using System.Security.Cryptography;
using System.Text;

namespace ConsoleApp2.Helpers;

public static class HashExtensions
{
    /// <summary>
    /// 计算32位MD5码
    /// </summary>
    /// <param name="word">字符串</param>
    /// <param name="toUpper">返回哈希值格式 true：英文大写，false：英文小写</param>
    /// <returns></returns>
    public static string ToMd5Hash(this string word, bool toUpper = true)
    {
        try
        {
            var MD5CSP = MD5.Create();
            var bytValue = Encoding.UTF8.GetBytes(word);
            var bytHash = MD5CSP.ComputeHash(bytValue);
            MD5CSP.Clear();
            //根据计算得到的Hash码翻译为MD5码
            var sHash = "";
            foreach (var t in bytHash)
            {
                long i = t / 16;
                var sTemp = i > 9 ? ((char)(i - 10 + 0x41)).ToString() : ((char)(i + 0x30)).ToString();
                i = t % 16;
                if (i > 9)
                {
                    sTemp += ((char)(i - 10 + 0x41)).ToString();
                }
                else
                {
                    sTemp += ((char)(i + 0x30)).ToString();
                }

                sHash += sTemp;
            }

            //根据大小写规则决定返回的字符串
            return toUpper ? sHash : sHash.ToLower();
        }
        catch (System.Exception ex)
        {
            throw new System.Exception(ex.Message);
        }
    }

    public static string ToMd5Hash(this Stream stream, bool toUpper = true)
    {
        using var md5Hash = MD5.Create();
        var bytes = md5Hash.ComputeHash(stream);
        return ToHashString(bytes, toUpper);
    }

    /// <summary>
    /// 计算SHA-1码
    /// </summary>
    /// <param name="word">字符串</param>
    /// <param name="toUpper">返回哈希值格式 true：英文大写，false：英文小写</param>
    /// <returns></returns>
    public static string ToSHA1Hash(this string word, bool toUpper = true)
    {
        try
        {
            var SHA1CSP = SHA1.Create();
            var bytValue = Encoding.UTF8.GetBytes(word);
            var bytHash = SHA1CSP.ComputeHash(bytValue);
            SHA1CSP.Clear();
            //根据计算得到的Hash码翻译为SHA-1码
            var sHash = "";
            foreach (var t in bytHash)
            {
                long i = t / 16;
                var sTemp = i > 9 ? ((char)(i - 10 + 0x41)).ToString() : ((char)(i + 0x30)).ToString();
                i = t % 16;
                if (i > 9)
                {
                    sTemp += ((char)(i - 10 + 0x41)).ToString();
                }
                else
                {
                    sTemp += ((char)(i + 0x30)).ToString();
                }

                sHash += sTemp;
            }

            //根据大小写规则决定返回的字符串
            return toUpper ? sHash : sHash.ToLower();
        }
        catch (System.Exception ex)
        {
            throw new System.Exception(ex.Message);
        }
    }

    /// <summary>
    /// 计算SHA-256码
    /// </summary>
    /// <param name="word">字符串</param>
    /// <param name="toUpper">返回哈希值格式 true：英文大写，false：英文小写</param>
    /// <returns></returns>
    public static string ToSHA256Hash(this string word, bool toUpper = true)
    {
        try
        {
            var SHA256CSP = SHA256.Create();
            var bytValue = Encoding.UTF8.GetBytes(word);
            var bytHash = SHA256CSP.ComputeHash(bytValue);
            SHA256CSP.Clear();
            //根据计算得到的Hash码翻译为SHA-1码
            var sHash = "";
            foreach (var t in bytHash)
            {
                long i = t / 16;
                var sTemp = i > 9 ? ((char)(i - 10 + 0x41)).ToString() : ((char)(i + 0x30)).ToString();
                i = t % 16;
                if (i > 9)
                {
                    sTemp += ((char)(i - 10 + 0x41)).ToString();
                }
                else
                {
                    sTemp += ((char)(i + 0x30)).ToString();
                }

                sHash += sTemp;
            }

            //根据大小写规则决定返回的字符串
            return toUpper ? sHash : sHash.ToLower();
        }
        catch (System.Exception ex)
        {
            throw new System.Exception(ex.Message);
        }
    }

    /// <summary>
    /// 计算SHA-256码
    /// </summary>
    /// <param name="stream"></param>
    /// <param name="toUpper"></param>
    /// <returns></returns>
    public static string ToSHA256Hash(this Stream stream, bool toUpper = true)
    {
        using var sha256Hash = SHA256.Create();
        var bytes = sha256Hash.ComputeHash(stream);
        return ToHashString(bytes, toUpper);
    }

    /// <summary>
    /// 计算SHA-384码
    /// </summary>
    /// <param name="word">字符串</param>
    /// <param name="toUpper">返回哈希值格式 true：英文大写，false：英文小写</param>
    /// <returns></returns>
    public static string ToSHA384Hash(this string word, bool toUpper = true)
    {
        try
        {
            var SHA384CSP = SHA384.Create();
            var bytValue = Encoding.UTF8.GetBytes(word);
            var bytHash = SHA384CSP.ComputeHash(bytValue);
            SHA384CSP.Clear();
            //根据计算得到的Hash码翻译为SHA-1码
            var sHash = "";
            foreach (var t in bytHash)
            {
                long i = t / 16;
                var sTemp = i > 9 ? ((char)(i - 10 + 0x41)).ToString() : ((char)(i + 0x30)).ToString();
                i = t % 16;
                if (i > 9)
                {
                    sTemp += ((char)(i - 10 + 0x41)).ToString();
                }
                else
                {
                    sTemp += ((char)(i + 0x30)).ToString();
                }

                sHash += sTemp;
            }

            //根据大小写规则决定返回的字符串
            return toUpper ? sHash : sHash.ToLower();
        }
        catch (System.Exception ex)
        {
            throw new System.Exception(ex.Message);
        }
    }

    /// <summary>
    /// 计算SHA-512码
    /// </summary>
    /// <param name="word">字符串</param>
    /// <param name="toUpper">返回哈希值格式 true：英文大写，false：英文小写</param>
    /// <returns></returns>
    public static string ToSHA512Hash(this string word, bool toUpper = true)
    {
        try
        {
            var SHA512CSP = SHA512.Create();
            var bytValue = Encoding.UTF8.GetBytes(word);
            var bytHash = SHA512CSP.ComputeHash(bytValue);
            SHA512CSP.Clear();
            //根据计算得到的Hash码翻译为SHA-1码
            var sHash = "";
            foreach (var t in bytHash)
            {
                long i = t / 16;
                var sTemp = i > 9 ? ((char)(i - 10 + 0x41)).ToString() : ((char)(i + 0x30)).ToString();
                i = t % 16;
                if (i > 9)
                {
                    sTemp += ((char)(i - 10 + 0x41)).ToString();
                }
                else
                {
                    sTemp += ((char)(i + 0x30)).ToString();
                }

                sHash += sTemp;
            }

            //根据大小写规则决定返回的字符串
            return toUpper ? sHash : sHash.ToLower();
        }
        catch (System.Exception ex)
        {
            throw new System.Exception(ex.Message);
        }
    }

    private static string ToHashString(byte[] bytes, bool toUpper = true)
    {
        var builder = new StringBuilder();
        foreach (var t in bytes)
        {
            builder.Append(t.ToString("x2"));
        }

        var str = builder.ToString();
        return toUpper ? str.ToUpper() : str.ToLower();
    }
}