const fs = require('fs');

const textUrl = process.argv[2];
const textContent = fs.readFileSync(textUrl, 'utf8');
const outputUrl = process.argv[3] || (textUrl + "_UniqueWords");

const uniqueAlphaStr = "rgBCDFLMNPbcSTGHjklmnpQRJKVWXZhvqwxstdfz";

const words = Object.keys(
    textContent
        .replace(/(\w+)\'(\w+)/g, "$1" + uniqueAlphaStr + "$2")
        .split(/\W/g)
        .filter(word => word.length > 0)
        .reduce((prev, curr) => {
            prev[curr.replace(new RegExp(uniqueAlphaStr, 'g'), '\'').toLowerCase()] = undefined;
            return prev;
        }, {})
);

fs.writeFileSync(
    outputUrl, words.sort().join('\n')
);