// tests/lib/stats-event-emit.test.mjs
// Cover lib/stats/event-emit.mjs:
//   - emit appends a JSONL line with required ISO-8601 ts
//   - known_event flag distinguishes recognized vs unknown events
//   - missing CLAUDE_PLUGIN_DATA does NOT throw (stats must never block)
//   - CLI shim parses --payload JSON and writes via emit()
//   - concurrent appends don't corrupt the file (smoke test)

import { test } from 'node:test';
import { strict as assert } from 'node:assert';
import { execFileSync } from 'node:child_process';
import { mkdtempSync, rmSync, readFileSync, existsSync } from 'node:fs';
import { dirname, join } from 'node:path';
import { tmpdir } from 'node:os';
import { fileURLToPath } from 'node:url';
import { emit, buildRecord, resolveStatsPath, KNOWN_EVENTS } from '../../lib/stats/event-emit.mjs';

const HERE = dirname(fileURLToPath(import.meta.url));
const SHIM = join(HERE, '..', '..', 'lib', 'stats', 'event-emit.mjs');

const ISO_8601_RE = /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/;

function tmp(prefix = 'stats-event-emit-') {
  return mkdtempSync(join(tmpdir(), prefix));
}

test('KNOWN_EVENTS contains plan-v2 spec set', () => {
  for (const e of ['brief-approved', 'main-merge-gate', 'user_input']) {
    assert.ok(KNOWN_EVENTS.has(e), `missing recognized event: ${e}`);
  }
});

test('buildRecord emits ISO-8601 ts (REQUIRED per SC4)', () => {
  const r = buildRecord('brief-approved', { foo: 1 });
  assert.match(r.ts, ISO_8601_RE);
  assert.equal(r.event, 'brief-approved');
  assert.equal(r.known_event, true);
  assert.deepEqual(r.payload, { foo: 1 });
});

test('buildRecord marks unrecognized events known_event: false', () => {
  const r = buildRecord('totally-made-up-event');
  assert.equal(r.known_event, false);
  assert.deepEqual(r.payload, {});
});

test('buildRecord rejects empty event name', () => {
  assert.throws(() => buildRecord(''), TypeError);
  assert.throws(() => buildRecord(null), TypeError);
});

test('emit appends one JSONL line per call', () => {
  const dir = tmp();
  try {
    const path = join(dir, 'stats.jsonl');
    const r1 = emit('brief-approved', { ok: true }, { path });
    const r2 = emit('main-merge-gate', { branch: 'main' }, { path });
    assert.equal(r1.written, true);
    assert.equal(r2.written, true);
    const lines = readFileSync(path, 'utf-8').trim().split('\n');
    assert.equal(lines.length, 2);
    const a = JSON.parse(lines[0]);
    const b = JSON.parse(lines[1]);
    assert.match(a.ts, ISO_8601_RE);
    assert.match(b.ts, ISO_8601_RE);
    assert.equal(a.event, 'brief-approved');
    assert.equal(b.event, 'main-merge-gate');
  } finally {
    rmSync(dir, { recursive: true, force: true });
  }
});

test('emit creates the stats directory on demand', () => {
  const dir = tmp();
  try {
    const path = join(dir, 'nested', 'stats.jsonl');
    const r = emit('user_input', {}, { path });
    assert.equal(r.written, true);
    assert.ok(existsSync(path));
  } finally {
    rmSync(dir, { recursive: true, force: true });
  }
});

test('emit with no CLAUDE_PLUGIN_DATA returns { written: false } (silent skip)', () => {
  const r = emit('brief-approved', {}, { env: {} });
  assert.equal(r.written, false);
  assert.equal(r.path, null);
  assert.match(r.reason, /CLAUDE_PLUGIN_DATA unset/);
});

test('emit never throws when stats path is unwritable', () => {
  // Pointing at a path under a non-existent dir on a readonly mount would
  // be brittle in CI; instead, force the env-resolved path to be empty
  // and confirm no exception leaks.
  let threw = false;
  try { emit('user_input', { foo: 'bar' }, { env: {} }); }
  catch { threw = true; }
  assert.equal(threw, false);
});

test('resolveStatsPath honors CLAUDE_PLUGIN_DATA env var', () => {
  const r = resolveStatsPath({ CLAUDE_PLUGIN_DATA: '/var/data/plugin' });
  assert.equal(r, '/var/data/plugin/ultraexecute-stats.jsonl');
  assert.equal(resolveStatsPath({}), null);
});

test('CLI shim writes via emit when CLAUDE_PLUGIN_DATA is set', () => {
  const dir = tmp();
  try {
    execFileSync(process.execPath, [
      SHIM, '--event', 'brief-approved', '--payload', '{"foo":42}',
    ], {
      env: { ...process.env, CLAUDE_PLUGIN_DATA: dir },
      encoding: 'utf-8',
    });
    const path = join(dir, 'ultraexecute-stats.jsonl');
    assert.ok(existsSync(path));
    const line = readFileSync(path, 'utf-8').trim();
    const parsed = JSON.parse(line);
    assert.equal(parsed.event, 'brief-approved');
    assert.deepEqual(parsed.payload, { foo: 42 });
    assert.match(parsed.ts, ISO_8601_RE);
  } finally {
    rmSync(dir, { recursive: true, force: true });
  }
});

test('CLI shim with malformed --payload returns reason payload-not-json (exit 0)', () => {
  const r = execFileSync(process.execPath, [
    SHIM, '--event', 'user_input', '--payload', 'not-json{{',
  ], { encoding: 'utf-8' });
  const parsed = JSON.parse(r.trim());
  assert.equal(parsed.written, false);
  assert.equal(parsed.reason, 'payload-not-json');
});

test('concurrent appends do not corrupt JSONL (smoke)', async () => {
  const dir = tmp();
  try {
    const path = join(dir, 'stats.jsonl');
    const N = 25;
    await Promise.all(
      Array.from({ length: N }, (_, i) =>
        Promise.resolve().then(() => emit('user_input', { i }, { path })),
      ),
    );
    const lines = readFileSync(path, 'utf-8').trim().split('\n');
    assert.equal(lines.length, N);
    for (const l of lines) {
      const parsed = JSON.parse(l); // throws if any line is corrupt
      assert.ok('ts' in parsed);
      assert.equal(parsed.event, 'user_input');
    }
  } finally {
    rmSync(dir, { recursive: true, force: true });
  }
});