"""One atomic Supply ARI write with readback, using the Python standard library."""

import json
import os
import re
import uuid
from urllib.error import HTTPError
from urllib.parse import urlencode
from urllib.request import Request, urlopen


required = (
    "OUTRESERVE_SUPPLY_BASE_URL",
    "OUTRESERVE_SUPPLY_API_KEY",
    "OUTRESERVE_PROPERTY_ID",
    "OUTRESERVE_UNIT_ID",
    "OUTRESERVE_DATE_FROM",
    "OUTRESERVE_DATE_TO",
    "OUTRESERVE_INCORPORATED_RESERVATION_SEQUENCE",
)
missing = [name for name in required if not os.environ.get(name)]
if missing:
    raise SystemExit(f"Set these environment variables first: {', '.join(missing)}")

base = os.environ["OUTRESERVE_SUPPLY_BASE_URL"].rstrip("/")
url = f'{base}/properties/{os.environ["OUTRESERVE_PROPERTY_ID"]}/ari'
query = urlencode(
    {
        "date_from": os.environ["OUTRESERVE_DATE_FROM"],
        "date_to": os.environ["OUTRESERVE_DATE_TO"],
    }
)
auth = f'Bearer {os.environ["OUTRESERVE_SUPPLY_API_KEY"]}'
sequence_text = os.environ["OUTRESERVE_INCORPORATED_RESERVATION_SEQUENCE"]
if not re.fullmatch(r"0|[1-9][0-9]*", sequence_text) or int(sequence_text) > 2**53 - 1:
    raise SystemExit("Set OUTRESERVE_INCORPORATED_RESERVATION_SEQUENCE to a nonnegative safe JSON integer")


def request(path, method="GET", body=None, headers=None):
    """Perform one request and report structured and non-JSON errors."""
    payload = json.dumps(body).encode() if body is not None else None
    request_headers = {"Authorization": auth, **(headers or {})}
    if payload is not None:
        request_headers["Content-Type"] = "application/json"
    operation = Request(path, data=payload, headers=request_headers, method=method)
    try:
        with urlopen(operation, timeout=30) as response:
            return json.load(response)
    except HTTPError as error:
        raw = error.read().decode("utf-8", errors="replace")
        try:
            detail = json.loads(raw)
        except json.JSONDecodeError:
            detail = raw
        raise SystemExit(f"Supply API {error.code}: {detail}") from error


current = request(f"{url}?{query}")
revision = current.get("data", {}).get("calendar_revision")
if revision is None:
    raise SystemExit("GET ARI did not return data.calendar_revision; inspect before writing")

update = {
    "updates": [
        {
            "scope": "unit",
            "unit_id": os.environ["OUTRESERVE_UNIT_ID"],
            "date_from": os.environ["OUTRESERVE_DATE_FROM"],
            "date_to": os.environ["OUTRESERVE_DATE_TO"],
            "available_count": 1,
            "incorporated_reservation_sequence": int(sequence_text),
            "rate_minor": 18500,
            "stop_sell": False,
        }
    ]
}
result = request(
    url,
    method="POST",
    body=update,
    headers={"If-Match": f'"{revision}"', "Idempotency-Key": str(uuid.uuid4())},
)
print(json.dumps({"applied": result, "readback": request(f"{url}?{query}")}, indent=2))