Add a method for checking the validity of the cookies

akibapass_downloader/const.py

@@ -1,2 +1,5 @@
-# Base URL of the Akibapass service
+# Base URL of the Akibapass service.
 BASE_URL = "https://akibapasstv.vhx.tv"
+
+# URL of Akibapass' login page.
+LOGIN_URL = f"{BASE_URL}/login"

akibapass_downloader/login.py

@@ -1,13 +1,17 @@
+import json
+import json.decoder
+import re
+
 import requests
 from bs4 import BeautifulSoup
 
-from akibapass_downloader.const import BASE_URL
+from akibapass_downloader.const import LOGIN_URL
 
 
 def login(email: str, password: str) -> dict[str, str] | None:
     """Performs a login on the Akibapass site and returns a set of cookies
     to use while performing other requests."""
-    login_page_req = requests.get(f"{BASE_URL}/login")
+    login_page_req = requests.get(LOGIN_URL)
     if login_page_req.status_code != 200:
         return None
 
@@ -18,7 +22,7 @@ def login(email: str, password: str) -> dict[str, str] | None:
     csrf_param = page.find("meta", attrs={"name": "csrf-param"}).attrs["content"]
 
     r = requests.post(
-        f"{BASE_URL}/login",
+        LOGIN_URL,
         cookies={
             # Use the session we received on the login page.
             "_session": login_page_req.cookies["_session"],
@@ -36,3 +40,40 @@ def login(email: str, password: str) -> dict[str, str] | None:
     return {
         "_session": r.cookies["_session"],
     }
+
+
+def is_logged_in(cookies: dict[str, str]) -> bool:
+    """Checks if the cookies in @cookies are stil valid."""
+    r = requests.get(
+        LOGIN_URL,
+        cookies=cookies,
+    )
+    if r.status_code != 200:
+        return False
+
+    soup = BeautifulSoup(r.text, "html.parser")
+    scripts = soup.find_all("script")
+    user_data_matcher = re.compile(r".*window._current_user\s*=\s*(\{.*?\}).*")
+    for script in scripts:
+        raw_content = "".join(script.contents)
+        content = "".join([line.strip() for line in raw_content.split("\n")])
+        if "window._current_user" not in content:
+            continue
+
+        match = user_data_matcher.match(content)
+        if match:
+            try:
+                # Use a try to guard against Akibapass doing something like
+                # `window._current_user = null;`, which is obviously not really JSON.
+                # (Or maybe it is?).
+                data = json.loads(match.group(1))
+            except json.decoder.JSONDecodeError:
+                continue
+
+            # Check that Akibapass doesn't do something like
+            # `window._current_user = {}`. Also, the variable is set, even when
+            # not logged in. But then the "id" attribute of the user is set to
+            # None.
+            return data != {} and data.get("id") is not None
+
+    return False