package com.fasterxml.jackson.annotation;

import java.util.HashMap;
import java.util.Map;

import com.fasterxml.jackson.annotation.ObjectIdGenerator.IdKey;

/**
 * Simple implementation of {@link ObjectIdResolver}
 * 
 * @author Pascal Gélinas
 */
public class SimpleObjectIdResolver implements ObjectIdResolver {
    protected Map<IdKey,Object> _items;

    public SimpleObjectIdResolver() { }

    @Override
    public void bindItem(IdKey id, Object ob)
    {
        if (_items == null) {
            _items = new HashMap<ObjectIdGenerator.IdKey,Object>();
        } else {
            Object old = _items.get(id);
            if (old != null) {
                // 11-Nov-2020, tatu: As per [annotations#180] allow duplicate calls:
                if (old == ob) {
                    return;
                }
                throw new IllegalStateException("Already had POJO for id (" + id.key.getClass().getName() + ") [" + id
                        + "]");
            }
        }
        _items.put(id, ob);
    }

    @Override
    public Object resolveId(IdKey id) {
        return (_items == null) ? null : _items.get(id);
    }

    @Override
    public boolean canUseFor(ObjectIdResolver resolverType) {
        return resolverType.getClass() == getClass();
    }

    @Override
    public ObjectIdResolver newForDeserialization(Object context) {
        // 19-Dec-2014, tatu: Important: must re-create without existing mapping; otherwise bindings leak
        //    (and worse, cause unnecessary memory retention)
        return new SimpleObjectIdResolver();
    }
}
