"""Razorpay integration with a mock fallback for local dev.

When RAZORPAY_KEY_ID/SECRET are unset (or MOCK), create_order returns a fake
order and verify_signature always succeeds, so the whole billing flow can be
exercised end-to-end without real keys.
"""
import hashlib
import hmac
import secrets
from typing import Optional

from app.core.config import settings


def is_live() -> bool:
    return settings.razorpay_configured


def create_order(amount_paise: int, receipt: str, notes: Optional[dict] = None) -> dict:
    if not is_live():
        return {
            "id": f"order_mock_{secrets.token_hex(8)}",
            "amount": amount_paise,
            "currency": "INR",
            "receipt": receipt,
            "status": "created",
            "mock": True,
        }
    import razorpay
    client = razorpay.Client(auth=(settings.razorpay_key_id, settings.razorpay_key_secret))
    return client.order.create({
        "amount": amount_paise,
        "currency": "INR",
        "receipt": receipt,
        "notes": notes or {},
    })


def verify_payment_signature(order_id: str, payment_id: str, signature: str) -> bool:
    if not is_live():
        return True  # mock: accept any payment
    body = f"{order_id}|{payment_id}"
    expected = hmac.new(
        settings.razorpay_key_secret.encode(), body.encode(), hashlib.sha256
    ).hexdigest()
    return hmac.compare_digest(expected, signature)


def verify_webhook_signature(payload: bytes, signature: str) -> bool:
    if not settings.razorpay_webhook_secret:
        return not is_live()  # accept in mock mode only
    expected = hmac.new(
        settings.razorpay_webhook_secret.encode(), payload, hashlib.sha256
    ).hexdigest()
    return hmac.compare_digest(expected, signature)