Fix notification System

worker/app/notifications/webhook.py

@@ -0,0 +1,74 @@
+"""
+Webhook sender (worker) – POST HTTP con firma HMAC-SHA256.
+
+Copia del sender backend: i due container sono separati.
+"""
+
+import hashlib
+import hmac
+import json
+import uuid as uuid_mod
+
+import httpx
+
+DEFAULT_TIMEOUT = 10.0
+
+
+class WebhookError(Exception):
+    def __init__(self, message: str, http_status: int | None = None):
+        super().__init__(message)
+        self.http_status = http_status
+
+
+async def send_webhook(
+    url: str,
+    payload: dict,
+    event_type: str = "new_message",
+    webhook_secret: str | None = None,
+    timeout: float = DEFAULT_TIMEOUT,
+) -> dict:
+    """
+    Invia un payload JSON a un webhook URL.
+
+    Returns:
+        dict con http_status, delivery_id
+
+    Raises:
+        WebhookError: in caso di timeout, errore di rete o HTTP >= 400
+    """
+    body = json.dumps(payload, ensure_ascii=False, default=str).encode("utf-8")
+    delivery_id = str(uuid_mod.uuid4())
+
+    headers = {
+        "Content-Type": "application/json",
+        "X-PEChub-Event": event_type,
+        "X-Delivery": delivery_id,
+        "User-Agent": "PEChub-Webhook/1.0",
+    }
+
+    if webhook_secret:
+        sig = hmac.new(
+            webhook_secret.encode("utf-8"),
+            body,
+            hashlib.sha256,
+        ).hexdigest()
+        headers["X-Hub-Signature-256"] = f"sha256={sig}"
+
+    async with httpx.AsyncClient(timeout=timeout) as client:
+        try:
+            response = await client.post(url, content=body, headers=headers)
+        except httpx.TimeoutException as exc:
+            raise WebhookError(f"Timeout webhook dopo {timeout}s") from exc
+        except httpx.RequestError as exc:
+            raise WebhookError(f"Errore di rete webhook: {exc}") from exc
+
+    if response.status_code >= 400:
+        raise WebhookError(
+            f"Webhook HTTP {response.status_code}: {response.text[:200]}",
+            http_status=response.status_code,
+        )
+
+    return {
+        "http_status": response.status_code,
+        "delivery_id": delivery_id,
+    }