Add Authentication extra features to Comments tab

portfolio/pom.xml

@@ -33,6 +33,11 @@
       <artifactId>appengine-api-1.0-sdk</artifactId>
       <version>1.9.59</version>
     </dependency>
+    <dependency>
+      <groupId>org.javatuples</groupId>
+      <artifactId>javatuples</artifactId>
+      <version>1.2</version>
+    </dependency>
     <dependency>
       <groupId>com.opencsv</groupId>
       <artifactId>opencsv</artifactId>

portfolio/src/main/java/com/google/sps/servlets/AuthenticationServlet.java

@@ -14,6 +14,8 @@
 
 package com.google.sps.servlets;
 
+import com.google.gson.Gson;
+import org.javatuples.Pair;
 import com.google.appengine.api.users.UserService;
 import com.google.appengine.api.users.UserServiceFactory;
 import java.io.IOException;
@@ -27,16 +29,25 @@ public class AuthenticationServlet extends HttpServlet {
 
   @Override
   public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
-    response.setContentType("text/html");
+    response.setContentType("application/json");
     UserService userService = UserServiceFactory.getUserService();
     String redirectUrl = "/index.html";
     if (userService.isUserLoggedIn()) {
+      String userEmail = userService.getCurrentUser().getEmail();
       String logoutUrl = userService.createLogoutURL(redirectUrl);
-      response.getWriter().println("<p>Logout <a href=\"" + logoutUrl + "\">here</a>.");
+      Pair<String, String> userInfo = new Pair<>(userEmail, logoutUrl);
+      sendJson(response, userInfo);
     } else {
       String loginUrl = userService.createLoginURL(redirectUrl);
-      response.getWriter().println("<p>Login <a href=\"" + loginUrl + "\">here</a>.");
+      Pair<String, String> userInfo = new Pair<>("N/A", loginUrl);
+      sendJson(response, userInfo);
     }
   }
+
+  private void sendJson(HttpServletResponse response, Pair<String, String> userInfo) throws IOException {
+    Gson gson = new Gson();
+    String json = gson.toJson(userInfo);
+    response.getWriter().println(json);
+  }
 
 }

portfolio/src/main/java/com/google/sps/servlets/ListCommentsServlet.java

@@ -60,8 +60,9 @@ private List<String> getCommentsToDisplay(PreparedQuery results, int max) {
     Iterator<Entity> iterator = results.asIterator();
     for (int i = 0; (i < max) && (iterator.hasNext()); ++i) {
       Entity entity = iterator.next();
+      String email = (String) entity.getProperty("email");
       String comment = (String) entity.getProperty("comment");
-      comments.add(comment);
+      comments.add(email + ": " + comment);
     }
     return comments;
   }

portfolio/src/main/java/com/google/sps/servlets/NewCommentServlet.java

@@ -14,6 +14,8 @@
 
 package com.google.sps.servlets;
 
+import com.google.appengine.api.users.UserService;
+import com.google.appengine.api.users.UserServiceFactory;
 import com.google.appengine.api.datastore.DatastoreService;
 import com.google.appengine.api.datastore.DatastoreServiceFactory;
 import com.google.appengine.api.datastore.Entity;
@@ -29,17 +31,20 @@ public class NewCommentServlet extends HttpServlet {
 
   @Override
   public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
+    UserService userService = UserServiceFactory.getUserService();
+    String email = userService.getCurrentUser().getEmail();
     String comment = request.getParameter("comment");
     long timestamp = System.currentTimeMillis();
-    Entity commentEntity = createEntity(comment, timestamp);
+    Entity commentEntity = createEntity(comment, timestamp, email);
     putEntity(commentEntity);
     response.sendRedirect("/index.html");
   }
 
-  private Entity createEntity(String comment, long timestamp) {
+  private Entity createEntity(String comment, long timestamp, String email) {
     Entity entity = new Entity("Comment");
     entity.setProperty("comment", comment);
     entity.setProperty("timestamp", timestamp);
+    entity.setProperty("email", email);
     return entity;
   }
 

portfolio/src/main/webapp/libraries.js

@@ -146,9 +146,30 @@ function drawCoronavirusChart() {
 
 async function getLoginStatus() {
   const response = await fetch('/authentication');
-  const responseHtml = await response.text();
-  document.getElementById('login-status').innerHTML = responseHtml;
-  if (responseHtml.includes('Logout')) {
-    document.getElementById('comments-form').style.display = 'block';
-  }
+  const json = await response.json();
+  const userEmail = getEmail(json);
+  const redirectUrl = getUrl(json);
+  if (userEmail == 'N/A') {
+    const html = loginHtml(redirectUrl);
+    document.getElementById('login-status').innerHTML = html;
+  } else {
+    const html = logoutHtml(userEmail, redirectUrl);
+    document.getElementById('login-status').innerHTML = html;
+    document.getElementById('comments-form').style.display = "block";
+}
+
+function getEmail(json) {
+  return json.val0;
+}
+
+function getUrl(json) {
+  return json.val1;
+}
+
+function loginHtml(loginUrl) {
+  return "<p>Login <a href=\"" + loginUrl + "\">here</a>.";
+}
+
+function logoutHtml(userEmail, logoutUrl) {
+  return "<p>Hi " + userEmail + "! Logout <a href=\"" + logoutUrl + "\">here</a>.";
 }