package org.cyclopsgroup.jmxterm.cc;
   
   import org.apache.commons.lang3.Validate;
   import org.cyclopsgroup.jmxterm.Command;
   import org.cyclopsgroup.jmxterm.CommandFactory;
   
   import java.util.Collections;
   import java.util.Map;
   
  /**
   * CommandFactory implementation based on a Map of command types
   * 
   * @author <a href="mailto:jiaqi.guo@gmail.com">Jiaqi Guo</a>
   */
  public class TypeMapCommandFactory implements CommandFactory {
    private final Map<String, Class<? extends Command>> commandTypes;
  
    /**
     * @param commandTypes Map of command types
     */
    public TypeMapCommandFactory(Map<String, Class<? extends Command>> commandTypes) {
      Validate.notNull(commandTypes, "Command type can't be NULL");
      this.commandTypes = Collections.unmodifiableMap(commandTypes);
    }
  
    @Override
    public Command createCommand(String commandName) {
      Validate.notNull(commandName, "commandName can't be NULL");
      Class<? extends Command> commandType = commandTypes.get(commandName);
      if (commandType == null) {
        throw new IllegalArgumentException(
            "Command " + commandName + " isn't valid, run help to see available commands");
      }
      try {
        return commandType.newInstance();
      } catch (InstantiationException e) {
        throw new RuntimeException("Can't instantiate instance", e);
      } catch (IllegalAccessException e) {
        throw new RuntimeException("Illegal access", e);
      }
    }
  
    @Override
    public Map<String, Class<? extends Command>> getCommandTypes() {
      return commandTypes;
    }
  }