Add support for Mailtrap

cahna · cahna · commit 73897b7fe9da · 2024-11-10T15:35:48.000-08:00
diff --git a/anymail/backends/mailtrap.py b/anymail/backends/mailtrap.py
@@ -0,0 +1,248 @@
+import warnings
+from typing import Any, Literal, NotRequired, TypedDict
+
+from ..exceptions import AnymailRequestsAPIError, AnymailWarning
+from ..message import AnymailMessage, AnymailRecipientStatus
+from ..utils import Attachment, EmailAddress, get_anymail_setting, update_deep
+from .base_requests import AnymailRequestsBackend, RequestsPayload
+
+
+class MailtrapAddress(TypedDict):
+    email: str
+    name: NotRequired[str]
+
+
+class MailtrapAttachment(TypedDict):
+    content: str
+    type: NotRequired[str]
+    filename: str
+    disposition: NotRequired[Literal["attachment", "inline"]]
+    content_id: NotRequired[str]
+
+
+MailtrapData = TypedDict(
+    "MailtrapData",
+    {
+        "from": MailtrapAddress,
+        "to": NotRequired[list[MailtrapAddress]],
+        "cc": NotRequired[list[MailtrapAddress]],
+        "bcc": NotRequired[list[MailtrapAddress]],
+        "attachments": NotRequired[list[MailtrapAttachment]],
+        "headers": NotRequired[dict[str, str]],
+        "custom_variables": NotRequired[dict[str, str]],
+        "subject": str,
+        "text": str,
+        "html": NotRequired[str],
+        "category": NotRequired[str],
+        "template_id": NotRequired[str],
+        "template_variables": NotRequired[dict[str, Any]],
+    },
+)
+
+
+class MailtrapPayload(RequestsPayload):
+    def __init__(
+        self,
+        message: AnymailMessage,
+        defaults,
+        backend: "EmailBackend",
+        *args,
+        **kwargs,
+    ):
+        http_headers = {
+            "Api-Token": backend.api_token,
+            "Content-Type": "application/json",
+            "Accept": "application/json",
+        }
+        self.backend = backend
+        self.metadata = None
+        super().__init__(
+            message, defaults, backend, *args, headers=http_headers, **kwargs
+        )
+
+    def get_api_endpoint(self):
+        if self.backend.testing_enabled:
+            return f"send/{self.backend.test_inbox_id}"
+        return "send"
+
+    def serialize_data(self):
+        return self.serialize_json(self.data)
+
+    #
+    # Payload construction
+    #
+
+    def init_payload(self):
+        self.data: MailtrapData = {
+            "from": {
+                "email": "",
+            },
+            "subject": "",
+            "text": "",
+        }
+
+    @staticmethod
+    def _mailtrap_email(email: EmailAddress) -> MailtrapAddress:
+        """Expand an Anymail EmailAddress into Mailtrap's {"email", "name"} dict"""
+        result = {"email": email.addr_spec}
+        if email.display_name:
+            result["name"] = email.display_name
+        return result
+
+    def set_from_email(self, email: EmailAddress):
+        self.data["from"] = self._mailtrap_email(email)
+
+    def add_recipient(
+        self, recipient_type: Literal["to", "cc", "bcc"], email: EmailAddress
+    ):
+        assert recipient_type in ["to", "cc", "bcc"]
+        self.data.setdefault(recipient_type, []).append(self._mailtrap_email(email))
+
+    def set_subject(self, subject):
+        self.data["subject"] = subject
+
+    def set_reply_to(self, emails):
+        self.unsupported_feature("Mailtrap does not support reply_to")
+
+    def set_extra_headers(self, headers):
+        self.data.setdefault("headers", {}).update(headers)
+
+    def set_text_body(self, body):
+        self.data["text"] = body
+
+    def set_html_body(self, body):
+        if "html" in self.data:
+            # second html body could show up through multiple alternatives,
+            # or html body + alternative
+            self.unsupported_feature("multiple html parts")
+        self.data["html"] = body
+
+    def add_attachment(self, attachment: Attachment):
+        att: MailtrapAttachment = {
+            "filename": attachment.name or "",
+            "content": attachment.b64content,
+        }
+        if attachment.mimetype:
+            att["type"] = attachment.mimetype
+        if attachment.inline:
+            att["disposition"] = "inline"
+            att["content_id"] = attachment.cid
+        self.data.setdefault("attachments", []).append(att)
+
+    def set_metadata(self, metadata):
+        self.data.setdefault("custom_variables", {}).update(
+            {str(k): str(v) for k, v in metadata.items()}
+        )
+        self.metadata = metadata  # save for set_merge_metadata
+
+    def set_template_id(self, template_id):
+        # Mailtrap requires integer (not string) TemplateID:
+        self.data["template_id"] = template_id
+
+    def set_merge_data(self, merge_data):
+        self.data.setdefault("template_variables", {}).update(merge_data)
+
+    def set_merge_global_data(self, merge_global_data):
+        self.data.setdefault("template_variables", {}).update(merge_global_data)
+
+    def set_esp_extra(self, extra):
+        update_deep(self.data, extra)
+
+
+class EmailBackend(AnymailRequestsBackend):
+    """
+    Mailtrap API Email Backend
+    """
+
+    esp_name = "Mailtrap"
+
+    def __init__(self, **kwargs):
+        """Init options from Django settings"""
+        self.api_token = get_anymail_setting(
+            "api_token", esp_name=self.esp_name, kwargs=kwargs, allow_bare=True
+        )
+        api_url = get_anymail_setting(
+            "api_url",
+            esp_name=self.esp_name,
+            kwargs=kwargs,
+            default="https://send.api.mailtrap.io/api/",
+        )
+        if not api_url.endswith("/"):
+            api_url += "/"
+
+        test_api_url = get_anymail_setting(
+            "test_api_url",
+            esp_name=self.esp_name,
+            kwargs=kwargs,
+            default="https://sandbox.api.mailtrap.io/api/",
+        )
+        if not test_api_url.endswith("/"):
+            test_api_url += "/"
+        self.test_api_url = test_api_url
+
+        bulk_api_url = get_anymail_setting(
+            "bulk_api_url",
+            esp_name=self.esp_name,
+            kwargs=kwargs,
+            default="https://bulk.api.mailtrap.io/api/",
+        )
+        if not bulk_api_url.endswith("/"):
+            bulk_api_url += "/"
+        self.bulk_api_url = bulk_api_url
+
+        self.test_inbox_id = get_anymail_setting(
+            "test_inbox_id",
+            esp_name=self.esp_name,
+            kwargs=kwargs,
+        )
+
+        self.testing_enabled = get_anymail_setting(
+            "testing",
+            esp_name=self.esp_name,
+            kwargs=kwargs,
+            default=False,
+        )
+
+        if self.testing_enabled:
+            if not self.test_inbox_id:
+                warnings.warn(
+                    "Mailtrap testing is enabled, but no test_inbox_id is set. "
+                    "You must set test_inbox_id for Mailtrap testing to work.",
+                    AnymailWarning,
+                )
+            api_url = self.test_api_url
+            self.bulk_api_url = self.test_api_url
+
+        super().__init__(api_url, **kwargs)
+
+    def build_message_payload(self, message, defaults):
+        return MailtrapPayload(message, defaults, self)
+
+    def parse_recipient_status(
+        self, response, payload: MailtrapPayload, message: AnymailMessage
+    ):
+        parsed_response = self.deserialize_json_response(response, payload, message)
+
+        if (
+            not parsed_response.get("success")
+            or ("errors" in parsed_response and parsed_response["errors"])
+            or ("message_ids" not in parsed_response)
+        ):
+            raise AnymailRequestsAPIError(
+                email_message=message, payload=payload, response=response, backend=self
+            )
+
+        # Not the best status reporting. Mailtrap only says that the order of
+        # message-ids will be in this order (but JSON is unordered?)
+        recipient_status_order = [*message.to, *message.cc, *message.bcc]
+        recipient_status = {
+            email: AnymailRecipientStatus(
+                message_id=message_id,
+                status="sent",
+            )
+            for email, message_id in zip(
+                recipient_status_order, parsed_response["message_ids"]
+            )
+        }
+
+        return recipient_status
diff --git a/anymail/urls.py b/anymail/urls.py
@@ -11,6 +11,7 @@
 )
 from .webhooks.mailgun import MailgunInboundWebhookView, MailgunTrackingWebhookView
 from .webhooks.mailjet import MailjetInboundWebhookView, MailjetTrackingWebhookView
+from .webhooks.mailtrap import MailtrapTrackingWebhookView
 from .webhooks.mandrill import MandrillCombinedWebhookView
 from .webhooks.postal import PostalInboundWebhookView, PostalTrackingWebhookView
 from .webhooks.postmark import PostmarkInboundWebhookView, PostmarkTrackingWebhookView
@@ -108,6 +109,11 @@
         MailjetTrackingWebhookView.as_view(),
         name="mailjet_tracking_webhook",
     ),
+    path(
+        "mailtrap/tracking/",
+        MailtrapTrackingWebhookView.as_view(),
+        name="mailtrap_tracking_webhook",
+    ),
     path(
         "postal/tracking/",
         PostalTrackingWebhookView.as_view(),
diff --git a/anymail/webhooks/mailtrap.py b/anymail/webhooks/mailtrap.py
@@ -0,0 +1,95 @@
+import json
+from datetime import datetime, timezone
+from typing import Literal, NotRequired, TypedDict
+
+from ..signals import AnymailTrackingEvent, EventType, RejectReason, tracking
+from .base import AnymailBaseWebhookView
+
+
+class MailtrapEvent(TypedDict):
+    event: Literal[
+        "delivery",
+        "open",
+        "click",
+        "unsubscribe",
+        "spam",
+        "soft bounce",
+        "bounce",
+        "suspension",
+        "reject",
+    ]
+    message_id: str
+    sending_stream: Literal["transactional", "bulk"]
+    email: str
+    timestamp: int
+    event_id: str
+    category: NotRequired[str]
+    custom_variables: NotRequired[dict[str, str | int | float | bool]]
+    reason: NotRequired[str]
+    response: NotRequired[str]
+    response_code: NotRequired[int]
+    bounce_category: NotRequired[str]
+    ip: NotRequired[str]
+    user_agent: NotRequired[str]
+    url: NotRequired[str]
+
+
+class MailtrapTrackingWebhookView(AnymailBaseWebhookView):
+    """Handler for Mailtrap delivery and engagement tracking webhooks"""
+
+    esp_name = "Mailtrap"
+    signal = tracking
+
+    def parse_events(self, request):
+        esp_events: list[MailtrapEvent] = json.loads(request.body.decode("utf-8")).get(
+            "events", []
+        )
+        return [self.esp_to_anymail_event(esp_event) for esp_event in esp_events]
+
+    # https://help.mailtrap.io/article/87-statuses-and-events
+    event_types = {
+        # Map Mailtrap event: Anymail normalized type
+        "delivery": EventType.DELIVERED,
+        "open": EventType.OPENED,
+        "click": EventType.CLICKED,
+        "bounce": EventType.BOUNCED,
+        "soft bounce": EventType.DEFERRED,
+        "blocked": EventType.REJECTED,
+        "spam": EventType.COMPLAINED,
+        "unsubscribe": EventType.UNSUBSCRIBED,
+        "reject": EventType.REJECTED,
+        "suspension": EventType.DEFERRED,
+    }
+
+    reject_reasons = {
+        # Map Mailtrap event type to Anymail normalized reject_reason
+        "bounce": RejectReason.BOUNCED,
+        "blocked": RejectReason.BLOCKED,
+        "spam": RejectReason.SPAM,
+        "unsubscribe": RejectReason.UNSUBSCRIBED,
+        "reject": RejectReason.BLOCKED,
+    }
+
+    def esp_to_anymail_event(self, esp_event: MailtrapEvent):
+        event_type = self.event_types.get(esp_event["event"], EventType.UNKNOWN)
+        timestamp = datetime.fromtimestamp(esp_event["timestamp"], tz=timezone.utc)
+        reject_reason = self.reject_reasons.get(esp_event["event"], RejectReason.OTHER)
+        custom_variables = esp_event.get("custom_variables", {})
+        tags = []
+        if "category" in esp_event:
+            tags.append(esp_event["category"])
+
+        return AnymailTrackingEvent(
+            event_type=event_type,
+            timestamp=timestamp,
+            message_id=esp_event["message_id"],
+            event_id=esp_event.get("event_id", None),
+            recipient=esp_event.get("email", None),
+            reject_reason=reject_reason,
+            mta_response=esp_event.get("response_code", None),
+            tags=tags,
+            metadata=custom_variables,
+            click_url=esp_event.get("url", None),
+            user_agent=esp_event.get("user_agent", None),
+            esp_event=esp_event,
+        )
