/**
 * This file is part of the Meeds project (https://meeds.io/).
 *
 * Copyright (C) 2020 - 2025 Meeds Association contact@meeds.io
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
package io.meeds.chat.service.utils;

import java.security.SecureRandom;
import java.util.Random;

public class PasswordKeyGenerator {

  private PasswordKeyGenerator() {
  }

  public static String generatePassword(int length) {

    // minimum length of generated password is 8
    if (length < 8) {
      length = 8;
    }

    final char[] lowercase = "abcdefghijklmnopqrstuvwxyz".toCharArray();
    final char[] uppercase = "ABCDEFGJKLMNPRSTUVWXYZ".toCharArray();
    final char[] numbers = "0123456789".toCharArray();
    final char[] symbols = "^$?!@#%&".toCharArray();
    final char[] allAllowed = "abcdefghijklmnopqrstuvwxyzABCDEFGJKLMNPRSTUVWXYZ0123456789^$?!@#%&".toCharArray();

    Random random = new SecureRandom();

    StringBuilder password = new StringBuilder();

    for (int i = 0; i < length - 4; i++) {
      password.append(allAllowed[random.nextInt(allAllowed.length)]);
    }
    password.insert(random.nextInt(password.length()), lowercase[random.nextInt(lowercase.length)]);
    password.insert(random.nextInt(password.length()), uppercase[random.nextInt(uppercase.length)]);
    password.insert(random.nextInt(password.length()), numbers[random.nextInt(numbers.length)]);
    password.insert(random.nextInt(password.length()), symbols[random.nextInt(symbols.length)]);

    return password.toString();
  }
}

