🚚 Refactor and simplify backend file structure (#609)

src/backend/app/utils.py

@@ -0,0 +1,106 @@
+import logging
+from datetime import datetime, timedelta
+from pathlib import Path
+from typing import Any, Dict, Optional
+
+import emails
+from emails.template import JinjaTemplate
+from jose import jwt
+
+from app.core.config import settings
+
+
+def send_email(
+    email_to: str,
+    subject_template: str = "",
+    html_template: str = "",
+    environment: Dict[str, Any] = {},
+) -> None:
+    assert settings.EMAILS_ENABLED, "no provided configuration for email variables"
+    message = emails.Message(
+        subject=JinjaTemplate(subject_template),
+        html=JinjaTemplate(html_template),
+        mail_from=(settings.EMAILS_FROM_NAME, settings.EMAILS_FROM_EMAIL),
+    )
+    smtp_options = {"host": settings.SMTP_HOST, "port": settings.SMTP_PORT}
+    if settings.SMTP_TLS:
+        smtp_options["tls"] = True
+    if settings.SMTP_USER:
+        smtp_options["user"] = settings.SMTP_USER
+    if settings.SMTP_PASSWORD:
+        smtp_options["password"] = settings.SMTP_PASSWORD
+    response = message.send(to=email_to, render=environment, smtp=smtp_options)
+    logging.info(f"send email result: {response}")
+
+
+def send_test_email(email_to: str) -> None:
+    project_name = settings.PROJECT_NAME
+    subject = f"{project_name} - Test email"
+    with open(Path(settings.EMAIL_TEMPLATES_DIR) / "test_email.html") as f:
+        template_str = f.read()
+    send_email(
+        email_to=email_to,
+        subject_template=subject,
+        html_template=template_str,
+        environment={"project_name": settings.PROJECT_NAME, "email": email_to},
+    )
+
+
+def send_reset_password_email(email_to: str, email: str, token: str) -> None:
+    project_name = settings.PROJECT_NAME
+    subject = f"{project_name} - Password recovery for user {email}"
+    with open(Path(settings.EMAIL_TEMPLATES_DIR) / "reset_password.html") as f:
+        template_str = f.read()
+    server_host = settings.SERVER_HOST
+    link = f"{server_host}/reset-password?token={token}"
+    send_email(
+        email_to=email_to,
+        subject_template=subject,
+        html_template=template_str,
+        environment={
+            "project_name": settings.PROJECT_NAME,
+            "username": email,
+            "email": email_to,
+            "valid_hours": settings.EMAIL_RESET_TOKEN_EXPIRE_HOURS,
+            "link": link,
+        },
+    )
+
+
+def send_new_account_email(email_to: str, username: str, password: str) -> None:
+    project_name = settings.PROJECT_NAME
+    subject = f"{project_name} - New account for user {username}"
+    with open(Path(settings.EMAIL_TEMPLATES_DIR) / "new_account.html") as f:
+        template_str = f.read()
+    link = settings.SERVER_HOST
+    send_email(
+        email_to=email_to,
+        subject_template=subject,
+        html_template=template_str,
+        environment={
+            "project_name": settings.PROJECT_NAME,
+            "username": username,
+            "password": password,
+            "email": email_to,
+            "link": link,
+        },
+    )
+
+
+def generate_password_reset_token(email: str) -> str:
+    delta = timedelta(hours=settings.EMAIL_RESET_TOKEN_EXPIRE_HOURS)
+    now = datetime.utcnow()
+    expires = now + delta
+    exp = expires.timestamp()
+    encoded_jwt = jwt.encode(
+        {"exp": exp, "nbf": now, "sub": email}, settings.SECRET_KEY, algorithm="HS256",
+    )
+    return encoded_jwt
+
+
+def verify_password_reset_token(token: str) -> Optional[str]:
+    try:
+        decoded_token = jwt.decode(token, settings.SECRET_KEY, algorithms=["HS256"])
+        return decoded_token["email"]
+    except jwt.JWTError:
+        return None