@using System.IO
@inject IJSRuntime JSRuntimeInstance
@inject HttpClient HttpClient
@inject NavigationManager NavigationManager

<PageTitle>Home</PageTitle>

<p>
    <TelerikButton OnClick="@OnDownloadExportedFileClick">Get file with GetFileAsync and download</TelerikButton>
</p>

<strong>@TestResult</strong>

<br />
<br />

<TelerikPdfViewer @ref="@PdfViewerRef"
                    Data="@PdfViewerData"
                    AnnotationMode="@PdfViewerAnnotationMode.EnableForms"
                    Height="400px">
</TelerikPdfViewer>

@code {
    #nullable enable

    private TelerikPdfViewer? PdfViewerRef { get; set; }
    private byte[]? PdfViewerData { get; set; }

    private string TestResult { get; set; } = string.Empty;

    public async Task OnDownloadExportedFileClick()
    {
        var result = await PdfViewerRef.GetFileAsync();

        TestResult = $"First PDF Viewer GetFileAsync() returned {result} at {DateTime.Now.ToString("HH:mm:ss")}";

        var base64String = Convert.ToBase64String(result);
        var dataUrl = ToDataUrl("application/pdf", base64String);
        _ = SaveFileAsDataUrlAsync("export.pdf", dataUrl);
    }

    private protected ValueTask SaveFileAsDataUrlAsync(string fileName, string dataUrl)
    {
        return InvokeVoidAsync("saveFile", fileName, dataUrl);
    }

    protected virtual ValueTask InvokeVoidAsync(string methodName, params object[] args)
    {
        try
        {
            return JSRuntimeInstance.InvokeVoidAsync($"TelerikBlazor.{methodName}", args);
        }
        catch (Exception)
        {
            return default;
        }
    }

    private protected string ToDataUrl(string mimeType, string base64String)
    {
        return $"data:{mimeType};base64,{base64String}";
    }

    protected override async Task OnInitializedAsync()
    {
        PdfViewerData = System.IO.File.ReadAllBytes(@"pdf-viewer-form-filling-original.pdf");
        await Task.Delay(1);
    }
}