Initial commit: 浼佷笟寰俊 AI 鏈哄櫒浜哄姪鐞?MVP

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/services/auth_service.py

@@ -0,0 +1,39 @@
+"""密码 bcrypt hash；JWT 创建与解码，带过期时间。"""
+from datetime import datetime, timedelta, timezone
+
+from jose import JWTError, jwt
+from passlib.context import CryptContext
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.config import settings
+from app.models import User
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+
+def hash_password(password: str) -> str:
+    return pwd_context.hash(password)
+
+
+def verify_password(plain: str, hashed: str) -> bool:
+    return pwd_context.verify(plain, hashed)
+
+
+def create_access_token(subject: str) -> str:
+    expire = datetime.now(timezone.utc) + timedelta(minutes=settings.jwt_expire_minutes)
+    to_encode = {"sub": subject, "exp": expire}
+    return jwt.encode(to_encode, settings.jwt_secret, algorithm=settings.jwt_algorithm)
+
+
+def decode_access_token(token: str) -> str | None:
+    try:
+        payload = jwt.decode(token, settings.jwt_secret, algorithms=[settings.jwt_algorithm])
+        return payload.get("sub")
+    except JWTError:
+        return None
+
+
+async def get_user_by_username(db: AsyncSession, username: str) -> User | None:
+    r = await db.execute(select(User).where(User.username == username))
+    return r.scalar_one_or_none()