import test from 'node:test';
import assert from 'node:assert/strict';
import { mkdtempSync, readFileSync, writeFileSync, rmSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { fileURLToPath } from 'node:url';
import { loadRequirements, checkRequirements, RequirementsError, REQUIREMENTS_FILE } from '../src/requirements.mjs';
// Row 90 (#1584): requirements.json against the approved PRD it names. The PRD's **REQ-...**
// bullets are the source; the list must hold the same ids in the same order, and the PRD's
// status line must give the list's version.
const list = loadRequirements();
const raw = () => JSON.parse(readFileSync(REQUIREMENTS_FILE, 'utf8'));
const REPO = fileURLToPath(new URL('../../../', import.meta.url));
const listError = (message) => (e) => e instanceof RequirementsError && (message === undefined || e.message === message);

test("the list holds the PRD's requirement ids, in its order, at its version", () => {
  const prd = readFileSync(join(REPO, list.prd), 'utf8');
  const ids = [...prd.matchAll(/^- \*\*(REQ-[A-Z]+-[0-9]+)\.\*\*/gm)].map((m) => m[1]);
  // Any other mention of a bold id would be a bullet this pattern missed.
  assert.equal(ids.length, [...prd.matchAll(/\*\*REQ-/g)].length);
  assert.equal(ids.length, 24);
  assert.deepEqual(list.requirements.map((r) => r.id), ids);
  assert.match(prd, new RegExp(`^- Status: approved, version ${list.version.replace('.', '\\.')}\\.`, 'm'));
  assert.deepEqual([list.prd, list.version], ['docs/prd/mosaic-stack.md', '1.0']);
});

test('the committed list loads frozen', () => {
  assert.ok(Object.isFrozen(list) && Object.isFrozen(list.requirements) && Object.isFrozen(list.requirements[0]));
  assert.deepEqual(checkRequirements(raw()), raw());
  assert.deepEqual(loadRequirements(), list);
});

test('the schema refuses any other shape', () => {
  const bad = {
    'an unknown top key': (l) => (l.source = 'x'),
    'no prd': (l) => delete l.prd,
    'a prd outside docs/prd': (l) => (l.prd = 'docs/plans/x.md'),
    'a prd that is not markdown': (l) => (l.prd = 'docs/prd/mosaic-stack.txt'),
    'a prd with a parent step': (l) => (l.prd = 'docs/prd/../x.md'),
    'no version': (l) => delete l.version,
    'a numeric version': (l) => (l.version = 1.5),
    'a version with no minor': (l) => (l.version = '1'),
    'a version 0': (l) => (l.version = '0.4'),
    'no requirements': (l) => delete l.requirements,
    'an empty list': (l) => (l.requirements = []),
    'requirements not a list': (l) => (l.requirements = {}),
    'an entry not an object': (l) => (l.requirements[0] = 'REQ-ROLE-1'),
    'an unknown entry key': (l) => (l.requirements[0].note = 'x'),
    'no id': (l) => delete l.requirements[0].id,
    'no title': (l) => delete l.requirements[0].title,
    'an id in lower case': (l) => (l.requirements[0].id = 'REQ-role-1'),
    'an id numbered 0': (l) => (l.requirements[0].id = 'REQ-ROLE-0'),
    'an id with a suffix': (l) => (l.requirements[0].id = 'REQ-ROLE-1a'),
    'an id twice': (l) => (l.requirements[1].id = l.requirements[0].id),
    'a blank title': (l) => (l.requirements[0].title = ' '),
    'a title over 120 characters': (l) => (l.requirements[0].title = 'x'.repeat(121)),
    'a title of two lines': (l) => (l.requirements[0].title = 'a\nb'),
    'a title that is not a string': (l) => (l.requirements[0].title = 1),
  };
  for (const x of [[], null, 'list']) assert.throws(() => checkRequirements(x), listError('list: not an object'));
  for (const [what, edit] of Object.entries(bad)) {
    const l = raw();
    edit(l);
    assert.throws(() => checkRequirements(l), listError(), what);
  }
  const ok = raw();
  ok.requirements[0].title = 'x'.repeat(120);
  assert.equal(checkRequirements(ok), ok);
  const dir = mkdtempSync(join(tmpdir(), 'requirements-'));
  try {
    writeFileSync(join(dir, 'cut.json'), '{"prd":');
    assert.throws(() => loadRequirements(join(dir, 'cut.json')), listError('requirements.json: not JSON'));
    assert.throws(() => loadRequirements(join(dir, 'absent.json')), listError('requirements.json: ENOENT'));
    const twice = raw();
    twice.requirements.push(structuredClone(twice.requirements[0]));
    writeFileSync(join(dir, 'twice.json'), JSON.stringify(twice));
    assert.throws(() => loadRequirements(join(dir, 'twice.json')), listError('requirements[24].id: REQ-ROLE-1 twice'));
  } finally {
    rmSync(dir, { recursive: true, force: true });
  }
});