/**
 * <copyright> Copyright 2006 by Know-Center, Graz, Austria </copyright>
 * PDF-AS has been contracted by the E-Government Innovation Center EGIZ, a
 * joint initiative of the Federal Chancellery Austria and Graz University of
 * Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 */
package at.gv.egiz.pdfas.web.helper;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;

import org.apache.commons.lang.text.StrSubstitutor;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import at.gv.egiz.pdfas.api.commons.Constants;
import at.gv.egiz.pdfas.api.exceptions.ConfigUtilsException;
import at.gv.egiz.pdfas.utils.ConfigUtils;
import at.knowcenter.wag.egov.egiz.exceptions.SettingsException;

/**
 * 
 * @author exthex
 *
 */
public class WebSettingsReader {
   
   /**
    * The configuration key that replaces a dynamically generated retrieve signature data url.
    */
   private final static String RETRIEVE_SIGNATURE_DATA_URL_OVERRIDE_KEY = "retrieve_signature_data_url_override";

   private final static String SIGNING_TIME_TOLERANCE_KEY = "signing_time_tolerance";

   private static final Log logger_ = LogFactory.getLog(WebSettingsReader.class);

   public static String RESOURCES_PATH = null;

   private static String TMP_PATH = null;

   private static String CONFIG_PATH;

   private static String CFG = "cfg";

   private String WEB_CONFIG_FILE_DEFAULT_NAME = "pdf-as-web.properties";

   public static synchronized void initialize(String work_dir) {

      String tmpDir = null;

      String defaultConfigDeployedTo = null;
      // resolve work directory
      // configuration explicitely given ?
      if (work_dir == null) {

         // configuration via system property ?
         logger_.debug("No configuration directory given. Looking for system property \""
               + Constants.CONFIG_DIR_SYSTEM_PROPERTY + "\".");
         work_dir = System.getProperty(Constants.CONFIG_DIR_SYSTEM_PROPERTY);
         if (work_dir == null) {

            // configuration via user's home directory ?
            logger_
                  .debug("System property not set. Trying to locate configuration within the user's home directory.");
            String userHome = System.getProperty("user.home");
            if (userHome == null || userHome.length() == 0) {
               throw new RuntimeException("Unable to resolve user's home directory.");
            }
            work_dir = ConfigUtils.assertFileSeparator(userHome) + Constants.USERHOME_CONFIG_FOLDER;
            try {
               defaultConfigDeployedTo = ConfigUtils.deployDefaultConfiguration(work_dir, false);
            } catch (ConfigUtilsException e) {
               throw new RuntimeException(e);
            }
            if (defaultConfigDeployedTo != null) {
               logger_.info("** Default configuration successfully deployed to \""
                     + defaultConfigDeployedTo + "\" **");
            } else {
               logger_
                     .debug("Default configuration has NOT been deployed. Maybe the configuration already exists.");
            }
         } else {
            logger_.debug("Configuration set by system property.");
            tmpDir = work_dir;
         }
      } else {
         logger_.debug("Configuration path explicitely set.");
      }
      File configdirFile = new File(StrSubstitutor.replaceSystemProperties(work_dir));
      try {
         work_dir = ConfigUtils.assertFileSeparator(configdirFile.getCanonicalPath());
      } catch (IOException e) {
         work_dir = ConfigUtils.assertFileSeparator(configdirFile.getPath());
      }
      if (!configdirFile.isDirectory()) {
         throw new IllegalArgumentException("The config directory \"" + work_dir
               + "\" does not exist or is not a directory.");
      }

      // resolve temporary dir
      if (tmpDir == null) {
         logger_
               .debug("Temporary directory not explicitely set. Looking for user's temp directory.");
         tmpDir = System.getProperty("java.io.tmpdir");
         if (tmpDir == null) {
            logger_
                  .debug("Unable to resolve user's temporary directory. Assuming temporary directory located within config dir.");
            tmpDir = work_dir;
         }
      } else {
         logger_.debug("Temporary directory explicitely set.");
      }
      File tmpdirFile = new File(StrSubstitutor.replaceSystemProperties(ConfigUtils
            .assertFileSeparator(tmpDir) + Constants.TEMP_DIR_NAME));
      try {
         tmpDir = ConfigUtils.assertFileSeparator(tmpdirFile.getCanonicalPath());
      } catch (IOException e) {
         tmpDir = ConfigUtils.assertFileSeparator(tmpdirFile.getPath());
      }

      RESOURCES_PATH = work_dir;
      TMP_PATH = tmpDir;
      File tmpFile = new File(TMP_PATH);
      if (!tmpFile.exists())
         tmpFile.mkdirs();
      CONFIG_PATH = RESOURCES_PATH + CFG + System.getProperty("file.separator");

      if (defaultConfigDeployedTo != null) {
         logger_.debug("** Default configuration successfully deployed to \""
               + defaultConfigDeployedTo + "\" **");
      }
      logger_.debug("Setting system property \"" + Constants.CONFIG_DIR_SYSTEM_PROPERTY
            + "\" to \"" + configdirFile.getPath() + "\".");
      System.setProperty(Constants.CONFIG_DIR_SYSTEM_PROPERTY, configdirFile.getPath());
   }

   private static WebSettingsReader instance;
   
   /**
    * 
    * @return
    * @throws SettingsException
    */
   public static synchronized WebSettingsReader getInstance() throws SettingsException {
      if (instance == null)
         instance = new WebSettingsReader();
      return instance;
   }

   /**
    * 
    */
   public static void clearTemporaryDirectory() {
      File temp_dir = new File(TMP_PATH);
      logger_.debug("Clearing temporary directory: " + temp_dir);

      if (!temp_dir.exists())
      {
        return;
      }

      File[] files = temp_dir.listFiles();
      for (int i = 0; i < files.length; i++)
      {
         // added by tknall: do not try to remove svn-metadata
         if (files[i].getName().endsWith(".svn")) {
            continue;
         }
         logger_.debug("  Clearing temporary file: " + files[i]);
        boolean delete_success = files[i].delete();
        if (!delete_success)
        {
           logger_.error("Couldn't delete the temporary file: " + files[i]);
        }
      }
   }

   /**
    * 
    * @return
    */
   public static File getTemporaryDirectory() {
      return new File(TMP_PATH);
   }
   
   private Properties props;
   
   private WebSettingsReader() throws SettingsException {
      String settingsFile = CONFIG_PATH + WEB_CONFIG_FILE_DEFAULT_NAME;
      props = new Properties();
      try {
         props.load(new FileInputStream(settingsFile));
      }catch(IOException ioe){
         throw new SettingsException("Setting file not loadable: " + settingsFile, ioe);
      }
   }

   /**
    * 
    * @return
    */
   public String getSigningTimeTolerance() {
      return props.getProperty(SIGNING_TIME_TOLERANCE_KEY);
   }

   /**
    * 
    * @return
    */
   public String getRetrieveSignatureDataURLOverride() {
      return props.getProperty(RETRIEVE_SIGNATURE_DATA_URL_OVERRIDE_KEY);
   }

}