#!/usr/bin/env python3
"""S-16c (#124): prove the golden-signal metrics pipeline works end to end.

Generate anonymous BFF traffic (GET /openbaar/register — no auth, no OpenZaak egress),
then query Prometheus and assert (1) every .NET service's scrape target is UP, and (2)
the http.server.request.duration histogram is actually being scraped — i.e. the services
expose /metrics AND Prometheus collects it, which is exactly what the golden-signal
dashboard reads.

Stdlib only (urllib/json) so it runs in a bare python:3-slim container in-network.
"""
import json
import os
import sys
import time
import urllib.error
import urllib.parse
import urllib.request

BFF = os.environ["BFF"]          # http://<bff-ip>:8080
PROM = os.environ["PROMETHEUS"]  # http://<prometheus-ip>:9090
TIMEOUT = int(os.environ.get("METRICS_TIMEOUT", "90"))
SERVICES = {"acl", "domain", "bff", "event-subscriber", "projection-api"}


def _get(url):
    with urllib.request.urlopen(url, timeout=10) as r:
        return r.read()


def generate_traffic():
    for _ in range(3):
        try:
            _get(f"{BFF}/openbaar/register")
        except urllib.error.HTTPError:
            pass  # a non-2xx still records an http.server metric


def query(promql):
    q = urllib.parse.quote(promql)
    try:
        data = json.loads(_get(f"{PROM}/api/v1/query?query={q}"))
    except Exception:
        return []
    return data.get("data", {}).get("result", [])


def jobs_up():
    return {r["metric"].get("job") for r in query("up == 1")}


def jobs_with_request_metric():
    return {r["metric"].get("job")
            for r in query("http_server_request_duration_seconds_count")}


def main():
    deadline = time.time() + TIMEOUT
    while time.time() < deadline:
        generate_traffic()
        up = jobs_up()
        scraped = jobs_with_request_metric()
        if SERVICES.issubset(up) and SERVICES.issubset(scraped):
            print(f"OK — targets up: {sorted(up & SERVICES)}; "
                  f"request metric scraped from: {sorted(scraped & SERVICES)}")
            return 0
        time.sleep(3)
    print(f"FAIL — up: {sorted(jobs_up() & SERVICES)}; "
          f"request metric from: {sorted(jobs_with_request_metric() & SERVICES)}; "
          f"expected all of {sorted(SERVICES)}", file=sys.stderr)
    return 1


if __name__ == "__main__":
    sys.exit(main())