package org.cyclopsgroup.jmxterm;
   
   import org.apache.commons.lang3.Validate;
   import org.cyclopsgroup.jcli.AutoCompletable;
   import org.cyclopsgroup.jcli.annotation.Option;
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
   import javax.management.JMException;
  import java.io.IOException;
  import java.util.List;
  
  /**
   * Base class of all commands. Command is executed in single thread. Extending classes don't need to
   * worry about concurrency. Command is transient, every command in console creates a new instance of
   * Command object which is disposed after execution finishes.
   *
   * @author <a href="mailto:jiaqi.guo@gmail.com">Jiaqi Guo</a>
   */
  public abstract class Command implements AutoCompletable {
    private static final Logger LOG = LoggerFactory.getLogger(Command.class);
  
    private boolean help;
  
    private Session session;
  
    /**
     * Provide a list of possible arguments for auto completion. This method returns list of
     * arguments(not option) and is called when user presses tab key.
     *
     * @return List of possible arguments used by auto completion or NULL
     * @throws IOException IO errors
     * @throws JMException JMX problemo
     */
    protected List<String> doSuggestArgument() throws IOException, JMException {
      return null;
    }
  
    /**
     * Provide a list of possible option values for auto completion
     *
     * @param optionName Name of option
     * @return List of possible arguments used by auto completion or NULL
     * @throws IOException Network communication errors
     * @throws JMException JMX errors
     */
    protected List<String> doSuggestOption(String optionName) throws IOException, JMException {
      return null;
    }
  
    /**
     * Execute command
     *
     * @throws IOException IO errors
     * @throws JMException JMX errors
     */
    public abstract void execute() throws IOException, JMException;
  
    /**
     * @return Session where command runs
     */
    public final Session getSession() {
      return session;
    }
  
    /**
     * @return True if help option is on
     */
    public final boolean isHelp() {
      return help;
    }
  
    /**
     * @param help True to display usage
     */
    @Option(name = "h", longName = "help", description = "Display usage")
    public final void setHelp(boolean help) {
      this.help = help;
    }
  
    /**
     * @param session Session where command runs
     */
    public final void setSession(Session session) {
      Validate.notNull(session, "Session can't be NULL");
      this.session = session;
    }
  
    public final List<String> suggestArgument(String partialArg) {
      if (partialArg != null) {
        return null;
      }
      try {
        return doSuggestArgument();
      } catch (IOException e) {
        if (LOG.isDebugEnabled()) {
          LOG.debug("Couldn't suggest option", e);
        }
        return null;
     } catch (JMException e) {
       if (LOG.isDebugEnabled()) {
         LOG.debug("Couldn't suggest option", e);
       }
       return null;
     }
   }
 
   public final List<String> suggestOption(String name, String partialValue) {
     if (partialValue != null) {
       return null;
     }
     try {
       return doSuggestOption(name);
     } catch (IOException e) {
       if (LOG.isDebugEnabled()) {
         LOG.debug("Couldn't suggest option", e);
       }
       return null;
     } catch (JMException e) {
       if (LOG.isDebugEnabled()) {
         LOG.debug("Couldn't suggest option", e);
       }
       return null;
     }
   }
 }