import { Page } from '@playwright/test';
import AxeBuilder from '@axe-core/playwright';
import { AccessibilityResult, Violation } from '../../types';

export class AccessibilityTester {
  constructor(private page: Page) {}

  async runAxeScan(pageName: string, url: string): Promise<AccessibilityResult> {
    const accessibilityScanResults = await new AxeBuilder({ page: this.page })
      .withTags(['wcag2a', 'wcag2aa', 'wcag21a', 'wcag21aa'])
      .analyze();

    const violations: Violation[] = accessibilityScanResults.violations.map(v => ({
      id: v.id,
      impact: v.impact || 'unknown',
      description: v.description,
      help: v.help,
      helpUrl: v.helpUrl,
      nodes: v.nodes.length
    }));

    const passes = accessibilityScanResults.passes.length;
    const incomplete = accessibilityScanResults.incomplete.length;
    const score = this.calculateScore(violations, passes, incomplete);

    return {
      score,
      violations,
      passes,
      incomplete,
      page: pageName,
      url
    };
  }

  private calculateScore(violations: Violation[], passes: number, incomplete: number): number {
    const total = violations.length + passes + incomplete;
    if (total === 0) return 100;
    return parseFloat(((passes / total) * 100).toFixed(1));
  }

  async checkColorContrast(): Promise<boolean> {
    const results = await new AxeBuilder({ page: this.page })
      .withTags(['wcag2aa'])
      .include('#content')
      .analyze();

    return results.violations.filter(v => v.id === 'color-contrast').length === 0;
  }

  async checkAltText(): Promise<{ total: number; withAlt: number; withoutAlt: number }> {
    const images = await this.page.locator('img').all();
    let withAlt = 0;
    let withoutAlt = 0;

    for (const image of images) {
      const alt = await image.getAttribute('alt');
      if (alt && alt.trim() !== '') {
        withAlt++;
      } else {
        withoutAlt++;
      }
    }

    return {
      total: images.length,
      withAlt,
      withoutAlt
    };
  }
}