/*
 * Copyright 2005 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.wamblee.usermgt.hibernate;

import org.hibernate.SessionFactory;

import org.springframework.orm.hibernate3.HibernateTemplate;

import org.wamblee.cache.Cache;

import org.wamblee.persistence.hibernate.HibernateSupport;

import org.wamblee.security.encryption.MessageDigester;

import org.wamblee.usermgt.AbstractUserSet;
import org.wamblee.usermgt.Group;
import org.wamblee.usermgt.NameValidator;
import org.wamblee.usermgt.User;

import java.util.List;
import java.util.Set;
import java.util.TreeSet;

/**
 * User set backed by the database.
 * 
 * @author Erik Brakkee
 */
public class HibernateUserSet extends AbstractUserSet {
    private static final String QUERY_FIND_BY_NAME = "findUserByName";

    private static final String QUERY_FIND_BY_GROUP_NAME = "findUserByGroupName";

    private static final String PARAM_NAME = "name";

    private static final String QUERY_COUNT_USERS = "countUsers";

    /**
     * Cache of users. Every user in the cache has its password validator and
     * encoder set.
     */
    private Cache<String, User> cache;

    /**
     * Spring hibernate support.
     */
    private HibernateSupport hibernateSupport;

    /**
     * Constructs a user set backed by the database.
     * 
     * @param aCache
     *            User cache to use.
     */
    public HibernateUserSet(Cache<String, User> aCache,
        NameValidator aPasswordValidator, MessageDigester aPasswordEncoder) {
        super(aPasswordValidator, aPasswordEncoder);
        cache = aCache;
        hibernateSupport = new HibernateSupport();
    }

    /**
     * Sets the session factory.
     * 
     * @param aFactory
     *            Session factory.
     */
    public void setSessionFactory(SessionFactory aFactory) {
        hibernateSupport.setSessionFactory(aFactory);
    }

    /**
     * Gets the hibernate template.
     * 
     * @return Hibernate template.
     */
    private HibernateTemplate getHibernateTemplate() {
        return hibernateSupport.getHibernateTemplate();
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.wamblee.usermgt.UserSet#userModified(org.wamblee.usermgt.User)
     */
    public void userModified(User aUser) {
        assert aUser.getPrimaryKey() != null;
        hibernateSupport.merge(aUser);
        cache.remove(aUser.getName());
        setPasswordInfo(aUser);
        cache.put(aUser.getName(), new User(aUser));
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.wamblee.usermgt.UserSet#find(java.lang.String)
     */
    public User find(String aName) {
        User user = cache.get(aName);

        if (user != null) {
            return user;
        }

        List result = getHibernateTemplate().findByNamedQueryAndNamedParam(
            QUERY_FIND_BY_NAME, PARAM_NAME, aName);

        if (result.size() > 1) {
            throw new RuntimeException(
                "Implementation problem, more than one user with the same name!");
        }

        if (result.size() == 0) {
            return null;
        }

        user = (User) result.get(0);
        setPasswordInfo(user);
        cache.put(aName, user);

        return new User(user);
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.wamblee.usermgt.UserSet#contains(org.wamblee.usermgt.User)
     */
    public boolean contains(User aUser) {
        return find(aUser.getName()) != null;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.wamblee.usermgt.UserSet#add(org.wamblee.usermgt.User)
     */
    public boolean add(User aUser) {
        assert aUser.getPrimaryKey() == null;

        if (contains(aUser)) {
            return false;
        }

        getHibernateTemplate().saveOrUpdate(aUser);
        setPasswordInfo(aUser);
        cache.put(aUser.getName(), aUser);

        return true;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.wamblee.usermgt.UserSet#remove(org.wamblee.usermgt.User)
     */
    public boolean remove(User aUser) {
        assert aUser.getPrimaryKey() != null;

        if (!contains(aUser)) {
            return false;
        }

        User user = (User) getHibernateTemplate().merge(aUser);
        getHibernateTemplate().delete(user);
        aUser.setPersistedVersion(-1);
        aUser.setPrimaryKey(null);
        cache.remove(aUser.getName());

        return true;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.wamblee.usermgt.UserSet#list()
     */
    public Set<User> list() {
        Set<User> users = new TreeSet<User>();
        List<User> list = getHibernateTemplate().loadAll(User.class);

        for (User user : list) {
            setPasswordInfo(user);
            users.add(new User(user));
        }

        return users;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.wamblee.usermgt.UserSet#list(org.wamblee.usermgt.Group)
     */
    public Set<User> list(Group aGroup) {
        Set<User> users = new TreeSet<User>();
        List<User> list = getHibernateTemplate().findByNamedQueryAndNamedParam(
            QUERY_FIND_BY_GROUP_NAME, PARAM_NAME, aGroup.getName());

        for (User user : list) {
            setPasswordInfo(user);
            users.add(new User(user));
        }

        return users;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.wamblee.usermgt.UserSet#size()
     */
    public int size() {
        Long result = (Long) getHibernateTemplate().findByNamedQuery(
            QUERY_COUNT_USERS).get(0);

        return result.intValue();
    }
}