feat: provide governed notification email delivery

src/govoplan_mail/backend/capabilities.py

@@ -1,10 +1,13 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
+from email.message import EmailMessage
+from email.utils import formatdate, make_msgid
 from typing import Any
 
 from sqlalchemy.orm import Session
 
+from govoplan_core.core.mail import NotificationMailDeliveryRequest
 from govoplan_core.core.modules import ModuleContext
 from govoplan_mail.backend.mail_profiles import (
     MailProfileError,
@@ -554,3 +557,102 @@ def delivery_outbox_capability(context: ModuleContext):
 
     configure_runtime(settings=context.settings)
     return MailDeliveryOutboxCapability()
+
+
+class MailNotificationDeliveryCapability:
+    """Submit notification email to the Mail-owned durable outbox."""
+
+    def submit_notification_mail(
+        self,
+        session: Session,
+        request: NotificationMailDeliveryRequest,
+    ) -> dict[str, object]:
+        profile_id = str(request.mail_profile_id or "").strip()
+        from_address = str(request.from_address or "").strip()
+        if not profile_id or not from_address:
+            return {
+                "status": "paused",
+                "provider": "mail.notificationDelivery",
+                "error": (
+                    "Notification email requires a Mail profile and sender "
+                    "selected by tenant policy."
+                ),
+            }
+        try:
+            transport = campaign_profile_delivery_summary(
+                session,
+                tenant_id=request.tenant_id,
+                profile_id=profile_id,
+                smtp_server_id=request.smtp_server_id,
+                smtp_credential_id=request.smtp_credential_id,
+            )
+        except MailProfileError:
+            return {
+                "status": "paused",
+                "provider": "mail.notificationDelivery",
+                "error": (
+                    "The selected notification Mail profile is unavailable or "
+                    "blocked by effective policy."
+                ),
+            }
+        if not transport.get("smtp_available"):
+            return {
+                "status": "paused",
+                "provider": "mail.notificationDelivery",
+                "error": "The selected notification Mail profile has no usable SMTP transport.",
+            }
+
+        message = EmailMessage()
+        message["Date"] = formatdate(localtime=True)
+        message["Message-ID"] = make_msgid()
+        message["Subject"] = request.subject
+        message["From"] = from_address
+        message["To"] = request.recipient
+        message.set_content(request.body_text)
+        if request.body_html:
+            message.add_alternative(request.body_html, subtype="html")
+
+        from govoplan_mail.backend.delivery_outbox import submit_delivery_command
+
+        command = submit_delivery_command(
+            session,
+            tenant_id=request.tenant_id,
+            command_type="notification",
+            source_module="notifications",
+            source_resource_type="notification",
+            source_resource_id=request.notification_id,
+            source_version_id=None,
+            idempotency_key=f"notification:{request.notification_id}",
+            profile_id=profile_id,
+            smtp_server_id=(
+                str(transport.get("smtp_server_id"))
+                if transport.get("smtp_server_id")
+                else request.smtp_server_id
+            ),
+            smtp_credential_id=(
+                str(transport.get("smtp_credential_id"))
+                if transport.get("smtp_credential_id")
+                else request.smtp_credential_id
+            ),
+            message_bytes=bytes(message),
+            envelope_from=from_address,
+            envelope_recipients=[request.recipient],
+            from_header=from_address,
+            expected_smtp_transport_revision=str(
+                transport["smtp_transport_revision"]
+            ),
+        )
+        return {
+            "status": "accepted",
+            "provider": "mail.delivery_outbox",
+            "external_message_id": command["id"],
+            "delivery_status": command["status"],
+            "duplicate": bool(command.get("duplicate")),
+        }
+
+
+def notification_delivery_capability(
+    context: ModuleContext,
+) -> MailNotificationDeliveryCapability:
+    configure_runtime(settings=context.settings)
+    return MailNotificationDeliveryCapability()