#!/usr/bin/env python3
"""Request an authenticated production refresh after a remote project update."""

from __future__ import annotations

import argparse
import json
import os
import sys
from urllib.error import HTTPError, URLError
from urllib.request import Request, urlopen


DISPATCH_URL = (
    "https://git.labyricorn.com/api/v1/repos/Labyricorn/labyricorn-site/"
    "actions/workflows/deploy.yml/dispatches"
)
TOKEN_ENVIRONMENT_VARIABLE = "LABYRICORN_REFRESH_TOKEN"


class RefreshError(RuntimeError):
    """Raised when Gitea does not accept a refresh request."""


def dispatch_refresh(token: str, *, timeout: float = 15.0) -> None:
    token = token.strip()
    if not token:
        raise RefreshError("the refresh token is empty")
    if "\r" in token or "\n" in token:
        raise RefreshError("the refresh token contains an invalid newline")

    request = Request(
        DISPATCH_URL,
        data=json.dumps({"ref": "main"}).encode("utf-8"),
        headers={
            "Accept": "application/json",
            "Authorization": f"token {token}",
            "Content-Type": "application/json",
            "User-Agent": "labyricorn-project-refresh/1",
        },
        method="POST",
    )
    try:
        with urlopen(request, timeout=timeout) as response:
            status = response.getcode()
    except HTTPError as exc:
        raise RefreshError(f"Gitea rejected the refresh request (HTTP {exc.code})") from exc
    except URLError as exc:
        reason = getattr(exc, "reason", "connection failed")
        raise RefreshError(f"could not contact Gitea: {reason}") from exc
    except OSError as exc:
        raise RefreshError(f"could not send the refresh request: {exc}") from exc

    if not 200 <= status < 300:
        raise RefreshError(f"Gitea returned unexpected HTTP status {status}")


def main(argv: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="show the target workflow without sending a request or reading a token",
    )
    parser.add_argument(
        "--timeout",
        type=float,
        default=15.0,
        help="request timeout in seconds (default: 15)",
    )
    args = parser.parse_args(argv)

    if args.timeout <= 0:
        parser.error("--timeout must be greater than zero")

    if args.dry_run:
        print(f"Would dispatch deploy.yml for main via {DISPATCH_URL}")
        return 0

    token = os.environ.get(TOKEN_ENVIRONMENT_VARIABLE)
    if token is None:
        print(
            f"project-refresh: ERROR: {TOKEN_ENVIRONMENT_VARIABLE} is not set",
            file=sys.stderr,
        )
        return 2

    try:
        dispatch_refresh(token, timeout=args.timeout)
    except RefreshError as exc:
        print(f"project-refresh: ERROR: {exc}", file=sys.stderr)
        return 1

    print("Production refresh requested for site main.")
    print("Verify the Deploy production Action and the published project revision.")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())