package com.github.yin.flags;

import com.google.common.collect.*;

import java.util.Map;

/**

* Stores value objects indexed by <code>FlagID</code> in a <code>Multimap</code> fashion

* and allows for easy access by any FlagID attribute.

* @author yin

*/

public final class FlagIndex<T> {

private final Multimap<String, T> byName = HashMultimap.create();

private final Multimap<String, T> byClass = HashMultimap.create();

private final Map<String, T> byFQN = Maps.newTreeMap();

private ImmutableMultimap<String, T> _byName;

private ImmutableMultimap<String, T> _byClass;

private ImmutableMap<String, T> _byFQN;

public void add(FlagID flagID, T flag) {

String clazz = flagID.className();

String name = flagID.flagName();

String fqn = flagID.fqn();

byName.put(name, flag);

byClass.put(clazz, flag);

byFQN.put(fqn, flag);

_byName = null;

_byClass = null;

_byFQN = null;

}

public Multimap<String, T> byName() {

return _byName != null ? _byName : (_byName = ImmutableMultimap.copyOf(byName));

}

public ImmutableMultimap<String, T> byClass() {

return _byClass != null ? _byClass : (_byClass = ImmutableMultimap.copyOf(byClass));

}

public Map<String, T> byFQN() {

return _byFQN != null ? _byFQN : (_byFQN = ImmutableMap.copyOf(byFQN));

}

}