import math
from fastapi import HTTPException

def haversine(lat1, lon1, lat2, lon2):
    R = 6371  # Earth radius in KM

    dLat = math.radians(lat2 - lat1)
    dLon = math.radians(lon2 - lon1)

    a = (
        math.sin(dLat / 2) ** 2 +
        math.cos(math.radians(lat1)) *
        math.cos(math.radians(lat2)) *
        math.sin(dLon / 2) ** 2
    )

    c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))

    return R * c


def calculate_eta(distance):
    prep_time = 10  # mins
    travel_time = distance * 5  # mins per km

    eta = prep_time + travel_time

    return f"{int(eta)}-{int(eta + 5)} mins"

# ================= AUTH =================
from passlib.context import CryptContext
from jose import jwt
from datetime import datetime, timedelta

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

SECRET_KEY = "secret123"
ALGORITHM = "HS256"


def hash_password(password: str):
    password = password[:72]   # 🔥 FIX
    return pwd_context.hash(password)


def verify_password(plain, hashed):
    plain = plain[:72]
    return pwd_context.verify(plain, hashed)


def create_token(data: dict):
    to_encode = data.copy()
    to_encode["exp"] = datetime.utcnow() + timedelta(days=30)
    return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)

# Admin
from fastapi import Depends
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials

security = HTTPBearer()

def get_current_admin(
    credentials: HTTPAuthorizationCredentials = Depends(security)
):
    try:
        payload = jwt.decode(
            credentials.credentials,
            SECRET_KEY,
            algorithms=[ALGORITHM]
        )
        return payload
    except Exception as e:
        raise HTTPException(
            status_code=401,
            detail="Invalid token"
        )