package com.ecyrd.jspwiki.plugin;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.log4j.Logger;

import com.ecyrd.jspwiki.PageManager;
import com.ecyrd.jspwiki.TextUtil;
import com.ecyrd.jspwiki.WikiContext;
import com.ecyrd.jspwiki.WikiEngine;
import com.ecyrd.jspwiki.WikiPage;
import com.ecyrd.jspwiki.WikiProvider;
import com.ecyrd.jspwiki.providers.ProviderException;

/**
 * <p>GategoryWeblogPlugin.java</p>
 * 
 * <p>
 * <a href="GategoryWeblogPlugin.java.java.html"><i>View Source</i></a>
 * </p>
 * 
 * @author $Author$
 * @version $Reversion$ $Date$
 */
public class WeblogCategoryPlugin implements WikiPlugin {
	private static Logger log = Logger.getLogger(WeblogPlugin.class);

	public static final int DEFAULT_DAYS = 7;
	//public static final String DEFAULT_PAGEFORMAT = "%p_blogentry_";

	public static final String DEFAULT_DATEFORMAT = "ddMMyy";

	//emptry for all category
	public static final String DEFAULT_CATEGORY = "";

	public static final String PARAM_STARTDATE = "startDate";
	public static final String PARAM_DAYS = "days";
	public static final String PARAM_ALLOWCOMMENTS = "allowComments";
	public static final String PARAM_MAXENTRIES = "maxEntries";
	//public static final String PARAM_PAGE = "page";
	//category param key
	public static final String PARAM_CATEGORY = "category";
	//public static final String PARAM_MAXENTRYLENGTH = "maxEntryLength";

//	public static String makeEntryPage(
//		String pageName,
//		String date,
//		String entryNum) {
//		return TextUtil.replaceString(DEFAULT_PAGEFORMAT, "%p", pageName)
//			+ date
//			+ "_"
//			+ entryNum;
//	}
//
//	public static String makeEntryPage(String pageName) {
//		return TextUtil.replaceString(DEFAULT_PAGEFORMAT, "%p", pageName);
//
//	}
//
//	public static String makeEntryPage(String pageName, String date) {
//		return TextUtil.replaceString(DEFAULT_PAGEFORMAT, "%p", pageName)
//			+ date;
//	}

	public String execute(WikiContext context, Map params)
		throws PluginException {
		Calendar startTime;
		Calendar stopTime;
		int numDays;
		WikiEngine engine = context.getEngine();

		//
		//  Parse parameters.
		//
		String days;
		String startDay = null;
		boolean hasComments = false;
		int maxEntries;
		String weblogName;
		int maxEntryLength;

//		if ((weblogName = (String) params.get(PARAM_PAGE)) == null) {
//			weblogName = context.getPage().getName();
//		}

		if ((days = context.getHttpParameter("weblog." + PARAM_DAYS))
			== null) {
			days = (String) params.get(PARAM_DAYS);
		}

		if (days != null && days.equalsIgnoreCase("all")) {
			numDays = Integer.MAX_VALUE;
		} else {
			numDays = TextUtil.parseIntParameter(days, DEFAULT_DAYS);
		}

		if ((startDay = (String) params.get(PARAM_STARTDATE)) == null) {
			startDay = context.getHttpParameter("weblog." + PARAM_STARTDATE);
		}

		if (TextUtil.isPositive((String) params.get(PARAM_ALLOWCOMMENTS))) {
			hasComments = true;
		}

		maxEntries =
			TextUtil.parseIntParameter(
				(String) params.get(PARAM_MAXENTRIES),
				Integer.MAX_VALUE);

		//Category
		String category = (String) params.get(PARAM_CATEGORY);
		if (null == category || 0 >= category.length()) {
			//all category
			category = "";
		} else {
			//
			// ;General;Java;Art;
			// for compare the page is in category list or not...
			// such as:category.indexOf(";Java;");...
			//
			category = ";" + category + ";";
		}

//		maxEntryLength =
//			TextUtil.parseIntParameter(
//				(String) params.get(PARAM_MAXENTRYLENGTH),
//				Integer.MAX_VALUE);

		//
		//  Determine the date range which to include.
		//

		startTime = Calendar.getInstance();
		stopTime = Calendar.getInstance();

		if (startDay != null) {
			SimpleDateFormat fmt = new SimpleDateFormat(DEFAULT_DATEFORMAT);
			try {
				Date d = fmt.parse(startDay);
				startTime.setTime(d);
				stopTime.setTime(d);
			} catch (ParseException e) {
				return "Illegal time format: " + startDay;
			}
		}

		//
		//  We make a wild guess here that nobody can do millisecond
		//  accuracy here.
		//
		startTime.add(Calendar.DAY_OF_MONTH, -numDays);
		startTime.set(Calendar.HOUR, 0);
		startTime.set(Calendar.MINUTE, 0);
		startTime.set(Calendar.SECOND, 0);
		stopTime.set(Calendar.HOUR, 23);
		stopTime.set(Calendar.MINUTE, 59);
		stopTime.set(Calendar.SECOND, 59);

		String result = "";
		try {
			List blogEntries =
				findBlogEntries(
					engine.getPageManager(),
					//weblogName,
					startTime.getTime(),
					stopTime.getTime(),
					category);
			//generate blog entry list...
			result =
				generateBlogEntryList(
					engine,
					hasComments,
					maxEntries,
					blogEntries,
					category);
		} catch (ProviderException e) {
			log.error("Could not locate blog entries", e);
			throw new PluginException(
				"Could not locate blog entries: " + e.getMessage());
		}
		//Result of blog entry list...
		return result;
	}

	/**
	 * Generate blog entry list
	 * 
	 * @param engine
	 * @param hasComments
	 * @param maxEntries
	 * @param blogEntries
	 * @return
	 * @throws ProviderException
	 */
	private String generateBlogEntryList(
		WikiEngine engine,
		boolean hasComments,
		int maxEntries,
		List blogEntries,
		String categoryCfg)
		throws ProviderException {
		StringBuffer sb = new StringBuffer();

		Collections.sort(blogEntries, new PageDateComparator());
		SimpleDateFormat entryDateFmt =
			new SimpleDateFormat("yyyy-MM-dd HH:mm");

		// category set,if the category is not seted...
		Set categorySet = new HashSet();

		//blog entry list content
		sb.append("<div class=\"weblog\">\n");
		for (Iterator i = blogEntries.iterator();
			i.hasNext() && maxEntries-- > 0;
			) {
			WikiPage p = (WikiPage) i.next();

			sb.append("<div class=\"weblogentry\">\n");

			//
			//  Heading
			//
			sb.append("<div class=\"weblogentryheading\">\n");

			Date entryDate = p.getLastModified();
			sb.append(entryDateFmt.format(entryDate));

			sb.append("</div>\n");

			// 
			// Category for each blog entry
			//
			String pageName = p.getName();
			String category = pageName.substring(0, pageName.indexOf("_"));
			categorySet.add(category);
			sb
				.append("<div class=\"weblogentrycategory\">\n")
				.append(
					"<b>&nbsp;&nbsp;Category:<a href=\""
						+ engine.getViewURL(category)
						+ "\">")
				.append(category + "</a></b></div>\n");

			//
			//  Append the text of the latest version.  Reset the
			//  context to that page.
			//

			sb.append("<div class=\"weblogentrybody\">\n");

			WikiContext entryCtx = new WikiContext(engine, p);

			sb.append(engine.getHTML(entryCtx, engine.getPage(p.getName())));

			sb.append("</div>\n");

			//
			//  Append footer
			//
			sb.append("<div class=\"weblogentryfooter\">\n");

			String author = p.getAuthor();

			if (author != null) {
				if (engine.pageExists(author)) {
					author =
						"<a href=\""
							+ engine.getViewURL(author)
							+ "\">"
							+ engine.beautifyTitle(author)
							+ "</a>";
				}
			} else {
				author = "AnonymousCoward";
			}

			sb.append("By " + author + "&nbsp;&nbsp;");
			sb.append(
				"<a href=\""
					+ engine.getViewURL(p.getName())
					+ "\">Permalink</a>");
			String commentPageName =
				TextUtil.replaceString(p.getName(), "blogentry", "comments");

			if (hasComments) {
				int numComments =
					guessNumberOfComments(engine, commentPageName);

				//
				//  We add the number of comments to the URL so that
				//  the user's browsers would realize that the page
				//  has changed.
				//
				sb.append("&nbsp;&nbsp;");
				sb.append(
					"<a target=\"_blank\" href=\""
						+ engine.getBaseURL()
						+ "Comment.jsp?page="
						+ engine.encodeName(commentPageName)
						+ "&nc="
						+ numComments
						+ "\">Comments? ("
						+ numComments
						+ ")</a>");
			}

			sb.append("</div>\n");

			//
			//  Done, close
			//
			sb.append("</div>\n");
		} //end for...all blog entry...

		sb.append("</div>\n");

		//Add category head...
		StringBuffer categorysb =
			new StringBuffer("<div><h4><b>Category</b></h4><ul>");
		if (categoryCfg.length() > 2) {
			String[] cgList = categoryCfg.split(";");
			for (int i = 0; i < cgList.length; i++) {
				String name = cgList[i];
				//ignore empty string
				if (0 < name.length()) {
					categorysb.append(
						"<li><a href=\""
							+ engine.getViewURL(name)
							+ "\">"
							+ name
							+ "</a></li>");
				}
			}
		} else {
			//list category
			Iterator it = categorySet.iterator();
			while (it.hasNext()) {
				String name = (String) it.next();
				categorysb.append(
					"<li><a href=\""
						+ engine.getViewURL(name)
						+ "\">"
						+ name
						+ "</a></li>");
			}
		}

		categorysb.append("</ul></div>");
		//combine category head and blog list result
		categorysb.append(sb);
		return categorysb.toString();
	}

	private int guessNumberOfComments(WikiEngine engine, String commentpage)
		throws ProviderException {
		String pagedata =
			engine.getPureText(commentpage, WikiProvider.LATEST_VERSION);

		return TextUtil.countSections(pagedata);
	}

	/**
	 *  Attempts to locate all pages that correspond to the 
	 *  blog entry pattern.  Will only consider the days on the dates; not the hours and minutes.
	 *
	 *  Returns a list of pages with their FIRST revisions.
	 */
	public List findBlogEntries(
		PageManager mgr,
		//String baseName,
		Date start,
		Date end,
		String category)
		throws ProviderException {
		Collection everyone = mgr.getAllPages();

		//log.info("------Page Counts:" + everyone.size());
		ArrayList result = new ArrayList();

		//baseName = makeEntryPage(baseName);
        
		SimpleDateFormat fmt = new SimpleDateFormat(DEFAULT_DATEFORMAT);

		for (Iterator i = everyone.iterator(); i.hasNext();) {
			WikiPage p = (WikiPage) i.next();

			String pageName = p.getName();
			String categoryName = "";
			boolean isInCategory = true;
			//empty category cfg will be ";;"
			if (2 >= category.length()) {
				isInCategory = true;
			} else {
				int index = pageName.indexOf("_blogentry_");
				categoryName = pageName.substring(0, index >= 0 ? index : 0);
				if (0 >= categoryName.length()) {
					isInCategory = true;
				} else {
					if (0 <= category.indexOf(";" + categoryName + ";")) {
						isInCategory = true;
					} else {
						isInCategory = false;
					}
				}
			}

			//all blog entry...
            int index = pageName.indexOf("_blogentry_");
			if (isInCategory && 0 < index) {
				
                
                String baseName = pageName.substring(0,index + 11);

				//if (pageName.startsWith(baseName)) {
				//
				//  Check the creation date from the page name.
				//  We do this because RCSFileProvider is very slow at getting a
				//  specific page version.
				//
				try {
					//log.debug("Checking: "+pageName);
					int firstScore =
						pageName.indexOf('_', baseName.length() - 1);
					if (firstScore != -1
						&& firstScore + 1 < pageName.length()) {
						int secondScore = pageName.indexOf('_', firstScore + 1);

						if (secondScore != -1) {
							String creationDate =
								pageName.substring(firstScore + 1, secondScore);

							//log.debug("   Creation date: "+creationDate);

							Date pageDay = fmt.parse(creationDate);

							//
							//  Add the first version of the page into the list.  This way
							//  the page modified date becomes the page creation date.
							//
							if (pageDay != null
								&& pageDay.after(start)
								&& pageDay.before(end)) {
								WikiPage firstVersion =
									mgr.getPageInfo(pageName, 1);
								result.add(firstVersion);
							}
						}
					}
				} catch (Exception e) {
					log.debug(
						"Page name :"
							+ pageName
							+ " was suspected as a blog entry but it isn't because of parsing errors",
						e);
				}
			}
		}

		return result;
	}

	/**
	 *  Reverse comparison.
	 */
	private class PageDateComparator implements Comparator {
		public int compare(Object o1, Object o2) {
			if (o1 == null || o2 == null) {
				return 0;
			}

			WikiPage page1 = (WikiPage) o1;
			WikiPage page2 = (WikiPage) o2;

			return page2.getLastModified().compareTo(page1.getLastModified());
		}
	}
}