/*
 *  Copyright 2013 Anyware Services
 *
 *  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.ametys.core.ui;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.configuration.DefaultConfiguration;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.LoggerFactory;

import org.ametys.runtime.i18n.I18nizableText;
import org.ametys.runtime.plugin.component.ThreadSafeComponentManager;

/**
 * This element creates a control button with a menu
 */
public class SimpleMenu extends StaticClientSideElement implements MenuClientSideElement
{
    /** The client side element component manager for menu items. */
    protected ThreadSafeComponentManager<ClientSideElement> _menuItemManager;
    /** The ribbon control manager */
    protected RibbonControlsManager _ribbonControlManager;
    /** The service manager */
    protected ServiceManager _smanager;
    
    /** The menu items */
    protected List<ClientSideElement> _menuItems;
    /** The gallery items */
    protected List<GalleryItem> _galleryItems;
    /** The primary menu item */
    protected ClientSideElement _primaryMenuItem;
    /** The unresolved menu items */
    protected List<UnresolvedItem> _unresolvedMenuItems;
    
    /** The client side element component manager for gallery items. */
    private ThreadSafeComponentManager<ClientSideElement> _galleryItemManager;
    
    @Override
    public void service(ServiceManager smanager) throws ServiceException
    {
        super.service(smanager);
        _smanager = smanager;
        _ribbonControlManager = (RibbonControlsManager) smanager.lookup(RibbonControlsManager.ROLE);
    }
    
    @Override
    public void configure(Configuration configuration) throws ConfigurationException
    {
        _menuItemManager = new ThreadSafeComponentManager<>();
        _menuItemManager.setLogger(LoggerFactory.getLogger("cms.plugin.threadsafecomponent"));
        _menuItemManager.service(_smanager);
        
        _initializeGalleryItemManager();
        
        super.configure(configuration);
        
        _galleryItems = new ArrayList<>();
        
        _menuItems = new ArrayList<>();
        _unresolvedMenuItems = new ArrayList<>();
        
        _configureGalleries (configuration);
        _configureItemsMenu(configuration);
    }
    
    @Override
    protected String _configureClass(Configuration configuration) throws ConfigurationException
    {
        String jsClassName = configuration.getAttribute("name", "");
        if (StringUtils.isNotEmpty(jsClassName))
        {
            if (getLogger().isDebugEnabled())
            {
                getLogger().debug("Js class configured is '" + jsClassName + "'");
            }
        }
        return jsClassName;   
    }
    
    /**
     * Initialize the gallery item manager
     */
    protected void _initializeGalleryItemManager()
    {
        if (_galleryItemManager != null)
        {
            _galleryItemManager.dispose();
        }
        
        _galleryItemManager = new ThreadSafeComponentManager<>();
        _galleryItemManager.setLogger(LoggerFactory.getLogger("cms.plugin.threadsafecomponent"));
        _galleryItemManager.service(_smanager);
    }
    
    
    /**
     * Get the gallery item manager
     * @return the gallery item manager
     */
    protected ThreadSafeComponentManager<ClientSideElement> _getGalleryItemManager()
    {
        return _galleryItemManager;
    }

    /**
     * Get the gallery items
     * @return the gallery items
     */
    protected List<GalleryItem> _getGalleryItems()
    {
        return _galleryItems;
    }

    @Override
    public List<Script> getScripts(boolean ignoreRights, Map<String, Object> contextParameters)
    {
        try
        {
            // ensure all menu items have been resolved
            _resolveMenuItems();
            
            // ensure all gallery items have been resolved
            _resolveGalleryItems();
        }
        catch (Exception e)
        {
            throw new IllegalStateException("Unable to lookup client side element local components", e);
        }
        
        // FIXME handle rights for workspace admin, here is a temporary workaround
        if (ignoreRights || hasRight(getRights(contextParameters)))
        {
            List<Script> scripts = super.getScripts(ignoreRights, contextParameters);
            Map<String, Object> parameters = new HashMap<>();
            List<ScriptFile> cssFiles = new ArrayList<>();
            List<ScriptFile> scriptFiles = new ArrayList<>();
            for (Script script : scripts)
            {
                cssFiles.addAll(script.getCSSFiles());
                scriptFiles.addAll(script.getScriptFiles());
                parameters.putAll(script.getParameters());
            }
            
            String scriptClassName = _script.getScriptClassname();
            
            if (_primaryMenuItem != null)
            {
                List<Script> itemScripts = _primaryMenuItem.getScripts(ignoreRights, contextParameters);
                for (Script script : itemScripts)
                {
                    Map<String, Object> primaryParameters = script.getParameters();
                    parameters.put("primary-menu-item-id", script.getId());
                    for (String paramId : primaryParameters.keySet())
                    {
                        if (!parameters.containsKey(paramId))
                        {
                            parameters.put(paramId, primaryParameters.get(paramId));
                        }
                    }
                    
                    if (StringUtils.isEmpty(scriptClassName))
                    {
                        scriptClassName = script.getScriptClassname();
                    }
                }
            }
            
            if (StringUtils.isNotBlank(scriptClassName))
            {
                // Gallery items
                _getGalleryItems(parameters, contextParameters);
    
                // Menu items
                _getMenuItems(parameters, contextParameters);
                
                List<Script> result = new ArrayList<>();
                result.add(new Script(this.getId(), scriptClassName, scriptFiles, cssFiles, parameters));
                return result;
            }
        }
        
        return new ArrayList<>();
    }
    
    @Override
    public Map<String, String> getRights(Map<String, Object> contextParameters)
    {
        Map<String, String> rights = super.getRights(contextParameters);
        
        if (rights.size() == 0 && _primaryMenuItem != null)
        {
            return _primaryMenuItem.getRights(contextParameters);
        }
        
        return rights;
    }
    
    /**
     * Get the gallery items
     * @param parameters Contextual the parameters given to the control script class.
     * @param contextualParameters Contextual parameters transmitted by the environment.
     */
    @SuppressWarnings("unchecked")
    protected void _getGalleryItems (Map<String, Object> parameters, Map<String, Object> contextualParameters)
    {
        List<GalleryItem> galleryItems = _getGalleryItems();
        
        if (galleryItems.size() > 0)
        {
            parameters.put("gallery-item", new LinkedHashMap<String, Object>());
            
            for (GalleryItem galleryItem : galleryItems)
            {
                Map<String, Object> galleryItemsParams = (Map<String, Object>) parameters.get("gallery-item");
                galleryItemsParams.put("gallery-groups", new ArrayList<>());
                
                for (GalleryGroup galleryGp : galleryItem.getGroups())
                {
                    List<Object> galleryGroups = (List<Object>) galleryItemsParams.get("gallery-groups");
                    
                    Map<String, Object> groupParams = new LinkedHashMap<>();
                    
                    I18nizableText label = galleryGp.getLabel();
                    groupParams.put("label", label);
                    
                    // Group items
                    List<String> gpItems = new ArrayList<>();
                    for (ClientSideElement element : galleryGp.getItems())
                    {
                        gpItems.add(element.getId());
                    }
                    groupParams.put("items", gpItems);
                    
                    galleryGroups.add(groupParams);
                }
            }
        }
    }
    
    /**
     * Get the menu items
     * @param parameters Contextual the parameters given to the control script class.
     * @param contextualParameters Contextual parameters transmitted by the environment.
     */
    protected void _getMenuItems (Map<String, Object> parameters, Map<String, Object> contextualParameters)
    {
        if (_menuItems.size() > 0)
        {
            List<String> menuItems = new ArrayList<>();
            for (ClientSideElement element : _menuItems)
            {
                menuItems.add(element.getId());
            }
            parameters.put("menu-items", menuItems);
        }
    }
    
    @Override
    public List<ClientSideElement> getReferencedClientSideElements(Map<String, Object> contextParameters)
    {
        List<ClientSideElement> result = new ArrayList<>();
        
        if (hasRight(getRights(contextParameters)))
        {
            result.addAll(_menuItems);
            
            _getGalleryItems().stream()
                              .map(GalleryItem::getGroups)
                              .flatMap(List::stream)
                              .map(GalleryGroup::getItems)
                              .forEach(result::addAll);
        }
        
        return result;
    }
    
    /**
     * Configure the galleries
     * @param configuration the configuration
     * @throws ConfigurationException If the configuration has an issue
     */
    protected void _configureGalleries(Configuration configuration) throws ConfigurationException
    {
        for (Configuration galleryConfiguration : configuration.getChildren("gallery-item"))
        {
            GalleryItem galleryItem = new GalleryItem();
            
            for (Configuration gpConfiguration : galleryConfiguration.getChildren("gallery-group"))
            {
                galleryItem.addGroup(_configureGroupGallery(gpConfiguration));
            }
            
            _galleryItems.add(galleryItem);
        }
        
        // FIXME
        if (_galleryItems.size() > 0)
        {
            try
            {
                _getGalleryItemManager().initialize();
            }
            catch (Exception e)
            {
                throw new ConfigurationException("Unable to lookup parameter local components", configuration, e);
            }
        }
    }
    
    /**
     * Configure a group gallery
     * @param configuration the configuration
     * @return The configured group gallery
     * @throws ConfigurationException If the configuration has an issue
     */
    protected GalleryGroup _configureGroupGallery(Configuration configuration) throws ConfigurationException
    {
        I18nizableText label;
        
        Configuration labelConfig = configuration.getChild("label");
        if (labelConfig.getAttributeAsBoolean("i18n", false))
        {
            label = new I18nizableText("plugin." + _pluginName, labelConfig.getValue(""));
        }
        else
        {
            label = new I18nizableText(labelConfig.getValue(""));
        }
        
        GalleryGroup galleryGroup = new GalleryGroup(label);
        
        for (Configuration itemConfig : configuration.getChildren("item"))
        {
            if (itemConfig.getAttribute("ref", null) != null)
            {
                galleryGroup.addItem(new UnresolvedItem(itemConfig.getAttribute("ref"), false));
            }
            else
            {
                String id = itemConfig.getAttribute("id");
                DefaultConfiguration conf = new DefaultConfiguration("extension");
                conf.setAttribute("id", id);
                conf.addChild(itemConfig.getChild("class"));
                
                Map<String, List<String>> childDependencies = _configureDependencies(itemConfig);
                _addDependencies(childDependencies);
                
                if (itemConfig.getChild("right", false) != null)
                {
                    conf.addChild(itemConfig.getChild("right"));
                }
                if (itemConfig.getChild("rights", false) != null)
                {
                    conf.addChild(itemConfig.getChild("rights"));
                }
                
                _getGalleryItemManager().addComponent(_pluginName, null, id, StaticClientSideElement.class, conf);
                
                galleryGroup.addItem(new UnresolvedItem(id, true));
            }
        }
        
        return galleryGroup;
    }
    
    
    /**
     * Configure the items menu
     * @param configuration the configuration
     * @throws ConfigurationException If the configuration has an issue
     */
    protected void _configureItemsMenu(Configuration configuration) throws ConfigurationException
    {
        for (Configuration menuItemConfiguration : configuration.getChildren("menu-items"))
        {
            for (Configuration itemConfig : menuItemConfiguration.getChildren("item"))
            {
                boolean isPrimary = itemConfig.getAttributeAsBoolean("primaryItem", false);
                
                if (itemConfig.getAttribute("ref", null) != null)
                {
                    _unresolvedMenuItems.add(new UnresolvedItem(itemConfig.getAttribute("ref"), false, isPrimary));
                }
                else
                {
                    String id = itemConfig.getAttribute("id");
                    DefaultConfiguration conf = new DefaultConfiguration("extension");
                    conf.setAttribute("id", id);
                    conf.addChild(itemConfig.getChild("class"));
                    
                    Map<String, List<String>> childDependencies = _configureDependencies(itemConfig);
                    _addDependencies(childDependencies);
                    
                    if (itemConfig.getChild("menu-items", false) != null || itemConfig.getChild("gallery-item", false) != null)
                    {
                        if (itemConfig.getChild("menu-items", false) != null)
                        {
                            conf.addChild(itemConfig.getChild("menu-items"));
                        }
                        
                        if (itemConfig.getChild("gallery-item", false) != null)
                        {
                            conf.addChild(itemConfig.getChild("gallery-item"));
                        }
                        
                        _menuItemManager.addComponent(_pluginName, null, id, SimpleMenu.class, conf);
                    }
                    else
                    {
                        _menuItemManager.addComponent(_pluginName, null, id, StaticClientSideElement.class, conf);
                    }
                    
                    _unresolvedMenuItems.add(new UnresolvedItem(id, true, isPrimary));
                }
            }
        }        
    }
    
    private void _resolveMenuItems () throws Exception
    {
        if (_unresolvedMenuItems != null)
        {
            _menuItemManager.initialize();
            
            for (UnresolvedItem unresolvedItem : _unresolvedMenuItems)
            {
                String id = unresolvedItem.getId();
                ClientSideElement element;
                if (unresolvedItem.isLocalItem())
                {
                    try
                    {
                        element = _menuItemManager.lookup(id);
                    }
                    catch (ComponentException e)
                    {
                        throw new Exception("Unable to lookup client side element role: '" + id + "'", e);
                    }
                }
                else
                {
                    element = _ribbonControlManager.getExtension(id);
                }
                
                if (unresolvedItem.isPrimary())
                {
                    _primaryMenuItem = element;
                }
                
                _menuItems.add(element);
                
                _addDependencies(element.getDependencies());
            }
        }
        
        _unresolvedMenuItems = null;
    }
    
    private void _resolveGalleryItems()
    {
        for (GalleryItem item : _getGalleryItems())
        {
            for (GalleryGroup group : item.getGroups())
            {
                group.getItems();
            }
        }
    }
    
    /**
     * Add additional dependencies to the Menu, such as dependencies inherited from its menu items or gallery items.
     * @param additionalDependencies The dependencies to add
     * @throws ConfigurationException If an error occurs
     */
    protected void _addDependencies(Map<String, List<String>> additionalDependencies) throws ConfigurationException
    {
        if (!additionalDependencies.isEmpty())
        {
            for (Entry<String, List<String>> additionalDependency : additionalDependencies.entrySet())
            {
                String key = additionalDependency.getKey();
                if (!_dependencies.containsKey(key))
                {
                    _dependencies.put(key, new ArrayList<String>());
                }
                List<String> dependenciesList = _dependencies.get(key);
                
                for (String dependency : additionalDependency.getValue())
                {
                    if (!dependenciesList.contains(dependency))
                    {
                        dependenciesList.add(dependency);
                    }
                }
            }
        }
    }
    
    /**
     * Class representing a gallery item
     *
     */
    public class GalleryItem
    {
        private final List<GalleryGroup> _groups;
        
        /**
         * Constructor
         */
        public GalleryItem()
        {
            _groups = new ArrayList<>();
        }
        
        /**
         * Add a group of this gallery
         * @param group The gallery group to add
         */
        public void addGroup (GalleryGroup group)
        {
            _groups.add(group);
        }
        
        /**
         * Get gallery's groups
         * @return The gallery's group
         */
        public List<GalleryGroup> getGroups ()
        {
            return _groups;
        }
        
    }
    
    /**
     * Class representing a gallery group
     *
     */
    public class GalleryGroup
    {
        private final I18nizableText _label;
        private List<UnresolvedItem> _unresolvedGalleryItems;
        private final List<ClientSideElement> _items;
        
        /**
         * Constructor 
         * @param label The group's label
         */
        public GalleryGroup(I18nizableText label)
        {
            _label = label;
            _items = new ArrayList<>();
            _unresolvedGalleryItems = new ArrayList<>();
        }
        
        /**
         * Add a new item to group
         * @param item The item to add
         */
        public void addItem (UnresolvedItem item)
        {
            _unresolvedGalleryItems.add(item);
        }
        
        /**
         * Get the group's label
         * @return The group's label
         */
        public I18nizableText getLabel ()
        {
            return _label;
        }
        
        /**
         * Get the gallery item
         * @return The gallery item
         */
        public List<ClientSideElement> getItems ()
        {
            try
            {
                _resolveGalleryItems();
            }
            catch (Exception e)
            {
                throw new IllegalStateException("Unable to lookup client side element local components", e);
            }
            
            return _items;
        }
        
        private void _resolveGalleryItems () throws Exception
        {
            if (_unresolvedGalleryItems != null)
            {
                for (UnresolvedItem unresolvedItem : _unresolvedGalleryItems)
                {
                    ClientSideElement element;
                    String id = unresolvedItem.getId();
                    if (unresolvedItem.isLocalItem())
                    {
                        try
                        {
                            element = _getGalleryItemManager().lookup(id);
                        }
                        catch (ComponentException e)
                        {
                            throw new Exception("Unable to lookup client side element role: '" + id + "'", e);
                        }
                    }
                    else
                    {
                        element = _ribbonControlManager.getExtension(id);
                    }
                    
                    _items.add(element);
                }
            }
            
            _unresolvedGalleryItems = null;
        }
    }
    
    /**
     * The unresolved item
     *
     */
    protected class UnresolvedItem
    {
        private final String _itemId;
        private final boolean _local;
        private final boolean _primary;
        
        /**
         * Constructor
         * @param id The item id
         * @param local true if it is a local item
         */
        public UnresolvedItem(String id, boolean local)
        {
            _itemId = id;
            _local = local;
            _primary = false;
        }
        
        /**
         * Constructor
         * @param id The item id
         * @param local true if it is a local item
         * @param primary true if it is a primary item
         */
        public UnresolvedItem(String id, boolean local, boolean primary)
        {
            _itemId = id;
            _local = local;
            _primary = primary;
        }
        
        /**
         * Get the item id
         * @return the item id
         */
        public String getId ()
        {
            return _itemId;
        }
        
        /**
         * Return true if it is a local item
         * @return true if it is a local item
         */
        public boolean isLocalItem ()
        {
            return _local;
        }
        
        /**
         * Return true if it is a primary item
         * @return true if it is a primary item
         */
        public boolean isPrimary ()
        {
            return _primary;
        }
    }
}