/**
 * Accessibility Testing Helper
 * Provides reusable axe-core configuration and utilities for Playwright tests
 */

import AxeBuilder from '@axe-core/playwright';

/**
 * Default WCAG 2.1/2.2 tags for accessibility testing
 */
const WCAG_TAGS = ['wcag2a', 'wcag2aa', 'wcag21a', 'wcag21aa', 'wcag22aa'];

/**
 * Create a pre-configured AxeBuilder instance
 * @param {import('@playwright/test').Page} page - Playwright page object
 * @param {Object} options - Configuration options
 * @param {string[]} [options.tags] - WCAG tags to test (default: WCAG 2.1/2.2 A/AA)
 * @param {string[]} [options.exclude] - Selectors to exclude from scan
 * @param {string[]} [options.disableRules] - Rule IDs to disable
 * @returns {AxeBuilder} Configured AxeBuilder instance
 */
export function createAxeBuilder(page, options = {}) {
    const {
        tags = WCAG_TAGS,
        exclude = [],
        disableRules = []
    } = options;

    let builder = new AxeBuilder({ page })
        .withTags(tags);

    // Add exclusions
    exclude.forEach(selector => {
        builder = builder.exclude(selector);
    });

    // Disable specific rules if provided
    if (disableRules.length > 0) {
        builder = builder.disableRules(disableRules);
    }

    return builder;
}

/**
 * Filter violations by impact level
 * @param {Object[]} violations - Array of violation objects
 * @param {string[]} impacts - Impact levels to include ('critical', 'serious', 'moderate', 'minor')
 * @returns {Object[]} Filtered violations
 */
function filterByImpact(violations, impacts) {
    return violations.filter(v => impacts.includes(v.impact));
}

/**
 * Get critical and serious violations only
 * @param {Object[]} violations - Array of violation objects
 * @returns {Object[]} Critical and serious violations
 */
export function getCriticalViolations(violations) {
    return filterByImpact(violations, ['critical', 'serious']);
}

/**
 * Format violations for console output
 * @param {Object[]} violations - Array of violation objects
 * @returns {string} Formatted string
 */
export function formatViolations(violations) {
    if (violations.length === 0) {
        return 'No accessibility violations found.';
    }

    const lines = violations.map(v => {
        const nodes = v.nodes.map(n => `    - ${n.target.join(', ')}`).join('\n');
        return `\n[${v.impact.toUpperCase()}] ${v.id}: ${v.description}\n  Help: ${v.helpUrl}\n  Affected elements:\n${nodes}`;
    });

    return `Found ${violations.length} accessibility violation(s):${lines.join('\n')}`;
}

export { WCAG_TAGS };