from datetime import datetime, timedelta
from typing import Any, Dict, Optional, Union

from jose import jwt
from passlib.context import CryptContext

from app.core.config import settings

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

def verify_password(plain_password: str, hashed_password: str) -> bool:
    """Verify a password against a hash."""
    return pwd_context.verify(plain_password, hashed_password)

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

# JWT token functions
def create_access_token(subject: Union[str, Any], expires_delta: Optional[timedelta] = None) -> str:
    """
    Create a JWT access token.
    """
    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

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

def create_password_reset_token(subject: Union[str, Any]) -> str:
    """
    Create a password reset token.
    """
    expire = datetime.utcnow() + timedelta(hours=settings.PASSWORD_RESET_TOKEN_EXPIRE_HOURS)
    to_encode = {"exp": expire, "sub": str(subject), "type": "password_reset"}
    encoded_jwt = jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)
    return encoded_jwt