var readline = require('readline');
var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    terminal: false
});

var starting;
var ending;
rl.question('Enter starting value: ', function(startingValue) {
    // Prompt user for inputting starting value
    starting = startingValue;
    rl.question('Enter ending value: ', function(endingValue) {
        // Prompt user for inputting ending value
        ending = endingValue;
        console.log('starting:' + starting + ', ending:' + ending);
        generateBarcode(starting);

        rl.close();
        process.stdin.destroy();
    });

});

function generateBarcode(toPrint) {
    // Method to generate barcode
    console.log(toPrint);
    var bwipjs = require('bwip-js');
    var fs = require('fs');
    // Optionally load some custom fonts.  Maximum 8.
    // OpenType and TrueType are supported.
    bwipjs.loadFont('Inconsolata', 108,
        require('fs').readFileSync('fonts/Inconsolata.otf', 'binary'));

    bwipjs.toBuffer({
        bcid: 'code128', // Barcode type
        text: toPrint, // Text to encode
        scale: 3, // 3x scaling factor
        height: 10, // Bar height, in millimeters
        includetext: true, // Show human-readable text
        textxalign: 'center', // Always good to set this
        textfont: 'Inconsolata', // Use your custom font
        textsize: 13 // Font size, in points
    }, function(err, png) {
        if (err) {
            // Decide how to handle the error
            // `err` may be a string or Error object
        } else {
            // Write the barcode as image file and save it
            fs.writeFile(__dirname + '/' + toPrint + '.png', png, function() {
                console.log('Generated Barcode');

                toPrint++;
                if (toPrint < ending) {
                    generateBarcode(toPrint);
                }
            });
        }
    });
}