#!/usr/bin/env python3
"""Webhook delivery helpers for MACP events."""

from __future__ import annotations

import json
import sys
import time
import urllib.error
import urllib.request
from collections.abc import Callable
from typing import Any


def _warn(message: str) -> None:
    print(f"[macp-webhook] {message}", file=sys.stderr)


def _webhook_config(config: dict[str, Any]) -> dict[str, Any]:
    macp = config.get("macp")
    if isinstance(macp, dict) and isinstance(macp.get("webhook"), dict):
        return dict(macp["webhook"])
    return dict(config)


def send_webhook(event: dict[str, Any], config: dict[str, Any]) -> bool:
    """POST event to webhook URL. Returns True on success."""

    webhook = _webhook_config(config)
    url = str(webhook.get("url") or "").strip()
    if not url:
        _warn("missing webhook url")
        return False

    timeout_seconds = max(1.0, float(webhook.get("timeout_seconds") or 10))
    retry_count = max(0, int(webhook.get("retry_count") or 0))
    auth_token = str(webhook.get("auth_token") or "").strip()
    payload = json.dumps(event, ensure_ascii=True).encode("utf-8")
    headers = {"Content-Type": "application/json"}
    if auth_token:
        headers["Authorization"] = f"Bearer {auth_token}"

    attempts = retry_count + 1
    for attempt in range(1, attempts + 1):
        request = urllib.request.Request(url, data=payload, headers=headers, method="POST")
        try:
            with urllib.request.urlopen(request, timeout=timeout_seconds) as response:
                status = getattr(response, "status", response.getcode())
                if 200 <= int(status) < 300:
                    return True
                _warn(f"webhook returned HTTP {status} on attempt {attempt}/{attempts}")
        except (urllib.error.HTTPError, urllib.error.URLError, TimeoutError, ValueError) as exc:
            _warn(f"webhook attempt {attempt}/{attempts} failed: {exc}")
        if attempt < attempts:
            time.sleep(min(timeout_seconds, 2 ** (attempt - 1)))
    return False


def create_webhook_callback(config: dict[str, Any]) -> Callable[[dict[str, Any]], None]:
    """Factory that creates a watcher callback from config."""

    def callback(event: dict[str, Any]) -> None:
        if not send_webhook(event, config):
            _warn(f"delivery failed for event {event.get('event_type', '<unknown>')}")

    return callback