import type { Page, Frame } from 'playwright';
import {
  findAssignmentScope,
  readScopeVisibleDeepText,
  scopeHasVisibleDeepText,
} from '../selectors';
import { SELECTORS } from '../selectors';

type Scope = Page | Frame;

export interface SubmissionState {
  scope: Scope | null;
  hasExistingSubmission: boolean;
  hasResubmitAction: boolean;
  hasUploadForm: boolean;
}

async function hasVisible(scope: Scope, selector: string, timeoutMs = 1000): Promise<boolean> {
  return scope.locator(selector).first().isVisible({ timeout: timeoutMs }).catch(() => false);
}

async function hasVisibleActionText(scope: Scope, textMatches: string[]): Promise<boolean> {
  return scope
    .evaluate((matches: string[]) => {
      const normalizedMatches = matches.map((value) => value.toLowerCase());
      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 candidates: Element[] = [];
      for (const root of roots) {
        candidates.push(
          ...Array.from(
            root.querySelectorAll(
              'button, a, input, tdl-button, tii-grn-button, tdl-labeled-button, [role="button"]',
            ),
          ),
        );
      }

      return candidates.some((el) => {
        if (!isVisible(el)) return false;
        const text = [
          (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'),
          el.getAttribute('with-px-label'),
        ]
          .filter(Boolean)
          .join(' ')
          .replace(/\s+/g, ' ')
          .trim()
          .toLowerCase();
        if (
          text.includes('setting info') ||
          text.includes('resubmissions are allowed') ||
          text.includes('late submissions are allowed') ||
          text.includes('collapse details') ||
          text.includes('assignment details') ||
          text.includes('rubric') ||
          text.includes('template')
        ) {
          return false;
        }
        return normalizedMatches.some((match) => text.includes(match));
      });
    }, textMatches)
    .catch(() => false);
}

async function hasInitialSubmitAction(scope: Scope): Promise<boolean> {
  return 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 hasAncestorSignal = (el: Element): boolean => {
        let current: Element | null = el;
        const visited = new Set<Element>();
        while (current && !visited.has(current)) {
          visited.add(current);
          const className = current.getAttribute('class') || '';
          const slot = current.getAttribute('slot') || '';
          const tag = current.tagName.toLowerCase();
          if (
            slot === 'submission-action' ||
            className.includes('submission-action') ||
            className.includes('submission-slot-container') ||
            tag === 'tii-workflow-student-summary-panel-new' ||
            tag === 'tii-workflow-lfw-student-show-assignment'
          ) {
            return true;
          }

          const parent: HTMLElement | null = current.parentElement;
          if (parent) {
            current = parent;
            continue;
          }
          const root = current.getRootNode();
          current = root instanceof ShadowRoot ? root.host : null;
        }
        return false;
      };

      for (const root of roots) {
        for (const el of Array.from(
          root.querySelectorAll('tii-grn-button, button, tdl-button, [role="button"], input[type="submit"]'),
        )) {
          if (!isVisible(el)) continue;
          const text = [
            (el as HTMLElement).innerText,
            el.textContent,
            el.getAttribute('aria-label'),
            el.getAttribute('value'),
          ]
            .filter(Boolean)
            .join(' ')
            .replace(/\s+/g, ' ')
            .trim();
          const normalized = text.toLowerCase();
          if (!/(^|\s)submit(\s|$)/i.test(text)) continue;
          if (
            normalized.includes('resubmit') ||
            normalized.includes('submit file') ||
            normalized.includes('upload and preview') ||
            normalized.includes('collapse details') ||
            normalized.includes('setting info')
          ) {
            continue;
          }
          if (hasAncestorSignal(el)) return true;
        }
      }

      return false;
    })
    .catch(() => false);
}

/**
 * Detect what Turnitin is currently showing after opening an assignment.
 * This is intentionally based on the live page, because account history can
 * differ from the requested job mode.
 */
export async function detectSubmissionState(page: Page): Promise<SubmissionState> {
  const scope =
    (await findAssignmentScope(
      page,
      [
        SELECTORS.resubmit.resubmitButton,
        SELECTORS.similarity.viewSubmissionButton,
        SELECTORS.upload.browseButton,
        SELECTORS.upload.fileInput,
        SELECTORS.resubmit.submissionActionPanel,
        'tii-workflow-lfw-student-show-assignment',
        'div[slot="submission-action"].submission-action',
        'tii-grn-button:has-text("Submit")',
      ].join(', '),
      3000,
    ));

  if (!scope) {
    return {
      scope: null,
      hasExistingSubmission: false,
      hasResubmitAction: false,
      hasUploadForm: false,
    };
  }

  const visibleText = (await readScopeVisibleDeepText(scope)).toLowerCase();
  const hasSubmitAction = await hasInitialSubmitAction(scope);
  const hasResubmitAction =
    (await hasVisible(scope, SELECTORS.resubmit.resubmitButton, 1500)) ||
    (await hasVisible(
      scope,
      'a:has-text("Resubmit"), button:has-text("Resubmit"), tdl-button:has-text("Resubmit"), [aria-label*="Resubmit"], [data-px*="Resubmit"]',
      1500,
    )) ||
    (await hasVisibleActionText(scope, ['resubmit']));

  const hasUploadForm =
    (await hasVisible(scope, SELECTORS.upload.fileInput, 1500)) ||
    (await hasVisible(scope, SELECTORS.upload.browseButton, 1500)) ||
    hasSubmitAction ||
    visibleText.includes('browse files') ||
    visibleText.includes('drag and drop file') ||
    visibleText.includes('your device');

  const hasViewSubmissionAction =
    (await hasVisible(
      scope,
      'button.link-button[aria-label*="View submission"], a[aria-label*="View submission"], a.view-mark, .similarity-button',
      1500,
    )) ||
    (await hasVisibleActionText(scope, ['view submission']));

  const hasExistingSubmission =
    hasResubmitAction ||
    hasViewSubmissionAction ||
    (await hasVisible(scope, SELECTORS.similarity.similarityDisplay, 1500)) ||
    (await hasVisible(scope, SELECTORS.similarity.similarityBadge, 1500)) ||
    (visibleText.includes('similarity:') || visibleText.includes('view submission')) ||
    ((await scopeHasVisibleDeepText(scope, ['submitted'])) && !hasUploadForm);

  return {
    scope,
    // If the first-submission upload form is visible and there is no visible
    // submission action, prefer upload. Turnitin web components often keep
    // hidden "Resubmit" text in the DOM before any file exists.
    hasExistingSubmission: hasUploadForm && !hasResubmitAction && !hasViewSubmissionAction
      ? false
      : hasExistingSubmission,
    hasResubmitAction,
    hasUploadForm,
  };
}