refactor: optimize backend module

domain/email/service.py

@@ -0,0 +1,151 @@
+import asyncio
+import re
+import smtplib
+from email.message import EmailMessage
+from email.utils import formataddr
+from pathlib import Path
+from string import Template
+from typing import Any, Dict, List, Optional
+
+from domain.config.service import ConfigService
+from domain.email.types import EmailConfig, EmailSecurity, EmailSendPayload
+
+
+class EmailTemplateRenderer:
+    ROOT = Path("templates/email")
+
+    @classmethod
+    def _resolve_path(cls, template_name: str) -> Path:
+        if not re.fullmatch(r"[A-Za-z0-9_\-]+", template_name):
+            raise ValueError("Invalid template name")
+        return cls.ROOT / f"{template_name}.html"
+
+    @classmethod
+    async def list_templates(cls) -> list[str]:
+        cls.ROOT.mkdir(parents=True, exist_ok=True)
+        return sorted(
+            path.stem for path in cls.ROOT.glob("*.html") if path.is_file()
+        )
+
+    @classmethod
+    async def load(cls, template_name: str) -> str:
+        path = cls._resolve_path(template_name)
+        if not path.is_file():
+            raise FileNotFoundError(f"Email template '{template_name}' not found")
+        return await asyncio.to_thread(path.read_text, encoding="utf-8")
+
+    @classmethod
+    async def save(cls, template_name: str, content: str) -> None:
+        path = cls._resolve_path(template_name)
+        path.parent.mkdir(parents=True, exist_ok=True)
+        await asyncio.to_thread(path.write_text, content, encoding="utf-8")
+
+    @classmethod
+    async def render(cls, template_name: str, context: Dict[str, Any]) -> str:
+        raw = await cls.load(template_name)
+        context = {k: str(v) for k, v in (context or {}).items()}
+        return Template(raw).safe_substitute(context)
+
+
+class EmailService:
+    CONFIG_KEY = "EMAIL_CONFIG"
+
+    @classmethod
+    async def _load_config(cls) -> EmailConfig:
+        raw_config = await ConfigService.get(cls.CONFIG_KEY)
+        return EmailConfig.parse_config(raw_config)
+
+    @staticmethod
+    def _html_to_text(html: str) -> str:
+        stripped = re.sub(r"<[^>]+>", " ", html)
+        return " ".join(stripped.split())
+
+    @classmethod
+    async def _deliver(cls, config: EmailConfig, payload: EmailSendPayload, html_body: str):
+        message = EmailMessage()
+        message["Subject"] = payload.subject
+        message["From"] = formataddr(
+            (config.sender_name or str(config.sender_email), str(config.sender_email))
+        )
+        message["To"] = ", ".join([str(addr) for addr in payload.recipients])
+
+        plain_body = cls._html_to_text(html_body)
+        message.set_content(plain_body or html_body)
+        message.add_alternative(html_body, subtype="html")
+
+        await asyncio.to_thread(cls._deliver_sync, config, message)
+
+    @staticmethod
+    def _deliver_sync(config: EmailConfig, message: EmailMessage):
+        if config.security == EmailSecurity.SSL:
+            smtp: smtplib.SMTP = smtplib.SMTP_SSL(
+                config.host, config.port, timeout=config.timeout
+            )
+        else:
+            smtp = smtplib.SMTP(config.host, config.port, timeout=config.timeout)
+
+        try:
+            if config.security == EmailSecurity.STARTTLS:
+                smtp.starttls()
+            if config.username and config.password:
+                smtp.login(config.username, config.password)
+            smtp.send_message(message)
+        finally:
+            try:
+                smtp.quit()
+            except Exception:
+                pass
+
+    @classmethod
+    async def enqueue_email(
+        cls,
+        recipients: List[str],
+        subject: str,
+        template: str,
+        context: Optional[Dict[str, Any]] = None,
+    ):
+        from domain.tasks.task_queue import TaskProgress, task_queue_service
+
+        payload = EmailSendPayload(
+            recipients=recipients,
+            subject=subject,
+            template=template,
+            context=context or {},
+        )
+
+        task = await task_queue_service.add_task(
+            "send_email",
+            payload.model_dump(mode="json"),
+        )
+
+        await task_queue_service.update_progress(
+            task.id,
+            TaskProgress(stage="queued", percent=0.0, detail="Waiting to send"),
+        )
+        return task
+
+    @classmethod
+    async def send_from_task(cls, task_id: str, data: Dict[str, Any]):
+        from domain.tasks.task_queue import TaskProgress, task_queue_service
+
+        payload = EmailSendPayload(**data)
+
+        await task_queue_service.update_progress(
+            task_id,
+            TaskProgress(stage="preparing", percent=10.0, detail="Rendering template"),
+        )
+
+        config = await cls._load_config()
+        html_body = await EmailTemplateRenderer.render(payload.template, payload.context)
+
+        await task_queue_service.update_progress(
+            task_id,
+            TaskProgress(stage="sending", percent=60.0, detail="Sending message"),
+        )
+
+        await cls._deliver(config, payload, html_body)
+
+        await task_queue_service.update_progress(
+            task_id,
+            TaskProgress(stage="completed", percent=100.0, detail="Email sent"),
+        )