import { closeElectronApp, expect, getStableWindow, installIpcMocks, test } from './fixtures/electron';

const SESSION_KEY = 'agent:main:main';

function stableStringify(value: unknown): string {
  if (value == null || typeof value !== 'object') return JSON.stringify(value);
  if (Array.isArray(value)) return `[${value.map((item) => stableStringify(item)).join(',')}]`;
  const entries = Object.entries(value as Record<string, unknown>)
    .sort(([left], [right]) => left.localeCompare(right))
    .map(([key, entryValue]) => `${JSON.stringify(key)}:${stableStringify(entryValue)}`);
  return `{${entries.join(',')}}`;
}

const seededHistory = Array.from({ length: 36 }, (_, idx) => ({
  role: idx % 2 === 0 ? 'user' : 'assistant',
  content: `${idx === 0 ? 'Very first message' : 'Chat history message'} ${idx + 1}`,
  timestamp: Date.now() + idx,
}));

test.describe('ClawX chat scroll-to-latest affordance', () => {
  test('shows a jump button when reading older messages and returns to the latest message', async ({ launchElectronApp }) => {
    const app = await launchElectronApp({ skipSetup: true });

    try {
      await installIpcMocks(app, {
        gatewayStatus: { state: 'running', port: 18789, pid: 12345 },
        gatewayRpc: {
          [stableStringify(['sessions.list', {}])]: {
            success: true,
            result: {
              sessions: [{ key: SESSION_KEY, displayName: 'main' }],
            },
          },
          [stableStringify(['chat.history', { sessionKey: SESSION_KEY, limit: 200 }])]: {
            success: true,
            result: { messages: seededHistory },
          },
          [stableStringify(['chat.history', { sessionKey: SESSION_KEY, limit: 1000 }])]: {
            success: true,
            result: { messages: seededHistory },
          },
        },
        hostApi: {
          [stableStringify(['/api/gateway/status', 'GET'])]: {
            ok: true,
            data: {
              status: 200,
              ok: true,
              json: { state: 'running', port: 18789, pid: 12345 },
            },
          },
          [stableStringify(['/api/agents', 'GET'])]: {
            ok: true,
            data: {
              status: 200,
              ok: true,
              json: { success: true, agents: [{ id: 'main', name: 'main' }] },
            },
          },
        },
      });

      const page = await getStableWindow(app);
      try {
        await page.reload();
      } catch (error) {
        if (!String(error).includes('ERR_FILE_NOT_FOUND')) {
          throw error;
        }
      }

      await expect(page.getByTestId('main-layout')).toBeVisible();
      await expect(page.getByText('Chat history message 36')).toBeVisible({ timeout: 30_000 });

      const scrollContainer = page.getByTestId('chat-scroll-container');
      await scrollContainer.evaluate((element) => {
        element.scrollTop = 0;
        element.dispatchEvent(new Event('scroll', { bubbles: true }));
      });

      const jumpButton = page.getByTestId('chat-scroll-to-latest');
      await expect(jumpButton).toBeVisible();
      await jumpButton.click();

      await expect(jumpButton).toBeHidden({ timeout: 10_000 });
      await expect(page.getByText('Chat history message 36')).toBeVisible();
    } finally {
      await closeElectronApp(app);
    }
  });
});
