package org.cyclopsgroup.jmxterm;
   
   import java.io.IOException;
   import java.util.Map;
   
   import javax.management.remote.JMXServiceURL;
   
   import org.apache.commons.lang3.Validate;
   import org.cyclopsgroup.jmxterm.io.CommandInput;
  import org.cyclopsgroup.jmxterm.io.CommandOutput;
  import org.cyclopsgroup.jmxterm.io.UnimplementedCommandInput;
  import org.cyclopsgroup.jmxterm.io.VerboseCommandOutput;
  import org.cyclopsgroup.jmxterm.io.VerboseCommandOutputConfig;
  import org.cyclopsgroup.jmxterm.io.VerboseLevel;
  
  /**
   * JMX communication context. This class exists for the whole lifecycle of a command execution. It
   * is NOT thread safe. The caller(CommandCenter) makes sure all calls are synchronized.
   * 
   * @author <a href="mailto:jiaqi.guo@gmail.com">Jiaqi Guo</a>
   */
  public abstract class Session implements VerboseCommandOutputConfig {
    private String bean;
  
    private boolean closed;
  
    private String domain;
  
    private final CommandInput input;
  
    /**
     * Public output field. TODO Reevaluate if this field should be public or exposed by a getter
     * method
     */
    public final CommandOutput output;
  
    private final JavaProcessManager processManager;
  
    private VerboseLevel verboseLevel = VerboseLevel.BRIEF;
  
    /**
     * @param output Output destination
     * @param input Command line input
     * @param processManager Process manager
     */
    protected Session(CommandOutput output, CommandInput input, JavaProcessManager processManager) {
      Validate.notNull(output, "Output can't be NULL");
      Validate.notNull(processManager, "Process manager can't be NULL");
      this.output = new VerboseCommandOutput(output, this);
      this.input = input == null ? new UnimplementedCommandInput() : input;
      this.processManager = processManager;
    }
  
    /**
     * Close JMX terminal console. Supposedly, process terminates after this call
     */
    public void close() {
      if (closed) {
        return;
      }
      closed = true;
    }
  
    /**
     * Connect to MBean server
     * 
     * @param url URL to connect
     * @param env Environment variables
     * @throws IOException allows IO exceptions.
     */
    public abstract void connect(JMXServiceURL url, Map<String, Object> env) throws IOException;
  
    /**
     * Close JMX connector
     * 
     * @throws IOException Thrown when connection can't be closed
     */
    public abstract void disconnect() throws IOException;
  
    /**
     * @return Current selected bean
     */
    public final String getBean() {
      return bean;
    }
  
    /**
     * @return Current open JMX server connection
     */
    public abstract Connection getConnection();
  
    /**
     * @return Current domain
     */
    public final String getDomain() {
      return domain;
    }
  
    /**
    * @return General input of command lines, which could be interactive environment, a file or piped
    *         input
    */
   public final CommandInput getInput() {
     return input;
   }
 
   /**
    * @return Java process manager to load processes
    */
   public JavaProcessManager getProcessManager() {
     return processManager;
   }
 
   @Override
   public final VerboseLevel getVerboseLevel() {
     return verboseLevel;
   }
 
   /**
    * @return True if {@link #close()} has been called
    */
   public final boolean isClosed() {
     return closed;
   }
 
   /**
    * @return True if there's a open connection to JMX server
    */
   public abstract boolean isConnected();
 
   /**
    * Set current selected bean
    * 
    * @param bean Bean to select
    */
   public final void setBean(String bean) {
     this.bean = bean;
   }
 
   /**
    * Set current selected domain
    * 
    * @param domain Domain to select
    */
   public final void setDomain(String domain) {
     Validate.notNull(domain, "domain can't be NULL");
     this.domain = domain;
   }
 
   /**
    * @param verboseLevel Level of verbose
    */
   public final void setVerboseLevel(VerboseLevel verboseLevel) {
     Validate.notNull(verboseLevel, "Verbose level can't be NULL");
     this.verboseLevel = verboseLevel;
   }
 
   /**
    * Set domain and bean to be NULL
    */
   public void unsetDomain() {
     bean = null;
     domain = null;
   }
 }