import type { Page } from '@playwright/test';
import { expect } from '@playwright/test';

/**
 * Navigate to a chat conversation ready for message input.
 *
 * Minimal signature by design — a helper that starts growing options
 * becomes a second API surface. If a test needs a specific conversation
 * id, a specific room type, or pre-seeded messages, that test should
 * fetch via the API + set store state directly rather than extending
 * this helper. Keep it boring.
 *
 * Flow:
 *   1. /chat must already be loaded and the sidebar rendered.
 *   2. If at least one conversation row exists: click the first one.
 *   3. Otherwise: click "New Channel", create a disposable room.
 *   4. Wait for the message input to become enabled — that's the
 *      observable signal that `currentConversationId` is set in the
 *      chat store (ChatInput.tsx disables on `!currentConversationId`).
 *
 * Returns the conversation id chosen (via data-conversation-id attr)
 * when an existing one is selected, or null when a new one was
 * created (the id is assigned by the backend after dialog submit).
 *
 * Target selectors use testids added in v1.0.7-rc1-day2:
 *   - chat-conversation-item (on ConversationItem button)
 *   - chat-new-channel-cta   (on the "New Channel" footer button)
 * The pre-rc1 tests used `button[type="button"]` which ambiguously
 * matched the "New Channel" CTA itself, producing the 22-failure
 * cascade.
 */
export async function navigateToConversation(
  page: Page,
): Promise<string | null> {
  const existing = page.getByTestId('chat-conversation-item').first();
  const existingCount = await page.getByTestId('chat-conversation-item').count();

  if (existingCount > 0) {
    const id = await existing.getAttribute('data-conversation-id');
    await existing.click();
    await expectInputReady(page);
    return id;
  }

  // No conversation exists — create a disposable one. Room name is
  // timestamped to avoid collisions across concurrent test workers.
  const roomName = `e2e-helper-${Date.now()}`;
  await page.getByTestId('chat-new-channel-cta').click();

  const nameInput = page.locator('#room-name');
  await expect(nameInput).toBeVisible({ timeout: 5_000 });
  await nameInput.fill(roomName);

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

  // Dialog closes, new conversation becomes current.
  await expect(nameInput).toBeHidden({ timeout: 5_000 });
  await expectInputReady(page);
  return null;
}

async function expectInputReady(page: Page): Promise<void> {
  const input = page.getByLabel('Type a message');
  await expect(input).toBeVisible({ timeout: 8_000 });
  await expect(input).toBeEnabled({ timeout: 8_000 });
}