// 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 Microsoft.CodeAnalysis.Text;
using System;
using System.Collections.Generic;
using System.Text;
 
namespace Roslyn.Test.Utilities.Syntax
{
    internal sealed class RandomizedSourceText : SourceText
    {
        private readonly char[] _buffer = new char[2048];
 
        public RandomizedSourceText()
        {
            var random = new Random(12345);
            for (var i = 0; i < _buffer.Length; i++)
            {
                _buffer[i] = (char)random.Next();
            }
        }
 
        public override char this[int position] => _buffer[position % _buffer.Length];
 
        public override Encoding Encoding => Encoding.UTF8;
 
        public override int Length
        {
            get
            {
                return 40 * 1000 * 1000;
            }
        }
 
        public override void CopyTo(int sourceIndex, char[] destination, int destinationIndex, int count)
        {
            for (var i = 0; i < count; i++)
            {
                destination[destinationIndex + i] = this[sourceIndex + i];
            }
        }
    }
}