from __future__ import annotations

from dataclasses import dataclass
from datetime import datetime, timedelta, timezone
from uuid import uuid4

from jose import JWTError, jwt
from passlib.context import CryptContext

from app.core.config import get_settings
from app.core.exceptions import UnauthorizedError

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
settings = get_settings()
ACCESS_TOKEN_TYPE = "access"  # nosec B105


@dataclass(slots=True)
class TokenPayload:
    user_id: int


def verify_password(plain_password: str, hashed_password: str) -> bool:
    return pwd_context.verify(plain_password, hashed_password)


def get_password_hash(password: str) -> str:
    return pwd_context.hash(password)


def create_access_token(subject: str) -> str:
    now = datetime.now(timezone.utc)
    expire = now + timedelta(minutes=settings.access_token_expire_minutes)
    to_encode = {
        "sub": subject,
        "iat": int(now.timestamp()),
        "nbf": int(now.timestamp()),
        "exp": int(expire.timestamp()),
        "jti": str(uuid4()),
        "type": ACCESS_TOKEN_TYPE,
        "iss": settings.jwt_issuer,
        "aud": settings.jwt_audience,
    }
    return jwt.encode(to_encode, settings.jwt_secret_key, algorithm=settings.jwt_algorithm)


def decode_access_token(token: str) -> TokenPayload:
    try:
        payload = jwt.decode(
            token,
            settings.jwt_secret_key,
            algorithms=[settings.jwt_algorithm],
            issuer=settings.jwt_issuer,
            audience=settings.jwt_audience,
        )
        subject = payload.get("sub")
        token_type = payload.get("type")
        if subject is None or token_type != ACCESS_TOKEN_TYPE:
            raise UnauthorizedError("Could not validate credentials")
        return TokenPayload(user_id=int(subject))
    except (JWTError, ValueError) as exc:
        raise UnauthorizedError("Could not validate credentials") from exc