"""JWT authentication utilities."""
import uuid
from datetime import datetime, timedelta
from typing import Optional

from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from jose import JWTError, jwt
from passlib.context import CryptContext
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select

from app.config import settings
from app.database import get_db
from app.models.user import User

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
bearer_scheme = HTTPBearer()


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(user_id: str, role: str) -> str:
    expires = datetime.utcnow() + timedelta(minutes=settings.jwt_access_token_expire_minutes)
    payload = {"sub": user_id, "role": role, "exp": expires}
    return jwt.encode(payload, settings.jwt_secret_key, algorithm=settings.jwt_algorithm)


def decode_token(token: str) -> dict:
    try:
        return jwt.decode(token, settings.jwt_secret_key, algorithms=[settings.jwt_algorithm])
    except JWTError as exc:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token") from exc


async def get_current_user(
    credentials: HTTPAuthorizationCredentials = Depends(bearer_scheme),
    db: AsyncSession = Depends(get_db),
) -> User:
    payload = decode_token(credentials.credentials)
    user_id = payload.get("sub")
    if not user_id:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token")

    result = await db.execute(select(User).where(User.id == uuid.UUID(user_id)))
    user = result.scalar_one_or_none()
    if not user or not user.is_active:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="User not found or inactive")
    return user


async def require_admin(user: User = Depends(get_current_user)) -> User:
    if user.role.value != "admin":
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Admin access required")
    return user


async def require_admin_or_pm(user: User = Depends(get_current_user)) -> User:
    if user.role.value not in ("admin", "project_manager"):
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Admin or Project Manager access required",
        )
    return user