import type { Page, Frame } from 'playwright';
import { logger } from '../../utils/logger';
import {
  SELECTORS,
  deepClickByText,
  findAssignmentScope,
  findScopeByDeepText,
  readScopeVisibleDeepText,
} from '../selectors';
import { detectQuotaLimit, confirmQuotaWarning } from './quota-detect';
import { uploadFile, SubmissionQuotaLimitError, hasSubmissionCard } from './upload';

type Scope = Page | Frame;

async function clickVisibleResubmit(scope: Scope): Promise<boolean> {
  // New UI: tii-grn-button inside tii-workflow-student-summary-panel-new
  // Old UI: tdl-button or button with text "Resubmit"
  const locator = scope
    .locator(
      'tii-grn-button:has-text("Resubmit"), a:has-text("Resubmit"), button:has-text("Resubmit"), tdl-button:has-text("Resubmit"), [aria-label*="Resubmit"], [data-px*="Resubmit"], [with-data-px*="Resubmit"]',
    )
    .first();

  if (await locator.isVisible({ timeout: 3000 }).catch(() => false)) {
    await locator.click({ force: true });
    return true;
  }

  const clickedByDom = await scope
    .evaluate(() => {
      const roots: (Document | ShadowRoot)[] = [document];
      const seen = new Set<Element>();

      for (let i = 0; i < roots.length; i++) {
        const root = roots[i];
        for (const el of Array.from(root.querySelectorAll('*'))) {
          if (seen.has(el)) continue;
          seen.add(el);
          if (el.shadowRoot) roots.push(el.shadowRoot);
        }
      }

      const isVisible = (el: Element): boolean => {
        if (!(el instanceof HTMLElement)) return false;
        const style = window.getComputedStyle(el);
        const rect = el.getBoundingClientRect();
        return (
          style.visibility !== 'hidden' &&
          style.display !== 'none' &&
          rect.width > 0 &&
          rect.height > 0
        );
      };

      const readText = (el: Element): string =>
        [
          (el as HTMLElement).innerText,
          el.textContent,
          el.getAttribute('aria-label'),
          el.getAttribute('value'),
          el.getAttribute('part'),
          el.getAttribute('data-px'),
          el.getAttribute('with-data-px'),
        ]
          .filter(Boolean)
          .join(' ')
          .replace(/\s+/g, ' ')
          .trim()
          .toLowerCase();

      const candidates: Element[] = [];
      for (const root of roots) {
        candidates.push(
          ...Array.from(
            root.querySelectorAll(
              // Include tii-grn-button for new UI
              'button, a, input, tdl-button, tii-grn-button, [role="button"]',
            ),
          ),
        );
      }

      const target = candidates.find((el) => isVisible(el) && readText(el).includes('resubmit'));
      if (!target) return false;

      const shadowButton = target.shadowRoot?.querySelector(
        'button:not([disabled]), [role="button"]:not([disabled])',
      );
      const clickTarget =
        shadowButton instanceof HTMLElement ? shadowButton : (target as HTMLElement);
      clickTarget.scrollIntoView({ block: 'center', inline: 'center' });
      clickTarget.click();
      return true;
    })
    .catch(() => false);

  if (clickedByDom) return true;
  return deepClickByText(scope, ['resubmit']);
}

/**
 * Handle the new Turnitin resubmission confirmation modal.
 * The dialog#tii-resubmission-last-submission-modal is rendered INSIDE a
 * web component's shadow DOM, so standard document.querySelector() and even
 * Playwright's page.locator() may not find it.
 *
 * This function uses a full recursive shadow-DOM traversal to locate the
 * dialog and click its "Continue to File Upload" (or any accept-like) button.
 */
async function confirmResubmissionModal(page: Page): Promise<boolean> {
  // Helper: find dialog anywhere in the full shadow DOM tree
  const findDialog = () => page.evaluate(() => {
    const roots: (Document | ShadowRoot)[] = [document];
    const seen = new Set<Element>();
    for (let i = 0; i < roots.length; i++) {
      const root = roots[i];
      for (const el of Array.from(root.querySelectorAll('*'))) {
        if (seen.has(el)) continue;
        seen.add(el);
        if ((el as any).shadowRoot) roots.push((el as any).shadowRoot);
      }
    }
    for (const root of roots) {
      if (root.querySelector('dialog#tii-resubmission-last-submission-modal,dialog[open]')) return true;
    }
    return false;
  }).catch(() => false);

  // Wait up to 6s for the modal to appear (shadow DOM traversal)
  let found = false;
  const deadline = Date.now() + 6000;
  while (!found && Date.now() < deadline) {
    found = await findDialog();
    if (!found) await page.waitForTimeout(400);
  }

  if (!found) {
    // Also try the standard Playwright locator as a fallback (works when dialog is in light DOM)
    found = await page
      .locator('dialog#tii-resubmission-last-submission-modal, dialog[open]')
      .first()
      .isVisible({ timeout: 2000 })
      .catch(() => false);
  }

  if (!found) {
    logger.info('No resubmission confirmation modal detected');
    return false;
  }

  logger.info('Resubmission confirmation modal detected; clicking Continue to File Upload...');

  // Click the accept button via full shadow-DOM traversal
  const clicked = await page.evaluate(() => {
    // Build complete shadow-DOM root list
    const roots: (Document | ShadowRoot)[] = [document];
    const seen = new Set<Element>();
    for (let i = 0; i < roots.length; i++) {
      const root = roots[i];
      for (const el of Array.from(root.querySelectorAll('*'))) {
        if (seen.has(el)) continue;
        seen.add(el);
        if ((el as any).shadowRoot) roots.push((el as any).shadowRoot);
      }
    }

    // Find the dialog first
    let dialog: Element | null = null;
    for (const root of roots) {
      dialog = root.querySelector('dialog#tii-resubmission-last-submission-modal') ||
               root.querySelector('dialog[open]');
      if (dialog) break;
    }
    if (!dialog) return false;

    // Traverse dialog's own shadow DOM
    const dialogRoots: (Element | ShadowRoot)[] = [dialog];
    const dSeen = new Set<Element>();
    for (let i = 0; i < dialogRoots.length; i++) {
      const root = dialogRoots[i];
      for (const el of Array.from(root.querySelectorAll('*'))) {
        if (dSeen.has(el as Element)) continue;
        dSeen.add(el as Element);
        if ((el as any).shadowRoot) dialogRoots.push((el as any).shadowRoot);
      }
    }

    // Priority: "Continue to File Upload" > any accept/submit/confirm button
    const priority = (text: string): number => {
      const t = text.toLowerCase();
      if (t.includes('continue to file upload')) return 100;
      if (t.includes('file upload')) return 90;
      if (t.includes('continue')) return 80;
      if (t.includes('accept')) return 70;
      if (t.includes('submit')) return 60;
      if (t.includes('confirm')) return 50;
      return 0;
    };

    const candidates: Array<{ el: Element; score: number }> = [];
    for (const root of dialogRoots) {
      for (const el of Array.from(
        root.querySelectorAll('tii-grn-button, button, tdl-button, [role="button"], [slot="accept-button"]'),
      )) {
        const text = [
          (el as HTMLElement).innerText,
          el.textContent,
          el.getAttribute('aria-label'),
          el.getAttribute('part'),
          el.getAttribute('slot'),
          el.getAttribute('data-px'),
          el.getAttribute('with-data-px'),
        ].filter(Boolean).join(' ').replace(/\s+/g, ' ').trim();

        const score = priority(text);
        if (score > 0) candidates.push({ el, score });
      }
    }

    candidates.sort((a, b) => b.score - a.score);
    const best = candidates[0];
    if (!best) {
      // Last resort: close the dialog directly
      if (dialog instanceof HTMLDialogElement) {
        dialog.close();
        return true;
      }
      return false;
    }

    // Click: prefer inner shadow <button>, else click host element
    const inner = (best.el as any).shadowRoot?.querySelector('button:not([disabled])');
    const target = inner instanceof HTMLElement ? inner : (best.el as HTMLElement);
    target.scrollIntoView({ block: 'center', inline: 'center' });
    target.click();
    return true;
  }).catch(() => false);

  if (clicked) {
    await page.waitForTimeout(2000);

    // Verify dialog actually closed (wait up to 3s)
    const stillOpen = await findDialog();
    if (stillOpen) {
      logger.warn('Dialog still open after click; trying dialog.close() fallback');
      await page.evaluate(() => {
        const roots: (Document | ShadowRoot)[] = [document];
        const seen = new Set<Element>();
        for (let i = 0; i < roots.length; i++) {
          const root = roots[i];
          for (const el of Array.from(root.querySelectorAll('*'))) {
            if (seen.has(el)) continue;
            seen.add(el);
            if ((el as any).shadowRoot) roots.push((el as any).shadowRoot);
          }
        }
        for (const root of roots) {
          const d = root.querySelector('dialog#tii-resubmission-last-submission-modal') ||
                    root.querySelector('dialog[open]');
          if (d instanceof HTMLDialogElement) { d.close(); return; }
        }
      }).catch(() => {});
      await page.waitForTimeout(1500);
    }
  }

  return clicked;
}

async function hasFirstSubmissionUploadForm(page: Page): Promise<boolean> {
  const scope =
    (await findAssignmentScope(
      page,
      `${SELECTORS.upload.browseButton}, ${SELECTORS.upload.fileInput}, ${SELECTORS.upload.uploadStepContainer}`,
      2000,
    )) || (await findScopeByDeepText(
      page,
      ['browse files', 'drag and drop file', 'drag and drop your file', 'your device'],
      2000,
    ));

  if (!scope) return false;
  const visibleText = (await readScopeVisibleDeepText(scope)).toLowerCase();
  return (
    (await scope.locator(SELECTORS.upload.fileInput).first().isVisible({ timeout: 500 }).catch(() => false)) ||
    (await scope.locator(SELECTORS.upload.browseButton).first().isVisible({ timeout: 500 }).catch(() => false)) ||
    (await scope.locator(SELECTORS.upload.uploadStepContainer).first().isVisible({ timeout: 500 }).catch(() => false)) ||
    visibleText.includes('browse files') ||
    visibleText.includes('drag and drop file') ||
    visibleText.includes('drag and drop your file') ||
    visibleText.includes('your device')
  );
}

/**
 * Resubmit a file to an assignment that already has a prior submission.
 *
 * Steps:
 * 1. Assert quota is available
 * 2. Click Resubmit button
 * 3. Handle quota warnings (confirm and continue)
 * 4. Use same upload popup flow (Browse Files -> Upload and Preview -> Submit)
 * 5. If Resubmit button not found, fallback to initial upload
 */
export async function resubmitFile(
  page: Page,
  filePath: string,
): Promise<void> {
  logger.info('Resubmit requested; opening resubmission upload modal');

  // Check quota before attempting resubmit
  const quotaLimit = await detectQuotaLimit(page);
  if (quotaLimit) {
    throw new SubmissionQuotaLimitError(quotaLimit.message);
  }

  // Find the Resubmit button
  const scope =
    (await findAssignmentScope(
      page,
      'tii-grn-button:has-text("Resubmit"), a:has-text("Resubmit"), button:has-text("Resubmit"), tdl-button:has-text("Resubmit"), [aria-label*="Resubmit"], [data-px*="Resubmit"], [with-data-px*="Resubmit"]',
      5000,
    )) ||
    (await findScopeByDeepText(page, ['resubmit'], 8000));
  if (!scope) {
    if (await hasFirstSubmissionUploadForm(page)) {
      logger.warn(
        'Resubmit button was not found and first-submission upload form is visible; using initial upload flow',
      );
      await uploadFile(page, filePath);
      return;
    }
    throw new Error('Resubmit was requested, but no visible Resubmit button or first-upload form was found');
  }

  let clicked = await clickVisibleResubmit(scope);

  if (!clicked) {
    const submissionCardVisible = await hasSubmissionCard(scope);
    if (!submissionCardVisible && await hasFirstSubmissionUploadForm(page)) {
      logger.warn(
        'Resubmit button click failed, but no submission card is visible; using initial upload flow',
      );
      await uploadFile(page, filePath);
      return;
    }
    throw new Error('Resubmit button was found but could not be clicked');
  }

  await page.waitForTimeout(2000);

  // Handle NEW UI resubmission confirmation modal
  // (dialog#tii-resubmission-last-submission-modal with accept-button slot)
  const modalConfirmed = await confirmResubmissionModal(page);
  if (modalConfirmed) {
    logger.info('Resubmission confirmation modal accepted');
    await page.waitForTimeout(2000);
  }

  // Check quota again after clicking resubmit
  const quotaLimitAfter = await detectQuotaLimit(page);
  if (quotaLimitAfter) {
    throw new SubmissionQuotaLimitError(quotaLimitAfter.message);
  }

  // Handle quota warnings
  await confirmQuotaWarning(page);

  // Now proceed with the standard upload flow (the resubmit popup is the same)
  await uploadFile(page, filePath, { skipExistingCheck: true });
}