const http = require('http');
const puppeteer = require('puppeteer');
const urlModule = require('url');

// 用于存储浏览器实例，避免每次请求都重新启动浏览器
let browser;

const initBrowser = async () => {
    browser = await puppeteer.launch({
                headless: true,
                args: ["--no-sandbox"],
                executablePath: '/app/chrome/chrome-linux64/chrome'
            });
};

initBrowser();
let number = 0

const server = http.createServer(async (req, res) => {
    const parsedUrl = urlModule.parse(req.url, true); // 第二个参数为true表示解析查询参数
    const pathname = parsedUrl.pathname;
    console.log(pathname)
    const query = parsedUrl.query;
    console.log(query)
    
    if (pathname === '/screenshot' && req.method.toUpperCase() === 'GET') {
        console.log(number)
        const targetUrl = query.url;
        console.log(targetUrl)
        if (!targetUrl) {
            res.statusCode = 400;
            res.end('Missing url parameter');
            return;
        }

        try {
            if (!browser) {
                await initBrowser();
            }
            try {
                const page = await browser.newPage();
                // 这里确保传入完整协议的网址，比如 http:// 或 https:// 开头的
                await page.goto(targetUrl);
                const screenshotBuffer = await page.screenshot();
                await page.close();

                res.statusCode = 200;
                number++
                res.setHeader('Content-Type', 'image/png');
                res.end(screenshotBuffer);
            } catch (pageError) {
                console.error('Error accessing page:', pageError);
                await browser.close();
                res.statusCode = 500;
                res.end('Error accessing page');
            }
        } catch (launchError) {
            console.error('Error launching browser:', launchError);
            res.statusCode = 500;
            res.end('Error launching browser');
        }
    } else {
        res.statusCode = 404;
        res.end('Not Found');
    }
});

const port = process.env.PORT || 7860;
server.listen(port, () => {
    console.log(`Server running on port ${port}`);
});