from datetime import datetime, timedelta, timezone
from typing import Annotated
from jose import JWTError, jwt
from passlib.context import CryptContext
from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.ext.asyncio import AsyncSession
from sqlmodel import select
import os
import logging
from dotenv import load_dotenv

from ..database.connection import get_session
from ..database.models import User

load_dotenv()
logger = logging.getLogger(__name__)

SECRET_KEY = os.getenv("SECRET_KEY", "your-secret-key-for-dev")
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 60  # 1 hour
REFRESH_TOKEN_EXPIRE_DAYS = 7  # 1 week

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

def verify_password(plain_password, hashed_password):
    return pwd_context.verify(plain_password, hashed_password)

def get_password_hash(password):
    return pwd_context.hash(password)

def create_access_token(data: dict, expires_delta: timedelta = None):
    to_encode = data.copy()
    expire = datetime.now(timezone.utc) + (expires_delta or timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES))
    to_encode.update({"exp": expire, "type": "access"})
    return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)

def create_refresh_token(data: dict, expires_delta: timedelta = None):
    to_encode = data.copy()
    expire = datetime.now(timezone.utc) + (expires_delta or timedelta(days=REFRESH_TOKEN_EXPIRE_DAYS))
    to_encode.update({"exp": expire, "type": "refresh"})
    return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)

async def get_current_user(
    auth: Annotated[HTTPAuthorizationCredentials, Depends(security)],
    session: Annotated[AsyncSession, Depends(get_session)]
) -> User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    token = auth.credentials
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        if payload.get("type") != "access":
            raise credentials_exception
            
        phone_number: str = payload.get("sub")
        if phone_number is None:
            raise credentials_exception
    except JWTError:
        raise credentials_exception
    
    statement = select(User).where(User.phone_number == phone_number)
    result = await session.execute(statement)
    user = result.scalar_one_or_none()
    
    if user is None:
        raise credentials_exception
    return user