// import playwright dependencies
const { chromium } = require('playwright');
const { injectAxe, checkA11y } = require('axe-playwright');
const jsdom = require("jsdom");


/**
 * PlaywrightService class
 * 
 * This class is used to interact with the Playwright library
 */
class PlaywrightService {

    #domain; // domain of the site to be tested
    
    // constructor
    constructor(domain) {
        this.#domain = domain;
    }

    // get sitemap url for the this domain
    sitemapUrl() {
        return `${this.rootUrl()}/sitemap.xml`;
    }

    // get the url of the site to be tested
    rootUrl() {
        return `https://${this.#domain}`;
    }

    /**
     * Get the list of urls to be tested by querying
     * the sitemap and returning the list of urls
     * 
     * @param {string} url - The URL of the sitemap
     * 
     * @returns {Array} - The list of urls to be tested
     */
    async getUrlList() {
        const browser = await chromium.launch();
        const page = await browser.newPage();
        let urls = [];

        try {
            await page.goto(this.sitemapUrl());
            const content = await page.content();
            const dom = new jsdom.JSDOM(content);
            const sitemapUrls = dom.window.document.querySelectorAll('a[href]');
            urls = Array.from(sitemapUrls).map(link => link.href);

            console.log('Sitemap URLs:', urls);
        } catch (error) {
            console.error('Error fetching sitemap:', error);
        } finally {
            await browser.close();
        }

        return urls;
    }

    /**
     * Loops through the list of urls and runs the
     * accessibility test on each url
     * 
     * @returns {Array} - The list of results from the accessibility test
     */
    async getAccessibilityResults() {
        const urls = await this.getUrlList();
        let results = [];

        while (urls.length > 0) {
            const url = urls.pop();
            console.log('Running accessibility test on:', url);
            const result = await PlaywrightService.#runAccessibilityTest(url);
            results.push([url, result]);
        }

        return results;
    }

    /**
     * Run accessibility test on given url
     * 
     * @param {string} url - The URL of the page to test
     * // TODO: Queue all urls from sitemap
     */
    static async #runAccessibilityTest(url) {
        const browser = await chromium.launch();
        const page = await browser.newPage();
        let results = [];

        try {
            await page.goto(url);
            await injectAxe(page);
            results = await page.evaluate(async () => {
                return await window.axe.run();
            });
        } catch(error) {
            console.error('Error running accessibility test:', error);
        } finally {
            await browser.close();
        }

        return results?.violations || 'No violations found';
    }

}   

module.exports = PlaywrightService;