/**
 * Represents an abstract Person, independent of gender.
 * @dependency ITask accepts
 */
abstract class APerson {
    /**
     * Executes the appropriate case of the ITask visitor, returning the result.
     * @param task The visitor to execute.
     * @param param An arbitrary parameter that might be used by the visitor.
     * @return The return result of the appropriate case of the visitor.
     */
    public abstract Object execute(ITask task, Object param);
}



/**
 * Represents a female person.
 */
class Female extends APerson {
    /**
     * Executes the femaleCase of the ITask visitor, handing itself as the host.   
     * @param task The visitor to execute
     * @param param An arbitrary parameter passed unchanged to the femaleCase of the visitor.
     * @return The return value of the female case of  the visitor.
     */
    public Object execute(ITask task, Object param) {
        return task.femaleCase(this, param);
    }
}


/**
 * Represents a male person.  
 */
class Male extends APerson {
    /**
     * Executes the maleCase of the ITask visitor, handing itself as the host.
     * @param task The visitor to execute
     * @param param An arbitrary parameter passed unchanged to the maleCase of the visitor.
     * @return The return value of the male case of the visitor.
     */
    public Object execute(ITask task, Object param) {

        return task.maleCase(this, param);
    }
}


/**
 * Represents an abstract task for an abstract person to perform.
 * @dependency APerson uses
 */
interface ITask {
    /**
     * The task for a female person.
     * @param femaleHost The female person who is executing the task.
     * @param param An arbitrary parameter for the task.
     * @return The return value of the task.
     */
    public Object femaleCase(Female femaleHost, Object param);

    /**
     * The task for a male person.
     * @param maleHost The male person who is executing the task.
     * @param param An arbitrary parameter for the task.
     * @return The return value of the task.
     */
    public Object maleCase(Male maleHost, Object param);
}


/**
 * The task of eating.
 * 
 */
class EatTask implements ITask {
    /**
     * The eating task for a female person.
     * @param femaleHost The female person executing this task.
     * @param food Not used
     * @return Always returns "No thanks, may I have a salad with dressing on the side, please?"  
     */
    public Object femaleCase(Female femaleHost, Object food) {

        return "No thanks, may I have a salad with dressing on the side, please?";

    }

    /**
     * The eating task for a male person.
     * @param femaleHost The male person executing this task.
     * @param food The food being eaten as a String.
     * @return Always returns 
"You got a beer to go with that "+[food input value]
     */
    public Object maleCase(Male maleHost, Object food) {

        return "You got a beer to go with that " + food + "?";
    }
}


/**
 * The task of person getting dressed. 
 */
class GetDressedTask implements ITask {
    /**
     * The getting dressed task for a female person.
     * @param femaleHost The female person executing this task.
     * @param param not used
     * @return Always returns "I'll be ready in a minute!"
     */
    public Object femaleCase(Female femaleHost, Object param) {
        return "I'll be ready in a minute!";
    }

    /**
     * The getting dressed task for a male person.
     * @param femaleHost The male person executing this task.
     * @param param not used..
     * @return Always returns "Does "black tie" mean I can't wear shorts?"
     */
    public Object maleCase(Male maleHost, Object param) {

        return "Does \"black tie\" mean I can't wear shorts?";
    }
}


/**
 * The weekend tasks of a person.
 */
class WeekendTask implements ITask {
    /**
     * The weekend tasks for a female person.
     * @param femaleHost The female person executing this task.
     * @param time The number of hours to complete the task as a String
     * @return Always returns "Only have "+[time value]+" hours, so let's clean the house, wash the clothes and weed the garden!"
     */
    public Object femaleCase(Female femaleHost, Object time) {

        return "Only have "+time+" hours, so let's clean the house, wash the clothes and weed the garden!";
    }


    /**
     * The weekend tasks for a male person.
     * @param maleHost The male person executing this task.
     * @param time Not used.
     * @return Always returns "Where's the remote?"
     */
    public Object maleCase(Male maleHost, Object time) {

        return "Where's the remote?";
    }
}

/**
 * This class holds a Male and Female person instance and randomly assigns them to process the incoming ITask.
 * This class is used to demonstrate that the visitor (ITask) doesn't care what host (APerson) is executing it--the visitor will always return the correct result for that host.
 *
 */
class Tasker {
  APerson f = new Female();
  APerson m = new Male();
  
  /**
     * Runs the given task on a randomly chosen person.   The type of the selected host is printed to System.out.
     * @param t The task to perform.
     * @param p Passed on to the visitor unaltered.
     * @return The return value of the visitor.
     */
    Object doTask(ITask t, Object p) {
      if(Math.random() > 0.5) {
        System.out.println("Female host selected:");
        return f.execute(t, p);
      }
      else {
        System.out.println("Male host selected:");
        return m.execute(t, p);
      }
  }
}