import javax.servlet.http.*;
import java.io.IOException;
import javax.servlet.*;
import java.io.PrintWriter;
import com.facebook.api.*;
import java.io.*;

public class SocialJavaTutorial extends HttpServlet {
	
	int count;

	//Application API Key and application secret from creating app in FB
	String appapikey = new String("762- your api key here -a7fb73627afdda0");
	String appsecret = new String("90e- your api secret here -7b47df6d957e");

	//Facebook loginPage to this application.  Parameter canvas=true shows the result in Facebook canvas
	String loginPage = "http://www.facebook.com/login.php?api_key="+"00b0049fc7cf0d1e4a4ba2ea3e55b269"+"&v=1.0&canvas=true";
	FacebookJsonRestClient facebook;  // the facebook client, talks to REST Server
	PrintWriter servletOutput;  // output of servlet. HTML or FBML out

	public void doGet( HttpServletRequest req, HttpServletResponse res ) throws ServletException, IOException{
		servletOutput = res.getWriter(); // response is sent to ServletOutput
		res.setContentType( "text/html" );
		servletOutput.println("This is the doGet method");
	}

	public void doPost(HttpServletRequest req, 
			HttpServletResponse res) 
	throws ServletException, IOException {

		servletOutput = res.getWriter(); // response is sent to ServletOutput
		res.setContentType( "text/html" );
		servletOutput.println("This is the doPost method  -  5");
		servletOutput.println("<br>");

		String user =null;
		String sessionKey=null;
		sessionKey = req.getParameter(FacebookParam.SESSION_KEY.toString());  // Session Key passed as request parameter
		if (sessionKey==null) { // If there is not session key, they user not logged in
			servletOutput.println("<fb:redirect url=" + loginPage + "/>");  // Facebook Redirect to login page
		}
		else{
			facebook = new FacebookJsonRestClient(appapikey, appsecret,sessionKey);  // create Facebook Json Rest Client
//			servletOutput.println("Facebook Client created");
//			servletOutput.println("<br>");
			
			// with Facebook client created, now Facebook API calls can be made
			// In this case, a call to FQL to get username
			
			count++;                                                         
			servletOutput.println("Since the beginning, this servlet has been accessed " +
		                count + " times."); 
			
			
			try{
				
				String mockfbmltext = req.getParameter("mockfbmltext");
				String displayText = req.getParameter("profiletext");
				
				if (mockfbmltext!=null){
	    			servletOutput.println(mockfbmltext);
	    		}else{
	    			
	    			user = req.getParameter("fb_sig_user");  // get user as a string.  User info passed as request parameter
					servletOutput.println("User is " + user);  // displays numeric value
					servletOutput.println("<br>");

					
					
					String query = "SELECT name FROM user WHERE uid=" + user;
					org.json.JSONArray resultArray = (org.json.JSONArray)facebook.fql_query(query); // query return an object.  Casting it as a String
					servletOutput.println("User Name is " + resultArray); 
			   		
					Long userLong = new Long(user); // need user as a long for  API calls

	    			
	    			
		    		if (displayText!=null){
		        		facebook.profile_setFBML(displayText, userLong);
		    		}
	
		        	// Set up input form to mimic PHP Example code
		        	servletOutput.println("</pre>");
		        	servletOutput.println("<form action=\"\" method=\"post\">");
		        	servletOutput.println("<input name=\"profiletext\" type=\"text\" size=\"30\" value=\"\"><br>");
		        	servletOutput.println("<input name=\"submit\" type=\"submit\" value=\"Display text on profile\">");
		        	servletOutput.println("</form>");
		        	
		        	String appCallBackUrl = "http://www.socialjava.com/servlet/SocialJavaTutorial/";
		        	String mockAjax=null;
	
	
		        	mockAjax+="<form>";
		        	mockAjax+="<input name=\"mockfbmltext\" type=\"text\" size=\"30\">";
	
		        	
		        	mockAjax+="<br />";
		        	mockAjax+="<input type=\"submit\"";
		        	mockAjax+="  clickrewriteurl=\""+ appCallBackUrl +"\"";
		        	mockAjax+="  clickrewriteid=\"preview\" value=\"Draw text below\"";
		        	mockAjax+="/>";
		        	mockAjax+="<br />";
		        	mockAjax+="<div id=\"preview\" style=\"border-style: solid; border-color: black;";
		        	mockAjax+=" border-width: 1px; padding: 5px;\">";
		        	mockAjax+="</div>";
		        	mockAjax+="</form>";
	   				facebook.profile_setFBML(mockAjax.toString(), userLong);
	
	        		        	
		        	
				}
			}
			catch( FacebookException ex )
			{
				servletOutput.println(">Error: Couldn't talk to Facebook> "  + ex );
			}
		} //else user is logged in
		servletOutput.close();
	}  // end doPost()
	


	  public void init() throws ServletException {
	    // Try to load the initial count from our saved persistent state
	    FileReader fileReader = null;
	    BufferedReader bufferedReader = null;
	    try {
	      fileReader = new FileReader("InitDestroyCounter.initial");
	      bufferedReader = new BufferedReader(fileReader);
	      String initial = bufferedReader.readLine();
	      count = Integer.parseInt(initial);
	      return;
	    }
	    catch (FileNotFoundException ignored) { }  // no saved state
	    catch (IOException ignored) { }            // problem during read
	    catch (NumberFormatException ignored) { }  // corrupt saved state
	    finally {
	      // Make sure to close the file
	      try {
	        if (bufferedReader != null) {
	          bufferedReader.close();
	        }
	      }
	      catch (IOException ignored) { }
	    }

	    // No luck with the saved state, check for an init parameter
	    String initial = getInitParameter("initial");                    
	    try {                                                            
	      count = Integer.parseInt(initial);                             
	      return;                                                        
	    }                                                                
	    catch (NumberFormatException ignored) { }  // null or non-integer value
	                                                                     
	    // Default to an initial count of "0"                            
	    count = 0;                                                       
	  }                                                                  
	  
	  public void destroy() {                                            
		    super.destroy();  // entirely optional
		    saveState();                                                     
		  }                                                                  
		                                                                     
		  public void saveState() {                                          
		    // Try to save the accumulated count                             
		    FileWriter fileWriter = null;
		    PrintWriter printWriter = null;
		    try {                                                            
		      fileWriter = new FileWriter("InitDestroyCounter.initial");
		      printWriter = new PrintWriter(fileWriter);         
		      printWriter.println(count);                                  
		      return;                                                        
		    }                                                                
		    catch (IOException e) {  // problem during write                 
		      // Log the exception. See Chapter 5.                           
		    }
		    finally {
		      // Make sure to close the file
		      if (printWriter != null) {
		        printWriter.close();
		      }
		    }
		  }
	  
	  
	
	
	
}