#!/usr/bin/env node
// Operator report for the privacy-safe model counters (issue #19).
//
// It reads one snapshot from a running Timmy server and prints it. The token is a credential for the
// operator surface, so it is read from the environment or argv and never echoed — not in errors, not
// in the report, not in a stack trace.
import { formatOperatorReport } from '../src/model-metrics-report.js';

const USAGE = `Usage: node scripts/model_metrics_report.mjs [options]

  --url <origin>        base URL of the Timmy server (default http://127.0.0.1:4173)
  --token <token>       operator token (default: $TIMMY_METRICS_TOKEN)
  --json                print the raw snapshot instead of the text report
  --timeout-ms <ms>     request deadline (default 5000)
  --help                show this text
`;

function parseArgs(argv) {
  const options = {
    url: process.env.TIMMY_METRICS_URL || 'http://127.0.0.1:4173',
    token: process.env.TIMMY_METRICS_TOKEN || '',
    json: false,
    timeoutMs: 5_000,
    help: false,
  };
  for (let index = 0; index < argv.length; index += 1) {
    const arg = argv[index];
    if (arg === '--help' || arg === '-h') {
      options.help = true;
    } else if (arg === '--json') {
      options.json = true;
    } else if (arg === '--url') {
      options.url = argv[++index] ?? '';
    } else if (arg === '--token') {
      options.token = argv[++index] ?? '';
    } else if (arg === '--timeout-ms') {
      options.timeoutMs = Number(argv[++index]);
    } else {
      throw new Error(`unknown option: ${arg}`);
    }
  }
  return options;
}

async function main(argv) {
  const options = parseArgs(argv);
  if (options.help) {
    process.stdout.write(USAGE);
    return 0;
  }
  if (!options.token) {
    throw new Error('operator token required: pass --token or set TIMMY_METRICS_TOKEN');
  }
  const endpoint = new URL('api/metrics', options.url.endsWith('/') ? options.url : `${options.url}/`);
  let response;
  try {
    response = await fetch(endpoint, {
      headers: { authorization: `Bearer ${options.token}`, accept: 'application/json' },
      signal: AbortSignal.timeout(Number.isFinite(options.timeoutMs) ? options.timeoutMs : 5_000),
    });
  } catch (error) {
    process.stderr.write(`Could not read ${endpoint.origin}/api/metrics: ${error?.message || 'request failed'}\n`);
    return 1;
  }
  if (!response.ok) {
    if (response.status === 404) {
      // The route is absent rather than guarded: that is a deployment fact, not a credential problem.
      process.stderr.write('Metrics are disabled on this server: the route only exists when TIMMY_METRICS_TOKEN is set.\n');
      return 1;
    }
    if (response.status === 403) {
      process.stderr.write('The server rejected the operator token.\n');
      return 1;
    }
    process.stderr.write(`The server answered ${response.status} for /api/metrics.\n`);
    return 1;
  }
  const snapshot = await response.json();
  process.stdout.write(options.json ? `${JSON.stringify(snapshot, null, 2)}\n` : formatOperatorReport(snapshot));
  return 0;
}

main(process.argv.slice(2)).then(code => {
  process.exitCode = code;
}).catch(error => {
  process.stderr.write(`${error?.message || 'report failed'}\n`);
  process.exitCode = 2;
});