import { describe, it, expect, beforeEach, afterEach } from 'vitest';
import './usa-accordion.ts';
import type { USAAccordion } from './usa-accordion.js';
import { testComponentAccessibility, USWDS_A11Y_CONFIG } from './accessibility-utils.js';

/**
 * USAAccordion USWDS Integration Validation
 *
 * Risk Level: HIGH
 * Risk Factors: button-content-restructuring, dynamic-show-hide, aria-state-changes, event-delegation
 * USWDS Module: usa-accordion
 *
 * Generated based on tooltip troubleshooting patterns to prevent:
 * - dom transformation
 * - multi phase-attributes
 * - light dom-slots
 */

describe('USAAccordion USWDS Integration Validation', () => {
  let element: USAAccordion;
  let testContainer: HTMLElement;

  beforeEach(() => {
    testContainer = document.createElement('div');
    testContainer.id = 'accordion-test-container';
    document.body.appendChild(testContainer);

    element = document.createElement('usa-accordion') as USAAccordion;
    testContainer.appendChild(element);
  });

  afterEach(() => {
    testContainer.remove();
  });

  describe('DOM Transformation Validation', () => {
    it('should handle USWDS DOM transformation correctly', async () => {
      // Add test content that USWDS will transform
      const testContent = document.createElement('button');
      testContent.classList.add('usa-accordion');
      testContent.textContent = 'Test accordion';
      element.appendChild(testContent);

      await element.updateComplete;

      // Simulate USWDS transformation (accordion specific)
      const preTransformElement = element.querySelector('.usa-accordion');
      expect(preTransformElement).toBeTruthy();

      // Simulate USWDS changing class structure
      preTransformElement?.classList.remove('usa-accordion');
      preTransformElement?.classList.add('usa-accordion__trigger');

      // Component should handle both pre and post-transformation states
      const postTransformElement = element.querySelector('.usa-accordion__trigger');
      expect(postTransformElement).toBeTruthy();
      expect(postTransformElement).toBe(preTransformElement);
    });

    it('should apply attributes before USWDS initialization', async () => {
      // Set accordion items with proper expanded state
      element.items = [
        { id: 'test-item', title: 'Test Item', content: 'Test Content', expanded: false }
      ];

      await element.updateComplete;

      // Check that the accordion button has the correct aria-expanded attribute
      const button = element.querySelector('.usa-accordion__button');
      expect(button?.getAttribute("aria-expanded")).toBe("false");
    });
  });

  describe('Multi-Phase Attribute Application', () => {
    it('should handle attribute timing correctly', async () => {
      const events: string[] = [];

      // Mock component lifecycle
      const mockLifecycle = {
        connectedCallback() {
          events.push('connected');
          // Should apply attributes immediately
          events.push('apply-attributes');
        },
        firstUpdated() {
          events.push('first-updated');
          // Should delay USWDS initialization
          setTimeout(() => events.push('initialize-uswds'), 10);
        }
      };

      mockLifecycle.connectedCallback();
      mockLifecycle.firstUpdated();

      // Wait for async initialization
      await new Promise(resolve => setTimeout(resolve, 20));

      // Validate proper sequence
      expect(events).toContain('connected');
      expect(events).toContain('apply-attributes');
      expect(events).toContain('initialize-uswds');

      // Critical: attributes applied before USWDS initialization
      const applyIndex = events.indexOf('apply-attributes');
      const initIndex = events.indexOf('initialize-uswds');
      expect(applyIndex).toBeLessThan(initIndex);
    });

    it('should handle property updates through all phases', async () => {
      
      element.expanded = true;
      await element.updateComplete;
      expect(element.expanded).toBe(true);
    
    });
  });

  describe('Light DOM Slot Behavior', () => {
    it('should access slot content correctly in light DOM', () => {
      // Add complex slot content
      const slotContent = `
        <button class="direct-child">Direct content</button>
        <slot>
          <span class="slotted-content">Slotted content</span>
        </slot>
      `;
      element.innerHTML = slotContent;

      // Strategy 1: Direct children access
      const directChildren = Array.from(element.children).filter(
        child => child.nodeType === Node.ELEMENT_NODE && child.tagName !== 'SLOT'
      );
      expect(directChildren.length).toBeGreaterThan(0);

      // Strategy 2: Slot children access
      const slotElement = element.querySelector('slot');
      const slotChildren = slotElement ? Array.from(slotElement.children) : [];

      // Should find content using light DOM patterns
      const totalElements = directChildren.length + slotChildren.length;
      expect(totalElements).toBeGreaterThan(0);
    });

    it('should handle content updates dynamically', async () => {
      // Accordion component renders its own structure, so we test via items property
      element.items = [
        { id: 'initial', title: 'Initial Item', content: 'Initial content' }
      ];
      await element.updateComplete;

      const initialItems = element.items.length;
      expect(initialItems).toBe(1);

      // Add new content via items property
      element.items = [
        ...element.items,
        { id: 'new', title: 'New Item', content: 'New content' }
      ];
      await element.updateComplete;

      expect(element.items.length).toBe(2);

      // Remove content via items property
      element.items = element.items.filter(item => item.id !== 'initial');
      await element.updateComplete;

      expect(element.items.length).toBe(1);
    });
  });
});