package nabble.view.web.forum;

import fschmidt.util.servlet.CanonicalUrl;
import fschmidt.util.servlet.ServletUtils;
import nabble.model.ModelHome;
import nabble.model.Node;
import nabble.model.User;
import nabble.model.Site;
import nabble.view.lib.Jtp;
import nabble.view.lib.TopicView;
import nabble.view.lib.UrlMappable;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class Permalink extends HttpServlet implements UrlMappable, CanonicalUrl {

	public static String url(Node topic,Node post) {
		if( topic==null )
			topic = post.getTopic();
		return topic.getSite().getBaseUrl() + path(topic,post);
	}

	public static String path(Node topic,Node post) {
		if( topic==null )
			topic = post.getTopic();
		StringBuilder buf = new StringBuilder();
		buf.append( '/' );
		buf.append( Jtp.subjectEncode(topic.getSubject()) );
		buf.append( "-tp" );
		buf.append( topic.getId() );
		if( post != null && post != topic ) {
		    buf.append("p");
	    	buf.append(post.getId());
		}
		buf.append( ".html" );
		return buf.toString();
	}

	private static final Pattern URL_PATTERN = Pattern.compile("/([^/]*)-tp(\\d+)(p(\\d+))?(ef(\\d+))?\\.html$");

	public String getCanonicalUrl(HttpServletRequest request) {
		Site site = Jtp.getSite(request);
		if( site == null )
			return null;
		Node topic = site.getNode( Long.parseLong( request.getParameter("root") ) );
		String postS = request.getParameter("post");
		Node post = postS==null ? null : site.getNode( Long.parseLong(postS) );
		return url(topic,post);
	}

	public Map<String,String[]> getParameterMapFromUrl(HttpServletRequest request,String mappedUrl) {
		Matcher m = URL_PATTERN.matcher(mappedUrl);
		if( !m.find() )
			throw new RuntimeException();
		Map<String,String[]> params = new HashMap<String,String[]>();
		String subject = m.group(1);
		params.put("subject",new String[]{subject});
		String rootId = m.group(2);
		params.put("root",new String[]{rootId});
		String postId = m.group(4);
		if( postId != null )
			params.put( "post", new String[]{postId} );
		return params;
	}

	public Pattern getUrlPattern() {
		return URL_PATTERN;
	}

	protected void service(HttpServletRequest request, HttpServletResponse response)
		throws ServletException, IOException
	{
		String type = ServletUtils.getCookieValue(request,"tview");
		TopicView topicView = "threaded".equals(type)? TopicView.THREADED
			: "list".equals(type)? TopicView.LIST : TopicView.CLASSIC;

		long rootId = Long.parseLong( request.getParameter("root") );
		Site site = Jtp.getSite(request);
		if (site == null) {
			response.sendError(HttpServletResponse.SC_NOT_FOUND, "Page Not Found");
			return;
		}
		Node root = site.getNode(rootId);
		if (root == null) {
			response.sendError(HttpServletResponse.SC_NOT_FOUND, "Node Not Found");
			return;
		}
		User visitor = Jtp.getUser(request);

		String postIdS = request.getParameter("post");
		Node post = postIdS == null? root : site.getNode(Long.parseLong(postIdS));
		if (Jtp.canBeViewedBy(root, visitor))
			sendToTopicPage(root, post, topicView, response);
		else if (post.getOwner().equals(visitor))
			response.sendRedirect("/template/NamlServlet.jtp?macro=print_post&node="+post.getId());
		else
			sendToTopicPage(root, post, topicView, response);
	}

	private void sendToTopicPage(Node root, Node post, TopicView topicView, HttpServletResponse response) throws IOException {
		response.setHeader("Location", Jtp.topicViewPath(root, post.getId(), topicView));
		response.sendError(HttpServletResponse.SC_MOVED_PERMANENTLY);
	}

	public static Node getPostFromUrl(String url) {
		Site site = Jtp.getSiteFromUrl(url);
		if( site == null )
			return null;
		Matcher m = URL_PATTERN.matcher(url);
		if( !m.find() )
			return null;
		String post = m.group(4) == null? m.group(2) : m.group(4);
		return site.getNode(Long.parseLong(post));
	}

}