import { networkInterfaces } from 'os';
import { createHash, randomBytes } from 'crypto';
import { promises, constants } from 'fs';
import { dirname } from "path";

/**
 * Check to see if the input is a valid JSON string
 * 
 * @param {*} str The string to check for valud JSON
 * @returns {true|false}
 */
export const isJsonString = (str) => {
    try {
        JSON.parse(str);
    } catch (e) {
        return false;
    }
    return true;
}

/**
 * Check to see if a path exists, creating it if it does not
 * @returns {undefined}
 */
export const ensureDirectoryExists = async (filePath) => {
    const directory = dirname(filePath);
    try {
      await promises.access(directory, constants.F_OK);
    } catch (error) {
      await promises.mkdir(directory, { recursive: true });
    }
  };


/**
 * Generate a unique ID for a given device, this will also be unique on the same device at a different time. 
 * @returns {string} A generated unique ID
 */
export const generateUniqueID  = () => {
    const netInterfaces = networkInterfaces();
    let macAddress = '';

    // Find the first non-internal MAC address
    for (const key in netInterfaces) {
        const iface = netInterfaces[key][0];
        if (!iface.internal) {
            macAddress = iface.mac;
            break;
        }
    }

    // If no non-internal MAC address is found, fallback to a random value
    if (!macAddress) {
        macAddress = randomBytes(6).toString('hex').toUpperCase();
    }

    // Use MAC address and current timestamp to create a unique ID
    const timestamp = Date.now();
    const uniqueID = createHash('sha256')
        .update(macAddress + timestamp)
        .digest('hex');

    return uniqueID;
}


/**
 * Extracts the value after a specific pattern from a string using regular expressions.
 * @param {string} input - The input string.
 * @param {string} pattern - The pattern to match.
 * @returns {string|null} The value found after the pattern, or null if not found.
 */
export const extractValue = (input, pattern) => {
    const regex = new RegExp(`${pattern}`);
    const match = input.match(regex);
    return match ? match : null;
};