// Admin.NET 项目的版权、商标、专利和其他相关权利均受相应法律法规的保护。使用本项目应遵守相关法律法规和许可证的要求。
//
// 本项目主要遵循 MIT 许可证和 Apache 许可证（版本 2.0）进行分发和使用。许可证位于源代码树根目录中的 LICENSE-MIT 和 LICENSE-APACHE 文件。
//
// 不得利用本项目从事危害国家安全、扰乱社会秩序、侵犯他人合法权益等法律法规禁止的活动！任何基于本项目二次开发而产生的一切法律纠纷和责任，我们不承担任何责任！

namespace Admin.NET.Core;

/// <summary>
/// 文件流扩展方法
/// </summary>
public static class StreamExtensions
{
    /// <summary>
    /// 获取文件流字节
    /// </summary>
    /// <param name="stream"></param>
    /// <returns></returns>
    public static byte[] GetAllBytes(this Stream stream)
    {
        if (stream is MemoryStream memoryStream)
        {
            return memoryStream.ToArray();
        }

        using var ms = stream.CreateMemoryStream();
        return ms.ToArray();
    }

    /// <summary>
    /// 获取文件流字节，异步
    /// </summary>
    /// <param name="stream"></param>
    /// <param name="cancellationToken"></param>
    /// <returns></returns>
    public static async Task<byte[]> GetAllBytesAsync(this Stream stream, CancellationToken cancellationToken = default)
    {
        if (stream is MemoryStream memoryStream)
        {
            return memoryStream.ToArray();
        }

        using var ms = await stream.CreateMemoryStreamAsync(cancellationToken);
        return ms.ToArray();
    }

    /// <summary>
    /// 复制文件流，异步
    /// </summary>
    /// <param name="stream"></param>
    /// <param name="destination"></param>
    /// <param name="cancellationToken"></param>
    /// <returns></returns>
    public static Task CopyToAsync(this Stream stream, Stream destination, CancellationToken cancellationToken)
    {
        if (stream.CanSeek)
        {
            stream.Position = 0;
        }

        // 81920 已经是默认值，但是需要设置才能传递 cancellationToken
        return stream.CopyToAsync(destination, 81920, cancellationToken);
    }

    /// <summary>
    /// 创建内存流
    /// </summary>
    /// <param name="stream"></param>
    /// <returns></returns>
    public static MemoryStream CreateMemoryStream(this Stream stream)
    {
        if (stream.CanSeek)
        {
            stream.Position = 0;
        }

        MemoryStream memoryStream = new();
        stream.CopyTo(memoryStream);

        if (stream.CanSeek)
        {
            stream.Position = 0;
        }

        memoryStream.Position = 0;
        return memoryStream;
    }

    /// <summary>
    /// 创建内存流，异步
    /// </summary>
    /// <param name="stream"></param>
    /// <param name="cancellationToken"></param>
    /// <returns></returns>
    public static async Task<MemoryStream> CreateMemoryStreamAsync(this Stream stream, CancellationToken cancellationToken = default)
    {
        if (stream.CanSeek)
        {
            stream.Position = 0;
        }

        MemoryStream memoryStream = new();
        await stream.CopyToAsync(memoryStream, cancellationToken);

        if (stream.CanSeek)
        {
            stream.Position = 0;
        }

        memoryStream.Position = 0;
        return memoryStream;
    }
}