import express from "express";
import cors from "cors";
import bodyParser from "body-parser";
import path from "path";
import fs from "fs";
import formidable from "formidable";
import shellExec from "shell-exec";

const app = express();
app.use(cors());
app.use(bodyParser.json());
const port = process.env.PORT || 4000;
const formats = ['pdf','ps'];
const sizes = ['full', 'a4','a3','a2','a1','a0','letter','tabloid'];

app.get("/", async (req, res) => res.sendFile(path.resolve(__dirname+'/form.html')));
app.post("/", async (req, res) => {
  let form = new formidable.IncomingForm();
  form.parse(req, (err, fields, files) => {
    if(err || typeof files.svg === "undefined" ||
      formats.indexOf(fields.format) === -1 ||
      sizes.indexOf(fields.size) === -1
      ) return res.sendFile(path.resolve(__dirname+'/form.html'));
    let upload = files.svg.path;
    let cmd;
    if(fields.size === "full") { // Do not tile
      let target = `/tmp/pattern.${fields.format}`;
      cmd = `/usr/bin/inkscape --export-${fields.format}=${target} ${upload}`;
      shellExec(cmd).then(() => {
        return res.sendFile(target);
      });
    } else { // Do tile
      let untiled = "/tmp/untiled.ps";
      let tiled = "/tmp/tiled.ps";
      cmd = `/usr/bin/inkscape --export-ps=${untiled} ${upload}`;
      shellExec(cmd).then(() => {
        cmd = `/usr/local/bin/tile -a -m${fields.size} -s1 -t"On-demand tiler" ${untiled} > ${tiled}`;
        shellExec(cmd).then(() => {
          if(fields.format === "ps") return res.sendFile(tiled);
          cmd = `/usr/bin/ps2pdf14 ${tiled} ${tiled}.pdf`;
          shellExec(cmd).then(() => {
            return res.sendFile(tiled+'.pdf');
          });
        });
      });
    }
  });
});

app.post("/api", async (req, res) => {
  if(
    typeof req.body.svg === "undefined" ||
    typeof req.body.format === "undefined" ||
    typeof req.body.size === "undefined")
    return res.sendStatus(400);

  // Save svg to disk
  fs.writeFile("/tmp/draft.svg", req.svg, err => {
  	if(err) return res.sendStatus(500);
  	let cmd;
  	if(req.size === "full") { // Do not tile
  	  let target = `/tmp/pattern.${req.format}`;
  	  cmd = `/usr/bin/inkscape --export-${req.format}=${target} /tmp/draft.svg`;
  	  shellExec(cmd).then(() => {
  	    return res.sendFile(target);
  	  });
  	} else { // Do tile
    	let untiled = "/tmp/untiled.ps";
    	let tiled = "/tmp/tiled.ps";
    	cmd = `/usr/bin/inkscape --export-ps=${untiled} /tmp/draft.svg`;
    	shellExec(cmd).then(() => {
    	  cmd = `/usr/local/bin/tile -a -m${req.size} -s1 -t"On-demand tiler" ${untiled} > ${tiled}`;
    	  shellExec(cmd).then(() => {
    	    if(req.format === "ps") return res.sendFile(tiled);
    	    cmd = `/usr/bin/ps2pdf14 ${tiled} ${tiled}.pdf`;
    	    shellExec(cmd).then(() => {
    	      return res.sendFile(tiled+'.pdf');
    	    });
    	  });
  		});
		}
	});
});

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