import assert from 'node:assert/strict';
import test from 'node:test';
import {
  renderPrometheusMetrics,
  sendPrometheusMetrics,
} from '../../src/server/prometheusMetrics.js';

const observedAt = '2026-08-08T10:00:00.000Z';
const snapshot = {
  traffic: {
    gatewayBytes: '9007199254740993',
    proxyBytes: '3000',
    gatewayObservedAt: observedAt,
    proxyObservedAt: observedAt,
  },
  devices: [{
    id: 'dev_0011223344556677',
    alias: 'ТВ "Зал"\\основной\nэкран',
    hostname: 'tv.local',
    ip: '192.168.50.7',
    mac: '00:11:22:33:44:55',
    uploadBytes: '9007199254740993',
    downloadBytes: '100',
    trafficObservedAt: observedAt,
    proxyUploadBytes: '0',
    proxyDownloadBytes: '0',
    proxyTrafficObservedAt: null,
  }],
  domainTraffic: {
    observedAt,
    overflowConnections: '2',
    series: [{
      deviceId: 'dev_0011223344556677',
      domain: 'chatgpt.com',
      service: 'OpenAI / ChatGPT',
      source: 'proxy',
      uploadBytes: '12',
      downloadBytes: '345',
    }],
  },
};

test('Prometheus exposition keeps exact counters, stable identity and escaped names', () => {
  const output = renderPrometheusMetrics(snapshot);

  assert.match(output, /# TYPE harbor_traffic_bytes_total counter/);
  assert.match(output, /harbor_traffic_bytes_total\{source="gateway"\} 9007199254740993/);
  assert.match(output, /harbor_device_info\{device_id="dev_0011223344556677",name="ТВ \\"Зал\\"\\\\основной\\nэкран",ip="192\.168\.50\.7"\} 1/);
  assert.match(output, /harbor_device_traffic_bytes_total\{device_id="dev_0011223344556677",source="gateway",direction="upload"\} 9007199254740993/);
  assert.doesNotMatch(output, /harbor_device_traffic_bytes_total\{[^\n]*name=/);
  assert.doesNotMatch(output, /harbor_device_traffic_bytes_total\{[^\n]*source="proxy"/);
  assert.doesNotMatch(output, /00:11:22:33:44:55/);
  assert.match(output, /harbor_device_traffic_last_observed_timestamp_seconds\{device_id="dev_0011223344556677",source="gateway"\} 1786183200/);
  assert.match(output, /harbor_device_domain_traffic_bytes_total\{device_id="dev_0011223344556677",domain="chatgpt\.com",service="OpenAI \/ ChatGPT",source="proxy",direction="download"\} 345/);
  assert.match(output, /harbor_domain_traffic_last_observed_timestamp_seconds 1786183200/);
  assert.match(output, /harbor_domain_traffic_overflow_connections_total 2/);
  assert.doesNotMatch(output, /harbor_device_domain_traffic_bytes_total\{[^\n]*name=/);
  assert.equal(output.endsWith('\n'), true);
});

test('Prometheus response uses the negotiated legacy text contract without mutating the snapshot', () => {
  const before = structuredClone(snapshot);
  const response = {
    writeHead(status, headers) {
      this.status = status;
      this.headers = headers;
    },
    end(body) {
      this.body = body;
    },
  };

  sendPrometheusMetrics(response, snapshot);

  assert.equal(response.status, 200);
  assert.equal(response.headers['content-type'], 'text/plain; version=0.0.4; charset=utf-8');
  assert.match(response.body, /harbor_device_info/);
  assert.deepEqual(snapshot, before);
});

test('invalid canonical counters fail the scrape instead of publishing corrupt values', () => {
  const invalid = { traffic: { gatewayBytes: 'broken', proxyBytes: '0' }, devices: [] };
  assert.throws(
    () => renderPrometheusMetrics(invalid),
    /Invalid Prometheus counter/,
  );
  assert.throws(
    () => sendPrometheusMetrics({ writeHead() { throw new Error('headers sent'); } }, invalid),
    /Invalid Prometheus counter/,
  );
});