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

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

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

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

def generate_reset_token() -> str:
    """Generate a secure reset token"""
    return secrets.token_urlsafe(32)

def create_access_token(data: Dict[str, Any], expires_delta: Optional[timedelta] = None) -> str:
    """Create a JWT access 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, "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 a JWT refresh token"""
    to_encode = data.copy()
    expire = datetime.now(timezone.utc) + 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 verify_token(token: str) -> Optional[Dict[str, Any]]:
    """Verify and decode a JWT token"""
    try:
        payload = jwt.decode(token, settings.secret_key, algorithms=[settings.algorithm])
        return payload
    except JWTError:
        return None

def is_token_expired(payload: Dict[str, Any]) -> bool:
    """Check if a token is expired"""
    exp = payload.get("exp")
    if not exp:
        return True
    return datetime.now(timezone.utc) > datetime.fromtimestamp(exp, timezone.utc)

def extract_user_id_from_token(token: str) -> Optional[str]:
    """Extract user ID from JWT token"""
    payload = verify_token(token)
    if payload:
        return payload.get("sub")
    return None