// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Microsoft.Net.Http.Headers;
 
namespace Microsoft.AspNetCore.WebUtilities;
 
/// <summary>
/// Various extensions for converting multipart sections
/// </summary>
public static class MultipartSectionConverterExtensions
{
    /// <summary>
    /// Converts the section to a file section
    /// </summary>
    /// <param name="section">The section to convert</param>
    /// <returns>A file section</returns>
    public static FileMultipartSection? AsFileSection(this MultipartSection section)
    {
        ArgumentNullException.ThrowIfNull(section);
 
        try
        {
            return new FileMultipartSection(section);
        }
        catch
        {
            return null;
        }
    }
 
    /// <summary>
    /// Converts the section to a form section
    /// </summary>
    /// <param name="section">The section to convert</param>
    /// <returns>A form section</returns>
    public static FormMultipartSection? AsFormDataSection(this MultipartSection section)
    {
        ArgumentNullException.ThrowIfNull(section);
 
        try
        {
            return new FormMultipartSection(section);
        }
        catch
        {
            return null;
        }
    }
 
    /// <summary>
    /// Retrieves and parses the content disposition header from a section
    /// </summary>
    /// <param name="section">The section from which to retrieve</param>
    /// <returns>A <see cref="ContentDispositionHeaderValue"/> if the header was found, null otherwise</returns>
    public static ContentDispositionHeaderValue? GetContentDispositionHeader(this MultipartSection section)
    {
        if (!ContentDispositionHeaderValue.TryParse(section.ContentDisposition, out var header))
        {
            return null;
        }
 
        return header;
    }
}