Hyper Light Drifter script to find gearbit/key IDs

hld-savewatcher.js

'use strict';

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

const saveFilename = path.join(process.env.LOCALAPPDATA, 'HyperLightDrifter/HyperLight_RecordOfTheDrifter_0.sav');
let currentSaveData;
init(saveFilename);

fs.watch(saveFilename, { persistent: true }, (event, filename) => {
	if (event === 'change') {
		run(saveFilename);
	}
});

function init(filename) {
	const saveData = parseSave(filename);
	currentSaveData = saveData;

	const gearbits = getGearbits(saveData);
	const keys = getKeys(saveData);

	console.log(`Watcher initialized for save file ${saveFilename}.`);
	console.log(`Current count: ${gearbits.length} gearbits, ${keys.length} keys.`);
	console.log('-----------------------------');
	console.log('Collected gearbit IDs:');
	console.log(gearbits.join(', '));
	console.log('-----------------------------');
	console.log('Collected key IDs:');
	console.log(keys.join(', '));
}

function run(filename) {
	const newSaveData = parseSave(filename);
	const newGearbits = getGearbits(newSaveData);
	const newKeys = getKeys(newSaveData);

	const currentGearbits = getGearbits(currentSaveData);
	const currentKeys = getKeys(currentSaveData);

	const addedGearbits = without(newGearbits, currentGearbits);
	const removedGearbits = without(currentGearbits, newGearbits);

	const addedKeys = without(newKeys, currentKeys);
	const removedKeys = without(currentKeys, newKeys);

	let changed = false;

	if (removedGearbits.length) {
		console.log('---------------------------------');
		console.log(new Date());
		console.log(`WARNING: Gearbit(s) removed! ${removedGearbits.join(', ')}`);
		changed = true;
	}

	if (addedGearbits.length) {
		console.log('---------------------------------');
		console.log(new Date());
		console.log(`Gearbit(s) added: ${addedGearbits.join(', ')}`)
		changed = true;
	}

	if (removedKeys.length) {
		console.log('---------------------------------');
		console.log(new Date());
		console.log(`WARNING: Key(s) removed! ${removedKeys.join(', ')}`);
		changed = true;
	}

	if (addedKeys.length) {
		console.log('---------------------------------');
		console.log(new Date());
		console.log(`Key(s) added: ${addedKeys.join(', ')}`)
		changed = true;
	}

	if (changed) {
		console.log(`New count: ${newGearbits.length} gearbits, ${newKeys.length} keys.`);
	}

	currentSaveData = newSaveData;
}

function getGearbits(saveData) {
	return saveData.cl['0'] || [];
}

function getKeys(saveData) {
	return saveData.cl['2'] || [];
}

function parseSave(filename) {
	const base64str = fs.readFileSync(filename, 'utf8');
	const base64buf = new Buffer(base64str, 'base64');
	const jsonStrWithJunk = base64buf.toString();
	const jsonStr = jsonStrWithJunk
		.slice(jsonStrWithJunk.indexOf('{ '))
		.slice(0, -1);
	const saveData = JSON.parse(jsonStr);

	for (let key in saveData) {
		if (!Object.hasOwnProperty.call(saveData, key)) continue;
		saveData[key] = parseValue(saveData[key]);
	}

	return saveData;
}

function parseValue(value) {
	if (/>$/.test(value)) {
		return parseObjValue(value);
	} else if (/\+$/.test(value)) {
		return parseArrValue(value, '+');
	} else if (/&$/.test(value)) {
		return parseArrValue(value, '&');
	} else {
		return value;
	}
}

function parseObjValue(value) {
	const split = value.split('>').slice(0, -1);
	const result = {};
	split.forEach(segment => {
		const match = /(.+)=(.+)/.exec(segment);
		const key = match[1];
		const value = parseValue(match[2]);
		result[key] = value;
	});
	return result;
}

function parseArrValue(value, delim) {
	return value.split(delim).slice(0, -1);
}

function without(arr1, arr2) {
	return arr1.filter(x => arr2.indexOf(x) === -1);
}