/*
 * $Id: PdfVersionImp.java 4784 2011-03-15 08:33:00Z blowagie $
 *
 * This file is part of the iText (R) project.
 * Copyright (c) 1998-2011 1T3XT BVBA
 * Authors: Bruno Lowagie, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
 * 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * a covered work must retain the producer line in every PDF that is created
 * or manipulated using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */
package com.itextpdf.text.pdf.internal;

import java.io.IOException;

import com.itextpdf.text.DocWriter;
import com.itextpdf.text.pdf.OutputStreamCounter;
import com.itextpdf.text.pdf.PdfDeveloperExtension;
import com.itextpdf.text.pdf.PdfDictionary;
import com.itextpdf.text.pdf.PdfName;
import com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.text.pdf.interfaces.PdfVersion;

/**
 * Stores the PDF version information,
 * knows how to write a PDF Header,
 * and how to add the version to the catalog (if necessary).
 */

public class PdfVersionImp implements PdfVersion {
    
    /** Contains different strings that are part of the header. */
    public static final byte[][] HEADER = {
        DocWriter.getISOBytes("\n"),
        DocWriter.getISOBytes("%PDF-"),
        DocWriter.getISOBytes("\n%\u00e2\u00e3\u00cf\u00d3\n")
    };
    
        /** Indicates if the header was already written. */
        protected boolean headerWasWritten = false;
        /** Indicates if we are working in append mode. */
        protected boolean appendmode = false;
        /** The version that was or will be written to the header. */
        protected char header_version = PdfWriter.VERSION_1_4;
        /** The version that will be written to the catalog. */
        protected PdfName catalog_version = null;
        /**
         * The extensions dictionary.
         * @since       2.1.6
         */
        protected PdfDictionary extensions = null;
        
        /**
         * @see com.itextpdf.text.pdf.interfaces.PdfVersion#setPdfVersion(char)
         */
        public void setPdfVersion(char version) {
                if (headerWasWritten || appendmode) {
                        setPdfVersion(getVersionAsName(version));
                }
                else {
                        this.header_version = version;
                }
        }
        
        /**
         * @see com.itextpdf.text.pdf.interfaces.PdfVersion#setAtLeastPdfVersion(char)
         */
        public void setAtLeastPdfVersion(char version) {
                if (version > header_version) {
                        setPdfVersion(version);
                }
        }
        
        /**
         * @see com.itextpdf.text.pdf.interfaces.PdfVersion#setPdfVersion(com.itextpdf.text.pdf.PdfName)
         */
        public void setPdfVersion(PdfName version) {
                if (catalog_version == null || catalog_version.compareTo(version) < 0) {
                        this.catalog_version = version;
                }
        }
        
        /**
         * Sets the append mode.
         */
        public void setAppendmode(boolean appendmode) {
                this.appendmode = appendmode;
        }
        
        /**
         * Writes the header to the OutputStreamCounter.
         * @throws IOException 
         */
        public void writeHeader(OutputStreamCounter os) throws IOException {
                if (appendmode) {
                        os.write(HEADER[0]);
                }
                else {
                        os.write(HEADER[1]);
                        os.write(getVersionAsByteArray(header_version));
                        os.write(HEADER[2]);
                        headerWasWritten = true;
                }
        }
        
        /**
         * Returns the PDF version as a name.
         * @param version       the version character.
         */
        public PdfName getVersionAsName(char version) {
                switch(version) {
                case PdfWriter.VERSION_1_2:
                        return PdfWriter.PDF_VERSION_1_2;
                case PdfWriter.VERSION_1_3:
                        return PdfWriter.PDF_VERSION_1_3;
                case PdfWriter.VERSION_1_4:
                        return PdfWriter.PDF_VERSION_1_4;
                case PdfWriter.VERSION_1_5:
                        return PdfWriter.PDF_VERSION_1_5;
                case PdfWriter.VERSION_1_6:
                        return PdfWriter.PDF_VERSION_1_6;
                case PdfWriter.VERSION_1_7:
                        return PdfWriter.PDF_VERSION_1_7;
                default:
                        return PdfWriter.PDF_VERSION_1_4;
                }
        }
        
        /**
         * Returns the version as a byte[].
         * @param version the version character
         */
        public byte[] getVersionAsByteArray(char version) {
                return DocWriter.getISOBytes(getVersionAsName(version).toString().substring(1));
        }

        /** Adds the version to the Catalog dictionary. */
        public void addToCatalog(PdfDictionary catalog) {
                if(catalog_version != null) {
                        catalog.put(PdfName.VERSION, catalog_version);
                }
                if (extensions != null) {
                        catalog.put(PdfName.EXTENSIONS, extensions);
                }
        }

        /**
         * @see com.itextpdf.text.pdf.interfaces.PdfVersion#addDeveloperExtension(com.itextpdf.text.pdf.PdfDeveloperExtension)
         * @since       2.1.6
         */
        public void addDeveloperExtension(PdfDeveloperExtension de) {
                if (extensions == null) {
                        extensions = new PdfDictionary();
                }
                else {
                        PdfDictionary extension = extensions.getAsDict(de.getPrefix());
                        if (extension != null) {
                                int diff = de.getBaseversion().compareTo(extension.getAsName(PdfName.BASEVERSION));
                                if (diff < 0)
                                        return;
                                diff = de.getExtensionLevel() - extension.getAsNumber(PdfName.EXTENSIONLEVEL).intValue();
                                if (diff <= 0)
                                        return;
                        }
                }
                extensions.put(de.getPrefix(), de.getDeveloperExtensions());
        }
}