const { readFileSync, writeFileSync } = require("fs");
const { parseScript } = require("esprima");
const { js_beautify } = require("js-beautify")

class Deobfuscator {
    constructor (fileLocation = "") {
        this.fileLocation = fileLocation;

        this.script = "";
        this.parsedScript = {};
        this.cleanedScript = "";
        this.challengeObjects = [];

        this._ac = [];
        this._acNode = {};
        this._acObfuscatedObjects = [];
    }

    cleanFile() {
        try {
            this.script = readFileSync(this.fileLocation).toString();

            this.parsedScript = parseScript(this.script, null, (node, meta) => {
                this.challengeObjects.push({node: node, meta: meta});
            });

            this.challengeObjects.forEach(object => {
                if (object.node.type === "VariableDeclaration" && object.node.declarations.length === 1 && object.node.declarations[0].id.name === "_ac") {
                    this._acNode = object.node;
                    this.cleanedScript = this.script.slice(object.meta.end.offset, this.script.length);
                } else if (object.node.type === "MemberExpression" && object.node.computed === true && object.node.object.name === "_ac") {
                    let toReplace = this.script.slice(object.meta.start.offset, object.meta.end.offset);
                    this._acObfuscatedObjects.push({string: toReplace, index: object.node.property.value});
                };
            });

            this._acNode.declarations[0].init.elements.forEach(element => {
                this._ac.push(element.value);
            });

            this._acObfuscatedObjects.forEach(object => {
                this.cleanedScript = this.cleanedScript.replace(object.string, `'${this._ac[object.index]}'`);
            });

            let cleanedPath = this.fileLocation.replace(".js", ".cleaned.js");

            writeFileSync(cleanedPath, js_beautify(this.cleanedScript), 'utf-8');

            console.log(`[DEOBFS] [SUCCESS] [${cleanedPath}]`);
        } catch (err) {
            console.log(`[DEOBFS] [ERR CLEANFILE] [${err}]`);
        }
    }
};

module.exports = Deobfuscator;