using System;
using System.Collections.Generic;
using System.Text;
using System.Security.Cryptography;
using System.IO;
/**
* Copyright (c) 2018 Tencent Cloud. All rights reserved.
* 11/9/2018 9:53:39 PM
* bradyxiao
*/
namespace COSXML.Utils
{
    public sealed class DigestUtils
    {
        public static string GetSha1ToHexString(string content, Encoding encode)
        {
            return GetSha1ToHexString(encode.GetBytes(content));
        }

        public static string GetSha1ToHexString(byte[] content)
        {
            SHA1 sha1 = new SHA1CryptoServiceProvider();
            byte[] result = sha1.ComputeHash(content);
            sha1.Clear();
            var hexStr = new StringBuilder();
            foreach( byte b in result)
            {
                hexStr.Append(b.ToString("x2")); // to lower
            }

            return hexStr.ToString();
        }

        public static string GetSha1ToHexString(Stream inputStream)
        {
            SHA1 sha1 = new SHA1CryptoServiceProvider();
            byte[] result = sha1.ComputeHash(inputStream);
            sha1.Clear();
            var hexStr = new StringBuilder();
            foreach (byte b in result)
            {
                hexStr.Append(b.ToString("x2")); // to lower
            }

            return hexStr.ToString();
        }

        public static string GetHamcSha1ToHexString(string content, Encoding contentEncoding, string key, Encoding keyEncoding)
        {
            HMACSHA1 hmacSha1 = new HMACSHA1(keyEncoding.GetBytes(key));
            byte[] result = hmacSha1.ComputeHash(contentEncoding.GetBytes(content));
            hmacSha1.Clear();
            var hexStr = new StringBuilder();
            foreach (byte b in result)
            {
                hexStr.Append(b.ToString("x2")); // to lower
            }

            return hexStr.ToString();

        }

        public static string GetHamcSha1ToBase64(string content, Encoding contentEncoding, string key, Encoding keyEncoding)
        {
            HMACSHA1 hmacSha1 = new HMACSHA1(keyEncoding.GetBytes(key));
            byte[] result = hmacSha1.ComputeHash(contentEncoding.GetBytes(content));
            hmacSha1.Clear();
            return Convert.ToBase64String(result);
        }

        public static string GetMd5ToBase64(string content, Encoding encoding)
        {
            return GetMd5ToBase64(encoding.GetBytes(content));
        }

        public static string GetMd5ToBase64(byte[] content)
        {
            MD5 md5 = MD5.Create();
            byte[] result = md5.ComputeHash(content);
            md5.Clear();
            return Convert.ToBase64String(result);
        }

        public static string GetMd5ToBase64(Stream inStream)
        {
            MD5 md5 = MD5.Create();
            byte[] result = md5.ComputeHash(inStream);
            md5.Clear();
            return Convert.ToBase64String(result);
        }

        public static string GetMd5ToBase64(Stream inStream, long size)
        {
            int bufferSize = 1024 * 16;
            byte[] buffer = new byte[bufferSize];
            int readLength = 0;
            long total = 0L;
            byte[] data = new byte[bufferSize];
            MD5 md5 = MD5.Create();
            int count = (int)(size - total);
            while ((readLength = inStream.Read(buffer, 0, count > buffer.Length ? buffer.Length : count)) > 0)
            {
                md5.TransformBlock(buffer, 0, readLength, data, 0);
                total += readLength;
                count = (int)(size - total);
                if (count <= 0) break;
            }
            md5.TransformFinalBlock(buffer, 0, 0);
            string result = Convert.ToBase64String(md5.Hash);
            md5.Clear();
            return result;
        }

        public static string GetBase64(string content, Encoding encoding)
        {
            byte[] result = encoding.GetBytes(content);
            return Convert.ToBase64String(result);
        }
    }
}