import { test } from 'node:test';
import assert from 'node:assert/strict';
import { createRequire } from 'node:module';
import { mkdtempSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';

const require = createRequire(import.meta.url);
const { createIndexerService } = require('../app/indexer-service.js');

function manualTimers() {
  const timers = new Set();
  return {
    setTimeout(fn) {
      timers.add(fn);
      return fn;
    },
    clearTimeout(fn) {
      timers.delete(fn);
    },
    flush() {
      const pending = [...timers];
      timers.clear();
      for (const fn of pending) fn();
    },
  };
}

test('indexer service debounces repeated build requests', async () => {
  const timers = manualTimers();
  const calls = [];
  const service = createIndexerService({
    buildIndex: async ({ reason }) => calls.push(reason),
    watchProjects: () => null,
    writeHeartbeat: () => {},
    timers,
    stabilityMs: 0,
  });

  service.scheduleBuild('first');
  service.scheduleBuild('second');
  service.scheduleBuild('third');
  timers.flush();
  await service.idle();

  assert.deepEqual(calls, ['third']);
});

test('indexer service runs one pending build after an in-flight build finishes', async () => {
  const timers = manualTimers();
  const calls = [];
  let finishFirst;
  const service = createIndexerService({
    buildIndex: async ({ reason }) => {
      calls.push(reason);
      if (reason === 'first') await new Promise(resolve => { finishFirst = resolve; });
    },
    watchProjects: () => null,
    writeHeartbeat: () => {},
    timers,
    stabilityMs: 0,
  });

  const first = service.runBuildNow('first');
  service.scheduleBuild('second');
  timers.flush();

  assert.deepEqual(calls, ['first']);
  finishFirst();
  await first;
  await service.idle();

  assert.deepEqual(calls, ['first', 'pending']);
});

test('indexer service waits for a stability window before building', async () => {
  const timers = manualTimers();
  const calls = [];
  const service = createIndexerService({
    buildIndex: async ({ reason }) => calls.push(reason),
    watchProjects: () => null,
    writeHeartbeat: () => {},
    timers,
    stabilityMs: 500,
  });

  service.scheduleBuild('jsonl-change');
  timers.flush();
  await service.idle();
  assert.deepEqual(calls, []);

  timers.flush();
  await service.idle();
  assert.deepEqual(calls, ['jsonl-change']);
});

test('indexer service retries watcher setup when the projects directory is missing', () => {
  const timers = manualTimers();
  let attempts = 0;
  const service = createIndexerService({
    buildIndex: async () => {},
    watchProjects: () => {
      attempts++;
      return attempts === 1 ? null : { close() {} };
    },
    writeHeartbeat: () => {},
    timers,
    stabilityMs: 0,
  });

  service.start({ buildOnStart: false });
  assert.equal(attempts, 1);

  timers.flush();
  assert.equal(attempts, 2);

  timers.flush();
  assert.equal(attempts, 2);
});

test('indexer service watches Claude JSON files through chokidar', async () => {
  const projectsDir = mkdtempSync(join(tmpdir(), 'obelisk-chokidar-projects-'));
  const timers = manualTimers();
  const calls = [];
  let watchArgs = null;
  const handlers = {};
  const watcher = {
    on(event, handler) {
      handlers[event] = handler;
      return watcher;
    },
    closeCalled: false,
    close() {
      watcher.closeCalled = true;
    },
  };
  const chokidar = {
    watch(paths, options) {
      watchArgs = { paths, options };
      return watcher;
    },
  };

  const service = createIndexerService({
    projectsDir,
    buildIndex: async ({ reason }) => calls.push(reason),
    chokidar,
    writeHeartbeat: () => {},
    timers,
    stabilityMs: 0,
    debounceMs: 0,
  });

  try {
    service.start({ buildOnStart: false });
    assert.equal(watchArgs.paths, projectsDir);
    assert.equal(watchArgs.options.cwd, projectsDir);
    assert.equal(watchArgs.options.ignoreInitial, true);
    assert.ok(watchArgs.options.awaitWriteFinish);

    handlers.change('session.jsonl');
    timers.flush();
    await service.idle();
    assert.deepEqual(calls, ['watch']);
  } finally {
    service.stop();
  }

  assert.equal(watcher.closeCalled, true);
});

test('indexer service passes changed JSONL paths to the build worker', async () => {
  const projectsDir = mkdtempSync(join(tmpdir(), 'obelisk-changed-paths-'));
  const timers = manualTimers();
  const calls = [];
  const handlers = {};
  const watcher = {
    on(event, handler) {
      handlers[event] = handler;
      return watcher;
    },
    close() {},
  };
  const chokidar = {
    watch() {
      return watcher;
    },
  };

  const service = createIndexerService({
    projectsDir,
    buildIndex: async (args) => calls.push(args),
    chokidar,
    writeHeartbeat: () => {},
    timers,
    stabilityMs: 0,
    debounceMs: 0,
  });

  service.start({ buildOnStart: false });
  handlers.change('project-a/session-1.jsonl');
  handlers.add('project-a/session-2.json');
  timers.flush();
  await service.idle();

  assert.equal(calls.length, 1);
  assert.equal(calls[0].reason, 'watch');
  assert.deepEqual(calls[0].changedPaths, [
    'project-a/session-1.jsonl',
    'project-a/session-2.json',
  ]);
});

test('indexer service watches Claude projects and Codex sessions for app-side indexing', async () => {
  const claudeProjectsDir = mkdtempSync(join(tmpdir(), 'obelisk-watch-claude-'));
  const codexSessionsDir = mkdtempSync(join(tmpdir(), 'obelisk-watch-codex-sessions-'));
  const timers = manualTimers();
  const calls = [];
  const watchers = [];
  const watchArgs = [];
  const chokidar = {
    watch(paths, options) {
      const handlers = {};
      const watcher = {
        handlers,
        on(event, handler) {
          handlers[event] = handler;
          return watcher;
        },
        close() {},
      };
      watchers.push(watcher);
      watchArgs.push({ paths, options });
      return watcher;
    },
  };

  const service = createIndexerService({
    projectsDir: claudeProjectsDir,
    watchDirs: [claudeProjectsDir, codexSessionsDir],
    buildIndex: async (args) => calls.push(args),
    chokidar,
    writeHeartbeat: () => {},
    timers,
    stabilityMs: 0,
    debounceMs: 0,
  });

  service.start({ buildOnStart: false });
  assert.deepEqual(watchArgs.map(arg => arg.paths), [claudeProjectsDir, codexSessionsDir]);
  assert.deepEqual(watchArgs.map(arg => arg.options.cwd), [claudeProjectsDir, codexSessionsDir]);

  watchers[1].handlers.change('2026/06/15/rollout-2026-06-15T00-00-00-codex.jsonl');
  timers.flush();
  await service.idle();

  assert.equal(calls.length, 1);
  assert.deepEqual(calls[0].changedPaths, [
    '2026/06/15/rollout-2026-06-15T00-00-00-codex.jsonl',
  ]);
});