// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System.IO;
using System.Security.Cryptography;
using System.Text;
using Microsoft.Xml;
 
namespace System.IdentityModel
{
    internal abstract class CanonicalFormWriter
    {
        // internal static readonly UTF8Encoding Utf8WithoutPreamble = new UTF8Encoding(encoderShouldEmitUTF8Identifier = false);
        internal static readonly Encoding Utf8WithoutPreamble = Encoding.UTF8;
 
 
        protected static void EncodeAndWrite(Stream stream, byte[] workBuffer, string s)
        {
            if (s.Length > workBuffer.Length)
            {
                EncodeAndWrite(stream, s);
                return;
            }
 
            for (int i = 0; i < s.Length; i++)
            {
                char c = s[i];
                if (c < 127)
                {
                    workBuffer[i] = (byte)c;
                }
                else
                {
                    EncodeAndWrite(stream, s);
                    return;
                }
            }
 
            stream.Write(workBuffer, 0, s.Length);
        }
 
        protected static void EncodeAndWrite(Stream stream, byte[] workBuffer, char[] chars)
        {
            EncodeAndWrite(stream, workBuffer, chars, chars.Length);
        }
 
        protected static void EncodeAndWrite(Stream stream, byte[] workBuffer, char[] chars, int count)
        {
            if (count > workBuffer.Length)
            {
                EncodeAndWrite(stream, chars, count);
                return;
            }
 
            for (int i = 0; i < count; i++)
            {
                char c = chars[i];
                if (c < 127)
                {
                    workBuffer[i] = (byte)c;
                }
                else
                {
                    EncodeAndWrite(stream, chars, count);
                    return;
                }
            }
 
            stream.Write(workBuffer, 0, count);
        }
 
        private static void EncodeAndWrite(Stream stream, string s)
        {
            byte[] buffer = CanonicalFormWriter.Utf8WithoutPreamble.GetBytes(s);
            stream.Write(buffer, 0, buffer.Length);
        }
 
        private static void EncodeAndWrite(Stream stream, char[] chars, int count)
        {
            byte[] buffer = CanonicalFormWriter.Utf8WithoutPreamble.GetBytes(chars, 0, count);
            stream.Write(buffer, 0, buffer.Length);
        }
    }
}