A JS wrapper for TheLastMillenial's TI-84+CE HDPICV image converter (version beta 2)

convpng.js

/**
 * NAME:
 *    convpng.js - a JS wrapper for TheLastMillenial's TI-84+CE HDPICV image converter.
 * SYNOPSIS:
 *    node convpng.js [OPTIONS] [SOURCE.png]
 * DESCRIPTION:
 *    Since TLM is not as active on this project at the moment I decided to make a simple
 *    little wrapper for the old beta 2 version of the project. It requires Node.JS to be
 *    installed; apologies since JS is the language I am most proficient and fast with.
 *    Also, this only works on Windows.
 * REQUIREMENTS:
 *    imagemagick     https://imagemagick.org/ or package manager of choice
 *    nodejs          https://nodejs.org/ or package manager of choice
 *    convpng         specifically the windows_convpng.exe of beta 2 (v1.0.0-beta.2) here: 
 *                    https://github.com/TheLastMillennial/HD-Picture-Viewer/releases
 * PARAMETERS:
 *    SOURCE.png      [REQUIRED] the source image, unsplit and un-resized as this program 
 *                    uses imagemagick to do all that stuff. 
 *    OPTIONS
 *      -a            Appvar name. This is the calculator's version of a 'filename'. This
 *                    script will automatically add 'L' or 'R' to it to signify which is
 *                    the left or right half of the image. If not declared, it will be
 *                    the same as the input filename shortened to the first 7 characters.
 * NOTES:
 *    To make this script not too complicated and because I don't know how to implement
 *    space-separated argument vals, arguments are used like: -a=name, each argu-
 *    ment's val seprated by an equal.
 * EXAMPLE:
 *    node convpng.js -a=FOREST forest.png
 *      The above example will process the image "forest.png", and output two appVars 
 *      named "FORESTL.8xv" and "FORESTR.8xv" into the cwd.
 * CREDITS:
 *    Thank you, Miller Medeiros for your brilliant shell helper module. Edited a bit for
 *    conciseness.
 *      https://gist.github.com/millermedeiros/4724047
 *      used in func execSeries
 * WARNING - THE FOLLOWING CODE IS VERY DIRTY AND MAY CAUSE HEADACHES; PROCEED WITH CAUTION.
 */

var fs = require('fs');
var chp = require('child_process');

var input = process.argv.slice(2); // this trims off the first two elements we don't need.

var source;
var appVar = false;
var outHeader;

var execSeries = function(cmds, cb) {
  var execNext = function() {
    var parts = cmds.shift().split(/\s+/g); // splits by whitespaces.
    var p = chp.spawn(parts[0], parts.slice(1), {stdio: 'inherit'});

    p.on('exit', (code) => {
      var err;

      if(code) {
        err.code = code;
        err.cmd = cmds.shift();
        cb(code); // cb = CallBack
      } else if(cmds.length) {
        execNext(); // recursion babyyyyy
      } else {
        cb();
      }
    });
  };
  execNext();
};

var delMultiple = function(files, cb) {
  for(i = 0; i < files.length; i++) { 
    try { // try..catch..finally will catch errors even in sync methods rather than callbacks
      fs.unlinkSync(files[i]);
    } catch(err) {
      cb(err);
    } finally {
      cb(); // I know I shouldn't be callbacking multple times but who cares
    }
  }
};

input.forEach((arg) => {
  if(/-a=|-c|-o=/.test(arg)) { // a shortened form of "if the argument includes either of these"
    var opt = arg.split('=')[0];
    var val = arg.split('=')[1];
    
    // Appvar option
    if(opt == '-a' && val.length < 9) {
      outHeader = val.toUpperCase();
      appVar = val.toUpperCase().substring(0, 7); // shorten to the first 7 chars
    } else if(opt == '-a' && val.length > 8) {
      throw "Error: AppVar name must only be up to 8 characters long.";
    }
  } else if(fs.existsSync(arg)) { // assume that the arg without the dash is the required one
    source = arg;
    if(!appVar) {
      outHeader = arg.split('.')[0].toUpperCase().substring(0, 8);
      appVar = outHeader.substring(0, 7);
    }
  } else {
    throw "Error: Source image not found. Make sure it is in the same directory as the conving.exe!";
  }
});

execSeries([
  `convert ${source} -resize 320x240 temp.png`,
  'convert temp.png -crop 50%x100% crop_%d.png'
], (err) => {
  if(err) throw `ImageMagick Error! Code ${err.code}`;
  
  console.log('Successfully resized and split image.');
  
  fs.readFile('convpng.template', 'utf8', (err, data) => {
    if(err) throw `Error reading convpng: ${err}`;
    
    var side = 0;
    
    console.log("Successfully read the convpng template.");
    
    var convFinal = function(data, cb) {
      var sideLtr = (side == 0) ? 'L' : 'R';
      var convIni = data
        .replace(/@/g, `${side}`)
        .replace('%', `${appVar}${sideLtr}`)
        .replace('$', `${sideLtr}${outHeader.padEnd(8, '_')}`);
      
      fs.writeFile('convpng.ini', convIni, 'utf8', (err) => {
        if(err) throw `Error writing convpng: ${err}`;
        
        console.log(`Successfully wrote ${sideLtr}-side convpng.ini.`);

        chp.execFile('windows_convpng.exe', (err) => {
          if(err) throw `Error executing convpng.exe: ${err}`;

          console.log(`Successfully executed ${sideLtr}-side convpng.exe.`);
          side++;
          if(side == 1) {
            convFinal(data); // recursion babyyyyy
          } else {
            delMultiple(['crop_0.png', 'crop_1.png', 'temp.png'], (err) => { 
              if(err) throw `Error cleaning up excess files: ${err}`;
            }); 
            console.log('Done.');
          };
        });
      });
    };
    convFinal(data);
  });
});

convpng.template

#GroupICE          : all_gfx
#Palette           : xlibc

#PNGImages         :
 crop_@.png

#AppvarICE         : %

#OutputHeader      : HDPICV2$

#PNGImages         :
 crop_@.png