/*
 *  GooglePR.java
 *
 *  Copyright (c) 1998-2004, The University of Sheffield.
 *
 *  This file is part of GATE (see http://gate.ac.uk/), and is free
 *  software, licenced under the GNU Library General Public License,
 *  Version 2, June 1991 (in the distribution as file licence.html,
 *  and also available at http://gate.ac.uk/gate/licence.html).
 *
 *  Google API and other sources subject to Google License. Please
 *  see http://www.google.com/apis/
 *  
 *  $Id: GooglePR.java 7451 2006-06-15 14:10:50Z ian_roberts $  
 */

package google;

import gate.ProcessingResource;
import gate.Resource;
import gate.creole.*;
import gate.gui.MainFrame;
import gate.corpora.*;
import gate.util.*;
import gate.*;
import java.util.*;

import com.google.soap.search.*;

public class GooglePR extends AbstractLanguageAnalyser implements
		ProcessingResource {

	private String query = null;
	private int limit = -1;
	private String key = null;
	private Corpus google = null;
	private Boolean corpusAppendMode;
	private final static boolean DEBUG = false;
	private ArrayList pagesToExclude;
	
	/** Constructor of the class*/
	public GooglePR() {
	}

	/** Initialise this resource, and return it. */
	public Resource init() throws ResourceInstantiationException {
		return super.init();
	}

	/**
	 * Reinitialises the processing resource. After calling this method the
	 * resource should be in the state it is after calling init.
	 * If the resource depends on external resources (such as rules files) then
	 * the resource will re-read those resources. If the data used to create
	 * the resource has changed since the resource has been created then the
	 * resource will change too after calling reInit().
	 */
	public void reInit() throws ResourceInstantiationException {
		init();
	}

	/**
	 * This method runs the coreferencer. It assumes that all the needed parameters
	 * are set. If they are not, an exception will be fired.
	 */
	public void execute() throws ExecutionException {

		if (google == null) {
			throw new ExecutionException(
					"Corpus to store results in is not provided");
		}
		if (query == null) {
			throw new ExecutionException("Query is not initialized");
		}
		if (limit == -1) {
			throw new ExecutionException("Limit is not initialized");
		}
		if (key == null) {
			throw new ExecutionException("Key is not initialized");
		}

		if(!corpusAppendMode.booleanValue()) {
			while(google.size() > 0) {
				Resource resource = (Resource) google.get(0);
				google.remove(0);
				Factory.deleteResource(resource);
			}
		}
		
		// Create a Google Search object, set our authorization key
		GoogleSearch search = new GoogleSearch();
		search.setKey(key);
		//do search
		search.setQueryString(query);

		//set limit
		//search.setMaxResults(limit);
		int index = 0;
		try {
			while (index < limit) {
				search.setStartResult(index);
				if (limit - index < 10) {
					search.setMaxResults(limit - index);
				}
				//run search
				GoogleSearchResult results = search.doSearch();

				//An array that holds the list of result elements
				GoogleSearchResultElement[] rs = new GoogleSearchResultElement[limit];

				rs = results.getResultElements();
				if (rs != null) {
					for (int i = 0; i < rs.length; i++) {
						GoogleSearchResultElement rElement = rs[i];
						if(DEBUG)
							Err.println(index + i + ") " + rElement.getURL());
						
						String urlString = rElement.getURL();
						if(pagesToExclude != null && pagesToExclude.contains(urlString)) {
							continue;
						}
						
						String docName = rElement.getURL() + "_"
								+ Gate.genSym();
						FeatureMap params = Factory.newFeatureMap();
						params.put(Document.DOCUMENT_URL_PARAMETER_NAME,
								rElement.getURL());
						try {
							Document doc = (Document) Factory.createResource(
									DocumentImpl.class.getName(), params, null,
									docName);
							google.add(doc);

						} catch (ResourceInstantiationException e) {
							String nl = Strings.getNl();
							Err.prln("WARNING: could not intantiate document :"+e.getMessage());
							/*Err.prln("WARNING: could not intantiate document"
									+ nl + "  Document name was: " + docName
									+ nl + "  Exception was: " + e + nl + nl);
							*/
						}
					}
				}

				index += 10;
			}
		} catch (Exception gsf) {
			Err.println("Google Search Fault: " + gsf.getMessage());
			//gsf.printStackTrace();
		}
	}

	public void setQuery(String query) {
		this.query = query;
	}

	public String getQuery() {
		return this.query;
	}

	public void setKey(String key) {
		this.key = key;
	}

	public String getKey() {
		return this.key;
	}

	public void setLimit(Integer limit) {
		this.limit = limit.intValue();
	}

	public Integer getLimit() {
		return new Integer(this.limit);
	}

	public Corpus getCorpus() {
		return google;
	}

	public void setCorpus(Corpus corpus) {
		this.google = corpus;
	}
	
	public void setCorpusAppendMode(Boolean appendMode) {
		this.corpusAppendMode = appendMode;
	}
	
	public Boolean getCorpusAppendMode() {
		return this.corpusAppendMode;
	}
	
	public void setPagesToExclude(List pagesToExclude) {
    this.pagesToExclude = new ArrayList();
    // pagesToExclude is an optional param.
    // If it is null, the list should be empty.
    if (pagesToExclude == null) return ;
		Iterator iterator = pagesToExclude.iterator();
		while(iterator.hasNext()) {
			String page = (String) iterator.next();
			page = page.toLowerCase();
			this.pagesToExclude.add(page);
		}
	}
	
	public List getPagesToExclude() {
		return this.pagesToExclude;
	}
	 
}