from datetime import datetime, timedelta
from typing import Optional, Union, Any
from jose import jwt
from passlib.context import CryptContext
import hashlib
from app.core.config import settings

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

def verify_password(plain_password: str, hashed_password: str) -> bool:
    # Pre-hash the password with SHA-256 to ensure it's within bcrypt's 72-byte limit
    pre_hashed = hashlib.sha256(plain_password.encode()).hexdigest()
    
    # Try verifying the pre-hashed password first
    if pwd_context.verify(pre_hashed, hashed_password):
        return True
        
    # Fallback: Try verifying the raw password (legacy)
    try:
        return pwd_context.verify(plain_password, hashed_password)
    except ValueError:
        return False

def get_password_hash(password: str) -> str:
    # Pre-hash with SHA-256 to handle any length and stay under bcrypt's 72-byte limit
    pre_hashed = hashlib.sha256(password.encode()).hexdigest()
    return pwd_context.hash(pre_hashed)

def create_access_token(subject: Union[str, Any], expires_delta: Optional[timedelta] = None) -> str:
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(
            minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES
        )
    to_encode = {"exp": expire, "sub": str(subject)}
    encoded_jwt = jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)
    return encoded_jwt