import assert from 'node:assert/strict';
import test from 'node:test';
import { createSessionStreamStore } from './session-stream-store.mjs';

function createMockPool() {
  let clock = 1;
  const events = [];
  return {
    events,
    async query(sql, params = []) {
      if (sql.includes('INSERT INTO h5_session_stream_events')) {
        const createdAt = clock++;
        events.push({
          id: params[0],
          user_id: params[1],
          agent_session_id: params[2],
          event_type: params[3],
          payload_json: params[4],
          upstream_event_id: params[5],
          created_at: createdAt,
        });
        return [{ insertId: 1 }];
      }
      if (sql.includes('WHERE id = ? AND agent_session_id = ?')) {
        const row = events.find((item) => item.id === params[0]);
        return [[row ? { created_at: row.created_at } : undefined].filter(Boolean)];
      }
      if (sql.includes('created_at > ?')) {
        const after = Number(params[2]);
        const rows = events
          .filter(
            (item) =>
              item.agent_session_id === params[0] &&
              item.user_id === params[1] &&
              Number(item.created_at) > after,
          )
          .sort((a, b) => Number(a.created_at) - Number(b.created_at));
        return [rows];
      }
      if (sql.includes('ORDER BY created_at ASC, id ASC')) {
        const rows = events
          .filter(
            (item) => item.agent_session_id === params[0] && item.user_id === params[1],
          )
          .sort((a, b) => Number(a.created_at) - Number(b.created_at))
          .slice(0, params[2]);
        return [rows];
      }
      if (sql.includes('ORDER BY created_at DESC, id DESC')) {
        const row = events
          .filter(
            (item) => item.agent_session_id === params[0] && item.user_id === params[1],
          )
          .sort((a, b) => Number(b.created_at) - Number(a.created_at))[0];
        return [[row].filter(Boolean)];
      }
      throw new Error(`unexpected sql: ${sql}`);
    },
  };
}

test('session stream store append and replay with cursor', async () => {
  const pool = createMockPool();
  const store = createSessionStreamStore({ pool });
  const first = await store.appendEvent({
    userId: 'user-1',
    sessionId: 'sess-1',
    payload: { type: 'Message', message: { role: 'assistant', content: [] } },
    id: 'evt-1',
  });
  await store.appendEvent({
    userId: 'user-1',
    sessionId: 'sess-1',
    payload: { type: 'Finish' },
    id: 'evt-2',
  });

  const head = await store.listEventsForUser('user-1', 'sess-1');
  assert.equal(head.events.length, 2);

  const tail = await store.listEventsForUser('user-1', 'sess-1', { afterEventId: 'evt-1' });
  assert.equal(tail.events.length, 1);
  assert.equal(tail.events[0].payload.type, 'Finish');
  assert.equal(tail.cursorMiss, false);

  const miss = await store.listEventsForUser('user-1', 'sess-1', { afterEventId: 'missing' });
  assert.equal(miss.cursorMiss, true);
});