Create app.py

app.py

@@ -0,0 +1,446 @@
+import os
+import re
+import uuid
+import pytz
+import smtplib
+import psycopg2
+import requests
+import gradio as gr
+
+from email.mime.text import MIMEText
+from email.mime.multipart import MIMEMultipart
+from datetime import datetime, date
+from dotenv import load_dotenv
+from urllib.parse import parse_qs
+
+
+# ================= LOAD ENV =================
+
+load_dotenv()
+
+DB_URL = os.getenv("DB_URL")
+GMAIL_USER = os.getenv("GMAIL_USER")
+GMAIL_APP_PASSWORD = os.getenv("GMAIL_APP_PASSWORD")
+CRON_SECRET = os.getenv("CRON")
+HF_URL = os.getenv("HF_URL")
+
+LEETCODE_API = "https://leetcode-api-vercel.vercel.app"
+
+
+# ================= DB =================
+
+def get_db():
+    return psycopg2.connect(DB_URL, sslmode="require")
+
+
+# ================= EMAIL =================
+
+def send_email(to, subject, html):
+
+    msg = MIMEMultipart("alternative")
+    msg["From"] = f"LeetCode Tracker <{GMAIL_USER}>"
+    msg["To"] = to
+    msg["Subject"] = subject
+
+    msg.attach(MIMEText(html, "html"))
+
+    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())
+
+        print("✅ Email sent:", to)
+        return True
+
+    except Exception as e:
+        print("❌ Email error:", e)
+        return False
+
+
+# ================= VALIDATION =================
+
+EMAIL_REGEX = re.compile(
+    r"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$"
+)
+
+
+def valid_email(email):
+    return bool(email and EMAIL_REGEX.match(email))
+
+
+def valid_leetcode(username):
+
+    if not username or len(username) < 3:
+        return False
+
+    try:
+        r = requests.get(
+            f"{LEETCODE_API}/{username}",
+            timeout=8
+        )
+
+        if r.status_code != 200:
+            return False
+
+        data = r.json()
+
+        return "username" in data or "profile" in data
+
+    except Exception:
+        return False
+
+
+# ================= LEETCODE =================
+
+def get_daily_problem():
+
+    r = requests.get(f"{LEETCODE_API}/daily", timeout=10)
+    r.raise_for_status()
+
+    data = r.json()
+
+    if "questionTitle" in data:
+        return data["questionTitle"], data["titleSlug"]
+
+    if "title" in data:
+        return data["title"], data["titleSlug"]
+
+    raise ValueError("Invalid daily API format")
+
+
+def solved_today(username, slug):
+
+    try:
+        r = requests.get(
+            f"{LEETCODE_API}/{username}/acSubmission?limit=20",
+            timeout=10,
+        )
+
+        if r.status_code != 200:
+            return False
+
+        data = r.json()
+
+        # ✅ New API format (your case)
+        if isinstance(data, dict) and "submission" in data:
+            submissions = data["submission"]
+
+        # ✅ Old API format
+        elif isinstance(data, dict) and "data" in data:
+            submissions = data["data"]
+
+        # ✅ Direct list format
+        elif isinstance(data, list):
+            submissions = data
+
+        # ❌ Error / invalid format
+        else:
+            print("⚠️ Unknown submission format:", data)
+            return False
+
+        # Get today's timestamp (Unix day start)
+        today = date.today()
+
+        for s in submissions:
+
+            if not isinstance(s, dict):
+                continue
+
+            if s.get("titleSlug") != slug:
+                continue
+
+            ts = s.get("timestamp")
+
+            if not ts:
+                continue
+
+            # Convert Unix timestamp → date
+            solved_date = datetime.fromtimestamp(
+                int(ts),
+                tz=pytz.utc
+            ).date()
+
+            if solved_date == today:
+                return True
+
+        return False
+
+    except Exception as e:
+        print("⚠️ solved_today error:", e)
+        return False
+
+
+# ================= SUBSCRIBE =================
+
+def subscribe(username, email, timezone):
+
+    if not valid_leetcode(username):
+        return "❌ Invalid LeetCode username"
+
+    if not valid_email(email):
+        return "❌ Invalid email format"
+
+    conn = get_db()
+    cur = conn.cursor()
+
+    # ---- Duplicate / Rate limit ----
+    cur.execute("""
+        SELECT email_verified, verification_token
+        FROM users
+        WHERE email = %s
+    """, (email,))
+
+    row = cur.fetchone()
+
+    # ---- Existing user ----
+    if row:
+
+        verified, token = row
+
+        if verified:
+            cur.close()
+            conn.close()
+            return "⚠️ Already subscribed"
+
+        # Resend verification
+        link = f"{HF_URL}?verify={token}"
+
+        email_sent = send_email(
+            email,
+            "🔁 Verify your subscription",
+            f"""
+            <h3>Email Verification</h3>
+            <p>Click below to activate:</p>
+            <a href="{link}">Verify</a>
+            """
+        )
+
+        cur.close()
+        conn.close()
+        
+        if email_sent:
+            return "📩 Verification email re-sent"
+        else:
+            return "⚠️ Failed to send verification email"
+
+    # ---- New user ----
+
+    token = uuid.uuid4().hex
+
+    cur.execute("""
+        INSERT INTO users (
+            leetcode_username,
+            email,
+            timezone,
+            email_verified,
+            verification_token,
+            unsubscribed
+        )
+        VALUES (%s, %s, %s, false, %s, false)
+    """, (username, email, timezone, token))
+
+    conn.commit()
+    cur.close()
+    conn.close()
+
+    link = f"{HF_URL}?verify={token}"
+
+    email_sent = send_email(
+        email,
+        "✅ Verify your subscription",
+        f"""
+        <h3>Welcome!</h3>
+        <p>Confirm your email:</p>
+        <a href="{link}">Verify Email</a>
+        """
+    )
+
+    if email_sent:
+        return "📩 Verification email sent"
+    else:
+        return "⚠️ Subscription failed - could not send email"
+
+
+# ================= VERIFY =================
+
+def verify_user(token):
+
+    conn = get_db()
+    cur = conn.cursor()
+
+    cur.execute("""
+        UPDATE users
+        SET email_verified = true
+        WHERE verification_token = %s
+        AND email_verified = false
+    """, (token,))
+
+    affected = cur.rowcount
+    conn.commit()
+    cur.close()
+    conn.close()
+
+    if affected == 0:
+        return "❌ Invalid or already used verification link"
+
+    return "✅ Email verified successfully!"
+
+
+# ================= UNSUBSCRIBE =================
+
+def unsubscribe_user(token):
+
+    conn = get_db()
+    cur = conn.cursor()
+
+    cur.execute("""
+        UPDATE users
+        SET unsubscribed = true
+        WHERE verification_token = %s
+    """, (token,))
+
+    affected = cur.rowcount
+
+    conn.commit()
+    cur.close()
+    conn.close()
+
+    if affected == 0:
+        return "❌ Invalid unsubscribe link"
+
+    return "✅ You are unsubscribed"
+
+
+# ================= SCHEDULER =================
+
+def run_scheduler(secret):
+
+    if secret != CRON_SECRET:
+        return "❌ Unauthorized"
+
+    conn = get_db()
+    cur = conn.cursor()
+
+    cur.execute("""
+        SELECT id, leetcode_username, email, timezone,
+               last_sent_date, last_sent_slot,
+               verification_token
+        FROM users
+        WHERE email_verified = true
+        AND unsubscribed = false
+    """)
+
+    users = cur.fetchall()
+
+    title, slug = get_daily_problem()
+
+    now_utc = datetime.now(pytz.utc)
+
+    for uid, username, email, tz, last_date, last_slot, token in users:
+
+        local = now_utc.astimezone(pytz.timezone(tz))
+        hour = local.hour
+
+        if hour == 9:
+            slot = "morning"
+            subject = "📘 Today's LeetCode"
+            body = f"<b>{title}</b>"
+
+        elif hour == 15:
+            slot = "afternoon"
+            subject = "⏰ Reminder"
+            body = f"You haven't solved <b>{title}</b> yet."
+
+        elif hour == 20:
+            slot = "night"
+            subject = "⚠️ Final Reminder"
+            body = f"Last chance to solve <b>{title}</b> today."
+
+        else:
+            continue
+
+        today = date.today()
+
+        # Idempotency
+        if last_date == today and last_slot == slot:
+            continue
+
+        if solved_today(username, slug):
+            continue
+
+        unsubscribe_link = f"{HF_URL}?unsubscribe={token}"
+
+        send_email(
+            email,
+            subject,
+            f"""
+            {body}
+            <br><br>
+            <a href="{unsubscribe_link}">Unsubscribe</a>
+            """
+        )
+
+        cur.execute("""
+            UPDATE users
+            SET last_sent_date=%s,
+                last_sent_slot=%s
+            WHERE id=%s
+        """, (today, slot, uid))
+
+    conn.commit()
+    cur.close()
+    conn.close()
+
+    return "✅ Scheduler completed"
+
+
+# ================= HANDLE URL PARAMS =================
+
+def handle_url_params(request: gr.Request):
+    """Handle verify and unsubscribe links"""
+    try:
+        # Get query parameters from request
+        query_string = request.query_params
+        
+        if "verify" in query_string:
+            token = query_string["verify"]
+            return verify_user(token)
+        elif "unsubscribe" in query_string:
+            token = query_string["unsubscribe"]
+            return unsubscribe_user(token)
+        else:
+            return ""
+    except Exception as e:
+        print(f"Error handling URL params: {e}")
+        return ""
+
+
+# ================= UI =================
+
+with gr.Blocks(title="LeetCode Daily Notifier") as app:
+
+    # Handle URL parameters at startup
+    url_message = gr.Markdown("")
+    
+    gr.Markdown("## 📬 LeetCode Daily Email Notifier")
+
+    user = gr.Textbox(label="LeetCode Username")
+    mail = gr.Textbox(label="Email")
+    tz = gr.Dropdown(pytz.all_timezones, value="Asia/Kolkata", label="Timezone")
+
+    out = gr.Textbox(label="Status")
+
+    gr.Button("Subscribe").click(subscribe, [user, mail, tz], out)
+
+    gr.Markdown("### 🔒 Internal Scheduler")
+
+    secret = gr.Textbox(label="Cron Secret", type="password")
+
+    gr.Button("Run Scheduler").click(run_scheduler, secret, out)
+
+    # Handle URL parameters when app loads
+    app.load(handle_url_params, outputs=url_message)
+
+
+if __name__ == "__main__":
+    app.launch(debug=True)