// 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.Runtime.CompilerServices;

namespace CommunityToolkit.HighPerformance.Streams;

/// <summary>
/// A factory class to produce <see cref="MemoryStream{TSource}"/> instances.
/// </summary>
internal static partial class MemoryStream
{
    /// <summary>
    /// Validates the <see cref="Stream.Position"/> argument (it needs to be in the [0, length]) range.
    /// </summary>
    /// <param name="position">The new <see cref="Stream.Position"/> value being set.</param>
    /// <param name="length">The maximum length of the target <see cref="Stream"/>.</param>
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static void ValidatePosition(long position, int length)
    {
        if ((ulong)position > (ulong)length)
        {
            ThrowArgumentOutOfRangeExceptionForPosition();
        }
    }

    /// <summary>
    /// Validates the <see cref="Stream.Read(byte[],int,int)"/> or <see cref="Stream.Write(byte[],int,int)"/> arguments.
    /// </summary>
    /// <param name="buffer">The target array.</param>
    /// <param name="offset">The offset within <paramref name="buffer"/>.</param>
    /// <param name="count">The number of elements to process within <paramref name="buffer"/>.</param>
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static void ValidateBuffer(byte[]? buffer, int offset, int count)
    {
        if (buffer is null)
        {
            ThrowArgumentNullExceptionForBuffer();
        }

        if (offset < 0)
        {
            ThrowArgumentOutOfRangeExceptionForOffset();
        }

        if (count < 0)
        {
            ThrowArgumentOutOfRangeExceptionForCount();
        }

        if (offset + count > buffer!.Length)
        {
            ThrowArgumentExceptionForLength();
        }
    }

    /// <summary>
    /// Validates the <see cref="MemoryStream{TSource}.CanWrite"/> property.
    /// </summary>
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static void ValidateCanWrite(bool canWrite)
    {
        if (!canWrite)
        {
            ThrowNotSupportedException();
        }
    }

    /// <summary>
    /// Validates that a given <see cref="Stream"/> instance hasn't been disposed.
    /// </summary>
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static void ValidateDisposed(bool disposed)
    {
        if (disposed)
        {
            ThrowObjectDisposedException();
        }
    }
}