/*
 * Copyright 2007 AOL, LLC.
 * Portions Copyright 2009 Apache Software Foundation
 *
 * 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.apache.roller.weblogger.webservices.oauth;

import java.io.IOException;
import java.io.PrintWriter;

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

import net.oauth.OAuth;
import net.oauth.OAuthAccessor;
import net.oauth.OAuthMessage;
import net.oauth.server.OAuthServlet;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.roller.weblogger.business.OAuthManager;
import org.apache.roller.weblogger.business.WebloggerFactory;

/**
 * Autherization request handler.
 *
 * @author Praveen Alavilli
 * @author Dave Johnson (adapted for Roller)
 */
public class AuthorizationServlet extends HttpServlet {
    protected static Log log =
            LogFactory.getFactory().getInstance(AuthorizationServlet.class);
    
    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {
        
        try{
            OAuthMessage requestMessage = OAuthServlet.getMessage(request, null);
            
            OAuthManager omgr = WebloggerFactory.getWeblogger().getOAuthManager();
            OAuthAccessor accessor = omgr.getAccessor(requestMessage);
           
            if (Boolean.TRUE.equals(accessor.getProperty("authorized"))) {
                // already authorized send the user back
                returnToConsumer(request, response, accessor);
            } else {
                sendToAuthorizePage(request, response, accessor);
            }
        
        } catch (Exception e){
            handleException(e, request, response, true);
        }
    }
    
    @Override 
    public void doPost(HttpServletRequest request, HttpServletResponse response) 
            throws IOException, ServletException {
        
        try{
            OAuthMessage requestMessage = OAuthServlet.getMessage(request, null);
            
            OAuthManager omgr = WebloggerFactory.getWeblogger().getOAuthManager();
            OAuthAccessor accessor = omgr.getAccessor(requestMessage);

            String userId = request.getParameter("userId");
            if (userId == null) {
                userId = request.getParameter("xoauth_requestor_id");
            }
            
            if (userId == null) {
                // no user associted with the key, must be site-wide key,
                // so get user to login and do the authorization process
                sendToAuthorizePage(request, response, accessor);
            
            } else {

                // if consumer key is for specific user, check username match
                String consumerUserId = (String)accessor.consumer.getProperty("userId");
                if (consumerUserId != null && !userId.equals(consumerUserId)) {
                    throw new ServletException("ERROR: invalid or unspecified userId");
                }

                // set userId in accessor and mark it as authorized
                omgr.markAsAuthorized(accessor, userId);
                WebloggerFactory.getWeblogger().flush();
            }
            
            returnToConsumer(request, response, accessor);
            
        } catch (Exception e){
            handleException(e, request, response, true);
        }
    }
    
    private void sendToAuthorizePage(HttpServletRequest request, 
            HttpServletResponse response, OAuthAccessor accessor)
    throws IOException, ServletException{
        String callback = request.getParameter("oauth_callback");
        if(callback == null || callback.length() <=0) {
            callback = "none";
        }
        String consumer_description = (String)accessor.consumer.getProperty("description");
        request.setAttribute("CONS_DESC", consumer_description);
        request.setAttribute("CALLBACK", callback);
        request.setAttribute("TOKEN", accessor.requestToken);
        request.getRequestDispatcher("/roller-ui/oauthAuthorize.rol").forward(request, response);
    }
    
    private void returnToConsumer(HttpServletRequest request, 
            HttpServletResponse response, OAuthAccessor accessor)
        throws IOException, ServletException {

        // send the user back to site's callBackUrl
        String callback = request.getParameter("oauth_callback");
        if ("none".equals(callback)
            && accessor.consumer.callbackURL != null 
                && accessor.consumer.callbackURL.length() > 0){
            // first check if we have something in our properties file
            callback = accessor.consumer.callbackURL;
        }
        
        if ( "none".equals(callback) ) {
            // no call back it must be a client
            response.setContentType("text/plain");
            PrintWriter out = response.getWriter();
            out.println("You have successfully authorized for consumer key '"
                    + accessor.consumer.consumerKey
                    + "'. Please close this browser window and click continue"
                    + " in the client.");
            out.close();
        } else {
            // if callback is not passed in, use the callback from config
            if(callback == null || callback.length() <=0 ) {
                callback = accessor.consumer.callbackURL;
            }
            String token = accessor.requestToken;
            if (token != null && callback != null) {
                callback = OAuth.addParameters(callback, "oauth_token", token);
            }

            response.setStatus(HttpServletResponse.SC_MOVED_TEMPORARILY);
            response.setHeader("Location", callback);
        }
    }

    public void handleException(Exception e, HttpServletRequest request,
            HttpServletResponse response, boolean sendBody)
            throws IOException, ServletException {
        log.debug("ERROR authorizing token", e);
        String realm = (request.isSecure())?"https://":"http://";
        realm += request.getLocalName();
        OAuthServlet.handleException(response, e, realm, sendBody);
    }
}
