/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe 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 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.datamodel.ifs2;
  
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.StandardCopyOption;
  import java.nio.file.attribute.FileTime;
  import java.util.Date;
  
  import org.jdom2.JDOMException;
  import org.mycore.common.MCRUsageException;
  import org.mycore.common.content.MCRContent;
  import org.mycore.common.content.MCRPathContent;
  import org.xml.sax.SAXException;
  
  /**
   * Represents an XML metadata document that is stored in MCRMetadataStore.
   *
   * @author Frank Lützenkirchen
   */
  public class MCRStoredMetadata {
  
      /** The ID of the metadata document */
      protected int id;
  
      /** The file object in local filesystem storing the data */
      protected Path path;
  
      /** The store this document is stored in */
      protected MCRMetadataStore store;
  
      private String docType;
  
      protected boolean deleted;
  
      /**
       * Creates a new stored metadata object
       *
       * @param store
       *            the store this document is stored in
       * @param path
       *            the file object storing the data
       * @param id
       *            the ID of the metadata document
       * @param docType
       *            if not null overwrites any detected doctype
       */
      MCRStoredMetadata(MCRMetadataStore store, Path path, int id, String docType) {
          this.store = store;
          this.id = id;
          this.path = path;
          this.docType = docType;
          this.deleted = false;
      }
  
      /**
       * Creates a new local file to save XML to
       *
       * @param xml
       *            the XML to save to a new file
       * @throws JDOMException if content is not XML and corresponding
       *                       {@link MCRMetadataStore} forces MCRContent to be XML
       */
      void create(MCRContent xml) throws IOException, JDOMException {
          if (store.shouldForceXML()) {
              try {
                  xml = xml.ensureXML();
              } catch (SAXException e) {
                  throw new IOException(e);
              }
          }
          if (!Files.exists(path.getParent())) {
              Files.createDirectories(path.getParent());
          }
          xml.sendTo(path);
      }
  
      /**
       * Updates the stored XML document
       *
       * @param xml
      *            the XML document to be stored
      * @throws JDOMException if content is not XML and corresponding
      *                       {@link MCRMetadataStore} forces MCRContent to be XML
      */
     public void update(MCRContent xml) throws IOException, JDOMException {
         if (isDeleted()) {
             String msg = "You can not update a deleted data object";
             throw new MCRUsageException(msg);
         }
         if (store.shouldForceXML()) {
             try {
                 xml = xml.ensureXML();
             } catch (SAXException e) {
                 throw new IOException(e);
             }
         }
         xml.sendTo(path, StandardCopyOption.REPLACE_EXISTING);
     }
 
     /**
      * Returns the stored XML document
      *
      * @return the stored XML document
      */
     public MCRContent getMetadata() throws IOException {
         MCRPathContent pathContent = new MCRPathContent(path);
         pathContent.setDocType(docType);
         return pathContent;
     }
 
     /**
      * Returns the ID of this metadata document
      *
      * @return the ID of this metadata document
      */
     public int getID() {
         return id;
     }
 
     /**
      * Returns the store this metadata document is stored in
      *
      * @return the store this metadata document is stored in
      */
     public MCRMetadataStore getStore() {
         return store;
     }
 
     /**
      * Returns the date this metadata document was last modified
      *
      * @return the date this metadata document was last modified
      */
     public Date getLastModified() throws IOException {
         return Date.from(Files.getLastModifiedTime(path).toInstant());
     }
 
     /**
      * Sets the date this metadata document was last modified
      *
      * @param date
      *            the date this metadata document was last modified
      */
     public void setLastModified(Date date) throws IOException {
         if (!isDeleted()) {
             Files.setLastModifiedTime(path, FileTime.from(date.toInstant()));
         }
     }
 
     /**
      * Deletes the metadata document. This object is invalid afterwards, do not
      * use it any more.
      *
      */
     public void delete() throws IOException {
         if (!deleted) {
             store.delete(path);
             deleted = true;
         }
     }
 
     /**
      * Returns true if this object is deleted
      */
     public boolean isDeleted() throws IOException {
         return deleted;
     }
 }