n" +
                "Where options include:\n" +
                "    -f     write output to <pptfile>.xml file in the current directory"
            );
            return;
        }
        boolean outFile = false;
        for (String arg : args) {

            if (arg.startsWith("-")) {
                if ("-f".equals(arg)) {
                    //write output to a file
                    outFile = true;
                }
            } else {
                File ppt = new File(arg);
                PPTXMLDump dump = new PPTXMLDump(ppt);
                System.out.println("Dumping " + arg);

                if (outFile) {
                    OutputStream fos = Files.newOutputStream(Paths.get(ppt.getName() + ".xml"));
                    OutputStreamWriter out = new OutputStreamWriter(fos, StandardCharsets.UTF_8);
                    dump.dump(out);
                    out.close();
                } else {
                    dump.dump(new BufferedWriter(
                            new OutputStreamWriter(System.out, StandardCharsets.UTF_8)));
                }
            }
        }
    }


    /**
     *  write a string to {@code out} with the specified padding
     */
    private static void write(Writer out, String str, int padding) throws IOException {
        for (int i = 0; i < padding; i++) out.write("  ");
        out.write(str);
    }

    private String getPictureType(byte[] header){
        String type;
        int meta = LittleEndian.getUShort(header, 0);

        switch(meta){
            case 0x46A0: type = "jpeg"; break;
            case 0x2160: type = "wmf"; break;
            case 0x6E00: type = "png"; break;
            default: type = "unknown"; break;
        }
        return type;
    }

    /**
     *  dump binary data to {@code out} with the specified padding
     */
    private static void dump(Writer out, byte[] data, int offset, int length, int padding, boolean nl) throws IOException {
        int linesize = 25;
        for (int i = 0; i < padding; i++) out.write("  ");
        int i;
        for (i = offset; i < (offset + length); i++) {
            int c = data[i];
            out.write((char) hexval[(c & 0xF0) >> 4]);
            out.write((char) hexval[(c & 0x0F) >> 0]);
            out.write(' ');
            if((i+1-offset) % linesize == 0 && i != (offset + length-1)) {
                out.write(CR);
                for (int j = 0; j < padding; j++) out.write("  ");
            }
        }
        if(nl && length > 0)out.write(CR);
    }

    private static final byte[] hexval =
            {(byte) '0', (byte) '1', (byte) '2', (byte) '3',
                    (byte) '4', (byte) '5', (byte) '6', (byte) '7',
                    (byte) '8', (byte) '9', (byte) 'A', (byte) 'B',
                    (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F'};
}
