using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LifePayment.Domain.Shared;

public static class GlobalRandom
{
    // 字符集
    private static readonly string LowerCase = "abcdefghijklmnopqrstuvwxyz";
    private static readonly string UpperCase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    private static readonly string Digits = "0123456789";
    private static readonly string Symbols = "~`!@#$%^&*\\|()_-+=\\、{}\\[\\]'\"<>?.,:;/";

    /// <summary>
    /// 获取指定位数的随机数
    /// </summary>
    /// <param name="length"></param>
    /// <returns></returns>
    public static string GetRandomNum(int length)
    {

        var ranInt = 0;
        var minAMax = GetMinAndMaxNumByLength(length);

        ranInt = Random.Shared.Next(minAMax.Min, minAMax.Max + 1);

        return ranInt.ToString().PadLeft(length, '0');
    }

    /// <summary>
    /// 获取指定位数的十进制数的最大值和最小值
    /// </summary>
    /// <param name="length"></param>
    /// <param name="isOneMin"></param>
    /// <returns></returns>
    /// <exception cref="ArgumentException"></exception>
    public static (int Min, int Max) GetMinAndMaxNumByLength(int length, bool minIsOne = true)
    {
        if (length <= 0) throw new ArgumentException("length必须大于等于0");

        if (length == 0) return (0, 0);

        var min = minIsOne ? 1 : (int)Math.Pow(10, length - 1);
        var max = (int)Math.Pow(10, length) - 1;
        return (min, max);
    }

    /// <summary>
    /// 根据指定长度和字符池获取指定长度的随机字符串
    /// </summary>
    /// <param name="length"></param>
    /// <param name="charPool"></param>
    /// <returns></returns>
    public static string GetRandomStrFromCharPool(int length, char[] charPool)
    {
        string result = null;

        if (length > 0 && charPool.IsNotNullOrEmpty())
        {
            Shuffle(charPool);
            for (int i = 0; i < length; i++)
            {
                result += charPool[Random.Shared.Next(0, charPool.Length)];
            }
        }

        return result;
    }

    /// <summary>
    /// 获取随机密码
    /// </summary>
    /// <param name="length"></param>
    /// <param name="charPool"></param>
    /// <returns></returns>
    public static string GetRandomPassword(int minLenth = 6, int maxLenth = 6)
    {
        // 生成一个合法的字符串长度
        int length = minLenth == maxLenth ? minLenth : Random.Shared.Next(minLenth, maxLenth + 1); // 6 到 16 的随机长度

        // 至少包含一个字母、数字和符号
        var sb = new StringBuilder();
        sb.Append(LowerCase[Random.Shared.Next(LowerCase.Length)]); // 加一个小写字母
        sb.Append(UpperCase[Random.Shared.Next(UpperCase.Length)]); // 加一个大写字母
        sb.Append(Digits[Random.Shared.Next(Digits.Length)]); // 加一个数字
        //sb.Append(Symbols[Random.Shared.Next(Symbols.Length)]); // 加一个符号

        // 填充其余字符
        var allChars = LowerCase + UpperCase + Digits;
        for (int i = sb.Length; i < length; i++)
        {
            sb.Append(allChars[Random.Shared.Next(allChars.Length)]);
        }

        // 打乱字符顺序，以确保字符种类不被集中在前面
        return new string(sb.ToString().OrderBy(c => Random.Shared.Next()).ToArray());
    }

    /// <summary>
    /// 随机洗牌
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="array"></param>
    public static void Shuffle<T>(T[] array)
    {
        Random rng = new Random();
        int n = array.Length;
        for (int i = n - 1; i > 0; i--)
        {
            int j = rng.Next(i + 1);
            (array[i], array[j]) = (array[j], array[i]); // 交换元素
        }
    }

}