#!/usr/bin/env node
// tools/scripts/lint-protocol-sync.mjs
// Source: 04-CONTEXT.md D-19/D-25 — drift guard for the build-time copy of
// tools/protocol-doc/output/protocol.ts → packages/protocol/src/legacy-opcodes.ts.
//
// Usage: node tools/scripts/lint-protocol-sync.mjs
// Exit: 0 in-sync, 1 drift detected, 2 usage error.

import { readFileSync } from 'node:fs';

function fail(msg) {
  process.stderr.write(`lint-protocol-sync: ${msg}\n`);
  process.exit(1);
}

let src, copy;
try {
  src = readFileSync('tools/protocol-doc/output/protocol.ts', 'utf-8');
} catch (e) {
  fail(`source not found: ${e.message}`);
}
try {
  copy = readFileSync('packages/protocol/src/legacy-opcodes.ts', 'utf-8');
} catch (e) {
  fail(`copy not found: ${e.message}. Run \`pnpm --filter @rebno/protocol prebuild\`.`);
}

// The copy is HEADER + src. Check copy ENDS WITH src exactly.
if (!copy.endsWith(src)) {
  fail(
    'legacy-opcodes.ts is out of sync with tools/protocol-doc/output/protocol.ts. ' +
      'Run `pnpm --filter @rebno/protocol prebuild`.',
  );
}

console.log('lint-protocol-sync: OK');
process.exit(0);