/*
 * Created on Saturday, May 14 2010 17:08
 */
package com.jogamp.hungryharry;

import com.jogamp.hungryharry.Config.Feed;
import com.jogamp.hungryharry.Config.Planet;

import com.rometools.rome.feed.synd.SyndContent;
import com.rometools.rome.feed.synd.SyndEntry;
import com.rometools.rome.feed.synd.SyndFeed;
import com.rometools.rome.feed.synd.SyndFeedImpl;
import com.rometools.rome.io.FeedException;
import com.rometools.rome.io.SyndFeedInput;
import com.rometools.rome.io.SyndFeedOutput;
import com.rometools.rome.io.XmlReader;
import com.rometools.fetcher.FeedFetcher;
import com.rometools.fetcher.impl.FeedFetcherCache;
import com.rometools.fetcher.impl.HashMapFeedInfoCache;
import com.rometools.fetcher.impl.HttpURLFeedFetcher;

import freemarker.template.Configuration;
import freemarker.template.ObjectWrapper;
import freemarker.template.Template;
import freemarker.template.TemplateException;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.Writer;
import java.util.Comparator;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.logging.Logger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;

import static java.util.Collections.*;
import static java.util.logging.Level.*;
import static java.io.File.*;

/**
 * Always hungry, always.
 *
 * @author Michael Bien
 *
 */
public class FeedAggregator {
    
    private static final Logger LOG = Logger.getLogger(FeedAggregator.class.getName());
    private final String configFile;

    private FeedAggregator(String configFile) {
        this.configFile = configFile;
    }

    private void aggregate() {

        Config config = null;
        try {
            config = readConfiguration();
        } catch (JAXBException ex) {
            throw new RuntimeException("can not read configuration", ex);
        } catch (FileNotFoundException ex) {
            throw new RuntimeException("can not read configuration", ex);
        }

        List<Config.Feed> feeds = config.feed;
        List<SyndFeed> syndFeeds = new ArrayList<SyndFeed>();
        List<SyndEntry> entries = downloadFeeds(feeds, syndFeeds);

        Planet planet = config.planet;
        new File(planet.outputFolder).mkdirs();

        createAggregatedFeed(planet, entries);

        List<Map<String, Object>> aggregatedEntries = new ArrayList<Map<String, Object>>(entries.size());
        int n = 0;

        LOG.info(entries.size()+" entries found");

        for (SyndEntry entry : entries) {
            if(n++ >= planet.maxEntries) {
                break;
            }
            SyndContent descriptionSC = entry.getDescription();
            Map<String, Object> map = new HashMap<String, Object>();
            map.put("title", entry.getTitle());
            map.put("link", entry.getLink());
            map.put("author", entry.getAuthor());
            map.put("published", entry.getPublishedDate());
            map.put("updated", entry.getUpdatedDate());
            map.put("description", descriptionSC.getValue());
            
            StringBuilder sb = new StringBuilder();
            List contents = entry.getContents();
            for (Object content : contents) {
                sb.append(((SyndContent)content).getValue());
            }
            if(sb.length() == 0 && descriptionSC != null) {
                map.put("content", descriptionSC.getValue());
            }else{
                map.put("content", sb);
            }

            String link = entry.getLink();
            for (Config.Template template : config.template) {
                if(link.contains(template.keyword)) {
                    Matcher matcher = Pattern.compile(template.idpattern).matcher(link);
                    matcher.find();
                    String playercode = template.text.replaceAll("#id#", matcher.group(1));

                    map.put("player", playercode);

                    String filteredDescription = null;
                    //TODO sometimes there is only content
                    if(descriptionSC == null) {
                        filteredDescription = sb.toString();
                    }else{
                        filteredDescription = descriptionSC.getValue();
                        if(template.descriptionfilter != null) {
                            Pattern descPattern = Pattern.compile(template.descriptionfilter);
                            Matcher filter = descPattern.matcher(filteredDescription);
                            filter.find();
                            filteredDescription = filter.group(1);
                        }
                    }

                    map.put("filteredDescription", filteredDescription);

                    break;
                }
            }
            aggregatedEntries.add(map);

        }

        int max = planet.maxEntriesPerPage;
        int pages = (int) Math.ceil(aggregatedEntries.size() / (float)max);
        LOG.info("pagecount: "+pages);
        
        for(int i = 0; i < pages; i++) {
            List<Map<String, Object>> subList = aggregatedEntries.subList(i * max, Math.min(i * max + max, aggregatedEntries.size()-1));
            generatePage(i, pages, syndFeeds, subList, planet);
        }

    }

    private void generatePage(int index, int pages, List<SyndFeed> syndFeeds, List<Map<String, Object>> entries, Planet planet) {

        String name = pageName(planet, index, pages);

        Map<String, Object> root = new HashMap<String, Object>();
        root.put("entries", entries);
        root.put("planet", planet);
        root.put("feedlinks", planet.feeds);
        root.put("feeds", syndFeeds);
        root.put("page", index+1);
        root.put("pages", pages);
        root.put("filename", name);
        root.put("updated", new Date());
        root.put("prev", pageName(planet, index-1, pages));
        root.put("next", pageName(planet, index+1, pages));

        try {
            String templateFolder = cutoffTail(planet.templatePath, '/');
            String templateName = planet.templatePath.substring(templateFolder.length());

            Configuration cfg = new Configuration();
            // Specify the data source where the template files come from.
            // Here I set a file directory for it:
            cfg.setDirectoryForTemplateLoading(new File(templateFolder));
            // Specify how templates will see the data-model. This is an advanced topic...
            // but just use this:
            cfg.setObjectWrapper(ObjectWrapper.DEFAULT_WRAPPER);
            cfg.setDefaultEncoding("UTF-8");

            Template template = cfg.getTemplate(templateName);
            Writer writer = new FileWriter(new File(planet.outputFolder + separator + name));
            template.process(root, writer);
            writer.close();
        } catch (IOException ex) {
            LOG.log(SEVERE, null, ex);
        } catch (TemplateException ex) {
            LOG.log(SEVERE, null, ex);
        }
    }

    private String pageName(Planet planet, int index, int pages) {
        if(index < 0 || index >= pages) {
            return null;
        }
        return planet.name + (index == 0 ? "" : index) + ".html";
    }

    private void createAggregatedFeed(Planet planet, List<SyndEntry> entries) {

        for (Planet.PlanetFeed planetFeed : planet.feeds) {
            try {
                SyndFeed feed = new SyndFeedImpl();

                feed.setFeedType(planetFeed.type);
                feed.setTitle(planet.title);
                feed.setDescription(planet.description);
                feed.setAuthor(planet.author);
                feed.setLink(planet.link + separatorChar + planetFeed.getFileName());
                feed.setEntries(entries);

                SyndFeedOutput output = new SyndFeedOutput();
                output.output(feed, new File(planet.outputFolder + separatorChar + planetFeed.getFileName()));

            } catch (IOException ex) {
                LOG.log(SEVERE, null, ex);
            } catch (FeedException ex) {
                LOG.log(SEVERE, null, ex);
            }
        }
    }

    private List<SyndEntry> downloadFeeds(List<Feed> feeds, List<SyndFeed> downloadedFeeds) throws IllegalArgumentException {

        FeedFetcherCache feedInfoCache = HashMapFeedInfoCache.getInstance();
        FeedFetcher feedFetcher = new HttpURLFeedFetcher(feedInfoCache);
        // trust foreign doctype? feedFetcher.setAllowDoctypes(true);
        List<SyndEntry> collectedEntries = new ArrayList<SyndEntry>();
        
        Set<String> ids = new HashSet<String>();
        
        for (Config.Feed feed : feeds) {
            LOG.info("downloading "+feed);
            try {
                SyndFeed inFeed = feedFetcher.retrieveFeed(new URL(feed.url));
                downloadedFeeds.add(inFeed);
                List<SyndEntry> entries = inFeed.getEntries();

                LOG.info("downloaded "+entries.size()+ " entries");
                
                //skip duplicates
                for (SyndEntry entry : entries) {
                    String uid = entry.getLink();
                    if(!ids.contains(uid)) {
                        ids.add(uid);
                        collectedEntries.add(entry);
                    }else{
                        LOG.info("skiping duplicate entry: "+uid);
                    }
                }
                
            } catch (Exception ex) {
                LOG.log(WARNING, "skipping feed", ex);
            }
        }

        sort(collectedEntries, new Comparator<SyndEntry>() {
            @Override
            public int compare(SyndEntry o1, SyndEntry o2) {
                return o2.getPublishedDate().compareTo(o1.getPublishedDate());
            }
        });
        return collectedEntries;
    }

    private Config readConfiguration() throws JAXBException, FileNotFoundException {
        Unmarshaller unmarshaller = JAXBContext.newInstance(Config.class).createUnmarshaller();
        LOG.info("reading config file: " + configFile);
        InputStream is = getClass().getResourceAsStream(configFile);
        if(is == null) {
            is = new FileInputStream(configFile);
        }

        Object obj = unmarshaller.unmarshal(is);
        return (Config) obj;
    }

    private String cutoffTail(String text, char cut) {
        return text.substring(0, text.lastIndexOf(cut));
    }

    private StringBuilder replace(StringBuilder sb, String token, String replacement) {
        int start = sb.indexOf(token);
        sb.replace(start, start+token.length(), replacement);
        return sb;
    }

    public static void main(String... args) {

        if(args.length < 1) {
            System.out.println("args must contain a path to the configuration file");
            return;
        }

        new FeedAggregator(args[0]).aggregate();
    }

}