import { NotFoundException } from '@nestjs/common';
import path from 'path';
import { promises as fs } from 'fs';
/**
* Retrieves the complete file path based on filename and environment configuration.
*
* @param {string} filename - The original filename to process
* @returns {Promise<string>} The complete normalized file path
*/
export const getFilename = async (filename: string): Promise<string> => {
const { name, ext } = path.parse(filename);
const dirPath = process.env.PATH_UPLOAD_DIR;
if (!dirPath) throw new Error(`PATH_UPLOAD_DIR must be defined in .env file`);
const secret = process.env.SECRET_PHRASE;
let filePath;
if (!secret) {
filePath = `${dirPath}${filename}`;
} else {
const hash = await createHash(`${name}${secret}`);
filePath = `${dirPath}${hash}${ext}`;
}
const normalizedPath = filePath.normalize();
try {
await fs.access(normalizedPath);
} catch {
throw new NotFoundException(`File not found : ${filePath}`);
}
return filePath;
};
/**
* Creates a SHA-256 hash from input text and returns it as a hexadecimal string.
*
* @param {string} text - The text to be hashed
* @returns {Promise<string>} A hexadecimal string representation of the SHA-256 hash
*/
const createHash = async (text: string): Promise<string> => {
const encoder = new TextEncoder();
const data = encoder.encode(text);
const hashBuffer = await crypto.subtle.digest('SHA-256', data);
const hashArray = Array.from(new Uint8Array(hashBuffer));
return hashArray.map((b) => b.toString(16).padStart(2, '0')).join('');
};
