const fs = require("fs");

const zlib = require("zlib");

const path = require("path");

// Get the file paths from command line arguments

let [jsonFilePath, destDir] = process.argv.slice(2);

if (!jsonFilePath || !destDir) {

console.error("Usage: node script.js <json-file-path> <destination-directory>");

process.exit(1);

}

// Function to decompress the content

function decompressContent(base64Encoded) {

// Decode base64 string to buffer

const compressedData = Buffer.from(base64Encoded, "base64");

// Decompress the data

const decompressedData = zlib.inflateSync(compressedData);

// Convert buffer to string

return decompressedData.toString();

}

try {

// Read and parse the JSON file

const jsonContent = fs.readFileSync(jsonFilePath, "utf8");

const data = JSON.parse(jsonContent)[0];

console.log(data);

const id = data.id;

// The id becomes the extraction root, so it must be a single path component.

if (

typeof id !== "string" ||

id.length === 0 ||

id === "." ||

id === ".." ||

id.includes("/") ||

id.includes("\\") ||

id.includes("\0")

) {

throw new Error(`Unsafe worker id: ${id}`);

}

console.log(`Extracting files for: ${id} to ${destDir}`);

destDir = path.join(destDir, id);

console.log(`Extracting files to: ${destDir}`);

// Resolve the extraction root once so we can keep every file inside it.

const extractionRoot = path.resolve(destDir);

// Create the destination directory if it doesn't exist

fs.mkdirSync(extractionRoot, { recursive: true });

// Process each item in the array

const sourceFiles = data.metadata.sourceFiles;

sourceFiles.forEach((file) => {

// Decompress the contents

const decompressedContent = decompressContent(file.contents);

// Combine destination directory with file path

const fullPath = path.resolve(extractionRoot, file.filePath);

// Reject any path that escapes the extraction root (zip-slip via ../ etc.)

if (fullPath !== extractionRoot && !fullPath.startsWith(extractionRoot + path.sep)) {

throw new Error(`Refusing to write outside destination: ${file.filePath}`);

}

// Create directory structure if it doesn't exist

const dirPath = path.dirname(fullPath);

fs.mkdirSync(dirPath, { recursive: true });

// Write the decompressed content to the file

fs.writeFileSync(fullPath, decompressedContent);

console.log(`Created file: ${fullPath}`);

});

console.log(`\nAll files have been extracted to: ${extractionRoot}`);

} catch (error) {

console.error(error);

process.exit(1);

}