#!/usr/bin/env python3
"""Python 3, standard library. Dry run by default; --send creates ONE real order."""
import hashlib
import json
import os
import secrets
import sys
import time
import urllib.request
from pathlib import Path

URL = "https://transaction.hisspay.com/transaction/payin/v1/apply"

def sign(body, app_id, secret, timestamp, nonce):
    headers = {"appId": app_id, "timestamp": timestamp, "nonce": nonce}
    values = {**body, **headers}
    if any(not isinstance(v, str) for v in values.values()):
        raise ValueError("Use string top-level fields; cardExtra must be JSON text")
    canonical = "&".join(k + "=" + values[k] for k in sorted(values))
    headers["sign"] = hashlib.sha256((canonical + secret).encode("utf-8")).hexdigest()
    return headers

class NoRedirect(urllib.request.HTTPRedirectHandler):
    def redirect_request(self, *args, **kwargs):
        return None

def main():
    if len(sys.argv) not in (2, 3) or (len(sys.argv) == 3 and sys.argv[2] != "--send"):
        raise SystemExit("Usage: python3 wallet_request.py request.json [--send]")
    body = json.loads(Path(sys.argv[1]).read_text(encoding="utf-8"))
    if len(sys.argv) == 2:
        print(json.dumps(body, ensure_ascii=False, indent=2))
        return
    # Replace ALL example customer data, URLs and order number before --send.
    if body.get("clientIp") == "<PAYER_PUBLIC_IP>" or "REPLACE_UNIQUE" in body.get("merchantOrderNo", ""):
        raise SystemExit("Replace example payer IP and unique order number first")
    headers = sign(body, os.environ["HISSPAY_APP_ID"], os.environ["HISSPAY_APP_SECRET"],
                   str(int(time.time() * 1000)), secrets.token_hex(16))
    headers["Content-Type"] = "application/json"
    request = urllib.request.Request(URL,
        data=json.dumps(body, ensure_ascii=False, separators=(",", ":")).encode("utf-8"),
        headers=headers, method="POST")
    # No automatic application retry or redirects. On timeout, query the original order.
    with urllib.request.build_opener(NoRedirect).open(request, timeout=30) as response:
        print(response.read().decode("utf-8"))

if __name__ == "__main__":
    main()