const express = require('express');
const puppeteer = require('puppeteer');
const fs = require('fs');

const app = express();

(async () => {

    const width = 1600, height = 1040;
    const option = { headless: true, slowMo: true, args: [`--window-size=${width},${height}`] };
    const browser = await puppeteer.launch(option);
    const page = await browser.newPage();

    await page.goto('https://search.shopping.naver.com/search/all.nhn?query=%EC%96%91%EB%A7%90&cat_id=&frm=NVSHATC');

    await page.waitFor(5000);
    await page.waitForSelector('ul.goods_list');
    await page.addScriptTag({url: 'https://code.jquery.com/jquery-3.2.1.min.js'});

    const naver = await page.evaluate(() => {
        const data = {
            "naver" : []
        };

        $('ul.goods_list > li._itemSection').each(function () {

            const title = $.trim($(this).find('div.info > a.tit').text());
            const price = $(this).find('div.info > .price .num').text();
            const image = $(this).find('div.img_area img').attr('src');

            data.naver.push({ title, price, image })

        });

        return data;
    });

    if (await write_file('example.json', JSON.stringify(naver)) === false) {
        console.error('Error: Unable to write stores to example.json');
    }

    await browser.close();

})();

const write_file = (file, data) => new Promise((resolve, reject) => {
    fs.writeFile(file, data, 'utf8', error => {
        if (error) {
            console.error(error);
            reject(false);
        } else {
            resolve(true);
        }
    });
});

app.listen(3000, () => console.log("Express!!!"));