// tests/lib/living-paths.test.mjs
// Living tracked text names only plugin paths that exist. When a file is
// removed, every command, agent, skill, template and doc that still names it
// turns this test red, so a removal cannot leave a dead pointer behind.
//
// Scope: tracked *.md under agents/ commands/ skills/ templates/ docs/ and the
// root README.md, CLAUDE.md, CONTRIBUTING.md and SECURITY.md. Out of scope:
// CHANGELOG.md (history), *.local.* files (never tracked), and tests/,
// examples/ and evals/, whose text describes target repositories.
//
// A reference is (a) a whole backtick span that starts with a top-level plugin
// directory, with an optional ${CLAUDE_PLUGIN_ROOT}/ prefix and an optional
// :line suffix; (b) a ${CLAUDE_PLUGIN_ROOT}/<path> token anywhere; (c) a
// relative markdown link target. Spans with placeholder characters and spans
// on a credit line (an @<sha> or MIT on the line or the two lines above) are
// skipped: they name files in other repositories.
//
// When this test fails, fix the pointer or remove it; add an EXEMPT entry only
// for a path that is meant to be absent here, with the reason.

import { test } from 'node:test';
import { strict as assert } from 'node:assert';
import { execFileSync } from 'node:child_process';
import { existsSync, mkdtempSync, mkdirSync, writeFileSync, readFileSync, rmSync } from 'node:fs';
import { join, dirname, normalize } from 'node:path';
import { tmpdir } from 'node:os';
import { fileURLToPath } from 'node:url';

const HERE = dirname(fileURLToPath(import.meta.url));
const ROOT = join(HERE, '..', '..');

const TOP = '(?:agents|commands|docs|examples|hooks|lib|scripts|skills|templates|tests|evals)';
const PATH = `${TOP}/[A-Za-z0-9._/-]*[A-Za-z0-9_/-]`;
const LINES = '(?::\\d+(?:[-–]\\d+)?(?:, ?\\d+(?:[-–]\\d+)?)*)?';
const SPAN_RE = new RegExp(`^(?:\\$\\{CLAUDE_PLUGIN_ROOT\\}/)?(${PATH})${LINES}$`);
const ROOT_TOKEN_RE = new RegExp(`\\$\\{CLAUDE_PLUGIN_ROOT\\}/(${PATH})`, 'g');
const CREDIT_RE = /@[0-9a-f]{7,40}\b|\bMIT\b/;
const PLACEHOLDER_RE = /[<>{}*$…]|\.\.\./;

const SCOPE_DIRS = ['agents/', 'commands/', 'skills/', 'templates/', 'docs/'];
const SCOPE_ROOT = new Set(['README.md', 'CLAUDE.md', 'CONTRIBUTING.md', 'SECURITY.md']);

// Living tracked text in scope (see the header).
export function inScope(rel) {
  if (!rel.endsWith('.md') || /\.local\./.test(rel)) return false;
  if (rel === 'CHANGELOG.md') return false;
  return SCOPE_ROOT.has(rel) || SCOPE_DIRS.some(d => rel.startsWith(d));
}

// Every plugin path a text names, as { line, path } with path relative to the
// repository root. `rel` is the text's own path, for relative links.
export function extractPaths(text, rel) {
  const out = [];
  const lines = text.split('\n');
  lines.forEach((line, i) => {
    const context = lines.slice(Math.max(0, i - 2), i + 1).join('\n');
    if (CREDIT_RE.test(context)) return;
    const seen = new Set();
    const add = p => { if (!seen.has(p)) { seen.add(p); out.push({ line: i + 1, path: p }); } };
    for (const m of line.matchAll(/`([^`\n]+)`/g)) {
      const span = m[1].trim();
      const hit = SPAN_RE.exec(span);
      if (hit && !PLACEHOLDER_RE.test(hit[1])) add(hit[1]);
    }
    for (const m of line.matchAll(ROOT_TOKEN_RE)) {
      if (!PLACEHOLDER_RE.test(m[1])) add(m[1]);
    }
    for (const m of line.matchAll(/\]\(([^)\s]+)\)/g)) {
      const target = m[1].split('#')[0];
      if (!target || /^[a-z][a-z0-9+.-]*:/i.test(target) || target.startsWith('/')) continue;
      if (PLACEHOLDER_RE.test(target)) continue;
      const resolved = normalize(join(dirname(rel), target)).replace(/\\/g, '/');
      if (resolved.startsWith('..')) continue;
      add(resolved.replace(/\/$/, ''));
    }
  });
  return out;
}

// "file:line path" for every named path that does not exist under root.
export function deadPaths(root, files) {
  const dead = [];
  for (const rel of files) {
    const text = readFileSync(join(root, rel), 'utf-8');
    for (const { line, path } of extractPaths(text, rel)) {
      if (!existsSync(join(root, path))) dead.push(`${rel}:${line} ${path}`);
    }
  }
  return dead;
}

function trackedFiles(root) {
  const out = execFileSync('git', ['ls-files', '-z'], { cwd: root, encoding: 'utf-8' });
  return out.split('\0').filter(Boolean);
}

// Named exceptions: "file path" -> reason. Each must still be dead (a stale
// exemption fails below).
const TARGET = 'target-repo example';
const RB = 'removed in R-b';
const EXEMPT = new Map([
  ['commands/trekplan.md tests/e2e.sh', TARGET],
  ['docs/HANDOVER-CONTRACTS.md docs/specs/api.md', TARGET],
  ['templates/trekreview-template.md lib/foo.mjs', TARGET],
  ['docs/release-runbook.md scripts/release-plugin.mjs', "the catalog repo's script"],
  ['docs/T1-cc26-delegated-orchestration.md scripts/q3-cache-prefix-experiment.mjs', RB],
  ['docs/T1-cc26-delegated-orchestration.md docs/cc-upgrade-2.1.181-decision-matrix.md', RB],
  ['docs/T1-cc26-delegated-orchestration.md docs/subagent-delegation-audit.md', RB],
  ['docs/T1-cc26-delegated-orchestration.md agents/planning-orchestrator.md', RB],
  ['docs/T1-cc26-delegated-orchestration.md docs/T1-synthesis-poc-results.md', RB],
  ['docs/T1-cc26-delegated-orchestration.md agents/synthesis-agent.md', RB],
  ['docs/deep-research-engine-research.md docs/cc-upgrade-2.1.181-decision-matrix.md', RB],
]);

const exemptKey = hit => hit.replace(/:\d+ /, ' ');

test('extractPaths reads spans, plugin-root tokens and relative links (known-positive)', () => {
  const text = [
    'See `lib/util/present.mjs:12-14` and `lib/util/missing.mjs`.',
    'Run node ${CLAUDE_PLUGIN_ROOT}/scripts/gone.mjs --json.',
    'Read [the doc](../docs/away.md#part) or [site](https://example.com).',
    'Placeholder `tests/<name>.sh` and glob `tests/**/*.test.mjs` are skipped.',
    'Credit: someone/repo @c55ee46, `skills/other/SKILL.md`, MIT.',
  ].join('\n');
  const got = extractPaths(text, 'commands/x.md').map(h => `${h.line} ${h.path}`);
  assert.deepEqual(got, [
    '1 lib/util/present.mjs',
    '1 lib/util/missing.mjs',
    '2 scripts/gone.mjs',
    '3 docs/away.md',
  ]);
});

test('deadPaths reports only the missing paths (known-positive)', () => {
  const dir = mkdtempSync(join(tmpdir(), 'living-paths-'));
  try {
    mkdirSync(join(dir, 'lib'), { recursive: true });
    mkdirSync(join(dir, 'docs'), { recursive: true });
    writeFileSync(join(dir, 'lib', 'present.mjs'), '\n');
    writeFileSync(join(dir, 'docs', 'a.md'), 'Uses `lib/present.mjs` and `lib/absent.mjs`.\n');
    assert.deepEqual(deadPaths(dir, ['docs/a.md']), ['docs/a.md:1 lib/absent.mjs']);
  } finally {
    rmSync(dir, { recursive: true, force: true });
  }
});

test('scope keeps living docs and drops history and target-repo text', () => {
  assert.ok(inScope('commands/trekplan.md'));
  assert.ok(inScope('docs/architecture.md'));
  assert.ok(inScope('README.md'));
  assert.ok(!inScope('CHANGELOG.md'));
  assert.ok(!inScope('docs/notes.local.md'));
  assert.ok(!inScope('tests/fixtures/x.md'));
  assert.ok(!inScope('examples/02-real-cli/brief.md'));
  assert.ok(!inScope('lib/util/frontmatter.mjs'));
});

test('living tracked text names only paths that exist', () => {
  const files = trackedFiles(ROOT);
  assert.ok(files.length > 100, `git ls-files returned ${files.length} files; refusing to pass on an empty scan`);
  const hits = deadPaths(ROOT, files.filter(inScope)).filter(h => !EXEMPT.has(exemptKey(h)));
  assert.deepEqual(hits, [], `${hits.length} dead path reference(s):\n${hits.join('\n')}`);
});

test('every EXEMPT entry is still a dead reference in a tracked file', () => {
  const tracked = new Set(trackedFiles(ROOT));
  for (const key of EXEMPT.keys()) {
    const [rel, path] = key.split(' ');
    assert.ok(tracked.has(rel), `EXEMPT names untracked ${rel}`);
    const dead = deadPaths(ROOT, [rel]).map(exemptKey);
    assert.ok(dead.includes(key), `EXEMPT entry "${key}" is no longer dead; remove it`);
    assert.ok(!existsSync(join(ROOT, path)), `EXEMPT path ${path} exists`);
  }
});