package dk.thoerup.marketstats;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.Locale;
import java.util.concurrent.TimeUnit;
import java.util.logging.Logger;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.spy.memcached.MemcachedClient;

import com.gc.android.market.api.MarketSession;
import com.gc.android.market.api.model.Market.AppsRequest;
import com.gc.android.market.api.model.Market.CommentsRequest;


@WebServlet(urlPatterns={"/ShowStats"})
public class ShowStats extends HttpServlet {
	private static final long serialVersionUID = 1L;

	static final int MAXCOMMENTS = 30;
	static final int APP_TIMEOUT = 30*60;
	static final int COMMENT_TIMEOUT = APP_TIMEOUT * 4;
	
	static final Logger log = Logger.getLogger(ShowStats.class.getName());

	String login;
	String password;
	
	MemcachedClient memcache = null;


	@Override
	public void init() throws ServletException {
		super.init();

		login = getServletContext().getInitParameter("login");
		password = getServletContext().getInitParameter("password");
		
		try {
			memcache = new MemcachedClient(new InetSocketAddress("localhost", 11211));
		} catch (IOException e) {
			throw new ServletException(e);
		}
	}

	@Override
	public void destroy() {
		super.destroy();
		
		memcache.shutdown(3, TimeUnit.SECONDS);
		memcache = null;
	}

	protected AppBean lookupApp(String query) throws IOException {
		

		String key = "marketstats:" + query.replace(' ', '_');
		//String response = (String) memcache.get(key);
		AppBean response = (AppBean) memcache.get(key);

		if (response == null) {
			response = lookupAppWorker(query);
			if (response != null) {
				memcache.set(key, APP_TIMEOUT, response);
			}
		} 
		return response;
	}

	protected AppBean lookupAppWorker(String query) {

		MarketSession session = new MarketSession();
		session.login(login,password);


		AppsRequest appsRequest = AppsRequest.newBuilder()
		.setQuery(query)
		.setStartIndex(0)
		.setEntriesCount(1)
		.setWithExtendedInfo(true)
		.build();
		
		AppsCallback appsCb = new AppsCallback();
		session.append(appsRequest, appsCb);
		session.flush();
		
		return appsCb.getResult().get(0);
	}	
	
	CommentsRequest buildCommentRequest(String appId, int start, int count) {
		CommentsRequest commentsRequest = CommentsRequest.newBuilder()
		.setAppId(appId)
		.setStartIndex(start)
		.setEntriesCount(count)
		.build();
		
		return commentsRequest;
	}
	
	private ArrayList<CommentBean> loadComments(String appId) {
		
		ArrayList<CommentBean> commentBeans = new ArrayList<CommentBean>();
		MarketSession session = new MarketSession();
		session.login(login,password);
		
		CommentCallback commentsCb = new CommentCallback();
		commentsCb.setList( commentBeans ); 

		session.setLocale( Locale.ROOT );
		
		
		
		int start = 0;
		do {
			int count = 10;
			if (start > 0)				
				count = Math.min(10, commentsCb.getEntryCount() );
			
			//log.warning("count=" + count + " start=" + start + " entryCount=" + commentsCb.getEntryCount() );
			for (int i=0; i<5;i++) {
				CommentsRequest commentsRequest = buildCommentRequest(appId,start,count);			
				session.append(commentsRequest, commentsCb);
				start +=10;
			}
			
			session.flush();
						
			if (start >= MAXCOMMENTS)
				break; //emergency brake
			
		} while ( start < commentsCb.getEntryCount() );
		
		return commentBeans;
	}

	
	
	@SuppressWarnings("unchecked")
	public ArrayList<CommentBean> getComments(AppBean app) {		
		String key = "marketstats:comments:" + app.getId();
		ArrayList<CommentBean>  comments =  (ArrayList<CommentBean>) memcache.get(key);

		if (comments == null) {
			comments = loadComments(app.getId());
			memcache.set(key, COMMENT_TIMEOUT, comments); 
		} 
		return comments;
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String query = "pname:" + request.getParameter("app");
		
		AppBean app = lookupApp(query);
		if (app != null) {
			request.setAttribute("app", app);
		
			ArrayList<CommentBean> comments = getComments(app);
			request.setAttribute("comments", comments);
		
			getServletContext().getRequestDispatcher("/statsview.jsp").forward(request, response);
		} else {
			response.getWriter().print("No app found with query=" + query);
		}
	}

}