Update app.py

app.py

@@ -6,7 +6,13 @@ import smtplib
 import psycopg2
 import requests
 import gradio as gr
-
+import json
+import pickle
+from google.auth.transport.requests import Request
+from google.oauth2.credentials import Credentials
+from google_auth_oauthlib.flow import InstalledAppFlow
+from googleapiclient.discovery import build
+import base64
 from email.mime.text import MIMEText
 from email.mime.multipart import MIMEMultipart
 from datetime import datetime, date
@@ -33,27 +39,95 @@ def get_db():
     return psycopg2.connect(DB_URL, sslmode="require")
 
 
+SCOPES = ["https://www.googleapis.com/auth/gmail.send"]
+TOKEN_FILE = "token.pkl"
+
+
+def get_gmail_service():
+    """
+    Get authenticated Gmail API service.
+    Uses token.pkl if available.
+    Recreates if expired using credentials from ENV.
+    """
+
+    creds = None
+
+    # ---- Load cached token ----
+    if os.path.exists(TOKEN_FILE):
+        try:
+            with open(TOKEN_FILE, "rb") as f:
+                creds = pickle.load(f)
+        except Exception:
+            creds = None
+
+    # ---- If token invalid ----
+    if not creds or not creds.valid:
+
+        if creds and creds.expired and creds.refresh_token:
+            try:
+                creds.refresh(Request())
+            except Exception:
+                creds = None
+
+        # ---- Recreate using credentials ----
+        if not creds:
+
+            creds_json = os.getenv("GMAIL_CREDENTIALS")
+
+            if not creds_json:
+                raise Exception("Missing GMAIL_CREDENTIALS in secrets")
+
+            creds_dict = json.loads(creds_json)
+
+            flow = InstalledAppFlow.from_client_config(
+                creds_dict,
+                SCOPES,
+            )
+
+            creds = flow.run_local_server(port=0)
+
+        # ---- Save token ----
+        with open(TOKEN_FILE, "wb") as f:
+            pickle.dump(creds, f)
+
+    return build("gmail", "v1", credentials=creds)
+
+
+
 # ================= EMAIL =================
 
 def send_email(to, subject, html):
 
-    msg = MIMEMultipart("alternative")
-    msg["From"] = f"LeetCode Tracker <{GMAIL_USER}>"
-    msg["To"] = to
-    msg["Subject"] = subject
+    try:
+        service = get_gmail_service()
 
-    msg.attach(MIMEText(html, "html"))
+        message = MIMEText(html, "html")
+        message["To"] = to
+        message["From"] = GMAIL_USER
+        message["Subject"] = subject
 
-    try:
-        with smtplib.SMTP_SSL("smtp.gmail.com", 465) as server:
-            server.login(GMAIL_USER, GMAIL_APP_PASSWORD)
-            server.sendmail(msg["From"], to, msg.as_string())
+        raw = base64.urlsafe_b64encode(
+            message.as_bytes()
+        ).decode()
+
+        body = {"raw": raw}
 
-        print("✅ Email sent:", to)
+        service.users().messages().send(
+            userId="me",
+            body=body
+        ).execute()
+
+        print("✅ Gmail API sent:", to)
         return True
 
     except Exception as e:
-        print("❌ Email error:", e)
+        print("❌ Gmail API error:", e)
+
+        # If token is corrupted → delete and retry next time
+        if os.path.exists(TOKEN_FILE):
+            os.remove(TOKEN_FILE)
+            print("♻️ token.pkl deleted, will regenerate")
+
         return False