make-gpio-script

#!/usr/bin/env node

const fs = require('fs');
const path = require('path');
const util = require('util');

const OUTPUT_NAME = "set-gpio.sh";

var config = [];

console.log("\nRebuild the set-gpio.sh script using your Homebridge config.json\n");

if (process.argv.length < 4) {
    console.log("Usage: ./make-gpio-script input-config.json set-gpio.sh\n\n");
    process.exit();
} else {
    try {
        console.log("INFO:  Parsing %s", process.argv[2]);
        config = JSON.parse(fs.readFileSync(process.argv[2], 'utf8'));
    }
    catch (err) {
        console.log("ERROR: Cannot parse your config file (" + process.argv[2] + ")\nCheck it exists and is valid!", err);
        process.exit();    
    }
    try {
        //Force the output file to be named set-gpio.sh
        var inputPath = path.parse(process.argv[3]);
        if (inputPath.name + inputPath.ext != OUTPUT_NAME) {
            console.log("ERROR: Output file is not called %s - aborting", OUTPUT_NAME);
            process.exit();
        } else {
            console.log("INFO:  Truncating %s script", OUTPUT_NAME);
            if ( fs.existsSync(process.argv[3])) {
                fs.truncateSync(process.argv[3],0);
            }
            var scriptContents = configToScript(config);
            console.log("INFO:  Writing to %s", OUTPUT_NAME);
            fs.writeFileSync(process.argv[3], scriptContents);
        }
    }
    catch (err) {
        console.log("ERROR: Cannot write out to " + process.argv[3], err);
        process.exit();
    }
}

process.exit();

function configToScript(inputConfig)
{
    var piPlatform = inputConfig.platforms.filter(function (el) { return el.platform == "WiringPiPlatform"});
    var gpioPins = piPlatform[0].gpiopins;

    script  = "#!/bin/sh\n\n";
    script += "####\n";
    script += "# Do not edit this script - it is generated automatically by make-gpio-script\n";
    script += "####\n\n";
    script += "GPIO=/usr/local/bin/gpio\n\n";

    for (var i = 0, len = gpioPins.length; i < len; i++)
    {
        if (gpioPins[i].enabled.toUpperCase() == "TRUE") {
            script += util.format("## %s\n", gpioPins[i].name)
            script += util.format("$GPIO -g mode %s %s\n", gpioPins[i].pin, gpioPins[i].mode);
            script += util.format("$GPIO -g mode %s %s\n", gpioPins[i].pin, gpioPins[i].pull);
            script += util.format("$GPIO -g export %s %s\n\n", gpioPins[i].pin, gpioPins[i].mode);
        }  
    }

    return script;
}