/*
 *  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.cms.contenttype;

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

import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Redirector;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.environment.SourceResolver;

import org.ametys.cms.content.GetMetadataSetDefAction;
import org.ametys.core.cocoon.JSonReader;

/**
 * Get metadata set definition as JSON object from a given content type.
 * Be careful, this action is only based on a single content type and a metadata set.
 * All metadata of the asked metadata set are returned regardless of the current content and user's rights
 */
public class GetMetadataSetDefByContentTypeAction extends GetMetadataSetDefAction
{
    @Override
    public Map act(Redirector redirector, SourceResolver resolver, Map objectModel, String source, Parameters parameters) throws Exception
    {
        Request request = ObjectModelHelper.getRequest(objectModel);

        boolean isEditionMetadataSet = parameters.getParameterAsBoolean("isEditionMetadataSet", false);
        String metadataSetName = parameters.getParameter("metadataSetName", "main");
        String contentTypeId = parameters.getParameter("contentTypeId");
        
        Map<String, Object> jsonObject = new HashMap<>();
        
        List<String> languages = getLanguages(request);
        
        ContentType contentType = _contentTypeExtensionPoint.getExtension(contentTypeId);
        jsonObject.put("contentType", contentType2Json(contentType, metadataSetName, isEditionMetadataSet, languages));
        
        request.setAttribute(JSonReader.OBJECT_TO_READ, jsonObject);
        return EMPTY_MAP;
    }

    /**
     * Convert content to JSON object
     * @param contentType The content type
     * @param metadataSetName The metadata set name
     * @param isEditionMetadataSet true if it is metadataset for edition
     * @param languages the current languages requested by the client (an ordonned list)
     * @return The JSON object representing the content
     * @throws ProcessingException if an error occurred
     */
    protected Map<String, Object> contentType2Json (ContentType contentType, String metadataSetName, boolean isEditionMetadataSet, List<String> languages) throws ProcessingException
    {
        Map<String, Object> jsonObject = new LinkedHashMap<>();
        
        jsonObject.put("id", contentType.getId());
        jsonObject.put("title", contentType.getLabel());
        jsonObject.put("defaultTitle", contentType.getDefaultTitle());
        
        MetadataSet metadataSet = null;
        
        if (isEditionMetadataSet)
        {
            metadataSet = contentType.getMetadataSetForEdition(metadataSetName);
        }
        else
        {
            metadataSet = contentType.getMetadataSetForView(metadataSetName);
        }
        
        jsonObject.put("metadataSetName", metadataSetName); 
        jsonObject.put("isEditionMetadataSet", isEditionMetadataSet); 
        
        if (metadataSet == null)
        {
            _logger.warn("Unknown metadata set '{}' of type '{}' for content type(s) '{}'",
                                          metadataSetName, isEditionMetadataSet ? "edition" : "view", contentType.getId());
        }
        else
        {
            jsonObject.put("metadataSet", metadataSetElement2JsonObject(contentType, null, metadataSet, languages));
        }
        
        
        return jsonObject;
    }
    
    /**
     * Convert {@link AbstractMetadataSetElement} to JSON object
     * @param contentType The content type
     * @param metadataDefinition The metadata definition
     * @param metadataSetElement The metadataset element
     * @param languages the current languages requested by the client (an ordonned list)
     * @return The JSON object representing the metadataset element
     * @throws ProcessingException If an error occured
     */
    protected Map<String, Object> metadataSetElement2JsonObject(ContentType contentType, MetadataDefinition metadataDefinition, AbstractMetadataSetElement metadataSetElement, List<String> languages) throws ProcessingException
    {
        Map<String, Object> jsonObject = new LinkedHashMap<>();
        
        for (AbstractMetadataSetElement subMetadataSetElement : metadataSetElement.getElements())
        {
            if (subMetadataSetElement instanceof MetadataDefinitionReference)
            {
                MetadataDefinitionReference metadataDefRef = (MetadataDefinitionReference) subMetadataSetElement;
                String metadataName = metadataDefRef.getMetadataName();
                MetadataDefinition metaDef = _getMetadataDefinition(contentType, metadataDefinition, metadataName);
                
                if (metaDef == null)
                {
                    throw new IllegalArgumentException("Unable to get the metadata definition of metadata \"" + metadataName + "\"");
                }
                
                String metadataPath = metaDef.getId();
                jsonObject.put(metaDef.getName(), metadataDefinition2JsonObject(null, metadataDefRef, metaDef, metadataPath, new HashSet<>(), languages));
            }
            else
            {
                if (!jsonObject.containsKey("fieldsets"))
                {
                    jsonObject.put("fieldsets", new ArrayList<Map<String, Object>>());
                }
                
                @SuppressWarnings("unchecked")
                List<Map<String, Object>> fieldsets = (List<Map<String, Object>>) jsonObject.get("fieldsets");
                
                Fieldset fieldset = (Fieldset) subMetadataSetElement;
                
                Map<String, Object> fieldSetObject = new LinkedHashMap<>();
                fieldSetObject.put("role", fieldset.getRole());
                fieldSetObject.put("label", fieldset.getLabel());
                fieldSetObject.put("elements", metadataSetElement2JsonObject(contentType, metadataDefinition, fieldset, languages));
                
                fieldsets.add(fieldSetObject);
            }
        }
        
        return jsonObject;
    }
    
    /**
     * Retrieves a sub metadata definition from a content type or a parent metadata definition. 
     * @param contentType the content type.
     * @param parentMetadataDefinition the parent metadata definition.
     * @param metadataName the metadata name.
     * @return the metadata definition found or <code>null</code> otherwise.
     */
    protected MetadataDefinition _getMetadataDefinition(ContentType contentType, MetadataDefinition parentMetadataDefinition, String metadataName)
    {
        MetadataDefinition metadataDefinition = null;
        
        if (parentMetadataDefinition == null)
        {
            metadataDefinition =  contentType.getMetadataDefinition(metadataName);
        }
        else
        {
            metadataDefinition = parentMetadataDefinition.getMetadataDefinition(metadataName);
        }
        
        return metadataDefinition;
    }
}