/*
 *  Copyright 2015 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.cms.search.cocoon;

import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;

import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.generation.ServiceableGenerator;
import org.apache.cocoon.xml.AttributesImpl;
import org.apache.cocoon.xml.XMLUtils;
import org.xml.sax.SAXException;

import org.ametys.cms.search.solr.CriteriaSearchUIModelWrapper.Column;
import org.ametys.cms.search.solr.SolrQuerySearchAction;
import org.ametys.cms.search.ui.model.SearchUIColumn;
import org.ametys.cms.search.ui.model.SearchUIModel;
import org.ametys.cms.search.ui.model.SearchUIModelExtensionPoint;
import org.ametys.core.util.ServerCommHelper;
import org.ametys.runtime.i18n.I18nizableText;

/**
 * SAX the columns of a search tool model.
 */
public class ModelColumnsGenerator extends ServiceableGenerator
{
    /** The extenstion point for search UI */
    protected SearchUIModelExtensionPoint _searchModelManager;
    /** The servercomm helper */
    protected ServerCommHelper _serverCommHelper;
    
    @Override
    public void service(ServiceManager smanager) throws ServiceException
    {
        super.service(smanager);
        _searchModelManager = (SearchUIModelExtensionPoint) smanager.lookup(SearchUIModelExtensionPoint.ROLE);
        _serverCommHelper = (ServerCommHelper) manager.lookup(ServerCommHelper.ROLE);
    }
    
    @Override
    public void generate() throws IOException, SAXException, ProcessingException
    {
        Map<String, Object> jsParameters = _serverCommHelper.getJsParameters();
        
        contentHandler.startDocument();
        saxColumns(jsParameters);
        contentHandler.endDocument();
    }
    
    /**
     * Get search model.
     * @param jsParameters JS parameters
     * @return the search model
     */
    protected SearchUIModel getSearchModel(Map<String, Object> jsParameters)
    {
        String modelId = (String) jsParameters.get("model");
        return _searchModelManager.getExtension(modelId);
    }
    
    /**
     * Sax search columns.
     * @param jsParameters JS parameters
     * @throws SAXException if an error occurs
     */
    protected void saxColumns(Map<String, Object> jsParameters) throws SAXException
    {
        SearchUIModel model = getSearchModel(jsParameters);
        
        @SuppressWarnings("unchecked")
        Map<String, Object> contextualParameters = (Map<String, Object>) jsParameters.get("contextualParameters");
        List<Column> columns = getColumnsFromParameters(jsParameters);

        AttributesImpl attr = new AttributesImpl();
        XMLUtils.startElement(contentHandler, "columns", attr);
        
        if (columns.isEmpty())
        {
            for (SearchUIColumn column : model.getResultFields(contextualParameters).values())
            {
                saxColumn(column, Optional.empty());
            }
        }
        else
        {
            Map<String, SearchUIColumn> searchUiColumns = new HashMap<>();
            for (SearchUIColumn column : model.getResultFields(contextualParameters).values())
            {
                searchUiColumns.put(column.getId(), column);
            }
            for (Column column : columns)
            {
                String key = column.getId();
                if (searchUiColumns.containsKey(key))
                {
                    saxColumn(searchUiColumns.get(key), column.getLabel());
                }
            }
        }
        XMLUtils.endElement(contentHandler, "columns");
    }
    
    /**
     * Sax search column.
     * @param column Column to SAX
     * @param label The label of the column. Cannot be null
     * @throws SAXException if an error occurs
     */
    protected void saxColumn(SearchUIColumn column, Optional<String> label) throws SAXException
    {
        AttributesImpl attrs = new AttributesImpl();
        attrs.addCDATAAttribute("id", column.getId());
        // TODO Restore?
//        attrs.addCDATAAttribute("mapping", column.getMapping());
        attrs.addCDATAAttribute("type", column.getType().name());
        
        XMLUtils.startElement(contentHandler, "column", attrs);
        label.map(I18nizableText::new).orElseGet(column::getLabel).toSAX(contentHandler);
        XMLUtils.endElement(contentHandler, "column");
    }

    /**
     * Get the columns from JS parameters
     * @param jsParameters The JS parameters
     * @return the requested columns
     */
    @SuppressWarnings("unchecked")
    protected List<Column> getColumnsFromParameters(Map<String, Object> jsParameters)
    {
        Map<String, Object> values = (Map<String, Object>) jsParameters.get("values");

        if (values != null && values.containsKey("columns"))
        {
            Object columnsAsObj = values.get("columns");
            if (columnsAsObj instanceof String)
            {
                return SolrQuerySearchAction.getColumns((String) columnsAsObj);
            }
            else
            {
                return SolrQuerySearchAction.getColumns((List<String>) columnsAsObj);
            }
        }
        return Collections.EMPTY_LIST;
    }
}