PasswordManager.java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class PasswordManager {
 private List<Account> accounts;
 private String masterPassword;
 private CryptoUtils cryptoUtils;

 public PasswordManager(String masterPassword) {
 this.masterPassword = masterPassword;
 this.accounts = new ArrayList<>();
 this.cryptoUtils = new CryptoUtils(masterPassword);
 }

 public void addAccount(Account account) {
 accounts.add(account);
 }

 public List<Account> getAccounts() {
 return accounts;
 }

 public String generatePassword(int length) {
 if (length < 8) {
 length = 8;
 }

 String uppercaseChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 String lowercaseChars = "abcdefghijklmnopqrstuvwxyz";
 String numberChars = "0123456789";
 String specialChars = "!@#$%^&*()_-+=<>?";
 String allChars = uppercaseChars + lowercaseChars + numberChars + specialChars;

 SecureRandom random = new SecureRandom();
 StringBuilder password = new StringBuilder();

 // Ensure at least one character from each group
 password.append(uppercaseChars.charAt(random.nextInt(uppercaseChars.length())));
 password.append(lowercaseChars.charAt(random.nextInt(lowercaseChars.length())));
 password.append(numberChars.charAt(random.nextInt(numberChars.length())));
 password.append(specialChars.charAt(random.nextInt(specialChars.length())));

 // Fill the rest with random characters
 for (int i = 4; i < length; i++) {
 password.append(allChars.charAt(random.nextInt(allChars.length())));
 }

 // Shuffle the password characters
 char[] passwordArray = password.toString().toCharArray();
 for (int i = passwordArray.length - 1; i > 0; i--) {
 int index = random.nextInt(i + 1);
 char temp = passwordArray[index];
 passwordArray[index] = passwordArray[i];
 passwordArray[i] = temp;
 }

 return new String(passwordArray);
 }

 public void saveToFile(String filename) throws Exception {
 try (BufferedWriter writer = new BufferedWriter(new FileWriter(filename))) {
 for (Account account : accounts) {
 String plainText = account.toDataString();
 String encrypted = cryptoUtils.encrypt(plainText);
 writer.write(encrypted);
 writer.newLine();
 }
 }
 }

 public void loadFromFile(String filename) throws Exception {
 accounts.clear();
 try (BufferedReader reader = new BufferedReader(new FileReader(filename))) {
 String line;
 while ((line = reader.readLine()) != null) {
 try {
 String decrypted = cryptoUtils.decrypt(line);
 Account account = Account.fromString(decrypted);
 accounts.add(account);
 } catch (Exception e) {
 throw new Exception("Failed to decrypt data. Incorrect master password or corrupted file.");
 }
 }
 
 // Sort accounts by website name for better organization
 sortAccountsByWebsite();
 } catch (IOException e) {
 throw new Exception("Error reading file: " + e.getMessage());
 }
 }
 
 public void sortAccountsByWebsite() {
 Collections.sort(accounts, Comparator.comparing(Account::getWebsite, String.CASE_INSENSITIVE_ORDER));
 }
 
 public List<Account> searchAccounts(String searchTerm) {
 List<Account> results = new ArrayList<>();
 String lowerSearchTerm = searchTerm.toLowerCase();
 
 for (Account account : accounts) {
 if (account.getWebsite().toLowerCase().contains(lowerSearchTerm) ||
 account.getUsername().toLowerCase().contains(lowerSearchTerm)) {
 results.add(account);
 }
 }
 
 return results;
 }
}