package net.sourceforge.uiloader.ui.swing.languages;

/*
 * Program      : UILoader
 * Package      : net.sourceforge.uiloader.ui.swing.languages
 * File         : LanguageManager.java
 * Created      : Jan 15, 2005
 * By           : brian
 *
 * Description  : Handles String Internationlization
 * 
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License.
 *
 * 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 General Public License for more details ( see the LICENSE file ).
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

import net.sourceforge.uiloader.core.Constants;

import org.w3c.dom.*;
import org.xml.sax.*;

import javax.xml.parsers.*;
import java.io.*;

/**
 * @author brian
 * @version 1.0
 */

public class LanguageManager {
    class InvalidPhraseException extends Exception {
    };
    class InvalidLanguageException extends Exception {
    };
    class InvalidLanguageVersionException extends Exception {
    };
    class LanguageNotLoadedException extends Exception {
    };
    
    private LanguageParser languageParser = new LanguageParser();


    /**
     * @param phraseToGet The identifier of the phrase to retrive
     * @return A phrase from the current language file as a string
     * @throws InvalidPhraseException
     * @throws LanguageNotLoadedException
     */
    public String getPhrase(String phraseToGet) throws InvalidPhraseException, LanguageNotLoadedException {
        String phrase = null;

        try {
            phrase = this.languageParser.getPhrase(phraseToGet);
        } catch (InvalidPhraseException e) {
            throw new InvalidPhraseException();
        } catch (LanguageNotLoadedException e) {
            throw new LanguageNotLoadedException();
        }

        return phrase;
    }

    /**
     * Interface method for loading language files
     *
     * @param languageFile The Language File (XML Format) to load
     * @throws InvalidLanguageException
     * @throws InvalidLanguageVersionException
     *
     */
    public void loadLanguage(File languageFile) throws InvalidLanguageException, InvalidLanguageVersionException {
        try {
            this.languageParser.loadLanguage(languageFile);
        } catch (InvalidLanguageException e) {
            throw new InvalidLanguageException();
        } catch (InvalidLanguageVersionException e) {
            throw new InvalidLanguageVersionException();
        }
    }

    private class LanguageParser {
        private DocumentBuilderFactory xmlFactory = null;
        private DocumentBuilder xmlBuilder = null;
        private Element root = null;
        private NodeList langNodes = null;
        private Document parsedFile = null;
        private String currentLanguage = null;
        private String fileVersion = null;

        /**
         * Returns the name of the current language
         *
         * @return Name of current language as a string or null if none is loaded
         */
        public String getCurrentLanguage() {
            return currentLanguage;
        }

        /**
         * @param phraseToGet The identifier of the phrase to retrive
         * @return A phrase from the current language file as a string
         * @throws InvalidPhraseException
         * @throws LanguageNotLoadedException
         */
        public String getPhrase(String phraseToGet) throws InvalidPhraseException, LanguageNotLoadedException {
            if (xmlFactory == null) {
                throw new LanguageNotLoadedException();
            }

            return phraseToGet;
        }

        /**
         * Loads an XML File containing phrases into the parser
         *
         * @param languageFile The XML File Containing Phrases To Use
         * @throws InvalidLanguageException
         * @throws InvalidLanguageVersionException
         *
         */
        public void loadLanguage(File languageFile) throws InvalidLanguageException, InvalidLanguageVersionException {

            try {
                if (xmlFactory == null) {
                    xmlFactory = DocumentBuilderFactory.newInstance();
                    xmlFactory.setValidating(true);
                    xmlBuilder = xmlFactory.newDocumentBuilder();
                }
                if (parsedFile != null) {
                    parsedFile = null;
                }

                parsedFile = xmlBuilder.parse(languageFile);
                root = parsedFile.getDocumentElement();

                if (root.getTagName() != "UILoaderLanguage") {
                    throw new InvalidLanguageException();
                } else {
                    langNodes = root.getChildNodes();
                    fileVersion = langNodes.item(0).toString();
                    if (fileVersion != Constants.PROGRAM_VERSION) {
                        throw new InvalidLanguageVersionException();
                    }
                }


            } catch (ParserConfigurationException e) {
                //TODO : This is a prototype. Will standerdize the error handling with a central class later
                System.out.println("A Parser Configuration Exception Occured");
                System.out.println("This Usually Means You Are Running On An Old JRE");
                System.out.println("or that your language data file is corrupt");
                System.out.println("Please Update Your JRE To The Latest Version");
                System.out.println("----------------------------------------------");
                System.out.println("If you continue to recieve this error please send the following to dcatz@nc.rr.com");
                System.out.println("----------------------------------------------");
                System.out.println("Begin Stack Trace");
                System.out.println(e.getStackTrace());
                System.exit(10);
            } catch (IOException e) {
                throw new InvalidLanguageException();
            } catch (SAXException e) {
                throw new InvalidLanguageException();
            }


        }

    }

}