/*
 * $Id: a19293fc0b8f86eb9096f1e9c3e0406989905714 $
 *
 * This file is part of the iText (R) project.
 * Copyright (c) 1998-2015 iText Group NV
 * 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
 * ITEXT GROUP. ITEXT GROUP 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 version that user can use to get the actual version of PDF document **/
    protected char version = PdfWriter.VERSION_1_4;

	/**
	 * 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) {
		this.version = 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());
	}

    public char getVersion() {
        return version;
    }

}