from datetime import datetime, timedelta
from typing import Optional, Dict, Any
from jose import JWTError, jwt
from passlib.context import CryptContext
from app.config import settings

# Configure password context with explicit bcrypt backend
pwd_context = CryptContext(
    schemes=["bcrypt"],
    deprecated="auto",
    bcrypt__rounds=12,  # Adjust rounds for security vs performance
)


def verify_password(plain_password: str, hashed_password: str) -> bool:
    """Verify a password against its hash"""
    try:
        return pwd_context.verify(plain_password, hashed_password)
    except Exception as e:
        print(f"Password verification error: {e}")
        return False


def get_password_hash(password: str) -> str:
    """
    Hash a password using bcrypt.
    Bcrypt has a 72-byte limit, so we truncate if necessary.
    """
    # Bcrypt has a 72-byte limit, truncate password if needed
    if len(password.encode('utf-8')) > 72:
        password = password[:72]
    
    try:
        return pwd_context.hash(password)
    except Exception as e:
        print(f"Password hashing error: {e}")
        raise ValueError(f"Failed to hash password: {str(e)}")


def create_access_token(data: Dict[str, Any], expires_delta: Optional[timedelta] = None) -> str:
    """Create JWT access token"""
    to_encode = data.copy()
    
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
    
    to_encode.update({"exp": expire, "type": "access"})
    encoded_jwt = jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)
    return encoded_jwt


def create_refresh_token(data: Dict[str, Any]) -> str:
    """Create JWT refresh token"""
    to_encode = data.copy()
    expire = datetime.utcnow() + timedelta(days=settings.REFRESH_TOKEN_EXPIRE_DAYS)
    to_encode.update({"exp": expire, "type": "refresh"})
    encoded_jwt = jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)
    return encoded_jwt


def decode_token(token: str) -> Optional[Dict[str, Any]]:
    """Decode and verify JWT token"""
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM])
        return payload
    except JWTError as e:
        print(f"Token decode error: {e}")
        return None