/*
 *                     GNU AFFERO GENERAL PUBLIC LICENSE
 *                       Version 3, 19 November 2007
 *  Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
 *  Everyone is permitted to copy and distribute verbatim copies
 *  of this license document, but changing it is not allowed.
 */

using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;

namespace UVtools.Core.Extensions
{
    public static class StreamExtensions
    {
        /// <summary>
        /// Converts stream into byte array
        /// </summary>
        /// <param name="stream">Input</param>
        /// <returns>Byte array data</returns>
        public static byte[] ToArray(this Stream stream)
        {
            using var memoryStream = new MemoryStream();
            stream.CopyTo(memoryStream);
            return memoryStream.ToArray();
        }

        public static async Task CopyToAsync(this Stream source, Stream destination, int bufferSize, IProgress<long> progress = null, CancellationToken cancellationToken = default)
        {
            if (source == null)
                throw new ArgumentNullException(nameof(source));
            if (!source.CanRead)
                throw new ArgumentException("Has to be readable", nameof(source));
            if (destination == null)
                throw new ArgumentNullException(nameof(destination));
            if (!destination.CanWrite)
                throw new ArgumentException("Has to be writable", nameof(destination));
            if (bufferSize < 0)
                throw new ArgumentOutOfRangeException(nameof(bufferSize));

            var buffer = new byte[bufferSize];
            long totalBytesRead = 0;
            int bytesRead;
            while ((bytesRead = await source.ReadAsync(buffer.AsMemory(0, buffer.Length), cancellationToken).ConfigureAwait(false)) != 0)
            {
                await destination.WriteAsync(buffer.AsMemory(0, bytesRead), cancellationToken).ConfigureAwait(false);
                totalBytesRead += bytesRead;
                progress?.Report(totalBytesRead);
            }
        }
    }
}