// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
namespace Microsoft.AspNetCore.Components.Forms;
 
public class InputFileChangeEventArgsTest
{
    [Fact]
    public void SuppliesNumberOfFiles()
    {
        var emptySet = new InputFileChangeEventArgs(Array.Empty<IBrowserFile>());
        Assert.Equal(0, emptySet.FileCount);
 
        var twoItemSet = new InputFileChangeEventArgs(new[] { new BrowserFile(), new BrowserFile() });
        Assert.Equal(2, twoItemSet.FileCount);
    }
 
    [Fact]
    public void File_CanSupplySingle()
    {
        var file = new BrowserFile();
        var instance = new InputFileChangeEventArgs(new[] { file });
        Assert.Same(file, instance.File);
    }
 
    [Fact]
    public void File_ThrowsIfZeroFiles()
    {
        var instance = new InputFileChangeEventArgs(Array.Empty<IBrowserFile>());
        var ex = Assert.Throws<InvalidOperationException>(() => instance.File);
        Assert.StartsWith("No file was supplied", ex.Message);
    }
 
    [Fact]
    public void File_ThrowsIfMultipleFiles()
    {
        var instance = new InputFileChangeEventArgs(new[] { new BrowserFile(), new BrowserFile() });
        var ex = Assert.Throws<InvalidOperationException>(() => instance.File);
        Assert.StartsWith("More than one file was supplied", ex.Message);
    }
 
    [Fact]
    public void GetMultipleFiles_CanSupplyEmpty()
    {
        var instance = new InputFileChangeEventArgs(Array.Empty<IBrowserFile>());
        Assert.Empty(instance.GetMultipleFiles());
    }
 
    [Fact]
    public void GetMultipleFiles_CanSupplyFiles()
    {
        var files = new[] { new BrowserFile(), new BrowserFile() };
        var instance = new InputFileChangeEventArgs(files);
        Assert.Same(files, instance.GetMultipleFiles());
    }
 
    [Fact]
    public void GetMultipleFiles_ThrowsIfTooManyFiles()
    {
        var files = new[] { new BrowserFile(), new BrowserFile() };
        var instance = new InputFileChangeEventArgs(files);
        var ex = Assert.Throws<InvalidOperationException>(() => instance.GetMultipleFiles(1));
        Assert.Equal($"The maximum number of files accepted is 1, but 2 were supplied.", ex.Message);
    }
}