// @ts-check
import { test, expect } from '@playwright/test';
import { loadTestUser } from '../utils/testUser.js';

test.describe('@p0 Chat drawer — stream chunking', () => {
  test.setTimeout(20000);

  test('assistant reply is assembled from multiple chunks/lines', async ({ page }) => {
    const user = loadTestUser();

    // Stub threads list/create -> empty -> create {id}
    const threadId = 'thread-chunks';
    await page.route('**/api/chat/threads', async route => {
      if (route.request().method() === 'GET') {
        return route.fulfill({ status: 200, contentType: 'application/json', body: JSON.stringify({ threads: [] }) });
      }
      if (route.request().method() === 'POST') {
        return route.fulfill({ status: 200, contentType: 'application/json', body: JSON.stringify({ id: threadId }) });
      }
      return route.fallback();
    });
    await page.route(`**/api/chat/threads/${threadId}`, async route => {
      if (route.request().method() === 'GET') {
        return route.fulfill({ status: 200, contentType: 'application/json', body: JSON.stringify({ messages: [] }) });
      }
      return route.fallback();
    });

    // Stub stream with multiple line fragments (simulate chunked SSE)
    await page.route('**/api/chat/threads/*/stream', async route => {
      const body = [
        'This is line 1.',
        'This is line 2.',
        'Final line.',
      ].map(l => l + '\n').join('');
      await route.fulfill({ status: 200, headers: { 'Content-Type': 'text/event-stream' }, body });
    });

    // Sign in
    await page.context().clearCookies();
    await page.goto('/signin', { waitUntil: 'networkidle' });
    await page.getByPlaceholder('Username', { exact: true }).fill(user.username);
    await page.getByPlaceholder('Password', { exact: true }).fill(user.password);
    await page.getByRole('button', { name: /^Sign In$/ }).click();
    await page.waitForURL('**/signin-landing**', { timeout: 15000 });

    // Open chat
    await page.getByRole('button', { name: /^Open chat$/i }).click();

    // Send prompt
    const input = page.getByPlaceholder('Ask me anything…');
    const send  = page.getByRole('button', { name: /^Send$/i });
    await input.fill('test chunked stream');
    await send.click();

    // Expect all lines to appear merged in the **same** assistant message
    const assistantBubble = page.locator('div.text-left.text-gray-800').last();
    await expect(assistantBubble).toBeVisible({ timeout: 8000 });
    await expect(assistantBubble).toContainText('This is line 1.');
    await expect(assistantBubble).toContainText('This is line 2.');
    await expect(assistantBubble).toContainText('Final line.');
  });
});