/*
 * This file is part of ADDIS (Aggregate Data Drug Information System).
 * ADDIS is distributed from http://drugis.org/.
 * Copyright © 2009 Gert van Valkenhoef, Tommi Tervonen.
 * Copyright © 2010 Gert van Valkenhoef, Tommi Tervonen, Tijs Zwinkels,
 * Maarten Jacobs, Hanno Koeslag, Florin Schimbinschi, Ahmad Kamal, Daniel
 * Reid.
 * Copyright © 2011 Gert van Valkenhoef, Ahmad Kamal, Daniel Reid, Florin
 * Schimbinschi.
 * Copyright © 2012 Gert van Valkenhoef, Daniel Reid, Joël Kuiper, Wouter
 * Reckman.
 * Copyright © 2013 Gert van Valkenhoef, Joël Kuiper.
 *
 * 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 org.drugis.addis.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class AtcParser {

	public static class AtcDescription {
		private String d_code;
		private String d_desc;

		public AtcDescription () {
			this.d_code = null;
			this.d_desc = null;
		}

		public AtcDescription (String code, String desc) {
			this.d_code = code;
			this.d_desc = desc;
		}

		public String getCode() {
			return d_code;
		}

		public String getDescription() {
			return d_desc;
		}
	}

	private static final Pattern s_codePattern = Pattern.compile("<a href=\"[^\"]*/\\?code=([A-Z0-9]*)(&[^\"]*)?\">([^<]*)</a>", Pattern.CASE_INSENSITIVE);
	private static final int READ_TIMEOUT = 3000;
	private static final int CONNECTION_TIMEOUT = 3000;

	public List<AtcDescription> findDrugDetails(String inputLine) {
		Matcher matchCode = s_codePattern.matcher(inputLine);
		List<AtcDescription> detailsList = new ArrayList<AtcDescription>();
		while(matchCode.find()) {
			if (!matchCode.group(3).equals("Show text from Guidelines")) {
				detailsList.add(new AtcDescription((matchCode.group(1)), matchCode.group(3)));
			}
		}
		return detailsList;
	}

	public List<AtcDescription> parse(InputStream is) throws IOException {
		String inputLine;
		List<AtcDescription> finalList = new ArrayList<AtcDescription>();
		BufferedReader readCode = new BufferedReader(new InputStreamReader(is));
		while ((inputLine = readCode.readLine()) != null) {
			if(!findDrugDetails(inputLine).isEmpty()){
				finalList.addAll(findDrugDetails(inputLine));
			}
		}
		return finalList;
	}

	public AtcDescription getAtcCode(String drugName) throws IOException {
		if(drugName.length() != 0) {
			URLConnection d_urlStream = new URL("http://www.whocc.no/atc_ddd_index/?name="+drugName).openConnection();
			d_urlStream.setConnectTimeout(CONNECTION_TIMEOUT);
			d_urlStream.setReadTimeout(READ_TIMEOUT);
			InputStream is = d_urlStream.getInputStream();
			BufferedReader readCode = new BufferedReader(new InputStreamReader(is));
			String inputLine;
			AtcDescription result = new AtcDescription();
			while ((inputLine = readCode.readLine()) != null && result.getCode() == null) {
				if(!new AtcParser().findDrugDetails(inputLine).isEmpty()) {
					result = new AtcParser().findDrugDetails(inputLine).get(0);
				}
			}
			return result;
		}
		return new AtcDescription();
	}

	public List<AtcDescription> getAtcDetails(String atcCode) throws IOException {
		if(atcCode.length() != 0) {
			InputStream d_urlStream = new URL("http://www.whocc.no/atc_ddd_index/?code="+atcCode).openConnection().getInputStream();
			return new AtcParser().parse(d_urlStream);
		}
		return new ArrayList<AtcDescription>();
	}
}