feat: update stock monitoring to include Discord user mentions and validation

Dockerfile

@@ -8,6 +8,6 @@ WORKDIR /app
 COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
 
-COPY monitor.py .
+COPY main.py .
 
 CMD ["python", "main.py"]

main.py

@@ -9,9 +9,12 @@ import requests
 # Configuration
 # =========================
 
-PRODUCT_URL = f"{os.environ["PRODUCT_URL"]}.js"
+DISCORD_USER_ID_TO_PING = "736200712169455656"
-TARGET_VARIANT_ID = os.environ["TARGET_VARIANT_ID"]
+DISCORD_MENTION = f"<@{DISCORD_USER_ID_TO_PING}>"
-DISCORD_WEBHOOK_URL = os.environ["DISCORD_WEBHOOK_URL"]
+
+PRODUCT_URL = f"{os.environ.get('PRODUCT_URL', '').rstrip('/')}.js"
+TARGET_VARIANT_ID_RAW = os.environ.get("TARGET_VARIANT_ID", "")
+DISCORD_WEBHOOK_URL = os.environ.get("DISCORD_WEBHOOK_URL", "")
 
 CHECK_INTERVAL_SECONDS = 30
 POST_DETECTION_COOLDOWN_SECONDS = 600
@@ -36,54 +39,101 @@ console_handler.setFormatter(log_format)
 logger.addHandler(console_handler)
 
 
+def _require_env(name: str, value: str) -> str:
+    """Return the env var value; raises if missing or empty."""
+    value = (value or "").strip()
+    if not value:
+        raise RuntimeError(f"Missing required environment variable: {name}")
+    return value
+
+
+def _normalize_variant_id(raw: str) -> str:
+    """Return a string form of the variant id; raises if invalid."""
+    raw = (raw or "").strip()
+    if not raw:
+        raise RuntimeError("TARGET_VARIANT_ID is empty")
+    try:
+        return str(int(raw))
+    except ValueError as exc:
+        raise RuntimeError("TARGET_VARIANT_ID must be an integer-like value") from exc
+
+
+def validate_config() -> tuple[str, str, str]:
+    """Validate required config and return normalized (product_url, variant_id, webhook_url)."""
+    product_url = _require_env("PRODUCT_URL", PRODUCT_URL)
+    variant_id = _normalize_variant_id(TARGET_VARIANT_ID_RAW)
+    webhook_url = _require_env("DISCORD_WEBHOOK_URL", DISCORD_WEBHOOK_URL)
+
+    if not webhook_url.startswith("https://"):
+        raise RuntimeError("DISCORD_WEBHOOK_URL must start with https://")
+
+    return product_url, variant_id, webhook_url
+
+
 # =========================
 # Discord Notification
 # =========================
 
 def send_discord_notification(product_name, variant_name, checkout_link):
-    """
+    """Sends a stock alert to Discord using a webhook."""
-    Sends a stock alert to Discord using a webhook.
-    """
-
     logger.critical("Stock detected! Sending Discord notification.")
 
-    payload = {"content": ("🚨 **RESTOCK ALERT** 🚨\n\n"
+    payload = {"content": (f"{DISCORD_MENTION}\n"
+                           "🚨 **RESTOCK ALERT** 🚨\n\n"
                            f"**{product_name}**\n"
                            f"Variant: {variant_name}\n\n"
                            f"👉 [ONE-CLICK CHECKOUT]({checkout_link})")}
 
     try:
-        response = requests.post(DISCORD_WEBHOOK_URL, json=payload)
+        response = requests.post(DISCORD_WEBHOOK_URL, json=payload, timeout=10)
 
         if response.status_code == 204:
             logger.info("Discord notification sent successfully.")
         else:
             logger.error("Discord notification failed. "
-                         f"HTTP status code: {response.status_code}")
+                         f"HTTP status code: {response.status_code}; response: {response.text[:500]}")
 
     except Exception as exception:
         logger.error("Failed to send Discord notification due to an exception.", exc_info=exception)
 
 
+def send_startup_test_ping():
+    """Sends a one-time hello-world message to validate webhook + mentions."""
+    logger.info("Sending startup Discord test ping...")
+
+    payload = {"content": (f"{DISCORD_MENTION} Hello world! "
+                           "✅ Webhook connection is working and user mention should ping.")}
+
+    try:
+        response = requests.post(DISCORD_WEBHOOK_URL, json=payload, timeout=10)
+
+        if response.status_code == 204:
+            logger.info("Startup Discord test ping sent successfully.")
+        else:
+            logger.error("Startup Discord test ping failed. "
+                         f"HTTP status code: {response.status_code}; response: {response.text[:500]}")
+
+    except Exception as exception:
+        logger.error("Failed to send startup test ping due to an exception.", exc_info=exception)
+
+
 # =========================
 # Stock Monitoring Logic
 # =========================
 
 def check_stock_continuously():
-    """
+    """Continuously checks the product JSON endpoint to see if the target variant is available for purchase."""
-    Continuously checks the product JSON endpoint to see if the target
+    product_url, target_variant_id, _ = validate_config()
-    variant is available for purchase.
-    """
 
-    logger.info(f"Stock monitor started. Watching variant ID: {TARGET_VARIANT_ID}")
+    logger.info(f"Stock monitor started. Watching variant ID: {target_variant_id}")
 
     request_headers = {"User-Agent": ("Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
                                       "AppleWebKit/537.36 (KHTML, like Gecko) "
-                                      "Chrome/120.0.0.0 Safari/537.36"), "Accept": "application/json"}
+                                      "Chrome/120.0.0.0 Safari/537.36"), "Accept": "application/json", }
 
     while True:
         try:
-            response = requests.get(PRODUCT_URL, headers=request_headers, timeout=10)
+            response = requests.get(product_url, headers=request_headers, timeout=10)
 
             if response.status_code != 200:
                 logger.error(f"HTTP request failed. Status code: {response.status_code}")
@@ -94,10 +144,11 @@ def check_stock_continuously():
             product_name = product_data.get("title", "FormD T1")
             variants = product_data.get("variants", [])
 
-            target_variant = next((variant for variant in variants if variant.get("id") == TARGET_VARIANT_ID), None)
+            target_variant = next((variant for variant in variants if str(variant.get("id")) == target_variant_id),
+                None, )
 
             if not target_variant:
-                logger.error(f"Variant ID {TARGET_VARIANT_ID} was not found in the product data.")
+                logger.error(f"Variant ID {target_variant_id} was not found in the product data.")
                 time.sleep(CHECK_INTERVAL_SECONDS)
                 continue
 
@@ -107,7 +158,7 @@ def check_stock_continuously():
             if is_in_stock:
                 logger.warning(f"Stock available! Variant detected: {variant_name}")
 
-                checkout_link = (f"https://formdt1.com/cart/{TARGET_VARIANT_ID}:1")
+                checkout_link = f"https://formdt1.com/cart/{target_variant_id}:1"
 
                 send_discord_notification(product_name, variant_name, checkout_link)
 
@@ -123,7 +174,7 @@ def check_stock_continuously():
         except requests.exceptions.Timeout:
             logger.warning("Request timed out. The server may be slow or blocking requests.")
 
-        except Exception as exception:
+        except Exception:
             logger.exception("An unexpected error occurred during the stock check.")
 
         time.sleep(CHECK_INTERVAL_SECONDS)
@@ -134,4 +185,6 @@ def check_stock_continuously():
 # =========================
 
 if __name__ == "__main__":
+    validate_config()
+    send_startup_test_ping()
     check_stock_continuously()