/*
 * 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.navigation;

import com.arsdigita.bebop.PageState;
import com.arsdigita.categorization.Category;


import com.arsdigita.kernel.ACSObject;
import com.arsdigita.kernel.Kernel;
import com.arsdigita.kernel.Party;

import com.arsdigita.kernel.permissions.PermissionService;
import com.arsdigita.kernel.permissions.PrivilegeDescriptor;

import com.arsdigita.persistence.DataCollection;
import com.arsdigita.persistence.Filter;
import com.arsdigita.persistence.SessionManager;

import com.arsdigita.persistence.metadata.ObjectType;
import com.arsdigita.persistence.metadata.Property;

import com.arsdigita.util.Assert;
import com.arsdigita.util.LockableImpl;

import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;

import org.apache.log4j.Logger;

/**
 * A class for building up a definition of parameters to
 * later use for a DataCollection of ACSObjects.
 */
public class DataCollectionDefinition extends LockableImpl {

    private static Logger s_log = Logger.getLogger(
            DataCollectionDefinition.class);
    private String m_objectType = ACSObject.BASE_DATA_OBJECT_TYPE;
    private String m_specificObjectType = null;
    private boolean m_filterCategory = true;
    private boolean m_descendCategories = false;
    private boolean m_excludeIndexObjects = true;
    private boolean m_checkPermissions = false;
    private boolean m_blackListTypes = false;
    private ArrayList m_ordering = new ArrayList();
    private ArrayList m_excludedTypes = new ArrayList();
    private ArrayList m_properties = new ArrayList();
    private String m_dateAttribute = null;

    public final void setObjectType(String objectType) {
        Assert.isUnlocked(this);
        m_objectType = objectType;
        validateObjectType(objectType);
    }

    public final void setSpecificObjectType(String specificObjectType) {
        Assert.isUnlocked(this);

        if (specificObjectType != null) {
            validateObjectType(specificObjectType);
        }
        m_specificObjectType = specificObjectType;
    }

    public final void excludeSpecificObjectType(String specificObjectType) {
        Assert.isUnlocked(this);

        m_excludedTypes.add(specificObjectType);
    }

    public void setDateAttribute(DataCollectionRenderer renderer) {

        // Stop here, if the set object type is invalid a.k.a. not installed
        if(this.hasInvalidObjectType()) {
            return;
        }

        ObjectType type = SessionManager.getMetadataRoot().getObjectType(
                m_objectType);
        s_log.debug("set date attribute for collection of " + type.
                getQualifiedName());
        if (s_log.isDebugEnabled()) {
            Iterator properties = type.getProperties();
            while (properties.hasNext()) {
                Property prop = (Property) properties.next();
                s_log.debug("object has property " + prop.getName()
                            + " of class " + prop.getJavaClass().getName());
            }
        }
        Iterator it = (renderer.getAttributes().iterator());
        while (it.hasNext()) {
            String attribute = (String) it.next();
            s_log.debug("renderer is rendering attribute: " + attribute);
            Property property = type.getProperty(attribute);
            s_log.debug("property of object: " + property);
            if (property != null) {
                s_log.debug("Property class is " + property.getJavaClass().
                        getName());
            }
            if (property != null && property.getJavaClass().getName().equals(Date.class.
                    getName())) {
                m_dateAttribute = attribute;
                // if more than one date attribute is specified for the type included in this
                // definition, then we cannot determine in the code which is to be used as the
                // basis for ordering in XSL - therefore return the first encountered date.
                // User can control which of the dates is used as basis for sorting by specifying
                // that date attribute first in the navigation jsp
                break;
            }
        }
    }

    private final void validateObjectType(String objectType) {
        ObjectType type = SessionManager.getMetadataRoot().getObjectType(
                objectType);

        // WTF: I don't need an exception if the requested objecttype doesn't exists
        // That will only ruin your website
        //Assert.exists(type, ObjectType.class);
        if(type == null) {
            m_objectType = "";
        } else {
            validateObjectType(type);
        }
    }

    public boolean hasInvalidObjectType() {
        return m_objectType.isEmpty();
    }

    protected void validateObjectType(ObjectType type) {
        // Nada
    }

    public final void setFilterCategory(boolean filterCategory) {
        Assert.isUnlocked(this);
        m_filterCategory = filterCategory;
    }

    public final boolean getDescendCategories() {
        return m_descendCategories;
    }
    
    public final void setDescendCategories(boolean descendCategories) {
        Assert.isUnlocked(this);
        m_descendCategories = descendCategories;
    }

    public final void setExcludeIndexObjects(boolean excludeIndexObjects) {
        Assert.isUnlocked(this);
        m_excludeIndexObjects = excludeIndexObjects;
    }

    public final void setCheckPermissions(boolean checkPermissions) {
        Assert.isUnlocked(this);
        m_checkPermissions = checkPermissions;
    }

    /**
     * Activates a filter for content types which are blacklisted
     * in the AtoZ module.
     */
    public void setBlackListTypes(boolean blackListTypes) {
        Assert.isUnlocked(this);
        m_blackListTypes = blackListTypes;
    }

    public final void addOrder(String order) {
        Assert.isUnlocked(this);
        if(s_log.isDebugEnabled()) {
            s_log.debug(String.format("Adding order '%s' to current list of "
                    + "order attributes: ", order));
            for(Object orderAttr : m_ordering) {
                s_log.debug(String.format("\t%s", orderAttr));
            }
        }
        m_ordering.add(order);
    }

    public final void addProperty(DataCollectionProperty property) {
        Assert.isUnlocked(this);
        m_properties.add(property);
    }

    /**
     * Get a collection of objects from the database defined by model or
     * null if the requested object type is invalid
     * 
     * @param model
     * @return data collection or null 
     */
    public final DataCollection getDataCollection(NavigationModel model) {
        Assert.isLocked(this);

        // Stop here, if the set object type is invalid a.k.a. not installed
        if(this.hasInvalidObjectType()) {
            return null;
        }

        DataCollection objects = SessionManager.getSession().retrieve(
                m_objectType);

        applyFilters(objects, model);

        Iterator properties = m_properties.iterator();
        while (properties.hasNext()) {
            DataCollectionProperty property = (DataCollectionProperty) properties.
                    next();
            property.addProperty(objects);
        }

        if (model.getCategory() != null) {
            // for date ordered categories, if pagination occurs, we need to ensure
            // that primary ordering is the date attribute included in the renderer
            // if there is one
            if (s_log.isDebugEnabled()) {
                s_log.debug("Category is " + model.getCategory().getID() + ": " + model.
                        getCategory().getName());
                s_log.debug("getting data collection. Is category date ordered? "
                            + Navigation.getConfig().isDateOrderedCategory(model.
                        getCategory(), PageState.getPageState())
                            + " date attribute has been set to "
                            + m_dateAttribute);
            }
            if (Navigation.getConfig().isDateOrderedCategory(model.getCategory(), PageState.
                    getPageState()) && m_dateAttribute != null) {
                objects.addOrder(m_dateAttribute + " desc");
            }
        }

        if (m_ordering.size() > 0) {
            Iterator orders = m_ordering.iterator();
            while (orders.hasNext()) {
                objects.addOrder((String) orders.next());
            }
        } else {
            objects.addOrder("id desc");
        }

        return objects;
    }

    /** Can be overridden to extract differently the category to inspect. */
    protected Category getCategory(NavigationModel model) {
        return model.getCategory();
    }

    protected void applyFilters(DataCollection objects,
                                NavigationModel model) {
        if (m_specificObjectType != null) {
            objects.addEqualsFilter(ACSObject.OBJECT_TYPE, m_specificObjectType);
        }

        Iterator excludedTypes = m_excludedTypes.iterator();
        while (excludedTypes.hasNext()) {
            String excludedType = excludedTypes.next().toString();
            objects.addFilter(ACSObject.OBJECT_TYPE + " != '" + excludedType
                              + "'");
        }

        if (m_blackListTypes) {
            objects.addNotInSubqueryFilter(ACSObject.OBJECT_TYPE,
                                           "com.arsdigita.navigation.blackListTypes");
        }

        Category cat = getCategory(model);
        if (m_filterCategory && cat != null) {
            if (m_descendCategories) {
                Filter children = objects.addInSubqueryFilter(
                        getCategorizedObjectPath("id"),
                        "com.arsdigita.categorization.objectIDsInSubtree");
                children.set("categoryID", cat.getID());
                
                if (m_excludeIndexObjects) {
                    Filter moreChildren =
                           objects.addNotInSubqueryFilter(
                            getCategorizedObjectPath("id"),
                            "com.arsdigita.categorization.liveIndexItemsInSubtree");
                    moreChildren.set("categoryID", cat.getID());
                }
            } else {
                objects.addEqualsFilter(
                        getCategorizedObjectPath("categories.id"),
                        cat.getID());
                
                if (m_excludeIndexObjects) {
                    Filter moreChildren =
                           objects.addNotInSubqueryFilter(
                            getCategorizedObjectPath("id"),
                            "com.arsdigita.categorization.liveIndexItemsInCategory");
                    moreChildren.set("categoryID", cat.getID());
                }
            }
        }

        if (m_checkPermissions) {
            // allow subclasses to override the permission check
            checkPermissions(objects);
        }
    }

    protected void checkPermissions(DataCollection objects) {
        Party party = Kernel.getContext().getParty();
        if (party == null) {
            party = Kernel.getPublicUser();
        }

        PermissionService.filterObjects(
                objects,
                PrivilegeDescriptor.READ,
                party.getOID());
    }

    protected String getCategorizedObjectPath(String fragment) {
        return fragment;
    }
}