import { afterEach, describe, expect, test } from 'bun:test';
import { execFileSync } from 'node:child_process';
import * as fs from 'node:fs';
import * as os from 'node:os';
import * as path from 'node:path';
import { between } from './helpers/prompt-structure';

const ROOT = path.resolve(import.meta.dir, '..');
const BIN = path.join(ROOT, 'bin/gstack-ceo-plan-find');
const temps: string[] = [];

afterEach(() => {
  for (const dir of temps.splice(0)) fs.rmSync(dir, { recursive: true, force: true });
});

function fixture() {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'ceo-plan-find-'));
  temps.push(dir);
  const home = path.join(dir, 'home');
  fs.mkdirSync(home, { recursive: true });
  const plans = path.join(home, '.gstack/projects/proj/ceo-plans');
  const baseEnv = { PATH: process.env.PATH!, HOME: home };
  // The header /plan-ceo-review writes (plan-ceo-review/SKILL.md.tmpl, 0H).
  const write = (file: string, branch: string | null, ageSeconds: number) => {
    fs.mkdirSync(path.dirname(file), { recursive: true });
    const header = branch === null ? '' : `Branch: ${branch} | Mode: SELECTIVE EXPANSION\n`;
    fs.writeFileSync(file, `---\nstatus: ACTIVE\n---\n# CEO Plan: Feature\nGenerated by /plan-ceo-review on 2026-10-12\n${header}Repo: acme/widgets\n`);
    const t = Date.now() / 1000 - ageSeconds;
    fs.utimesSync(file, t, t);
    return file;
  };
  const find = (env: Record<string, string> = {}, args = ['proj', 'feat-x']) =>
    execFileSync(BIN, args, { cwd: dir, env: { ...baseEnv, ...env }, encoding: 'utf8', timeout: 10_000 }).trim();
  return { dir, home, plans, write, find };
}

describe('gstack-ceo-plan-find', () => {
  test('default root is ~/.gstack and prints nothing when no plan exists', () => {
    const f = fixture();
    expect(f.find()).toBe('');
    const plan = f.write(path.join(f.plans, '2026-10-01-feature.md'), 'feat/x', 100);
    expect(f.find()).toBe(plan);
  });

  test('GSTACK_HOME moves the state root', () => {
    const f = fixture();
    f.write(path.join(f.plans, '2026-10-01-a.md'), 'feat/x', 10);
    const custom = path.join(f.dir, 'custom-state');
    const plan = f.write(path.join(custom, 'projects/proj/ceo-plans/2026-10-02-b.md'), 'feat/x', 100);
    expect(f.find({ GSTACK_HOME: custom })).toBe(plan);
  });

  test('the plan for this branch wins over a newer plan for another branch', () => {
    const f = fixture();
    // gstack-slug reports feat/x as feat-x; the plan header keeps the slash.
    const mine = f.write(path.join(f.plans, '2026-10-01-mine.md'), 'feat/x', 500);
    const other = f.write(path.join(f.plans, '2026-10-03-other.md'), 'main', 10);
    expect(f.find()).toBe(mine);
    expect(f.find({}, ['proj', 'main'])).toBe(other);
    expect(f.find({}, ['proj', 'unrelated'])).toBe(other);
  });

  test('the newest plan for the branch wins, and a plan without a Branch line is still a fallback', () => {
    const f = fixture();
    f.write(path.join(f.plans, '2026-10-01-old.md'), 'feat-x', 500);
    const newer = f.write(path.join(f.plans, '2026-10-02-new.md'), 'feat-x', 100);
    const headerless = f.write(path.join(f.plans, '2026-10-03-headerless.md'), null, 10);
    expect(f.find()).toBe(newer);
    expect(f.find({}, ['proj', 'other'])).toBe(headerless);
  });

  test('only top-level plans count', () => {
    const f = fixture();
    const plan = f.write(path.join(f.plans, '2026-10-01-live.md'), 'feat/x', 500);
    f.write(path.join(f.plans, 'archive/2026-10-02-old.md'), 'feat/x', 10);
    expect(f.find()).toBe(plan);
  });

  test('usage errors exit 2', () => {
    const f = fixture();
    for (const args of [[], ['proj'], ['', 'feat-x']]) {
      let status: number | null = null;
      try { f.find({}, args); } catch (err) { status = (err as { status: number | null }).status; }
      expect(status).toBe(2);
    }
  });
});

describe('rendered plan-eng-review Design Doc Check (#280)', () => {
  const rendered = fs.readFileSync(path.join(ROOT, 'plan-eng-review/SKILL.md'), 'utf8');
  const check = between(rendered, '### Design Doc Check', '### Step 0');
  const at = check.indexOf('CEO_PLAN=$(~/.claude/skills/gstack/bin/gstack-ceo-plan-find');
  const block = check.slice(Math.max(at, 0)).split('\n').slice(0, 2).join('\n');

  test('the check renders one CEO-plan helper invocation before Step 0', () => {
    expect(at).toBeGreaterThanOrEqual(0);
    expect(block).toContain('gstack-ceo-plan-find "$SLUG" "$BRANCH"');
    expect(block).toContain('echo "CEO plan found: $CEO_PLAN"');
    expect(block).toContain('echo "No CEO plan found"');
  });

  test('finds the plan for this branch under a custom GSTACK_HOME and reports none elsewhere', () => {
    expect(at).toBeGreaterThanOrEqual(0);
    const f = fixture();
    const installed = path.join(f.home, '.claude/skills/gstack/bin');
    fs.mkdirSync(installed, { recursive: true });
    for (const bin of ['gstack-ceo-plan-find', 'gstack-paths', 'gstack-state-root.sh']) {
      fs.copyFileSync(path.join(ROOT, 'bin', bin), path.join(installed, bin));
      fs.chmodSync(path.join(installed, bin), 0o755);
    }
    const run = (env: Record<string, string>) => execFileSync('bash', ['-c', `SLUG=proj; BRANCH=feat-x; ${block}`],
      { cwd: f.dir, env: { PATH: process.env.PATH!, HOME: f.home, ...env }, encoding: 'utf8', timeout: 10_000 }).trim();
    const custom = path.join(f.dir, 'custom-state');
    const mine = f.write(path.join(custom, 'projects/proj/ceo-plans/2026-10-01-mine.md'), 'feat/x', 500);
    f.write(path.join(custom, 'projects/proj/ceo-plans/2026-10-03-other.md'), 'main', 10);
    expect(run({ GSTACK_HOME: custom })).toBe(`CEO plan found: ${mine}`);
    expect(run({})).toBe('No CEO plan found');
  });
});