package com.planet_ink.coffee_mud.core.interfaces;
import java.util.Enumeration;
import java.util.Set;
import com.planet_ink.coffee_mud.core.collections.Pair;
/**
* The Followable interface defines methods to both the follower, and
* the thing being followed, since it is assumed that following is a
* transitive property.
*
* @author Bo Zimmerman
*
* @param <T> an extension of Followable, showing that Followables follow/are followed by Followables
*/
public interface Followable<T extends Followable<T>> extends Physical
{
/**
* Adds/Alters a follower to this Followable, of the appropriate type, while
* also setting the order/rank they hold in the line. Orders don't have
* to be unique.
* This does NOT call setFollowing on the follower, so that would also need
* to be done, and, in fact, can be done instead if you like.
* @see Followable#setFollowing(Followable)
* @param follower the new follower to follow
* @param order the relative position of the new follower in the formation
*/
public void addFollower(T follower, int order);
/**
* Removes the given follower from this followable.
* @param follower the follower to remove
*/
public void delFollower(T follower);
/**
* Returns the total number of Direct followers
* @see Followable#totalFollowers()
* @return the total number of Direct followers
*/
public int numFollowers();
/**
* Returns the relative order/rank of the specific follower
* in the formation.
* @param thisOne the specific followable
* @return the relative order/rank of the specific follower
*/
public int fetchFollowerOrder(T thisOne);
/**
* Returns whether the given followable is following this
* followable.
* @param thisOne the followable follower to look for.
* @return true if thisOne is following, false otherwise
*/
public boolean isFollowedBy(T thisOne);
/**
* Returns an enumeration of the followers of this Followable,
* along with their relative rank/position in the formation.
* @return an enumeration of the followers of this Followable
*/
public Enumeration<Pair<T,Short>> followers();
/**
* Returns the followable follower at the give index in this collection
* @param index the index (0-based) of the followable follower
* @return the followable follower at the give index in this collection
*/
public T fetchFollower(int index);
/**
* Returns the followable follower that best matches the given search
* string name.
* @param named the search string name
* @return the followable follower that best matches
*/
public T fetchFollower(String named);
/**
* Returns the total number of followable followers following this followable
* by counting not only the followable followers of this followable, but also
* the followable followers of the followable followers of this followable,
* recursively.
* @see Followable#numFollowers()
* @return the total number of followers
*/
public int totalFollowers();
/**
* Returns the followable that this followable follower is following, or null.
* @return the followable that this followable follower is following, or null.
*/
public T amFollowing();
/**
* If this followable follower is following a followable that is also following
* a followable, then this will recursively determine the First followable and
* return it.
* @return the first followable
*/
public T amUltimatelyFollowing();
/**
* Alters who this followable follower is following. This also calls addFollower
* above.
* @see Followable#addFollower(Followable, int)
* @param mob the follower following
*/
public void setFollowing(T mob);
/**
* Fills the given set with the Complete set of all followable followers by
* counting not only this followable, but all the recursive followable
* followers of this followable, and all the followables followed by this
* followable and all their followable followers.
* @param list requires list to populate with followables
* @return the same list, filled
*/
public Set<T> getGroupMembers(Set<T> list);
}
