Fix expired session detection

The old code failed to detect the expiration of the session cookie,
causing problems in testing and submission. Now we detect if the session
cookie is usable by trying getting the progress of the user.

Author: ianding1

autoload/leetcode.py

@@ -41,6 +41,7 @@
 LC_SUBMISSION = LC_BASE + '/submissions/detail/{submission}/'
 LC_CHECK = LC_BASE + '/submissions/detail/{submission}/check/'
 LC_PROBLEM_SET_ALL = LC_BASE + '/problemset/all/'
+LC_PROGRESS_ALL = LC_BASE + '/api/progress/all/'
 
 EMPTY_FREQUENCIES = [0, 0, 0, 0, 0, 0, 0, 0]
 
@@ -69,7 +70,6 @@ def _make_headers():
     assert is_login()
     headers = {'Origin': LC_BASE,
                'Referer': LC_BASE,
-               'X-CSRFToken': session.cookies['csrftoken'],
                'X-Requested-With': 'XMLHttpRequest'}
     return headers
 
@@ -143,6 +143,19 @@ def is_login():
     return session and 'LEETCODE_SESSION' in session.cookies
 
 
+def get_progress():
+    headers = _make_headers()
+    res = session.get(LC_PROGRESS_ALL, headers=headers)
+    if res.status_code != 200:
+        _echoerr('cannot get the progress')
+        return None
+
+    data = res.json()
+    if 'solvedTotal' not in data:
+        return None
+    return data
+
+
 def load_session_cookie(browser):
     if browser_cookie3 is None:
         _echoerr('browser_cookie3 not installed: pip3 install browser_cookie3 --user')
@@ -170,9 +183,9 @@ def load_session_cookie(browser):
     session = requests.Session()
     session.cookies.set_cookie(session_cookie)
 
-    res = session.get(LC_BASE)
-    if res.status_code != 200:
-        _echoerr('cannot open ' + LC_BASE + '. Session might have expired.')
+    progress = get_progress()
+    if progress is None:
+        _echoerr('cannot get progress. Please relogin in your browser.')
         keyring.delete_password('leetcode.vim', 'SESSION_COOKIE')
         return False
 
@@ -182,7 +195,11 @@ def load_session_cookie(browser):
 def _get_category_problems(category):
     headers = _make_headers()
     url = LC_CATEGORY_PROBLEMS.format(category=category)
+    log.info('_get_category_problems request: url="%s" headers="%s"',
+             url, headers)
     res = session.get(url, headers=headers)
+    log.info('_get_category_problems response: status="%s" body="%s"',
+             res.status_code, res.text)
     if res.status_code != 200:
         _echoerr('cannot get the category: {}'.format(category))
         return []