'use strict';

/**
 * Behavioral tests for scripts/gen-adr-index.cjs — the ADR index generator and
 * lifecycle gate (#2340).
 *
 * These drive the real CLI as a subprocess against synthetic ADR corpora in a
 * temp dir, asserting on exit code and emitted text. No source-grepping: the
 * runtime behavior is the contract.
 */

const { test } = require('node:test');
const assert = require('node:assert/strict');
const fs = require('node:fs');
const path = require('node:path');
const { spawnSync } = require('node:child_process');

const { createTempDir, cleanup } = require('./helpers.cjs');

const REPO_ROOT = path.resolve(__dirname, '..');
const SCRIPT_REL = path.join('scripts', 'gen-adr-index.cjs');

const START = '<!-- ADR-INDEX:START — generated by scripts/gen-adr-index.cjs; do not edit by hand -->';
const END = '<!-- ADR-INDEX:END -->';

/**
 * Build a throwaway repo whose docs/adr/ contains exactly `files`, and whose
 * scripts/ holds a copy of the generator + its cli-exit dependency. A unique
 * mkdtemp per call keeps parallel tests from colliding, and the dir is removed
 * via `t.after()` so a failing assertion cannot leak it.
 */
function makeRepo(t, files) {
  // helpers.cleanup (not raw fs.rmSync) carries the Windows-EBUSY retry budget.
  const root = createTempDir('gsd-adr-index-');
  t.after(() => cleanup(root));
  fs.mkdirSync(path.join(root, 'docs', 'adr'), { recursive: true });
  fs.mkdirSync(path.join(root, 'scripts', 'lib'), { recursive: true });

  fs.copyFileSync(path.join(REPO_ROOT, SCRIPT_REL), path.join(root, SCRIPT_REL));
  fs.copyFileSync(
    path.join(REPO_ROOT, 'scripts', 'lib', 'cli-exit.cjs'),
    path.join(root, 'scripts', 'lib', 'cli-exit.cjs'),
  );

  for (const [name, body] of Object.entries(files)) {
    fs.writeFileSync(path.join(root, 'docs', 'adr', name), body);
  }
  fs.writeFileSync(
    path.join(root, 'docs', 'adr', 'README.md'),
    `# ADRs\n\n## Index\n\n${START}\n${END}\n`,
  );
  return root;
}

/**
 * Run the generator in `root`; never throws — returns {status, stdout, stderr}.
 *
 * spawnSync (not execFileSync) because BOTH streams matter on BOTH outcomes:
 * `--write` exits 0 while reporting outstanding violations on stderr, and
 * execFileSync only surfaces stderr via the thrown error on non-zero exit.
 */
function run(root, args = []) {
  const res = spawnSync(process.execPath, [path.join(root, SCRIPT_REL), ...args], {
    cwd: root,
    encoding: 'utf8',
    timeout: 30_000,
  });
  if (res.error) throw res.error;
  return { status: res.status, stdout: res.stdout || '', stderr: res.stderr || '' };
}

const adr = (title, fields) => `# ${title}\n\n${fields.map((f) => `- ${f}`).join('\n')}\n\n## Context\n\nBody.\n`;

test('a clean corpus generates an index and --check passes', (t) => {
  const root = makeRepo(t, {
    '0001-alpha.md': adr('Alpha module', ['**Status:** Accepted', '**Date:** 2026-01-01']),
    '900-beta.md': adr('ADR-900: Beta module', ['**Status:** Proposed', '**Date:** 2026-01-02']),
  });

  const write = run(root, ['--write']);
  assert.equal(write.status, 0, `--write failed: ${write.stderr}`);

  const check = run(root, ['--check']);
  assert.equal(check.status, 0, `--check failed: ${check.stderr}`);

  const readme = fs.readFileSync(path.join(root, 'docs', 'adr', 'README.md'), 'utf8');
  assert.match(readme, /\[ADR-0001\]\(0001-alpha\.md\)/, 'zero-padded id must render as written, not ADR-1');
  assert.match(readme, /\[ADR-900\]\(900-beta\.md\)/);
  assert.match(readme, /Active decisions \(1\)/);
  assert.match(readme, /Proposed \(1\)/);
});

test('--check fails when an ADR is added but the index is not regenerated', (t) => {
  const root = makeRepo(t, { '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']) });
  assert.equal(run(root, ['--write']).status, 0);

  // A new ADR lands without re-running --write. This is the exact drift that let
  // the hand-maintained index reach 40/65.
  fs.writeFileSync(path.join(root, 'docs', 'adr', '901-gamma.md'), adr('Gamma', ['**Status:** Accepted']));

  const check = run(root, ['--check']);
  assert.equal(check.status, 1, 'a missing index row must fail CI');
  assert.match(check.stderr, /stale/i);
});

test('a status outside the vocabulary is rejected and names the offender', (t) => {
  const root = makeRepo(t, { '0001-alpha.md': adr('Alpha', ['**Status:** Draft']) });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /0001-alpha\.md/);
  assert.match(res.stderr, /"Draft" is not one of/);
});

test('an ADR with no status field at all is rejected', (t) => {
  const root = makeRepo(t, { '0001-alpha.md': '# Alpha\n\nNo header fields.\n\n## Context\n\nBody.\n' });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /no `- \*\*Status:\*\* <Token>` field/);
});

test('the table header form is parsed as legitimately as the bullet form', (t) => {
  // ADR-2008 uses a markdown table for its header. Treating that as "missing a
  // status" would flag a correct ADR.
  const root = makeRepo(t, {
    '0001-alpha.md': '# Alpha\n\n| | |\n|---|---|\n| **Status** | Accepted |\n| **Date** | 2026-01-01 |\n\n## Context\n\nBody.\n',
  });
  const res = run(root, ['--write']);
  assert.equal(res.status, 0, `table-form header must parse: ${res.stderr}`);
  assert.match(fs.readFileSync(path.join(root, 'docs', 'adr', 'README.md'), 'utf8'), /Active decisions \(1\)/);
});

test('Superseded must name its successor as a file link, not a bare id', (t) => {
  const root = makeRepo(t, {
    '0001-alpha.md': adr('Alpha', ['**Status:** Superseded by ADR-900 (2026-02-01)']),
    '900-beta.md': adr('Beta', ['**Status:** Accepted', '**Supersedes:** [ADR-0001](0001-alpha.md)']),
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /not as a markdown link/);
});

test('Superseded with no successor at all is rejected', (t) => {
  const root = makeRepo(t, { '0001-alpha.md': adr('Alpha', ['**Status:** Superseded']) });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /names no successor/);
});

test('a one-way supersession is rejected and the message names the fix', (t) => {
  const root = makeRepo(t, {
    // Beta claims Alpha; Alpha says nothing back.
    '900-beta.md': adr('Beta', ['**Status:** Accepted', '**Supersedes:** [ADR-0001](0001-alpha.md)']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']),
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /0001-alpha\.md/);
  assert.match(res.stderr, /does not record it/);
  assert.match(res.stderr, /\*\*Superseded by:\*\* \[ADR-900\]\(900-beta\.md\)/);
});

test('a symmetric supersession pair passes', (t) => {
  const root = makeRepo(t, {
    '900-beta.md': adr('Beta', ['**Status:** Accepted', '**Supersedes:** [ADR-0001](0001-alpha.md)']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Superseded by [ADR-900](900-beta.md) (2026-02-01)']),
  });
  assert.equal(run(root, ['--check']).status, 1, 'index not yet written');
  assert.equal(run(root, ['--write']).status, 0);
  assert.equal(run(root, ['--check']).status, 0, 'a symmetric pair must pass');
});

test('subsumption is symmetry-checked but does NOT mark the target superseded', (t) => {
  // The EoS case: ADR-1239 subsumes ADR-1016 as an adapter. ADR-1016 stays
  // Accepted — collapsing this into supersession would kill a live decision.
  const root = makeRepo(t, {
    '900-eos.md': adr('EoS', ['**Status:** Accepted', '**Subsumes as adapters:** [ADR-0001](0001-alpha.md)']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted', '**Subsumed by:** [ADR-900](900-eos.md)']),
  });
  assert.equal(run(root, ['--write']).status, 0);
  const readme = fs.readFileSync(path.join(root, 'docs', 'adr', 'README.md'), 'utf8');
  assert.match(readme, /Active decisions \(2\)/, 'a subsumed ADR stays Active');
  // The subsumer is surfaced in the "Read first" column so EoS is discoverable
  // from the component ADR.
  assert.match(readme, /\| \[ADR-0001\]\(0001-alpha\.md\) \|[^|]*\| Accepted \| \[ADR-900\]\(900-eos\.md\) \|/);
});

test('a missing subsumption back-link is rejected', (t) => {
  const root = makeRepo(t, {
    '900-eos.md': adr('EoS', ['**Status:** Accepted', '**Subsumes:** [ADR-0001](0001-alpha.md)']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']),
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /\*\*Subsumed by:\*\* \[ADR-900\]\(900-eos\.md\)/);
});

test("a Proposed ADR's supersession claim is prospective — no back-link demanded", (t) => {
  // ADR-857 is Proposed and claims to generalize live ADRs. Demanding the
  // back-link would stamp an Accepted decision as superseded by an unratified one.
  const root = makeRepo(t, {
    '900-beta.md': adr('Beta', ['**Status:** Proposed', '**Supersedes:** [ADR-0001](0001-alpha.md)']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']),
  });
  assert.equal(run(root, ['--write']).status, 0);
  const check = run(root, ['--check']);
  assert.equal(check.status, 0, `a Proposed claimant must not force a back-link: ${check.stderr}`);
});

test('ratifying that Proposed ADR to Accepted then demands the back-link', (t) => {
  const root = makeRepo(t, {
    '900-beta.md': adr('Beta', ['**Status:** Accepted', '**Supersedes:** [ADR-0001](0001-alpha.md)']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']),
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1, 'on ratification the back-link becomes required');
  assert.match(res.stderr, /does not record it/);
});

test('"Supersedes: nothing" asserts no relation even when it name-drops an ADR', (t) => {
  // ADR-2264 says "Supersedes: nothing; amends the ADR-1239 harness". Reading that
  // as a supersession claim invents a link the author never made.
  const root = makeRepo(t, {
    '900-beta.md': adr('Beta', ['**Status:** Accepted', '**Supersedes:** nothing; amends the [ADR-0001](0001-alpha.md) harness']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']),
  });
  assert.equal(run(root, ['--write']).status, 0);
  const check = run(root, ['--check']);
  assert.equal(check.status, 0, `a negated relation field must assert nothing: ${check.stderr}`);
});

test('an em-dash relation value asserts no relation', (t) => {
  // Vacuous unless the negated field also carries a LINK: with a bare em-dash
  // there is nothing to mis-parse, so the test passes whether or not negation
  // works. Linking an ADR after the em-dash makes it discriminating — if the
  // field were read as a real claim, symmetry would demand 0001 record it.
  const root = makeRepo(t, {
    '900-beta.md': '# Beta\n\n| | |\n|---|---|\n| **Status** | Accepted |\n| **Supersedes** | — see [ADR-0001](0001-alpha.md) for context |\n\n## Context\n\nBody.\n',
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']),
  });
  assert.equal(run(root, ['--write']).status, 0);
  const check = run(root, ['--check']);
  assert.equal(check.status, 0, `an em-dash field must assert nothing: ${check.stderr}`);
  assert.doesNotMatch(check.stderr, /does not record it/);
});

test('a mixed field with one link and one bare id still flags the bare id', (t) => {
  // Regression: testing `rel.links.length` instead of the specific id meant a
  // field carrying ANY link silently dropped every bare claim beside it.
  const root = makeRepo(t, {
    '900-beta.md': adr('Beta', ['**Status:** Accepted', '**Supersedes:** [ADR-0001](0001-alpha.md), ADR-0002']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Superseded by [ADR-900](900-beta.md)']),
    '0002-gamma.md': adr('Gamma', ['**Status:** Accepted']),
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /names ADR-2 without a file link/);
});

test('a bare id repeated in prose beside its own link is not flagged', (t) => {
  // The corpus legitimately writes "…([ADR-0001](0001-alpha.md)) — see ADR-0001
  // below". That repeat must not be noise.
  const root = makeRepo(t, {
    '900-beta.md': adr('Beta', ['**Status:** Accepted', '**Supersedes:** Alpha ([ADR-0001](0001-alpha.md)) — see the ADR-0001 note below']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Superseded by [ADR-900](900-beta.md)']),
  });
  assert.equal(run(root, ['--write']).status, 0);
  const check = run(root, ['--check']);
  assert.equal(check.status, 0, `a linked-and-repeated id must not be flagged: ${check.stderr}`);
});

test('a dangling "Superseded by" is caught even though the ADR is not Accepted', (t) => {
  // Regression: the ratification guard skipped every non-Accepted ADR, which
  // killed the IN direction entirely — a Superseded ADR pointing at a successor
  // that never claims it went unchecked.
  const root = makeRepo(t, {
    '0001-alpha.md': adr('Alpha', ['**Status:** Superseded by [ADR-900](900-beta.md)']),
    '900-beta.md': adr('Beta', ['**Status:** Accepted']),
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1, 'a one-way superseded-by must fail');
  assert.match(res.stderr, /does not claim it|does not record it/);
});

test('a `## Supersedes` table section counts as the claim (ADR-0174 shape)', (t) => {
  // The richest form in the corpus declares supersession as a section+table, not
  // a header field. Reading only the header block reported the repo's
  // best-documented supersession as missing.
  const root = makeRepo(t, {
    '900-beta.md': '# Beta\n\n- **Status:** Accepted\n\n## Supersedes\n\n| ADR | What it said | Why superseded |\n|---|---|---|\n| [ADR-0001](0001-alpha.md) | a thing | a reason |\n\n## Context\n\nBody.\n',
    '0001-alpha.md': adr('Alpha', ['**Status:** Superseded by [ADR-900](900-beta.md)']),
  });
  assert.equal(run(root, ['--write']).status, 0);
  const check = run(root, ['--check']);
  assert.equal(check.status, 0, `a ## Supersedes table must satisfy symmetry: ${check.stderr}`);
});

test('a title id that disagrees with the filename is rejected', (t) => {
  // The real ADR-218 case: renamed to the issue# convention, title left behind.
  const root = makeRepo(t, { '218-release.md': adr('ADR-0175: Harden release validation', ['**Status:** Accepted']) });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /H1 declares ADR-175 but the filename says 218/);
});

test('a relation link to a nonexistent ADR is rejected', (t) => {
  const root = makeRepo(t, {
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted', '**Supersedes:** [ADR-404](404-ghost.md)']),
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /does not exist in docs\/adr\//);
});

test('a bare id naming a nonexistent ADR is steered toward issue syntax', (t) => {
  // ADR-1610 says "superseding the #597 tier-max ratchet" — #597 is an ISSUE.
  // Written as "ADR-597" it would be an unresolvable reference.
  const root = makeRepo(t, {
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted', '**Supersedes:** ADR-597 tier-max ratchet']),
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /If it is an ISSUE number, write "#597"/);
});

test('an ambiguous bare id reports every file it could mean', (t) => {
  const root = makeRepo(t, {
    '0011-one.md': adr('One', ['**Status:** Accepted']),
    '0011-two.md': adr('Two', ['**Status:** Accepted']),
    '900-beta.md': adr('Beta', ['**Status:** Accepted', '**Supersedes:** ADR-0011']),
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /ambiguous — resolves to 2 files/);
  assert.match(res.stderr, /0011-one\.md/);
  assert.match(res.stderr, /0011-two\.md/);
});

test('--check fails loudly when the README markers are missing', (t) => {
  const root = makeRepo(t, { '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']) });
  fs.writeFileSync(path.join(root, 'docs', 'adr', 'README.md'), '# ADRs\n\nNo markers here.\n');
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /missing the index markers/);
});

test('--write still emits the index while reporting outstanding violations', (t) => {
  // --write must remain usable as a repair tool on a corpus that is not yet clean,
  // but must not pretend the corpus is healthy.
  const root = makeRepo(t, {
    '900-beta.md': adr('Beta', ['**Status:** Accepted', '**Supersedes:** [ADR-0001](0001-alpha.md)']),
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']),
  });
  const res = run(root, ['--write']);
  assert.equal(res.status, 0, '--write proceeds');
  assert.match(res.stderr, /lifecycle violation\(s\) remain/);
  assert.match(fs.readFileSync(path.join(root, 'docs', 'adr', 'README.md'), 'utf8'), /Active decisions \(2\)/);
});

test('an ADR title cannot hijack the README splice with an index marker', (t) => {
  // Review finding: a title carrying the literal END marker was emitted verbatim
  // into the table cell, relocating the boundary so the NEXT --write spliced
  // against the wrong marker and ate the rest of README.md.
  const root = makeRepo(t, {
    '0001-alpha.md': adr(`Evil ${END} title`, ['**Status:** Accepted']),
  });
  assert.equal(run(root, ['--write']).status, 0);

  const readme = fs.readFileSync(path.join(root, 'docs', 'adr', 'README.md'), 'utf8');
  const endCount = readme.split(END).length - 1;
  assert.equal(endCount, 1, 'exactly one END marker must survive — the title must not forge another');

  // The splice must remain stable across repeated writes.
  assert.equal(run(root, ['--write']).status, 0);
  const again = fs.readFileSync(path.join(root, 'docs', 'adr', 'README.md'), 'utf8');
  assert.equal(again.split(END).length - 1, 1);
  assert.equal(run(root, ['--check']).status, 0, 'a hostile title must not leave the index permanently stale');
});

test('a title cannot inject raw HTML into the generated index', (t) => {
  const root = makeRepo(t, {
    '0001-alpha.md': adr('Alpha <script>x</script> module', ['**Status:** Accepted']),
  });
  assert.equal(run(root, ['--write']).status, 0);
  const readme = fs.readFileSync(path.join(root, 'docs', 'adr', 'README.md'), 'utf8');
  assert.ok(!readme.includes('<script>'), 'angle brackets must be escaped, not emitted raw');
  assert.match(readme, /&lt;script&gt;/);
});

test('a backslash-pipe in a title cannot break out of its table cell', (t) => {
  // CodeQL js/incomplete-sanitization: escaping `|` -> `\|` without escaping the
  // backslash FIRST turns the input `\|` into `\\|`, which markdown reads as a
  // literal backslash plus an UNESCAPED pipe — re-opening the very cell break the
  // pipe escape exists to prevent.
  const root = makeRepo(t, {
    '0001-alpha.md': adr('Alpha \\| Accepted \\| forged', ['**Status:** Proposed']),
  });
  assert.equal(run(root, ['--write']).status, 0);
  const readme = fs.readFileSync(path.join(root, 'docs', 'adr', 'README.md'), 'utf8');

  const row = readme.split(/\r?\n/).find((l) => l.includes('0001-alpha.md'));
  assert.ok(row, 'the ADR must still have a row');
  // 4 pipes = the row's own delimiters (| id | title | status | read-first |) = 5.
  // Any unescaped pipe from the title would add a 6th boundary and shift the cells.
  const unescaped = [...row.matchAll(/(?<!\\)\|/g)].length;
  assert.equal(unescaped, 5, `title pipes must stay escaped; row was: ${row}`);
  assert.match(readme, /Proposed \(1\)/, 'the forged cell must not land the ADR in Active');
});

test('a pipe in a title cannot break out of its table cell', (t) => {
  const root = makeRepo(t, {
    '0001-alpha.md': adr('Alpha | Accepted | fake', ['**Status:** Proposed']),
  });
  assert.equal(run(root, ['--write']).status, 0);
  const readme = fs.readFileSync(path.join(root, 'docs', 'adr', 'README.md'), 'utf8');
  assert.match(readme, /Alpha \\\| Accepted \\\| fake/, 'pipes must be escaped');
  assert.match(readme, /Proposed \(1\)/, 'the forged cell must not land the ADR in Active');
});

test('a file that does not match the naming convention is reported, not crashed on', (t) => {
  // Review finding: `notes.md` hit `file.match(/^([0-9]+)-/)[1]` → TypeError on
  // null. An unparseable name is also invisible to the index — the exact failure
  // this gate exists to prevent — so it must surface as a violation.
  const root = makeRepo(t, {
    '0001-alpha.md': adr('Alpha', ['**Status:** Accepted']),
    'notes.md': '# Scratch notes\n\nNot an ADR.\n',
  });
  const res = run(root, ['--check']);
  assert.equal(res.status, 1);
  assert.match(res.stderr, /notes\.md/);
  assert.match(res.stderr, /does not match the .*convention/);
  assert.doesNotMatch(res.stderr, /TypeError|Cannot read propert/, 'must be a gate violation, not a crash');
});

test('the real repo corpus is clean and its index is current', () => {
  // The gate must hold against docs/adr/ as committed, not only fixtures.
  const res = run(REPO_ROOT, ['--check']);
  assert.equal(res.status, 0, `docs/adr/ must satisfy its own gate:\n${res.stderr}`);
});