/*
 * Seldon -- open source prediction engine
 * =======================================
 * Copyright 2011-2015 Seldon Technologies Ltd and Rummble Ltd (http://www.seldon.io/)
 *
 **********************************************************************************************
 *
 * 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 io.seldon.importer.articles.dynamicextractors;

import org.apache.commons.lang3.StringUtils;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;

//@formatter:off
/*

example config:

{"attribute_detail_list":[
 {
     "name": "tagcategory",
     "is_required": false,
     "extractor_type": "CategoryFromKeywords",
     "extractor_args": ["head > meta[name=keywords]", "content", "bmw,"],
     "default_value": ""
 },
]}

*/
//@formatter:on


public class CategoryFromKeywordsDynamicExtractor extends DynamicExtractor {

	@Override
	public String extract(AttributeDetail attributeDetail, String url, Document articleDoc) throws Exception {

		String attrib_value = null;

		String[] tags = null;
		if ((attributeDetail.extractor_args != null) && (attributeDetail.extractor_args.size() >= 3)) {
			String cssSelector = attributeDetail.extractor_args.get(0);
			Element element = articleDoc.select(cssSelector).first();
			if (StringUtils.isNotBlank(cssSelector)) 
			{
				String value_name = attributeDetail.extractor_args.get(1);
				if (element != null && element.attr(value_name) != null) 
				{
					String rawList = element.attr(value_name);
					if (StringUtils.isNotBlank(rawList)) 
					{
						tags = rawList.split(",");
						for (int i = 0; i < tags.length; i++) {
							tags[i] = tags[i].trim().toLowerCase();
						}
						attrib_value = StringUtils.join(tags, ',');
					}
				}
			}
		}

		if (StringUtils.isNotBlank(attrib_value))
		{
			String[] categories = attributeDetail.extractor_args.get(2).split(",");
			for(String category : categories)
			{
				for(String tag : tags)
					if (category.equals(tag))
						return tag;
			}
		}
		
		return null;
	}


}