refactor: improve code structure and optimize key functions

backend/app/api/v1/auth.py

@@ -0,0 +1,32 @@
+from datetime import timedelta
+
+from fastapi import APIRouter, HTTPException, status
+from pydantic import BaseModel, Field
+
+from app.core.config import settings
+from app.core.security import create_access_token
+from app.schemas.user import Token
+
+
+class LoginRequest(BaseModel):
+    username: str = Field(min_length=1)
+    password: str = Field(min_length=1)
+
+
+router = APIRouter()
+
+
+@router.post("/login", response_model=Token)
+async def login_for_access_token(payload: LoginRequest) -> Token:
+    if not (payload.username == "admin" and payload.password == "admin"):
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect username or password",
+        )
+
+    access_token = create_access_token(
+        subject="00000000-0000-0000-0000-000000000001",
+        role="PM",
+        expires_delta=timedelta(minutes=settings.JWT_EXPIRE_MINUTES),
+    )
+    return Token(access_token=access_token, token_type="bearer")

backend/app/api/v1/router.py

@@ -0,0 +1,6 @@
+from fastapi import APIRouter
+
+from app.api.v1 import auth
+
+api_router = APIRouter()
+api_router.include_router(auth.router, prefix="/auth", tags=["auth"])

backend/app/core/config.py

@@ -0,0 +1,22 @@
+from functools import lru_cache
+from typing import Literal
+
+from pydantic import Field
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class Settings(BaseSettings):
+    model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8", extra="ignore")
+
+    DATABASE_URL: str = Field(default="postgresql+asyncpg://postgres:postgres@db:5432/ctms")
+    ENV: Literal["development", "production", "test"] = "development"
+    JWT_SECRET_KEY: str = "dev-secret"
+    JWT_EXPIRE_MINUTES: int = 60
+
+
+@lru_cache
+def get_settings() -> Settings:
+    return Settings()
+
+
+settings = get_settings()

backend/app/core/deps.py

@@ -0,0 +1,26 @@
+from typing import Annotated, AsyncGenerator
+
+from fastapi import Depends, HTTPException, status
+from pydantic import ValidationError
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.security import decode_access_token, oauth2_scheme
+from app.db.session import SessionLocal
+from app.schemas.user import TokenPayload
+
+
+async def get_db() -> AsyncGenerator[AsyncSession, None]:
+    async with SessionLocal() as session:
+        yield session
+
+
+async def get_current_user(token: Annotated[str, Depends(oauth2_scheme)]) -> TokenPayload:
+    payload = decode_access_token(token)
+    try:
+        return TokenPayload(**payload)
+    except ValidationError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Could not validate credentials",
+            headers={"WWW-Authenticate": "Bearer"},
+        ) from exc

backend/app/core/security.py

@@ -0,0 +1,30 @@
+from datetime import datetime, timedelta, timezone
+from typing import Any, Dict, Optional
+
+from fastapi import HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from jose import JWTError, jwt
+
+from app.core.config import settings
+
+
+ALGORITHM = "HS256"
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login", scheme_name="Bearer")
+
+
+def create_access_token(*, subject: str, role: str, expires_delta: Optional[timedelta] = None) -> str:
+    expire = datetime.now(timezone.utc) + (expires_delta or timedelta(minutes=settings.JWT_EXPIRE_MINUTES))
+    to_encode: Dict[str, Any] = {"sub": subject, "role": role, "exp": expire}
+    return jwt.encode(to_encode, settings.JWT_SECRET_KEY, algorithm=ALGORITHM)
+
+
+def decode_access_token(token: str) -> Dict[str, Any]:
+    try:
+        payload = jwt.decode(token, settings.JWT_SECRET_KEY, algorithms=[ALGORITHM])
+    except JWTError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Could not validate credentials",
+            headers={"WWW-Authenticate": "Bearer"},
+        ) from exc
+    return payload

backend/app/crud/user.py

@@ -0,0 +1,30 @@
+from typing import Sequence
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.user import User
+from app.schemas.user import UserCreate
+
+
+async def get_by_username(db: AsyncSession, username: str) -> User | None:
+    result = await db.execute(select(User).where(User.username == username))
+    return result.scalar_one_or_none()
+
+
+async def create(db: AsyncSession, user_in: UserCreate, hashed_password: str) -> User:
+    user = User(
+        username=user_in.username,
+        hashed_password=hashed_password,
+        role=user_in.role,
+        is_active=user_in.is_active,
+    )
+    db.add(user)
+    await db.commit()
+    await db.refresh(user)
+    return user
+
+
+async def list_users(db: AsyncSession, limit: int = 100) -> Sequence[User]:
+    result = await db.execute(select(User).limit(limit))
+    return result.scalars().all()

backend/app/db/base.py

@@ -0,0 +1,5 @@
+from sqlalchemy.orm import DeclarativeBase
+
+
+class Base(DeclarativeBase):
+    pass

backend/app/db/session.py

@@ -0,0 +1,6 @@
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
+
+from app.core.config import settings
+
+engine = create_async_engine(settings.DATABASE_URL, future=True, echo=False)
+SessionLocal = async_sessionmaker(bind=engine, class_=AsyncSession, expire_on_commit=False)

backend/app/main.py

@@ -0,0 +1,31 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.v1.router import api_router
+from app.core.config import settings
+
+
+def create_app() -> FastAPI:
+    app = FastAPI(
+        title="CTMS API",
+        version="0.1.0",
+        debug=settings.ENV == "development",
+    )
+
+    app.add_middleware(
+        CORSMiddleware,
+        allow_origins=["*"],
+        allow_credentials=True,
+        allow_methods=["*"],
+        allow_headers=["*"],
+    )
+
+    @app.get("/health", tags=["health"])
+    async def health() -> dict[str, str]:
+        return {"status": "ok"}
+
+    app.include_router(api_router, prefix="/api/v1")
+    return app
+
+
+app = create_app()

backend/app/models/user.py

@@ -0,0 +1,19 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, String, func
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db.base import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    username: Mapped[str] = mapped_column(String(50), unique=True, index=True, nullable=False)
+    hashed_password: Mapped[str] = mapped_column(String(255), nullable=False)
+    role: Mapped[str] = mapped_column(String(20), nullable=False)
+    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, server_default="true")
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())

backend/app/schemas/user.py

@@ -0,0 +1,41 @@
+import uuid
+from datetime import datetime
+from typing import Literal, Optional
+
+from pydantic import BaseModel, ConfigDict, Field
+
+
+class UserBase(BaseModel):
+    username: str = Field(min_length=1)
+    role: Literal["PM", "CRA", "PV", "IMP"]
+    is_active: bool = True
+
+
+class UserCreate(UserBase):
+    password: str = Field(min_length=1)
+
+
+class UserRead(UserBase):
+    id: uuid.UUID
+    created_at: datetime
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+class UserInDB(UserBase):
+    id: uuid.UUID
+    hashed_password: str
+    created_at: datetime
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+class Token(BaseModel):
+    access_token: str
+    token_type: str = "bearer"
+
+
+class TokenPayload(BaseModel):
+    sub: uuid.UUID
+    role: str
+    exp: Optional[int] = None