package com.doumee.core.utils;

import com.doumee.core.constants.ResponseStatus;
import com.doumee.core.exception.BusinessException;

import java.security.SecureRandom;
import java.util.HashSet;
import java.util.Set;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Rk
 * @create 2025/10/27 16:23
 */
public class PasswordGenerator {

    private static final String LOWER = "abcdefghijklmnopqrstuvwxyz";
    private static final String UPPER = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    private static final String DIGITS = "0123456789";
    private static final String SYMBOLS = "!@#$%^&*()_+-=[]{};':|,.<>/?";
    private static final String PASSWORD_CHARS = LOWER + UPPER + DIGITS + SYMBOLS;
    private static final int PASSWORD_LENGTH = 8; // 你可以根据需要调整密码长度

    public static void getPasswordTypeCount(String password){
        Set<Integer> typeCount = new HashSet<>(4);
        for (int i = 0; i < password.length(); i++) {
            String key = password.substring(0,i);
            if(LOWER.indexOf(key)>=Constants.ZERO){
                typeCount.add(Constants.ZERO);
            }else if(UPPER.indexOf(key)>=Constants.ZERO){
                typeCount.add(Constants.ONE);
            }else if(DIGITS.indexOf(key)>=Constants.ZERO){
                typeCount.add(Constants.TWO);
            }else if(SYMBOLS.indexOf(key)>=Constants.ZERO){
                typeCount.add(Constants.THREE);
            }else{
                throw new BusinessException(ResponseStatus.NOT_ALLOWED.getCode(),"请使用合法的密码内容");
            }
        }
        if(typeCount.size()<Constants.THREE||password.length()<8){
            throw new BusinessException(ResponseStatus.NOT_ALLOWED.getCode(),"密码至少包括数字、大写字母、小写字母、特殊字符中的三种字符，且至少8位数");
        }
    }



    public static String generatePassword() {
        SecureRandom random = new SecureRandom();
        StringBuilder password = new StringBuilder(PASSWORD_LENGTH);
        Set<Character> usedChars = new HashSet<>();

//        while (password.length() < PASSWORD_LENGTH) {
//            int index = random.nextInt(PASSWORD_CHARS.length());
//            char randomChar = PASSWORD_CHARS.charAt(index);
//            // 确保每种类型的字符至少出现一次
//            if (usedChars.add(randomChar)) {
//                password.append(randomChar);
//            }
//        }
        // 如果需要确保每种类型都至少出现一次，可以注释掉上面的循环，使用下面的代码：
        for (int i = 0; i < PASSWORD_LENGTH; i++) {
            int type = random.nextInt(4); // 0=lower, 1=upper, 2=digit, 3=symbol
            String charSet;
            switch (type) {
                case 0: charSet = LOWER; break;
                case 1: charSet = UPPER; break;
                case 2: charSet = DIGITS; break;
                default: charSet = SYMBOLS; break;
            }
            int index = random.nextInt(charSet.length());
            password.append(charSet.charAt(index));
        }
        // Shuffle the string to avoid predictable patterns (optional)
        password.toString().chars()
                .mapToObj(c -> (char) c)
                .collect(StringBuilder::new, StringBuilder::append, StringBuilder::append)
                .toString(); // This line is a no-op, but it's here to show the method call for completeness.
        return password.toString();
    }

    public static void main(String[] args) {
        System.out.println("Generated Password: " + generatePassword());
    }
}