"""Independent Punchblog loopback readiness lab; no external services."""
import json
import argparse
from datetime import datetime, timezone
import threading
import urllib.request
import urllib.error
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path
worker_stop = threading.Event()
worker = threading.Thread(target=lambda: worker_stop.wait(), daemon=True)
worker.start()
dependency = {'available': True}
class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        live = worker.is_alive()
        ready = live and dependency['available']
        status = 200 if self.path == '/healthz' or self.path == '/readyz' and ready else 503
        body = json.dumps({'http_process_responding': True, 'worker_alive': live,
                           'dependency_available': dependency['available'], 'ready': ready}).encode()
        self.send_response(status); self.send_header('Content-Type', 'application/json')
        self.send_header('Content-Length', str(len(body))); self.end_headers(); self.wfile.write(body)
    def log_message(self, *_): pass
server = ThreadingHTTPServer(('127.0.0.1', 0), Handler)
thread = threading.Thread(target=server.serve_forever, daemon=True); thread.start()
lab = []
def sample(phase):
    for path in ['/healthz', '/readyz']:
        try:
            response = urllib.request.urlopen(f'http://127.0.0.1:{server.server_port}{path}', timeout=2)
        except urllib.error.HTTPError as e:
            response = e
        with response:
            lab.append({'phase': phase, 'path': path, 'status': response.code, 'body': json.load(response)})
try:
    sample('healthy')
    dependency['available'] = False; sample('dependency_unavailable')
    dependency['available'] = True; worker_stop.set(); worker.join(1); sample('worker_stopped')
    worker_stop = threading.Event()
    worker = threading.Thread(target=lambda: worker_stop.wait(), daemon=True); worker.start()
    sample('recovered')
finally:
    worker_stop.set(); worker.join(1); server.shutdown(); server.server_close(); thread.join(1)
assert [r['status'] for r in lab] == [200, 200, 200, 503, 200, 503, 200, 200]


parser = argparse.ArgumentParser()
parser.add_argument('--output', required=True)
args = parser.parse_args()
output = Path(args.output)
if output.exists(): raise SystemExit('Output exists; choose a new path')
record = {'observed_at': datetime.now(timezone.utc).isoformat(), 'observations': lab}
output.write_text(json.dumps(record, ensure_ascii=False, indent=2) + '\n')
print('PASS: 8 loopback responses; own server and workers stopped')