import type { Page, Frame } from 'playwright';
import { logger } from '../../utils/logger';
import {
  EULA_SELECTORS,
  EULA_BODY_REGEX,
  EULA_DEEP_CLICK_TEXTS,
  SELECTORS,
  clickVisibleCheckbox,
  deepClickByText,
} from '../selectors';

// ---------------------------------------------------------------------------
// EULA acceptance helpers
// ---------------------------------------------------------------------------

type Scope = Page | Frame;

async function acceptEulaInScope(scope: Scope): Promise<boolean> {
  for (const selector of EULA_SELECTORS) {
    const button = scope.locator(selector).first();
    if (await button.isVisible({ timeout: 1500 }).catch(() => false)) {
      await button.click({ force: true });
      await scope.waitForTimeout(2500).catch(() => {});
      return true;
    }
  }

  const bodyText = await scope
    .locator('body')
    .innerText({ timeout: 1000 })
    .catch(() => '');
  if (EULA_BODY_REGEX.test(bodyText)) {
    await clickVisibleCheckbox(scope);
    if (await deepClickByText(scope, EULA_DEEP_CLICK_TEXTS)) {
      await scope.waitForTimeout(2500).catch(() => {});
      return true;
    }
  }

  return false;
}

export async function acceptEulaEverywhere(page: Page): Promise<boolean> {
  let accepted = await acceptEulaInScope(page);
  for (const frame of page.frames()) {
    accepted =
      (await acceptEulaInScope(frame).catch(() => false)) || accepted;
  }
  return accepted;
}

export async function acceptEulaUntilSettled(
  page: Page,
  timeoutMs = 15000,
): Promise<boolean> {
  const deadline = Date.now() + timeoutMs;
  let accepted = false;
  // BUG-8 FIX: Break early when no EULA detected after 2 consecutive checks.
  // Previously the loop always ran for the full timeoutMs (15s), wasting ~30s
  // per job in the common case where no EULA is shown at all.
  let consecutiveNoEula = 0;
  while (Date.now() < deadline) {
    const foundEula = await acceptEulaEverywhere(page);
    accepted = foundEula || accepted;
    if (!foundEula) {
      consecutiveNoEula++;
      if (consecutiveNoEula >= 2) break; // No EULA on 2 consecutive checks — stop
    } else {
      consecutiveNoEula = 0; // Reset counter when EULA was found and accepted
    }
    await page.waitForTimeout(1200);
  }
  return accepted;
}

// ---------------------------------------------------------------------------
// Login
// ---------------------------------------------------------------------------

const DEFAULT_TARGET_URL =
  'https://www.turnitin.com/login_page.asp?lang=en_us';
const STUDENT_HOME_URL =
  'https://www.turnitin.com/s_home.asp?lang=en_us';

/**
 * Log in to Turnitin with email/password, accept EULA if shown,
 * handle redirect to user-type page, and optionally save storage state.
 */
export async function loginToTurnitin(
  page: Page,
  email: string,
  password: string,
  storageStatePath?: string,
  targetUrl = DEFAULT_TARGET_URL,
): Promise<void> {
  logger.info('Navigating to Turnitin login page');
  let emailInputVisible = false;
  for (let attempt = 1; attempt <= 4; attempt++) {
    await page.goto(targetUrl || DEFAULT_TARGET_URL, {
      waitUntil: 'domcontentloaded',
      timeout: 60000,
    });

    emailInputVisible = await page
      .locator(SELECTORS.login.emailInput)
      .isVisible({ timeout: 15000 })
      .catch(() => false);

    if (emailInputVisible) break;

    await acceptEulaEverywhere(page);
    const bodyText = await page
      .locator('body')
      .innerText({ timeout: 3000 })
      .catch(() => '');
    const currentUrl = page.url();
    if (
      !currentUrl.includes('login_page.asp') ||
      /logout|student|class portfolio/i.test(bodyText)
    ) {
      logger.info('Login form not shown; continuing with existing Turnitin session', {
        url: currentUrl,
      });
      return;
    }

    if (/403 ERROR|Request blocked|could not be satisfied/i.test(bodyText)) {
      logger.warn('Turnitin login page was temporarily blocked; retrying', {
        attempt,
      });
      await page.waitForTimeout(2500 + attempt * 1500);
      continue;
    }

    await page.waitForTimeout(1500);
  }

  if (!emailInputVisible) {
    throw new Error(
      `Turnitin login form was not visible (URL: ${page.url()})`,
    );
  }

  await page.fill(SELECTORS.login.emailInput, email);
  await page.fill(SELECTORS.login.passwordInput, password);

  await Promise.all([
    page
      .waitForNavigation({ waitUntil: 'domcontentloaded', timeout: 60000 })
      .catch(() => null),
    page.click(SELECTORS.login.submitButton),
  ]);

  await page
    .waitForLoadState('domcontentloaded', { timeout: 30000 })
    .catch(() => {});

  // Check if we are still on the login page (i.e. login failed)
  const currentUrl = page.url();
  if (currentUrl.includes('login_page.asp')) {
    const errorText = await page
      .locator('.error, .error-message, #error_message_box, #error_box, td.errorText, .errorText')
      .first()
      .innerText({ timeout: 2000 })
      .catch(() => '');

    const cleanMsg = errorText ? errorText.trim().replace(/\s+/g, ' ') : 'Invalid email or password';
    throw new Error(`Login failed on Turnitin: ${cleanMsg} (URL: ${currentUrl})`);
  }

  await acceptEulaEverywhere(page);

  // Handle redirect to user type page
  if (page.url().includes('user_user_type.asp')) {
    await page.goto(STUDENT_HOME_URL, {
      waitUntil: 'domcontentloaded',
      timeout: 60000,
    });
    await acceptEulaEverywhere(page);
  }

  // Double check if we got kicked back to login page
  if (page.url().includes('login_page.asp')) {
    throw new Error(`Login failed on Turnitin: redirected back to login page (URL: ${page.url()})`);
  }

  // Save storage state if requested
  if (storageStatePath) {
    await page.context().storageState({ path: storageStatePath });
    logger.info('Storage state saved', { path: storageStatePath });
  }

  logger.info('Login successful', { url: page.url() });
}