require('dotenv').config();

const postgres = require('postgres');
const express = require('express');
const bodyParser = require('body-parser');
const app = express();
const Hashids = require('hashids');
const expressws = require('express-ws');
const { generateKey } = require('crypto');
const { promisify } = require('util');
const multer = require('multer');
const storage = multer.diskStorage({
  destination: 'uploads/',
  filename: async (req, file, cb) => {
    const key = (await promisify(generateKey)('hmac', {length: 64})).export().toString('hex');
    cb(null, key);
  }
});

const EventEmitter = require('events');
const images = new EventEmitter();

const jsonParser = bodyParser.json();

const upload = multer({ storage: storage, fileFilter: (req, file, cb) => {
  if (!imageFormats.includes(file.mimetype)) return cb(null, false);
  cb(null, true);
}});

const imageFormats = ['image/gif', 'image/jpeg', 'image/png', 'image/svg+xml', 'image/tiff', 'image/webp', 'image/bmp', 'image/avif', 'image/vnd.microsoft.icon'];

const idLength = 6;
const hashids = new Hashids('chartmaker', idLength);

const port = process.env.PORT || 5252;
const sql = postgres(`postgres://${process.env.DB_USER || 'chartmaker'}:${process.env.DB_PASS}@${process.env.DB_HOST || 'localhost'}:${process.env.DB_PORT || '5432'}/${process.env.DB_NAME || 'chartmaker'}`);

expressws(app);

app.use('/img', express.static('uploads'));

app.use((req, res, next) => {
	res = res.setHeader('Access-Control-Allow-Origin', '*');
	next();
});

app.post('/create', jsonParser, async (req, res) => {
  const [r] = await sql`SELECT id FROM charts ORDER BY id DESC LIMIT 1`;
  let newid = 1;
  if (r) newid = r.id + 1;

  console.log(req.body);

  let body = req.body || {};
  await sql`
    INSERT INTO charts VALUES (${newid}, ${body.name || ''}, ${body.left || ''}, ${body.right || ''}, ${body.top || ''}, ${body.bot || ''})
  `;

  res.status(200).send(hashids.encode(newid));
});

app.post('/add', upload.single('icon'), async (req, res) => {
  if (!req.body) return res.sendStatus(400);
  if (!req.file) return res.status(400).send('Send a file!');
  if (!req.body.id) return res.status(400).send('Supply a chart ID!');
  if (!req.body.name) return res.status(400).send('Supply a name!');
  if (!req.body.x || !req.body.y) return res.status(400).send('Supply a position!');
  const id = hashids.decode(req.body.id);
  if (!id[0]) return res.status(400).send('Invalid chart ID!');
  let [exists] = await sql`
    SELECT id FROM charts WHERE id = ${id[0]}
  `;
  if (!exists) return res.status(400).send('Chart doesn\'t exist!');
  await sql`
    INSERT INTO images VALUES (${id[0]}, ${req.file.filename}, ${req.body.name}, ${req.body.x}, ${req.body.y})
  `;
  images.emit('imageAdd', id[0], {name: req.body.name, x: req.body.x, y: req.body.y, file: req.file.filename})
  res.sendStatus(200);
});

app.ws('/connect', async (ws, req) => {
  if (!req.query.id) return ws.close(1008, 'Supply a chart ID in the query!');
  const id = hashids.decode(req.query.id)[0];
  if (!id) return ws.close(1008, 'Invalid chart ID!');
  let [chart] = await sql`
    SELECT * FROM charts WHERE id = ${id}
  `;
  if (!chart) return ws.close(1008, 'Chart doesn\'t exist!');
  
  console.log(chart);

  await ws.send(JSON.stringify({name: chart.name, leftText: chart.lefttext, rightText: chart.righttext, topText: chart.toptext, bottomText: chart.bottomtext}));

  await ws.send(JSON.stringify((await sql`SELECT * FROM images WHERE id = ${id}`).map(i => {return {name: i.name, x: i.x, y: i.y, file: i.filepath}})));

  const callback = (scrunklyId, scrunkly) => {
    console.log(scrunklyId, scrunkly);
    if (scrunklyId === id) {
      ws.send(JSON.stringify([scrunkly]));
    }
  };
  
  images.on('imageAdd', callback);
  ws.on('close', () => {images.off('imageAdd', callback)});
});

(async () => {
	await sql`
		CREATE TABLE IF NOT EXISTS charts (
      id         int PRIMARY KEY,
		  name       text,
      leftText   text,
      rightText  text,
      topText    text,
      bottomText text
		)
	`;
	await sql`
		CREATE TABLE IF NOT EXISTS images (
		  id       int,
      filepath text,
      name     text,
      x        real,
      y        real
		)
	`;

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