/*
 * Copyright 2005 the original author or authors.
 * 
 * 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.wamblee.crawler.kiss;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Properties;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.wamblee.crawler.Action;
import org.wamblee.crawler.Configuration;
import org.wamblee.crawler.Crawler;
import org.wamblee.crawler.Page;
import org.wamblee.crawler.PageException;
import org.wamblee.crawler.impl.ConfigurationParser;
import org.wamblee.crawler.impl.CrawlerImpl;

/**
 * The KiSS crawler for automatic recording of interesting TV shows.
 * 
 */
public class KissCrawler {

    private static final Log LOG = LogFactory.getLog(KissCrawler.class);

    /**
     * Log file name for the crawler.
     */
    private static final String LOG_FILE = "kiss.log";

    /**
     * Start URL of the electronic programme guide.
     */
    private static final String START_URL = "http://epg.kml.kiss-technology.com/login_core.php";

    /**
     * Crawler configuration file.
     */
    private static final String CRAWLER_CONFIG = "config.xml";

    /**
     * Configuration file describing interesting programs.
     */
    private static final String PROGRAM_CONFIG = "programs.xml";

    /**
     * Regular expression for matching time interval strings in the retrieved
     * pages.
     */
    private static final String TIME_REGEX = "([0-9]{2}):([0-9]{2})[^0-9]*([0-9]{2}):([0-9]{2}).*";

    /**
     * Compiled pattern for the time regular expression.
     */
    private Pattern _pattern;

    /**
     * Runs the KiSS crawler.
     * 
     * @param aArgs
     *            Arguments, currently all ignored because they are hardcoded.
     * @throws Exception
     *             In case of problems.
     */
    public static void main(String[] aArgs) throws Exception {
        new KissCrawler(START_URL, CRAWLER_CONFIG, PROGRAM_CONFIG);
    }

    /**
     * Constructs the crawler. This retrieves the TV guide by crawling the KiSS
     * EPG guide, filters the guide for interesting programs, tries to record
     * them, and sends a summary mail to the user.
     * 
     * @param aStartUrl
     *            Start URL of the electronic programme guide.
     * @param aCrawlerConfig
     *            Configuration file for the crawler.
     * @param aProgramConfig
     *            Configuration file describing interesting shows.
     * @throws IOException
     *             In case of problems reading files.
     * @throws MessagingException
     *             In case of problems sending a mail notification.
     */
    public KissCrawler(String aStartUrl, String aCrawlerConfig,
            String aProgramConfig) throws IOException, MessagingException {

        _pattern = Pattern.compile(TIME_REGEX);

        FileOutputStream fos = new FileOutputStream(new File(LOG_FILE));
        PrintStream os = new PrintStream(fos);

        try {
            HttpClient client = new HttpClient();
            // client.getHostConfiguration().setProxy("127.0.0.1", 3128);

            Crawler crawler = createCrawler(aCrawlerConfig, os, client);
            InputStream programConfigFile = new FileInputStream(new File(
                    aProgramConfig));
            List<ProgramFilter> programFilters = new ProgramConfigurationParser()
                    .parse(programConfigFile);

            Page page = getStartPage(aStartUrl, crawler);
            TVGuide guide = createGuide(page);
            PrintVisitor printer = new PrintVisitor(System.out);
            guide.accept(printer);
            processResults(programFilters, guide);
        } finally {
            os.flush();
            os.close();
            System.out.println("Output written on '" + LOG_FILE + "'");
        }
    }

    /**
     * Records interesting shows.
     * 
     * @param aProgramCondition
     *            Condition determining which shows are interesting.
     * @param aGuide
     *            Television guide.
     * @throws MessagingException
     *             In case of problems sending a summary mail.
     */
    private void processResults(List<ProgramFilter> aProgramCondition,
            TVGuide aGuide) throws MessagingException {
        ProgramActionExecutor executor = new ProgramActionExecutor();
        for (ProgramFilter filter : aProgramCondition) {
            List<Program> programs = filter.apply(aGuide);
            ProgramAction action = filter.getAction(); 
            for (Program program: programs) { 
                action.execute(program, executor);
            }
        }
        executor.commit();
        String msg = executor.getReport();
        System.out.println(msg);
        sendMail(msg);
    }

    /**
     * Creates the crawler.
     * 
     * @param aCrawlerConfig
     *            Crawler configuration file.
     * @param aOs
     *            Logging output stream for the crawler.
     * @param aClient
     *            HTTP Client to use.
     * @return Crawler.
     * @throws FileNotFoundException
     *             In case configuration files cannot be found.
     */
    private Crawler createCrawler(String aCrawlerConfig, PrintStream aOs,
            HttpClient aClient) throws FileNotFoundException {
        ConfigurationParser parser = new ConfigurationParser(aOs);
        InputStream crawlerConfigFile = new FileInputStream(new File(
                aCrawlerConfig));
        Configuration config = parser.parse(crawlerConfigFile);
        Crawler crawler = new CrawlerImpl(aClient, config);
        return crawler;
    }

    /**
     * Gets the start page of the electronic programme guide. This involves
     * login and navigation to a suitable start page after logging in.
     * 
     * @param aStartUrl
     *            URL of the electronic programme guide.
     * @param aCrawler
     *            Crawler to use.
     * @return Starting page.
     */
    private Page getStartPage(String aStartUrl, Crawler aCrawler) {
        try {
            Page page = aCrawler.getPage(aStartUrl);
            return page.getAction("channels-favorites").execute();
        } catch (PageException e) {
            throw new RuntimeException(
                    "Could not login to electronic program guide", e);
        }
    }

    /**
     * Creates the TV guide by web crawling.
     * 
     * @param aPage
     *            Starting page.
     * @return TV guide.
     */
    private TVGuide createGuide(Page aPage) {
        LOG.info("Obtaining full TV guide");
        Action[] actions = aPage.getActions();
        List<Channel> channels = new ArrayList<Channel>();
        for (Action action : actions) {
            try {
                LOG.info("Getting channel info for '" + action.getName() + "'");
                Channel channel = createChannel(action.getName(), action
                        .execute().getAction("right-now").execute());
                channels.add(channel);
                if (SystemProperties.isDebugMode()) {
                    break; // Only one channel is crawled.
                }
            } catch (PageException e) {
                LOG.error("Could not create channel information for '"
                        + action.getName() + "'", e);
            }
        }
        return new TVGuide(channels);
    }

    /**
     * Create channel information for a specific channel.
     * 
     * @param aChannel
     *            Channel name.
     * @param aPage
     *            Starting page for the channel.
     * @return Channel.
     */
    private Channel createChannel(String aChannel, Page aPage) {
        LOG.info("Obtaining program for " + aChannel);
        Action[] programActions = aPage.getActions();
        List<Program> programs = new ArrayList<Program>();
        for (Action action : programActions) {
            String time = action.getContent().element("time").getText().trim();
            Matcher matcher = _pattern.matcher(time);
            if (matcher.matches()) {
                Time begin = new Time(Integer.parseInt(matcher.group(1)),
                        Integer.parseInt(matcher.group(2)));
                Time end = new Time(Integer.parseInt(matcher.group(3)), Integer
                        .parseInt(matcher.group(4)));
                TimeInterval interval = new TimeInterval(begin, end);
                String description = "";
                String keywords = "";
                if (!SystemProperties.isNoProgramDetailsRequired()) {
                    try {
                        Page programInfo = action.execute();
                        description = programInfo.getContent().element(
                                "description").getText().trim();
                        keywords = programInfo.getContent().element("keywords")
                                .getText().trim();
                    } catch (PageException e) {
                        LOG
                                .warn("Program details could not be determined for '"
                                        + action.getName() + "'", e);
                    }
                }
                Program program = new Program(aChannel, action.getName(),
                        description, keywords, interval, action);

                LOG.info("Got program " + program);
                programs.add(program);
            }
        }
        return new Channel(aChannel, programs);
    }

    /**
     * Sends a summary mail to the user.
     * 
     * @param aText
     *            Text of the mail.
     * @throws MessagingException
     *             In case of problems sending mail.
     */
    private void sendMail(String aText) throws MessagingException {
        Properties props = new Properties();
        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.host", "falcon");
        props.put("mail.smtp.port", "25");

        Session mailSession = Session.getInstance(props);
        Message message = new MimeMessage(mailSession);

        message.setFrom(new InternetAddress("erik@brakkee.org"));
        message.setRecipient(Message.RecipientType.TO, new InternetAddress(
                "erik@brakkee.org"));
        message.setSentDate(new Date());
        message.setSubject("KiSS crawler update");
        message.setText(aText);
        Transport.send(message);
    }

}