/**
    * This file Copyright (c) 2017-2018 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.cms.core;
  
  import info.magnolia.cms.util.ClasspathResourcesUtil;
  import info.magnolia.init.MagnoliaConfigurationProperties;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  import java.nio.file.Paths;
  
  import javax.inject.Inject;
  import javax.inject.Singleton;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Class to retrieve files or directories used by Magnolia. Examples: app root dir, tmp dir, ..
   */
  @Singleton
  public class FileSystemHelper {
  
      private static final Logger log = LoggerFactory.getLogger(FileSystemHelper.class);
  
      private final MagnoliaConfigurationProperties magnoliaConfigurationProperties;
  
      @Inject
      public FileSystemHelper(MagnoliaConfigurationProperties magnoliaConfigurationProperties) {
          this.magnoliaConfigurationProperties = magnoliaConfigurationProperties;
      }
  
      /**
       * Gets the temporary directory set in magnolia properties.
       * {@link info.magnolia.init.MagnoliaConfigurationProperties#MAGNOLIA_UPLOAD_TMPDIR}
       */
      public File getTempDirectory() {
          String path = magnoliaConfigurationProperties.getProperty(MagnoliaConfigurationProperties.MAGNOLIA_UPLOAD_TMPDIR);
          if (path == null) {
              throw new IllegalArgumentException(MagnoliaConfigurationProperties.MAGNOLIA_UPLOAD_TMPDIR + " is not set in magnolia properties. Please revise your configuration.");
          }
          File tempDir;
          if (Paths.get(path).isAbsolute()) {
              tempDir = new File(path);
          } else {
              tempDir = new File(getAppRootDir(), path);
          }
          // check if temp directory exist, if not create it
          if (!tempDir.exists() && !tempDir.mkdir()) {
              throw new IllegalStateException("Can't create temporary directory under path [" + tempDir + "]. Magnolia configuration property '" + MagnoliaConfigurationProperties.MAGNOLIA_UPLOAD_TMPDIR + "' is set to [" + path +"]. Please revise your environment.");
          }
          if (!tempDir.canWrite()) {
              throw new IllegalStateException("Temp directory [" + tempDir + "] isn't writable. Magnolia configuration property '" + MagnoliaConfigurationProperties.MAGNOLIA_UPLOAD_TMPDIR + "' is set to [" + path +"]. Please revise your environment.");
          }
          return tempDir;
      }
  
      /**
       * Gets the root directory for the magnolia web application.
       */
      public File getAppRootDir() {
          return new File(magnoliaConfigurationProperties.getProperty(MagnoliaConfigurationProperties.MAGNOLIA_APP_ROOTDIR));
     }
 
     /**
      * Gets absolute filesystem path, adds application root if path is not absolute.
      */
     public String getAbsoluteFileSystemPath(String path) {
         if (path == null) {
             throw new IllegalArgumentException("Can't convert null path to an absolute file system path.");
         }
         if (Paths.get(path).isAbsolute()) {
             return path;
         }
 
         File file = new File(getAppRootDir(), path);
         try {
             return file.getCanonicalPath();
         } catch (IOException e) {
             log.debug("Can't resolve canonical path for {}. Returning absolute path.", path, e);
             return file.getAbsolutePath();
         }
     }
 
     /**
      * Try to get the configuration file and replace tokens.
      * Get it first in the file system, then from the resources.
      */
     public String getTokenizedConfigFile(String path) throws IOException {
         final InputStream stream = getConfigFile(path);
         if (stream == null) {
             throw new IOException("Can't load configuration file: " + path);
         }
         return replaceTokens(stream);
     }
 
     private InputStream getConfigFile(String fileName) {
         File file = new File(getAppRootDir(), fileName);
         // relative to webapp root
         if (file.exists()) {
             try {
                 URL url = new URL("file:" + file.getAbsolutePath());
                 return url.openStream();
             } catch (IOException e) {
                 log.error("Unable to read config file from [{}]: ", fileName, e);
                 return null;
             }
         }
 
         // try it directly
         file = new File(fileName);
         if (file.exists()) {
             try {
                 return new FileInputStream(file);
             } catch (FileNotFoundException e) {
                 log.error("Unable to read config file from [{}]:", fileName, e);
                 return null;
             }
         }
 
         // try resources
         try {
             return ClasspathResourcesUtil.getStream(fileName);
         } catch (IOException e) {
             log.error("Unable to read config file from the resources [{}]", fileName, e);
             return null;
         }
     }
 
     private String replaceTokens(InputStream stream) throws IOException {
         String config = IOUtils.toString(stream);
         IOUtils.closeQuietly(stream);
         for (String key: magnoliaConfigurationProperties.getKeys()) {
             config = StringUtils.replace(config, "${" + key + "}", magnoliaConfigurationProperties.getProperty(key));
         }
         return config;
     }
 
 }