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 * 
 * 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.pdfbox.preflight;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.pdfbox.preflight.ValidationResult.ValidationError;
import org.apache.pdfbox.preflight.parser.PreflightParser;
import org.apache.pdfbox.preflight.parser.XmlResultParser;
import org.apache.pdfbox.util.Version;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
 * This class is a simple main class used to check the validity of a pdf file.
 * 
 * Usage : java org.apache.pdfbox.preflight.Validator_A1b &lt;file path&gt;
 * 
 * @author gbailleul
 * 
 */
public class Validator_A1b
{

    public static void main(String[] args) 
            throws IOException, TransformerException, ParserConfigurationException
    {
        if (args.length == 0)
        {
            usage();
            System.exit(1);
        }

        // is output xml ?
        int posFile = 0;
        boolean outputXml = "xml".equals(args[posFile]);
        posFile += outputXml?1:0;
        // list
        boolean isGroup = "group".equals(args[posFile]);
        posFile += isGroup?1:0;
        // list
        boolean isBatch = "batch".equals(args[posFile]);
        posFile += isBatch?1:0;

        if (isGroup||isBatch)
        {
            // prepare the list
            List<File> ftp = listFiles(args[posFile]);
            int status = 0;
            if (!outputXml)
            {
                // simple list of files
                for (File file2 : ftp)
                {
                    status |= runSimple(file2);
                }
                System.exit(status);
            }
            else
            {
                @SuppressWarnings({"squid:S2755"}) // self-created XML
                Transformer transformer = TransformerFactory.newInstance().newTransformer();
                transformer.setOutputProperty(OutputKeys.INDENT, "yes");
                transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
                XmlResultParser xrp = new XmlResultParser();
                if (isGroup)
                {
                    @SuppressWarnings({"squid:S2755"}) // self-created XML
                    Document document = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
                    Element root = document.createElement("preflights");
                    document.appendChild(root);
                    root.setAttribute("count", String.format("%d", ftp.size()));
                    for (File file : ftp)
                    {
                        Element result = xrp.validate(document, file);
                        root.appendChild(result);
                    }
                    transformer.transform(new DOMSource(document), 
                            new StreamResult(new File(args[posFile]+".preflight.xml")));
                }
                else
                {
                    // isBatch
                    for (File file : ftp)
                    {
                        Element result = xrp.validate(file);
                        Document document = result.getOwnerDocument();
                        document.appendChild(result);
                        transformer.transform(new DOMSource(document), 
                                new StreamResult(new File(file.getAbsolutePath()+".preflight.xml")));
                    }
                }
            }
        } 
        else
        {
            if (!outputXml)
            {
                // simple validation 
                System.exit(runSimple(new File(args[posFile])));
            }
            else
            {
                // generate xml output
                XmlResultParser xrp = new XmlResultParser();
                Element result = xrp.validate(new File(args[posFile]));
                Document document = result.getOwnerDocument();
                document.appendChild(result);
                @SuppressWarnings({"squid:S2755"}) // self-created XML
                Transformer transformer = TransformerFactory.newInstance().newTransformer();
                transformer.setOutputProperty(OutputKeys.INDENT, "yes");
                transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
                transformer.transform(new DOMSource(document), new StreamResult(System.out));
            }
        }

    }

    private static void usage()
    {
        String version = Version.getVersion();

        System.out.println("Usage : java org.apache.pdfbox.preflight.Validator_A1b [xml] [<mode>] <file path>");
        System.out.println();
        System.out.println(" * xml : if set, generate xml output instead of text");
        System.out.println(" * <mode> : if set, <file path> must be a file containing the PDF files to parse. <mode> can have 2 values:");
        System.out.println("       batch : generate xml result files for each PDF file in the list");
        System.out.println("       group : generate one xml result file for all the PDF files in the list.");
        System.out.println("Version : " + version);
    }

    private static int runSimple(File file) throws IOException
    {
        ValidationResult result = PreflightParser.validate(file);

        if (result.isValid())
        {
            System.out.println("The file " + file.getName() + " is a valid PDF/A-1b file");
            System.out.println();
            return 0;
        }
        else
        {
            System.out.println("The file " + file.getName() + " is not a valid PDF/A-1b file, error(s) :");
            for (ValidationError error : result.getErrorsList())
            {
                System.out.print(error.getErrorCode() + " : " + error.getDetails());
                if (error.getPageNumber() != null)
                {
                    System.out.println(" on page " + (error.getPageNumber() + 1));
                }
                else
                {
                    System.out.println();
                }
            }
            System.out.println();
            return -1;
        }

    }


    private static List<File> listFiles(String path) throws IOException
    {
        List<File> files = new ArrayList<>();
        File f = new File(path);
        if (f.isFile())
        {
            FileReader fr = new FileReader(f);
            try (BufferedReader bufferedReader = new BufferedReader(fr))
            {
                while (bufferedReader.ready())
                {
                    File fn = new File(bufferedReader.readLine());
                    if (fn.exists())
                    {
                        files.add(fn);
                    } // else warn ?
                }
            }
        }
        else
        {
            File[] fileList = f.listFiles();
            if (fileList != null)
            {
                files.addAll(Arrays.asList(fileList));
            }
        }
        return files;
    }
}
