"""Enricher: Fetch HTTP headers for a URL and update entity metadata."""

import sys
import json

try:
    import httpx
except ImportError:
    import urllib.request


def main():
    entity = json.load(sys.stdin)
    url = (entity.get("metadata") or {}).get("url") or entity.get("name", "")

    if not url:
        json.dump({"error": "No URL found in entity"}, sys.stdout)
        return

    try:
        try:
            resp = httpx.head(url, follow_redirects=True, timeout=10)
            headers = dict(resp.headers)
            status = resp.status_code
        except NameError:
            req = urllib.request.Request(url, method="HEAD")
            with urllib.request.urlopen(req, timeout=10) as resp:
                headers = dict(resp.headers)
                status = resp.status
    except Exception as e:
        json.dump({"error": f"Failed to fetch headers: {e}"}, sys.stdout)
        return

    # Return metadata update for the source entity
    result = {
        "entities": [],
        "relations": [],
        "metadata_update": {
            "entity_id": entity["id"],
            "metadata": {
                "status_code": status,
                "server": headers.get("server", ""),
                "content_type": headers.get("content-type", ""),
                "x_powered_by": headers.get("x-powered-by", ""),
            },
        },
    }
    json.dump(result, sys.stdout, ensure_ascii=False)


if __name__ == "__main__":
    main()