#!/usr/bin/env bun
/**
 * Sanity check: every IP in `src/simulator-ips.ts` is referenced by
 * at least one non-code config file (Knot zone, unbound conf, shell
 * entrypoint).
 *
 * Why this exists: the e2e simulator IPs (`100.64.0.{53,54,55,56,57,100}`)
 * appear in code (TS) AND in non-code config files (Knot zones, shell
 * scripts). Code uses the canonical constants in `src/simulator-ips.ts`.
 * Non-code files hard-code the values because Knot zones and bash
 * scripts can't import TypeScript. This check fails CI when someone
 * renumbers a constant in code without updating the matching
 * hard-coded reference in a zone file or script — the cheapest way to
 * catch the inevitable "I changed it in one place" drift.
 *
 * Usage:
 *   bun run packages/e2e/scripts/check-simulator-ips.ts
 *
 * Exits 0 on clean, 1 on drift.
 */

import { execSync } from 'node:child_process';
import { readFileSync } from 'node:fs';
import { join } from 'node:path';
import { SIMULATOR_IPS } from '../src/simulator-ips';

const E2E_ROOT = join(__dirname, '..');

function listScannedFiles(): string[] {
  const find = execSync(
    `find ${E2E_ROOT}/config/dns ${E2E_ROOT}/config/resolver ${E2E_ROOT}/config/routing -type f \\( -name '*.zone' -o -name '*.conf' -o -name '*.sh' \\) 2>/dev/null`,
    { encoding: 'utf-8' },
  );
  return find.split('\n').filter(Boolean);
}

interface IpReference {
  ip: string;
  hits: Array<{ file: string; line: number; context: string }>;
}

function scan(): Map<string, IpReference> {
  const result = new Map<string, IpReference>();
  for (const [name, ip] of Object.entries(SIMULATOR_IPS)) {
    result.set(name, { ip, hits: [] });
  }

  const escapedIps = Object.values(SIMULATOR_IPS).map((ip) => ip.replace(/\./g, '\\.'));
  const pattern = new RegExp(`\\b(${escapedIps.join('|')})\\b`, 'g');

  for (const file of listScannedFiles()) {
    let content: string;
    try {
      content = readFileSync(file, 'utf-8');
    } catch {
      continue;
    }
    const lines = content.split('\n');
    for (let i = 0; i < lines.length; i++) {
      const matches = lines[i].matchAll(pattern);
      for (const m of matches) {
        const matchedIp = m[1];
        for (const [, entry] of result) {
          if (entry.ip === matchedIp) {
            entry.hits.push({ file, line: i + 1, context: lines[i].trim() });
            break;
          }
        }
      }
    }
  }

  return result;
}

function main(): void {
  const refs = scan();
  const orphans = [...refs.entries()].filter(([, e]) => e.hits.length === 0);

  if (orphans.length === 0) {
    console.log('✓ All simulator IPs are referenced by at least one non-code config file.');
    console.log(`  Canonical entries (${refs.size}):`);
    for (const [name, e] of refs) {
      console.log(`    ${name.padEnd(20)} ${e.ip}  (${e.hits.length} reference(s))`);
    }
    process.exit(0);
  }

  console.error(
    `✗ ${orphans.length} canonical simulator IP(s) have no references in config files:`,
  );
  for (const [name, e] of orphans) {
    console.error(`  ${name.padEnd(20)} ${e.ip}`);
  }
  console.error('');
  console.error('Either:');
  console.error('  - The IP was renumbered in src/simulator-ips.ts but the zone/conf/script');
  console.error('    files still hold the old value (search for the old IP and update).');
  console.error('  - The simulator was removed but the constant lingers (delete it).');
  console.error('  - The IP is genuinely unused outside code — add a `# canonical` comment');
  console.error('    in any config file to satisfy the check, or remove the constant.');
  process.exit(1);
}

main();