/**
 * Copyright (c) 2009--2012 Red Hat, Inc.
 *
 * This software is licensed to you under the GNU General Public License,
 * version 2 (GPLv2). There is NO WARRANTY for this software, express or
 * implied, including the implied warranties of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. You should have received a copy of GPLv2
 * along with this software; if not, see
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * Red Hat trademarks are not licensed under GPLv2. No permission is
 * granted to use or replicate Red Hat trademarks that are incorporated
 * in this software or its documentation.
 */
package com.redhat.rhn.domain.server.test;

import com.redhat.rhn.common.hibernate.HibernateFactory;
import com.redhat.rhn.domain.server.Server;
import com.redhat.rhn.domain.server.VirtualInstance;
import com.redhat.rhn.domain.user.User;
import com.redhat.rhn.testing.ServerTestUtils;

import org.hibernate.Session;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;



/**
 * HostBuilder is a class based on the GoF Builder pattern that constructs systems that are
 * virtual hosts. That is, systems with one of the virtualization entitlements.
 * @version $Rev$
 */
public class HostBuilder {

    private User owner;
    private Server host;

    public HostBuilder(User theOwner) {
        owner = theOwner;
    }

    /**
     * This is the final step in building or compiling a host. The host and its guests (if
     * there are any) will be persisted, flushed, and evicted from the current hibernate
     * session.
     *
     * <br/><br/>
     *
     * The builder does not maintain a reference to a host once it is built; so, calling
     * <code>build</code> successive times will simply return <code>null</code>. One of the
     * <i>create</i> methods must be called before every invocation of this method.
     *
     * @return The built host whose state will have persisted and synhronized with the
     * database. The host and its guests will have been removed from the hibernate session
     * cache.
     */
    public Server build() {
       if (host == null) {
           return null;
       }

       Server compiledHost;
       Session session = HibernateFactory.getSession();

       session.flush();
       session.evict(host);

       for (Iterator iterator = host.getGuests().iterator(); iterator.hasNext();) {
           session.evict(iterator.next());
       }

       compiledHost = host;
       host = null;

       return compiledHost;
    }

    /**
     * Creates a Server with the Virtualization Host entitlement.
     *
     * @return This builder
     *
     * @throws Exception if an error occurs
     */
    public HostBuilder createVirtHost() throws Exception {
        host = ServerTestUtils.createVirtHostWithGuests(owner, 0);
        return this;
    }

    /**
     * Creates a server without any of the virtualization entitlements. Note that a non-virt
     * host is useful in those situations in which a guest consumes physical entitlements.
     *
     * @return This builder
     *
     * @throws Exception if an error occurs
     */
    public HostBuilder createNonVirtHost() throws Exception {
        host = ServerTestUtils.createTestSystem(owner);
        return this;
    }

    /**
     * Creates the specified number of guests for the host under construction. Each guest
     * will be registered and therefore have an associated system.
     *
     * @param numberOfGuests The number of guests to create
     *
     * @return This builder
     *
     * @throws Exception if an error occurs
     */
    public HostBuilder withGuests(int numberOfGuests) throws Exception {
        createGuests(owner, numberOfGuests, true);
        return this;
    }

    /**
     * Creates the specified number of guests for the host under construction. None of the
     * guests will be registered and therefore will not have an associated system.
     *
     * @param numberOfGuests The number of guests to create
     *
     * @return This builder
     *
     * @throws Exception if an error occurs
     */
    public HostBuilder withUnregisteredGuests(int numberOfGuests) throws Exception {
        createGuests(owner, numberOfGuests, false);
        return this;
    }

    /**
     * Creates the specified number of guests for the host under construction. Each guest
     * will be registered and therefore have an associated system.
     *
     * @param guests a map of users to the number of guests to create owned by that user.
     *              This is useful when you want the guests to be in orgs different to
     *               what the host .
     *
     * @return This builder
     * @throws Exception if an error occurs
     */

    public  HostBuilder withGuests(Map<User, Integer> guests,
                                boolean register) throws Exception {
        for (User u : guests.keySet()) {
            createGuests(u, guests.get(u), register);
        }
        return this;
    }

    private  List<VirtualInstance> createGuests(User user, int numberOfGuests,
                                                boolean register) throws Exception {
        List<VirtualInstance> guests = new LinkedList<VirtualInstance>();
        for (int i = 0; i < numberOfGuests; i++) {
            VirtualInstanceManufacturer vim = new VirtualInstanceManufacturer(user);

            VirtualInstance vi = null;

            if (register) {
                vi = vim.newRegisteredGuestWithoutHost();
            }
            else {
                vi = vim.newUnregisteredGuest();
            }

            if (host != null) {
                vi.setConfirmed(1L);
                host.addGuest(vi);
            }
            else {
                vi.setConfirmed(0L);
            }
            guests.add(vi);
        }
        return guests;
    }

    public List<VirtualInstance> withOrphanedGuests(int numberOfGuests) throws Exception {
        return createGuests(owner, numberOfGuests, true);
    }

}