// Phase 5b-2b: verifies incremental (resume) indexing through the full rewired
// buildIndex path (needsReindex → cursor → claude.parse → persist). A force
// --build re-scans everything (skip=0) and never exercises resume, so this
// appends new lines to an already-indexed session and drives an incremental
// build. The 30s shouldSkipBuild debounce is cleared between steps (it would
// otherwise skip a build this soon after the previous one).

import { test } from 'node:test';
import assert from 'node:assert/strict';
import { createRequire } from 'node:module';
import { mkdtempSync, mkdirSync, writeFileSync, appendFileSync, utimesSync, statSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { dirname, join, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';
import { spawnSync } from 'node:child_process';

const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), '..');
const require = createRequire(import.meta.url);
const { DatabaseSync } = require('node:sqlite');

function runRuntime(args, home) {
  return spawnSync(process.execPath, ['scripts/runtime.mjs', ...args], {
    cwd: repoRoot, env: { ...process.env, HOME: home }, encoding: 'utf8',
  });
}

function line(uuid, type, ts) {
  return JSON.stringify({ uuid, type, timestamp: ts, cwd: '/tmp/proj', message: { role: type, content: `${type} ${uuid}` } });
}

function clearBuildDebounce(home) {
  const db = new DatabaseSync(join(home, '.obelisk', 'obelisk.sqlite'));
  db.prepare("DELETE FROM index_state WHERE jsonl_path='__last_build__'").run();
  db.close();
}

function counts(home) {
  writeFileSync(join(home, 'q.mjs'), "return { mc: sql(\"SELECT message_count FROM sessions WHERE id='sess'\")[0]?.message_count ?? null, n: sql('SELECT COUNT(*) c FROM messages')[0].c, lp: sql(\"SELECT lines_processed lp FROM index_state WHERE jsonl_path LIKE '%sess.jsonl'\")[0]?.lp ?? null };");
  const r = runRuntime(['--query', join(home, 'q.mjs')], home);
  assert.equal(r.status, 0, r.stderr || r.stdout);
  return JSON.parse(r.stdout);
}

test('incremental buildIndex resumes from cursor and accumulates message_count', () => {
  const home = mkdtempSync(join(tmpdir(), 'obelisk-incr-'));
  const projDir = join(home, '.claude', 'projects', '-tmp-proj');
  mkdirSync(projDir, { recursive: true });
  const jsonl = join(projDir, 'sess.jsonl');

  writeFileSync(jsonl, [line('u1', 'user', '2026-06-10T10:00:00Z'), line('a1', 'assistant', '2026-06-10T10:00:05Z')].join('\n') + '\n');
  assert.equal(runRuntime(['--build'], home).status, 0);

  const afterBuild = counts(home);
  assert.equal(afterBuild.mc, 2, 'full build indexed both messages');
  assert.equal(afterBuild.n, 2);
  assert.equal(afterBuild.lp, 2, 'cursor recorded 2 lines processed');

  // Append two messages; bump mtime so needsReindex detects the change.
  appendFileSync(jsonl, [line('u2', 'user', '2026-06-10T10:01:00Z'), line('a2', 'assistant', '2026-06-10T10:01:05Z')].join('\n') + '\n');
  const t = statSync(jsonl).mtimeMs / 1000 + 10;
  utimesSync(jsonl, t, t);
  clearBuildDebounce(home);

  // Incremental build: resume at line 2, add exactly the two new messages.
  // mc=4 proves resume+accumulate; 6 would mean re-count from stale base, 2 a miss.
  const afterAppend = counts(home);
  assert.equal(afterAppend.mc, 4, 'message_count accumulated to 4');
  assert.equal(afterAppend.n, 4, 'exactly four messages, no duplicates');
  assert.equal(afterAppend.lp, 4, 'cursor advanced to 4 lines');
});