package emissary.directory;
   
   import emissary.util.xml.SaferJDOMUtil;
   
   import jakarta.annotation.Nullable;
   import org.jdom2.Document;
   import org.jdom2.Element;
   import org.jdom2.JDOMException;
   import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.List;
  import java.util.Map;
  
  /**
   * This class acts as a container and producer for turning a directory entry list into a full xml document
   */
  public class DirectoryXmlContainer {
  
      private static final Logger logger = LoggerFactory.getLogger(DirectoryXmlContainer.class);
  
      public static final String DIRECTORY = "directory";
      public static final String LOC_ATTR = "location";
      public static final String DATAID_ATTR = "dataid";
  
      /**
       * Build an xml document from the contents of a directory place
       */
      public static Document buildDocument(final IDirectoryPlace dir) {
          final Element root = new Element(DIRECTORY);
          root.setAttribute(LOC_ATTR, dir.getKey());
  
          // Each directory entry
          for (final String dataId : dir.getEntryKeys()) {
              final DirectoryEntryList list = dir.getEntryList(dataId);
              if (list != null) {
                  final Element listEl = list.getXml();
                  listEl.setAttribute(DATAID_ATTR, dataId);
                  root.addContent(listEl);
              }
          }
  
          return new Document(root);
      }
  
      /**
       * Build an xml document from the map.
       * 
       * @param map the map of entries
       * @param loc directory location key
       */
      public static Document buildDocument(final DirectoryEntryMap map, final String loc) {
          final Element root = new Element(DIRECTORY);
          root.setAttribute(LOC_ATTR, loc);
  
          // Each directory entry
          for (final Map.Entry<String, DirectoryEntryList> entry : map.entrySet()) {
              final String dataId = entry.getKey();
              final DirectoryEntryList list = entry.getValue();
              if (list != null) {
                  final Element listEl = list.getXml();
                  listEl.setAttribute(DATAID_ATTR, dataId);
                  root.addContent(listEl);
              }
          }
  
          return new Document(root);
      }
  
      /**
       * Build an xml document from the contents of the directory as if proxied through the place itself. Except when the
       * entries actually belong to the requester.
       * 
       * @param dir the directory that will act as a proxy
       * @param requester the directory doing the requesting
       */
      public static Document buildProxyDocument(final IRemoteDirectory dir, final String requester) {
          final String proxyKey = dir.getKey();
          final Element root = new Element(DIRECTORY);
          root.setAttribute(LOC_ATTR, proxyKey);
  
          logger.debug("Building proxy view of dir contents for {}", requester);
  
          // Each directory entry
          for (final String dataId : dir.getEntryKeys()) {
              final DirectoryEntryList list = dir.getEntryList(dataId);
              logger.debug("List of {} for {} has {} entries", dataId, requester, list.size());
              // set up proxy for each entry
              for (final DirectoryEntry e : list) {
                  e.proxyFor(proxyKey);
              }
  
              // Add them to the xml
              if (!list.isEmpty()) {
                  final Element listEl = list.getXml();
                  listEl.setAttribute(DATAID_ATTR, dataId);
                  root.addContent(listEl);
              }
          }
         return new Document(root);
     }
 
     /**
      * Build an xml string from the contents of a directory place This method pulls the main entryMap of the directory.
      * 
      * @param dir the directory to pull the entryMap contents from
      * @return xml string representing the keys
      */
     public static String toXmlString(final IDirectoryPlace dir) {
         final Document jdom = buildDocument(dir);
         return SaferJDOMUtil.toString(jdom);
     }
 
     /**
      * Build an xml string from the contents of a directory place making it appear that the place represented by proxyKey
      * acts as a proxy for all or the keys in the directory map
      * 
      * @param dir the directory to pull the entryMap contents from
      * @param proxyKey place to appear as the proxy
      * @param requester the key of the remote directory that is requesting the local directory contents
      * @return xml string representing the proxied keys
      */
     public static String toXmlString(final IDirectoryPlace dir, @Nullable final String proxyKey, final String requester) {
         logger.debug("Building xml string for {}", requester);
         final String xml;
         if ((proxyKey == null) || !(dir instanceof IRemoteDirectory)) {
             xml = toXmlString(dir);
         } else {
             final Document jdom = buildProxyDocument((IRemoteDirectory) dir, requester);
             xml = SaferJDOMUtil.toString(jdom);
         }
         return xml;
     }
 
     /**
      * Build a DirectoryEntryList map from string xml
      */
     public static DirectoryEntryMap buildEntryListMap(final String xml) throws JDOMException {
         final Document jdom = SaferJDOMUtil.createDocument(xml);
         return buildEntryListMap(jdom);
     }
 
     /**
      * Build a DirectoryEntryList map from a JDOM document
      */
     public static DirectoryEntryMap buildEntryListMap(final Document jdom) {
         final Element el = jdom.getRootElement();
         return buildEntryListMap(el);
     }
 
     /**
      * Build a DirectoryEntryMap from a JDOM Element
      */
     public static DirectoryEntryMap buildEntryListMap(final Element el) {
         final DirectoryEntryMap map = new DirectoryEntryMap();
         final List<Element> entryLists = el.getChildren(DirectoryEntryList.ENTRYLIST);
         for (final Element listElement : entryLists) {
             final DirectoryEntryList d = DirectoryEntryList.fromXml(listElement);
             final String dataId = listElement.getAttributeValue(DATAID_ATTR);
             map.put(dataId, d);
         }
         logger.debug("Constructed map of {} directory entry lists from xml", map.size());
 
         return map;
     }
 
     /** This class is not meant to be instantiated. */
     private DirectoryXmlContainer() {}
 }