const express = require('express');
const { chromium } = require('playwright');
const QRCode = require('qrcode');
const Jimp = require('jimp');
const QrCodeReader = require('qrcode-reader');
//const fetch = require('node-fetch');

const app = express();
const port = 7860;

// Global variable to hold the browser instance and context
let browser;
let browserContext;

app.use(express.json());

app.get('/', (req, res) => {
	console.log('request to /');
	res.send('halo kontol');
});

app.post('/screenshot', async (req, res) => {
	console.log('request to /screenshot');
	const { ua, url, type, width, height, language, fullpage } = req.body;
	if (!url) return res.send('please input url');
	await processScreenshot(req, res, { ua, url, type, width, height, language, fullpage });
});

app.get('/screenshot', async (req, res) => {
	console.log('request to /screenshot (get)');
	const { ua, url, type, width, height, language, fullpage } = req.query;
	if (!url) return res.send('please input url');
	await processScreenshot(req, res, { ua, url, type, width, height, language, fullpage });
});

app.get('/qrcode', async (req, res) => {
	try {
		const { mode, url } = req.query;

		if (!mode || !url) {
			return res.status(400).send('what?');
		}

		if (mode === 'create') {
			QRCode.toDataURL(url, (err, src) => {
				if (err) return res.send({ error: 'Error generating QR code' });
				res.type('png').send(Buffer.from(src.split(",")[1], "base64"));
			});
		} else if (['read', 'scan'].includes(mode)) {
			const rts = await fetch(url);
			if (!rts.ok || rts.status !== 200) return res.send({ status: 400, message: 'Can\'t buffer url' });
			if (!/image/.test(rts.headers.get('content-type'))) return res.send({ status: 400, message: 'Only image type' });
			const buffer = Buffer.from(await rts.arrayBuffer());
			const image = await Jimp.read(buffer);

			image.grayscale().contrast(1).normalize();

			const qrCodeReader = new QrCodeReader();

			qrCodeReader.callback = (err, value) => {
				if (err) return res.send({ error: 'Error reading QR code' });
				res.json({ result: value.result });
			};

			const bitmap = image.bitmap;
			qrCodeReader.decode({ width: bitmap.width, height: bitmap.height, data: bitmap.data });
		} else {
			QRCode.toDataURL(url, (err, src) => {
				if (err) return res.send({ error: 'Error generating QR code' });
				res.type('png').send(Buffer.from(src.split(",")[1], "base64"));
			});
		}
	} catch (error) {
		console.error(error);
		res.send({ error: 'Internal Server Error' });
	}
});

async function processScreenshot(req, res, { ua, url, type, width, height, language, fullpage }) {
	try {
		console.log('process screenshot');

		// Launch browser and create a context if it doesn't exist
		if (!browser) {
			browser = await chromium.launch({
				headless: true,
				args: ["--no-sandbox", "--disable-setuid-sandbox"]
			});
		}

		// Reuse or create a new context
		if (!browserContext) {
			browserContext = await browser.newContext({
				userAgent: ua || 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
				viewport: { width: width || 1280, height: height || 800 },
				deviceScaleFactor: 2
			});
		}

		const page = await browserContext.newPage();

		if (language) {
			await page.emulateMedia({ colorScheme: language });
		}

		await page.goto(url, { waitUntil: 'networkidle' });

		// Handle JavaScript challenges
		await page.waitForLoadState('networkidle');

		let screenshotOptions = {
			fullPage: fullpage == 1 ? true : false,
			type: 'png',
			omitBackground: false
		};

		if (type === 'desktop') {
			await page.setViewportSize({
				width: 1920,
				height: 1080,
			});
		} else if (type === 'mobile') {
			await page.setViewportSize({
				width: 375,
				height: 667,
			});
		} else if (type === 'tablet') {
			await page.setViewportSize({
				width: 768,
				height: 1024,
			});
		} else if (type === 'iphone') {
			await page.setViewportSize({
				width: 375,
				height: 667,
			});
		} else if (type === 'custom') {
			if (width && height > 4096) {
				await page.close();
				return res.json({
					"status": 400,
					"message": "Width and height values should not exceed 4096 pixels."
				});
			}
			if (width && height < 400) {
				await page.close();
				return res.json({
					"status": 400,
					"message": "Width and height values should not be less than 400 pixels."
				});
			}
			await page.setViewportSize({
				width: Number(width) || 375,
				height: Number(height) || 667,
			});
		}

		await page.waitForTimeout(5000);

		const screenshot = await page.screenshot(screenshotOptions);

		res.writeHead(200, {
			'Content-Type': 'image/png',
			'Content-Length': screenshot.length,
		});
		res.end(screenshot);
		console.log('process done');
		await page.close(); // Close the tab instead of the browser

		// Periodically close and reopen the browser to avoid memory bloat
		if (browserContext.pages().length > 10) { // Arbitrary threshold
			await browserContext.close();
			browserContext = await browser.newContext();
		}

		// Trigger garbage collection
		if (global.gc) {
			global.gc();
		}
	} catch (e) {
		console.error(e);
		return res.json({
			status: 400,
			message: 'error when take a screenshot'
		});
	}
}

app.listen(port, () => {
	console.log(`Server is running on port ${port}`);
});