chore: include authentication services

app/email.py

@@ -0,0 +1,39 @@
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+import resend
+from flask import current_app
+
+
+class EmailConfigurationError(RuntimeError):
+    """Raised when transactional email has not been configured."""
+
+
+class EmailDeliveryError(RuntimeError):
+    """Raised when Resend rejects or cannot deliver an email request."""
+
+
+def send_transactional_email(*, to: str, subject: str, html: str) -> dict[str, Any]:
+    """Send one application-generated email through Resend."""
+    api_key = current_app.config["RESEND_API_KEY"]
+    from_email = current_app.config["RESEND_FROM_EMAIL"]
+    if not api_key or not from_email:
+        raise EmailConfigurationError(
+            "邮件服务尚未配置，请设置 RESEND_API_KEY 和 RESEND_FROM_EMAIL。"
+        )
+
+    resend.api_key = api_key
+    try:
+        return resend.Emails.send(
+            {
+                "from": from_email,
+                "to": [to],
+                "subject": subject,
+                "html": html,
+            }
+        )
+    except Exception as exc:
+        logging.exception("Resend 邮件发送失败: %s", exc)
+        raise EmailDeliveryError("邮件发送失败，请稍后重试。") from exc