/**
 * `bun run test`: run only the tests related to the files that changed.
 *
 * Changed files = everything since origin/main (commits not pushed yet + uncommitted + untracked).
 * If that is empty (already pushed), the last commit is used. `TEST_BASE=<ref>` overrides the base.
 *
 * - one game (packages/games/src/<id>, apps/web/src/games/<id>) → that game's test files, plus that
 *   game's cases in the all-games test files (`-t <id>`)
 * - bots/ → every bot test · apps/server → server tests · web screens → web tests
 * - docs, e2e, deploy, scripts → nothing
 * - engine, shared, game registry, root config, anything unknown → every test (`bun run test:all`)
 *
 * `bun run test -- --dry-run` prints the choice without running.
 */
import { Glob } from 'bun';

const BUN_TEST = ['bun', 'test', '--parallel=4', '--timeout', '60000'];
/** Test files that loop over every game; for a game-only change they run just that game's cases. */
const ALL_GAMES_TESTS = [
  'packages/games/src/bots/bots.test.ts',
  'apps/web/src/games/help.test.ts',
  'apps/server/src/rooms/replay.test.ts',
  'apps/server/src/rooms/bots.room.test.ts',
];
const IGNORED = [/\.md$/, /^docs\//, /^e2e\//, /^deploy\//, /^scripts\//, /^test-results\//, /^\.(gitignore|editorconfig|dockerignore)$/];

function git(...args: string[]): string[] | null {
  const r = Bun.spawnSync(['git', ...args], { stderr: 'ignore' });
  if (r.exitCode !== 0) return null;
  return r.stdout.toString().split('\n').filter(Boolean);
}

function changedFiles(): { files: string[]; from: string } | null {
  const base = process.env.TEST_BASE ?? (git('rev-parse', '--verify', '-q', 'origin/main') ? 'origin/main' : null);
  if (base) {
    const mb = git('merge-base', 'HEAD', base)?.[0];
    const diff = mb ? git('diff', '--name-only', '--no-renames', mb) : null;
    const untracked = git('ls-files', '--others', '--exclude-standard');
    if (!diff || !untracked) return null;
    const files = [...new Set([...diff, ...untracked])];
    if (files.length > 0 || process.env.TEST_BASE) return { files, from: `${base} 이후 + 커밋 안 한 변경` };
  }
  const last = git('diff', '--name-only', '--no-renames', 'HEAD~1', 'HEAD');
  return last ? { files: last, from: '마지막 커밋' } : null;
}

const allTests = [...new Glob('{apps,packages}/**/*.test.{ts,tsx}').scanSync('.')].filter((f) => !f.includes('node_modules')).sort();
const gameIds = new Set([...new Glob('packages/games/src/*/index.ts').scanSync('.')].map((f) => f.split('/')[3]!).filter((id) => id !== 'bots'));

type Plan = { all: true; why: string } | { all: false; files: Set<string>; games: Set<string> };

function plan(changed: string[]): Plan {
  const files = new Set<string>();
  const games = new Set<string>();
  const add = (pred: (t: string) => boolean) => allTests.filter(pred).forEach((t) => files.add(t));
  for (const p of changed) {
    if (IGNORED.some((re) => re.test(p))) continue;
    const game = p.match(/^packages\/games\/src\/([^/]+)\//)?.[1] ?? p.match(/^apps\/web\/src\/games\/([^/]+)\//)?.[1] ?? p.match(/^apps\/server\/src\/rooms\/([^/.]+)\.room\.test\.ts$/)?.[1];
    if (game && gameIds.has(game)) {
      games.add(game);
      add((t) => t.startsWith(`packages/games/src/${game}/`) || t.startsWith(`apps/web/src/games/${game}/`) || t === `apps/server/src/rooms/${game}.room.test.ts`);
      if (p.startsWith('apps/web/')) add((t) => t === 'apps/web/src/no-money-wording.test.ts');
    } else if (p.startsWith('packages/games/src/bots/')) {
      add((t) => /^packages\/games\/src\/[^/]+\/bots?\.test\.ts$/.test(t) || t === 'apps/server/src/rooms/bots.room.test.ts' || t === 'apps/server/src/bots.test.ts');
    } else if (p.startsWith('apps/server/src/')) {
      add((t) => t.startsWith('apps/server/'));
    } else if (/^apps\/web\/src\/(components|lib|net)\//.test(p) || /^apps\/web\/src\/games\/[^/]+$/.test(p)) {
      add((t) => t.startsWith('apps/web/')); // shared by every game screen
    } else if (/^apps\/web\/(src\/|public\/|index\.html$|sw\.js$|vite\.config\.ts$)/.test(p)) {
      add((t) => /^apps\/web\/src\/[^/]+\.test\.tsx?$/.test(t)); // other screens: home, pages, store, styles
    } else {
      return { all: true, why: p };
    }
  }
  return { all: false, files, games };
}

const shown = (cmd: string[]) => cmd.map((a) => (/^[\w./=-]+$/.test(a) ? a : `'${a}'`)).join(' ');

function run(cmd: string[]): number {
  console.log(`\n$ ${shown(cmd)}`);
  return Bun.spawnSync(cmd, { stdio: ['inherit', 'inherit', 'inherit'] }).exitCode ?? 1;
}

const dry = process.argv.includes('--dry-run');
const changed = changedFiles();
const p: Plan = changed ? plan(changed.files) : { all: true, why: 'git으로 바뀐 파일을 알 수 없음' };
if (changed) console.log(`바뀐 파일 ${changed.files.length}개 (${changed.from})`);

if (p.all) {
  console.log(`전체 테스트: ${p.why}`);
  process.exit(dry ? 0 : run(BUN_TEST));
}

const cross = ALL_GAMES_TESTS.filter((t) => !p.files.has(t) && allTests.includes(t));
const runs: string[][] = [];
if (p.files.size > 0) runs.push([...BUN_TEST, ...[...p.files].map((f) => `./${f}`)]);
if (p.games.size > 0 && cross.length > 0) {
  // Whole id only: "poker" must not pick "cockroach-poker" cases.
  runs.push([...BUN_TEST, '-t', `(?<![\\w-])(?:${[...p.games].join('|')})(?![\\w-])`, ...cross.map((f) => `./${f}`)]);
}
if (runs.length === 0) {
  console.log('관련 테스트 없음 (문서·E2E·배포 파일만 바뀜)');
  process.exit(0);
}
if (p.games.size > 0) console.log(`게임: ${[...p.games].join(', ')}`);
if (dry) {
  for (const r of runs) console.log(`$ ${shown(r)}`);
  process.exit(0);
}
let code = 0;
for (const r of runs) code = run(r) || code;
process.exit(code);