Clear user cache if seesion expired

Signed-off-by: Eric Wang <skygragon@gmail.com>

Author: skygragon

lib/core.js

@@ -10,8 +10,10 @@ core.getProblems = function(cb) {
   if (cached) return cb(null, cached);
 
   client.getProblems(function(e, problems) {
+    if (e) return cb(e);
+
     cache.set('all', problems);
-    return cb(e, problems);
+    return cb(null, problems);
   });
 };
 
@@ -61,19 +63,24 @@ core.updateProblem = function(problem, kv) {
 };
 
 core.login = function(user, cb) {
+  var self = this;
   client.login(user, function(e, user) {
     if (e) return cb(e);
 
-    // NOTE: need invalidate any user related cache
-    cache.del('all');
+    self.logout();
+
     cache.set('.user', user);
     return cb(null, user);
   });
 };
 
 core.logout = function(user) {
   user = this.getUser();
-  if (user) cache.del('.user');
+  if (user) {
+    // NOTE: need invalidate any user related cache
+    cache.del('.user');
+    cache.del('all');
+  }
   return user;
 };
 

lib/leetcode_client.js

@@ -20,9 +20,13 @@ function checkError(e, resp, expectedStatus, msg) {
   if (e) return e;
 
   if (resp && resp.statusCode !== expectedStatus) {
-    if (resp.statusCode === 403)
+    if (resp.statusCode === 403) {
       msg = msg || 'session expired, please login again';
 
+      var core = require('./core');
+      core.logout();
+    }
+
     return {
       msg:        msg || 'http error',
       statusCode: resp.statusCode
@@ -37,7 +41,14 @@ leetcodeClient.getProblems = function(cb) {
     e = checkError(e, resp, 200);
     if (e) return cb(e);
 
-    var problems = JSON.parse(body).stat_status_pairs.map(function(p) {
+    var json = JSON.parse(body);
+
+    // leetcode permits anonymous access to the problem list
+    // while we require login first to make a better experience.
+    if (json.user_name.length === 0)
+      return cb('session expired, please login again');
+
+    var problems = json.stat_status_pairs.map(function(p) {
       return {
         state:   p.status || 'None',
         id:      p.stat.question_id,