/*
 * Copyright (C) 2001-2004 Red Hat Inc. All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */
package com.arsdigita.cms;

import com.arsdigita.cms.lifecycle.Lifecycle;
import com.arsdigita.cms.lifecycle.LifecycleService;
import com.arsdigita.domain.DomainObject;
import com.arsdigita.kernel.ACSObject;
import com.arsdigita.persistence.metadata.Property;
import com.arsdigita.persistence.OID;
import com.arsdigita.util.Assert;
import org.apache.log4j.Logger;

import java.util.HashSet;

/**
 * Extends
 * <code>ObjectCopier</code> to create a live version for an item. Clones the
 * item, making sure that live versions of all subitems point only to other live
 * versions.
 *
 * @author <a href="mailto:sfreidin@arsdigita.com">Stanislav Freidin</a>
 * @version $Id: VersionCopier.java 2140 2011-01-16 12:04:20Z pboy $
 */
class VersionCopier extends ObjectCopier {

    private static Logger s_log = Logger.getLogger(VersionCopier.class);
    private final Lifecycle m_lifecycle;
    private boolean m_once = false;
    private long m_start = 0;
    private final HashSet m_traversedComponents;
    private OID m_topLevelSourceOID = null;

    /**
     * Creates a new
     * <code>VersionCopier</code> with a given Lifecycle
     *
     * @param lifecycle The Lifecycle
     */
    VersionCopier(final Lifecycle lifecycle) {
        m_traversedComponents = new HashSet();
        m_lifecycle = lifecycle;
    }

    /**
     * Creates a new
     * <code>VersionCopier</code> with no Lifecycle
     */
    VersionCopier() {
        m_traversedComponents = new HashSet();
        m_lifecycle = null;
    }

    /**
     * Copy a {@link ContentItem}, along with all of its component sub-objects,
     * and return the copy. Note that the categories to which the source item
     * belongs are not automatically transferred to the copy; the user must call {@link #copyServices(ContentItem,
     * ContentItem)} in order to transfer the categories and other services.
     *
     * @param item the item to be copied
     * @return a copy of the item
     */
    @Override
    public ContentItem copyItem(final ContentItem item) {
        m_trace.enter("copyItem", item);

        if (s_log.isInfoEnabled()) {
            s_log.info("Publishing " + item);
            m_start = System.currentTimeMillis();
        }

        if (Assert.isEnabled()) {
            //Assert.isFalse(item instanceof ContentBundle);
            //Assert.isFalse(item instanceof Folder);
            Assert.isFalse(m_once);
            m_once = true;
        }

        m_topLevelSourceOID = item.getOID();
        final ContentItem version = createVersion(item);
        //Assert.isTrue(m_topLevelSourceOID == null,
        //	     "CopyItem should be called only once for a given copier instance");

        if (m_lifecycle != null) {
            LifecycleService.setLifecycle(version, m_lifecycle);
        }

        m_trace.exit("copyItem", version);

        if (Assert.isEnabled()) {
            // Reset the reentrance detection.
            m_once = false;
        }

        if (s_log.isInfoEnabled()) {
            s_log.info("Done publishing " + item + " (" + (System.
                                                           currentTimeMillis()
                                                           - m_start)
                       + " millis)");
        }

        return version;
    }

    /**
     * This copier is used to create published copies of items
     */
    @Override
    public int getCopyType() {
        return ItemCopier.VERSION_COPY;
    }

    /**
     * Kicks off the copying process. Creates a copy by value of
     * <code>source</code> and then traverses its associations and repeats the
     * process.
     *
     * @param source the
     * <code>DomainObject</code> from which to copy
     */
    @Override
    public DomainObject copy(final DomainObject object) {
        if (object != null) {
            m_traversedComponents.add(object);
        }
        return super.copy(object);
    }

    /**
     * Copies properties. This method is called from {@link
     * #copy(DomainObject)} for each property of the object being copied.
     *
     * Copying behavior depends on the following: <dl> <dt>
     * <code>object instanceof ContentItem && prop.isComponent()</code></dt>
     * <dd> Copy ContentItem recursively, setting the version attribute,
     * etc.</dd> <dt>
     * <code>object instanceof ContentItem &&
     *       !prop.isComponent() (and target is an already-traversed
     *       component of the top-level item )</code></dt> <dd> Return reference to
     * already-created copy of this item</dd> <dt>
     * <code>object instanceof ContentItem &&
     *       !prop.isComponent() && prop.isRequired (and target is not an already-traversed
     *       component of the top-level item )</code></dt> <dd> Assert failure:
     * required top-level item associations are not allowed here.</dd> <dt>
     * <code>object instanceof ContentItem &&
     *       !prop.isComponent() && !prop.isRequired (and target is not an already-traversed
     *       component of the top-level item )</code></dt> <dd> Create PublishedLink
     * for association; return null</dd> <dt>
     * <code>!object instanceof ContentItem </code></dt> <dd> object is not a
     * ContentItem, rely on default DomainCopier behavior</dd> </dl>
     *
     * @param source the
     * <code>DomainObject</code> being copied
     * @param target the new copy
     * @param prop the
     * <code>Property</code> currently under consideration
     */
    @Override
    protected DomainObject copy(final DomainObject source,
                                final DomainObject target,
                                final DomainObject object,
                                final Property prop) {
        m_trace.enter("copy", object, prop);

        if (s_log.isDebugEnabled()) {
            s_log.debug("Copying property " + prop + " of " + object);
        }

        Assert.exists(source, DomainObject.class);
        Assert.exists(target, DomainObject.class);
        Assert.exists(object, DomainObject.class);
        Assert.exists(prop, Property.class);

        if (object instanceof ContentItem) {
            s_log.debug("The property is a content item");

            final ContentItem item = (ContentItem) object;

            if (Assert.isEnabled()) {
                item.assertDraft();
            }

            if (prop.isComponent()) {
                s_log.debug("The property is a component; creating a "
                            + "live or pending version");

                final ContentItem copy = createVersion(item);

                m_trace.exit("copy", copy);

                return copy;
            } else if (m_traversedComponents.contains(object)) {
                final DomainObject copy = copy(object);

                m_trace.exit("copy", copy);

                return copy;
            } else if (prop.isRequired()) {
                Assert.fail(
                        "1..1 associations to non-component top-level ContentItems are not allowed");
                return null;
            } else {
                s_log.debug("The property is not a component; creating "
                            + "PublishedLink for the item");

                if (source instanceof ContentItem) {
                    PublishedLink.create(
                            (ContentItem) getCopy(m_topLevelSourceOID),
                            target,
                            prop.getName(),
                            item,
                            (ContentItem) source);
                } else {
                    PublishedLink.create(
                            (ContentItem) getCopy(m_topLevelSourceOID),
                            target,
                            prop.getName(),
                            item,
                            null);
                }
                m_trace.exit("copy", null);

                return null;
            }
        } else {
            s_log.debug("The property is not a content item; using "
                        + "domain object copier");

            final DomainObject copy = super.copy(source, target, object, prop);

            m_trace.exit("copy", copy);

            return copy;
        }
    }

    private ContentItem createVersion(final ContentItem item) {
        m_trace.enter("createVersion", item);

        if (Assert.isEnabled()) {
            item.assertDraft();
        }

        final ContentItem version = (ContentItem) copy(item);

        s_log.debug("The copy is pending; associating it with "
                    + "the draft item");

        version.setVersion(ContentItem.PENDING);
        item.addPendingVersion(version);

        version.copyServicesFrom(item);

        m_trace.exit("createVersion", version);

        return version;
    }
}