# pip install requests flask
import hmac, hashlib, time, requests
from flask import Flask, request, abort

GATEWAY, API_KEY, API_SECRET = "https://pay.yourdomain.com", "PASTE_API_KEY", "PASTE_API_SECRET"

def create_invoice(order_id: str, amount: str, network: str | None = None) -> dict:
    f = {"api_key": API_KEY, "order_id": order_id, "amount": amount,
         "callback_url": "https://yourshop.com/gateway/callback"}
    if network: f["network"] = network
    f["sign"] = hmac.new(API_SECRET.encode(), f"{API_KEY}|{order_id}|{amount}".encode(), hashlib.sha256).hexdigest()
    j = requests.post(f"{GATEWAY}/api/create.php", data=f, timeout=20).json()
    if not j.get("success"): raise RuntimeError(j.get("error"))
    return j

app = Flask(__name__)

@app.post("/gateway/callback")
def callback():
    ts = request.headers.get("X-Gateway-Timestamp", ""); sig = request.headers.get("X-Gateway-Signature", "")
    body = request.get_data(as_text=True)
    exp = hmac.new(API_SECRET.encode(), f"{ts}.{body}".encode(), hashlib.sha256).hexdigest()
    if abs(time.time() - int(ts or 0)) > 600 or not hmac.compare_digest(sig, exp): abort(403)
    d = request.get_json()
    if d["event"] == "invoice.paid": pass  # order paid mark करें (idempotent)
    return "OK"