from datetime import datetime, timedelta, timezone
from typing import Optional

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

from app.core.config import settings

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


def verify_password(plain_password: str, hashed_password: str) -> bool:
    """Verifica una password contro il suo hash"""
    return pwd_context.verify(plain_password, hashed_password)


def get_password_hash(password: str) -> str:
    """Genera l'hash di una password"""
    # bcrypt ha un limite di 72 byte, tronchiamo se necessario
    # Questo è sicuro perché 72 byte forniscono comunque entropia sufficiente
    if len(password.encode('utf-8')) > 72:
        password = password.encode('utf-8')[:72].decode('utf-8', errors='ignore')
    return pwd_context.hash(password)


def create_access_token(data: dict, expires_delta: Optional[timedelta] = None) -> str:
    """Crea un JWT token"""
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(
            minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES
        )
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)
    return encoded_jwt


def decode_access_token(token: str) -> Optional[dict]:
    """Decodifica e valida un JWT token"""
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM])
        return payload
    except JWTError:
        return None