WiktionaryUtils.java

/*******************************************************************************
 * Copyright (C) 2020 Ram Sadasiv
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package io.outofprintmagazine.nlp.utils;

import java.io.IOException;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Deque;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import org.apache.http.Header;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicNameValuePair;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import com.fasterxml.jackson.databind.JsonNode;

import io.outofprintmagazine.util.IParameterStore;


public class WiktionaryUtils {
	
	@SuppressWarnings("unused")
	private static final Logger logger = LogManager.getLogger(WiktionaryUtils.class);
	private static final int BATCH_SIZE = 50;
	private static final int CACHE_SIZE = 10000;
	
	//private String apiKey = null;
	private Deque mruWordList = new LinkedList<String>();
	private Map<String, String> wordCache = new HashMap<String, String>();
	private IParameterStore parameterStore = null;
	
	private WiktionaryUtils(IParameterStore parameterStore) throws IOException {
		//this.apiKey = parameterStore.getProperty("wikipedia_apikey");
		this.parameterStore = parameterStore;
	}
	
	private static Map<IParameterStore, WiktionaryUtils> instances = new HashMap<IParameterStore, WiktionaryUtils>();
	
    public static WiktionaryUtils getInstance(IParameterStore parameterStore) throws IOException { 
        if (instances.get(parameterStore) == null) {
        	WiktionaryUtils instance = new WiktionaryUtils(parameterStore);
            instances.put(parameterStore, instance);
        }
        return instances.get(parameterStore); 
    }
    
    public String getWordCache(String token) {
    	String retval = wordCache.get(token);
    	return retval;
    }
    
    public boolean checkWordCache(String token) {
    	String retval = wordCache.get(token);
    	if (retval != null) {
    		mruWordList.remove(token);
    		mruWordList.push(token);
    		return true;
    	}
    	return false;
    }
    
    public void pruneWordCache() {
    	for (int i=WiktionaryUtils.CACHE_SIZE;i<mruWordList.size();i++) {
    		String token = (String)mruWordList.pollLast();
    		if (token != null) {
    			wordCache.remove(token);
    		}
    	}
    }
    
    public void addToWordCache(List<String> tokens) {
		List<String> queries = new ArrayList<String>();
		for (int i=0;i<tokens.size();i++) {
			String token = tokens.get(i);
			if (!checkWordCache(token) && !queries.contains(token)) {
				queries.add(token);
			}
			if (queries.size() == WiktionaryUtils.BATCH_SIZE) {
				try {
					Map<String, String> scores = getSearchResultsBatch(queries);
					for (String key : scores.keySet()) {
						mruWordList.push(key);
						wordCache.put(key, scores.get(key));
					}
				}
				catch (Exception e) {
					logger.error("wiktionary error", e);
				}
				queries.clear();
			}
		}
		if (queries.size() > 0) {
			try {
				Map<String, String> scores = getSearchResultsBatch(queries);
				for (String key : scores.keySet()) {
					mruWordList.push(key);
					wordCache.put(key, scores.get(key));
				}
			}
			catch (Exception e) {
				logger.error("wiktionary error", e);
			}
		}
		logger.debug("wordCache length: " + wordCache.size());
    }
        
    private Map<String, String> getSearchResultsBatch(List<String> queries) throws IOException, URISyntaxException {
		List<NameValuePair> nvps = HttpUtils.getInstance(parameterStore).getWikionaryParameters();
		nvps.add(new BasicNameValuePair("titles", String.join("|", queries)));			
		List<Header> headers = new ArrayList<Header>();
		headers.add(new BasicHeader("User-Agent", parameterStore.getProperty("wikipedia_apikey")));
		PageHandler handler = new PageHandler();
		HttpUtils.getInstance(parameterStore)
				.httpGetJsonCB(
						HttpUtils.getInstance(parameterStore)
						.buildUri(
								HttpUtils.getInstance(parameterStore).getWikipediaApi(), 
								nvps
						),
						headers,
						handler
				);
		return handler.getValues();

    }
    
    protected class PageHandler implements IJsonResponseHandler {
    	Map<String, String> retval = new HashMap<String, String>();
    	
    	public PageHandler() {
    		super();
    	}
    	
    	public Map<String, String> getValues() {
    		return retval;
    	}
    	
    	@Override
		public void onPage(JsonNode page) {
    		if (page != null && page.has("query") && page.get("query").has("pages")) {
				JsonNode pages = page.get("query").get("pages");
				Iterator<String> resultIter = pages.fieldNames();
				while (resultIter.hasNext()) {
					String resultName = resultIter.next();
					JsonNode result = pages.get(resultName);
					if (result.has("pageid")) {
						retval.put(result.get("title").asText(),result.get("pageid").asText() );
					}
		    	}
			}   		
    	}
    }
   
}