package nl.amis.mds;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.faces.event.ActionEvent;

import oracle.adf.share.ADFContext;

import oracle.adf.share.security.SecurityContext;

import oracle.mds.core.MDSInstance;
import oracle.mds.core.MDSSession;
import oracle.mds.exception.MDSException;
import oracle.mds.internal.query.NameQueryImpl;
import oracle.mds.query.ConditionFactory;
import oracle.mds.query.QueryResult;
import oracle.mds.transfer.MDSTransfer;
import oracle.mds.transfer.TransferUnitList;


/*
 * based on work described in http://multikoop.blogspot.com/2012/01/adf-mds-power-user-layer-and-to-control.html
 *
 * */
public class MDSCoordinator {
  private String fragmentName;

  public void removePersonalizations(ActionEvent actionEvent) {
    ADFContext adfCtx = ADFContext.getCurrent();
    SecurityContext secCntx = adfCtx.getSecurityContext();
    String username = secCntx.getUserName();
    List<String> listOfFilesToDelete= queryFiles("/pages/mdssys/cust/user/" + username
                                                 , getFragmentName()+"%");
    try {
      deleteDocuments(listOfFilesToDelete);
      FacesContext.getCurrentInstance().addMessage(null,
                                                   new FacesMessage(FacesMessage.SEVERITY_INFO,
                                                                    null,
                                                                    "Deleted the following MDS-Documents for user " +
                                                                    username +
                                                                    ": " +
                                                                    listOfFilesToDelete));
    } catch (MDSException e) {
      e.printStackTrace();
    }
  }


  /**
   * Query Files from MDS matching the given substr.
   * @return list of document file paths
   */
  public static List<String> queryFiles(final String path, final String name) {
    final MDSSession mdsSession = getCurrentMDSSession();
    final NameQueryImpl nameQuery =
      new NameQueryImpl(mdsSession, ConditionFactory.createNameCondition(path,
                                                                         name,
                                                                         true));
    final Iterator<QueryResult> result = nameQuery.execute();
    final ArrayList<String> listOfFiles = new ArrayList<String>();
    while (result.hasNext()) {
      final QueryResult qr = result.next();
      final String absoluteName = qr.getAbsoluteName();
      listOfFiles.add(absoluteName);
    }
    return listOfFiles;
  }


  /**
   * Deletes the given file paths from MDS using the current MDS Instance
   * @param listOfFiles
   * @throws MDSException
   */
  public static void deleteDocuments(final List<String> listOfFiles) throws MDSException {
    if (listOfFiles == null || listOfFiles.isEmpty()) {
      System.out.println("listOfFiles is empty");
      return;
    }
    deleteDocuments(getCurrentMDSInstance(), listOfFiles);
  }

  public static void deleteDocuments(final MDSInstance mdsInstance,
                                     final List<String> listOfFiles) throws MDSException {

    MDSTransfer transferInstance = MDSTransfer.getInstance(mdsInstance);

    TransferUnitList transferUnitList =
      TransferUnitList.create(mdsInstance, listOfFiles, null, true, true);
    transferInstance.delete(transferUnitList, false) /* cancelOnException */;
    transferInstance.release(mdsInstance);
  }


  public static MDSInstance getCurrentMDSInstance() {
    final MDSInstance mdsInstance =
      (MDSInstance)ADFContext.getCurrent().getMDSInstanceAsObject();

    return mdsInstance;
  }

  public static MDSSession getCurrentMDSSession() {
    final MDSSession mdsSession =
      (MDSSession)ADFContext.getCurrent().getMDSSessionAsObject();
    return mdsSession;
  }


  public void setFragmentName(String fragmentName) {
    this.fragmentName = fragmentName;
  }

  public String getFragmentName() {
    return fragmentName;
  }
}