/*
 * 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.main;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.mail.MessagingException;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.NameValuePair;
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;
import org.wamblee.crawler.kiss.guide.Channel;
import org.wamblee.crawler.kiss.guide.PrintVisitor;
import org.wamblee.crawler.kiss.guide.Program;
import org.wamblee.crawler.kiss.guide.TVGuide;
import org.wamblee.crawler.kiss.guide.Time;
import org.wamblee.crawler.kiss.guide.TimeInterval;
import org.wamblee.crawler.kiss.notification.NotificationException;
import org.wamblee.crawler.kiss.notification.Notifier;
import org.wamblee.general.BeanFactory;
import org.wamblee.xml.ClasspathUriResolver;
import org.wamblee.xml.XslTransformer;

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

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

    /**
     * Start URL of the electronic programme guide.
     */
    private static final String START_URL = "http://epg.kml.kiss-technology.com/login.php";
    
    /**
     * Default socket timeout to use. 
     */
    private static final int SOCKET_TIMEOUT = 10000; 

    /**
     * Regular expression for matching time interval strings in the retrieved
     * pages.
     */
    private static final String TIME_REGEX = "[^0-9]*([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 {
        String crawlerConfig = new File(aArgs[0]).getCanonicalPath(); 
        String programConfig = new File(aArgs[1]).getCanonicalPath(); 

        BeanFactory factory = new StandaloneCrawlerBeanFactory();
        Notifier notifier = factory.find(Notifier.class);
        new KissCrawler(START_URL, SOCKET_TIMEOUT, crawlerConfig, programConfig, notifier, new Report());
    }
    
    /**
     * 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 aCrawlerConfig
     *            Configuration file for the crawler.
     * @param aProgramConfig
     *            Configuration file describing interesting shows.
     * @param aNotifier Object used to send notifications of the results.           
     * @param aReport Report to use. 
     * @throws IOException
     *             In case of problems reading files.
     * @throws NotificationException In case notification fails.
     * @throws PageException In case of problems retrieving the TV guide. 
     */
    public KissCrawler(String aCrawlerConfig,
            String aProgramConfig, Notifier aNotifier, Report aReport) throws IOException, NotificationException, PageException {
        this(START_URL, SOCKET_TIMEOUT, aCrawlerConfig, aProgramConfig, aNotifier, aReport);
    }


    /**
     * 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 aSocketTimeout Socket timeout to use. 
     * @param aCrawlerConfig
     *            Configuration file for the crawler.
     * @param aProgramConfig
     *            Configuration file describing interesting shows.
     * @param aNotifier Object used to send notifications of the results.           
     * @param aReport Report to use. 
     * @throws IOException
     *             In case of problems reading files.
     * @throws NotificationException In case notification fails.
     * @throws PageException In case of problems retrieving the TV guide.   
     */
    public KissCrawler(String aStartUrl, int aSocketTimeout, String aCrawlerConfig,
            String aProgramConfig, Notifier aNotifier, Report aReport) throws IOException, NotificationException, PageException {

        _pattern = Pattern.compile(TIME_REGEX);

        try {
            HttpClient client = new HttpClient();
            // client.getHostConfiguration().setProxy("127.0.0.1", 3128);
            client.getParams().setParameter("http.socket.timeout", SOCKET_TIMEOUT);

            XslTransformer transformer = new XslTransformer(
                    new ClasspathUriResolver());

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

            try {
                Page page = getStartPage(aStartUrl, crawler, aReport);
                TVGuide guide = createGuide(page, aReport);
                PrintVisitor printer = new PrintVisitor(System.out);
                guide.accept(printer);
                processResults(programFilters, guide, aNotifier,
                        aReport);
            } catch (PageException e) {
                aReport.addMessage("Problem getting TV guide", e);
                LOG.info("Problem getting TV guide", e);
                throw e; 
            }
            aNotifier.send(aReport.asXml());
        } finally {
            System.out.println("Crawler finished");
        }
    }

    /**
     * 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, Notifier aNotifier, Report aReport) {
        ProgramActionExecutor executor = new ProgramActionExecutor(aReport);
        for (ProgramFilter filter : aProgramCondition) {
            List<Program> programs = filter.apply(aGuide);
            ProgramAction action = filter.getAction();
            for (Program program : programs) {
                action.execute(program, executor);
            }
        }
        executor.commit();

    }

    /**
     * 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, HttpClient aClient,
            XslTransformer aTransformer) throws FileNotFoundException {
        ConfigurationParser parser = new ConfigurationParser(aTransformer);
        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.
     * @param aReport
     *            Report to use.
     * @return Starting page.
     */
    private Page getStartPage(String aStartUrl, Crawler aCrawler, Report aReport)
            throws PageException {
        try {
            Page page = aCrawler.getPage(aStartUrl, new NameValuePair[0]);
            page = page.getAction("login").execute();
            Action favorites = page.getAction("channels-favorites");
            if (favorites == null) {
                String msg = "Channels favorites action not found on start page";
                throw new PageException(msg);
            }
            return favorites.execute();
        } catch (PageException e) {
            String msg = "Could not complete login to electronic programme guide.";
            throw new PageException(msg, e);
        }
    }

    /**
     * Creates the TV guide by web crawling.
     * 
     * @param aPage
     *            Starting page.
     * @param aReport
     *            Report to use.
     * @return TV guide.
     * @throws PageException In case of problem getting the tv guide.
     */
    private TVGuide createGuide(Page aPage, Report aReport) throws PageException {
        LOG.info("Obtaining full TV guide");
        Action[] actions = aPage.getActions();
        if ( actions.length == 0 ) { 
            LOG.error("No channels found");
            throw new PageException("No channels found");
        }
        List<Channel> channels = new ArrayList<Channel>();
        for (Action action : actions) {
            try {
                LOG.info("Getting channel info for '" + action.getName() + "'");
                Action rightNow = action.execute().getAction("right-now");
                if (rightNow == null) {
                    throw new PageException("Channel summary page for '"
                            + action.getName()
                            + "' does not contain required information");
                }
                Channel channel = createChannel(action.getName(), rightNow
                        .execute(), aReport);
                channels.add(channel);
                if (SystemProperties.isDebugMode()) {
                    break; // Only one channel is crawled.
                }
            } catch (PageException e) {
                aReport.addMessage("Could not create channel information for '"
                        + action.getName() + "'");
                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, Report aReport) {
        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) {
                        String msg =   "Program details could not be determined for '"
                            + action.getName() + "'";
                        aReport.addMessage(msg, e);
                        LOG.warn(msg, 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);
    }
}