@(Html.Kendo().TabStrip()
      .Name("tabStrip1")
      .SelectedIndex(0)
      .Animation(animation => animation.Open(open => open.Fade(FadeDirection.In)))
      .Items(items =>
      {
	      items.Add().SpriteCssClasses("fa-duotone fa-clock-rotate-left").Text("History").Content(@<text>@Html.DisplayFor(m => m.History, "LetterHistory")</text>);
	      items.Add().SpriteCssClasses("fa-duotone fa-thumbs-up").Text("Approvers").Content(@<text>@Html.DisplayFor(m => m.Approvers, "LetterApprovers")</text>);
	      items.Add().SpriteCssClasses("fa-duotone fa-magnifying-glass").Text("Details").Content("");
		  items.Add().SpriteCssClasses("fa-duotone fa-link").Text("Attachments").Content(@<text>@await Component.InvokeAsync(viewName, new { LetterGuid = Model.IdCode.ToString() })</text>);
      })
)

<kendo-tabstrip name="tabStrip">
	<popup-animation>
		<open effects="fade:in" />
	</popup-animation>
	<items>
		<tabstrip-item text="History" icon-class="fa-duotone fa-clock-rotate-left" selected="true">
			<content>@Html.DisplayFor(m => m.History, "LetterHistory")</content>
		</tabstrip-item>

		<tabstrip-item text="Approvers" icon-class="fa-duotone fa-thumbs-up">
			<content></content>
		</tabstrip-item>

		<tabstrip-item text="Details" icon-class="fa-duotone fa-magnifying-glass">
			<content>@Html.DisplayFor(m => m.Approvers, "LetterApprovers")</content>
		</tabstrip-item>

		<tabstrip-item text="Attachments" icon-class="fa-duotone fa-link">
			<content>@await Component.InvokeAsync(viewName, new { LetterGuid = Model.IdCode.ToString() })</content>
		</tabstrip-item>
	</items>
</kendo-tabstrip>

@using DACRL.Portal.ColorAdmin.Controllers
@using DACRL.Portal.ColorAdmin.Extensions

@model Guid?

@{
    string[] extensions = { ".jpg", ".png", ".pdf", ".ppt", ".pptx", ".doc", ".docx", ".xls", ".xlsx" };
}

@Html.HiddenFor(m => m)

<kendo-upload name="letterFiles" multiple="true">
    <async save-url="@Url.Action(nameof(UploadController.ChunkSave), ControllerExtensions.Nameof<UploadController>())"
           remove-url="@Url.Action(nameof(UploadController.Remove), ControllerExtensions.Nameof<DashboardController>())"
           auto-upload="true"
           chunk-size="11000" />
    <validation allowed-extensions="@extensions" max-file-size="36700160" />
</kendo-upload>

@model LetterModel

@using (Html.BeginForm("", "Letter", FormMethod.Post))
{
	@Html.AntiForgeryToken()

	@Html.HiddenFor(m => m.IdCode)

	<div class="panel mt-20px" data-sortable-id="ui-widget-16">
		<div class="panel-heading bg-da-blue text-white">
			<h4 class="panel-title">RL Info</h4>
		</div>
		<div class="panel-body">
			@Html.EditorFor(m => m, "Letter")
		</div>
	</div>

	<div class="panel mt-20px" data-sortable-id="ui-widget-16">
		<div class="panel-heading bg-da-blue text-white">
			<h4 class="panel-title">Attachments</h4>
		</div>
		<div class="panel-body">
			@Html.EditorFor(m => m.IdCode, "LetterAttachmentsManage")
		</div>
	</div>
	
	<div class="row mt-3">
		<div class="col-md-1">
			<button type="submit" class="btn btn-primary w-100 me-5px" formaction="CreateSave" title="@(Model.IsUpdateCase ? "Update letter" : "Save letter")">@(Model.IsUpdateCase ? "Update" : "Save")</button>
		</div>
		<div class="col-md-1">
			<button type="submit" class="btn btn-default w-100" formaction="CreateSubmit" title="@(Model.IsUpdateCase ? "Update letter & submit" : "Save letter & submit")">Submit</button>
		</div>
	</div>
}

public class UploadController : BaseControllerWithAuth<UploadController>
{
    private readonly IWebHostEnvironment hostEnvironment;

    public UploadController(IWebHostEnvironment hostingEnvironment, IHttpContextAccessor httpContextAccess, IUserService userService) : base(httpContextAccess, userService) => hostEnvironment = hostingEnvironment;

    public async Task<ActionResult> ChunkSave([Bind(Prefix = "IdCode.letterFiles")] IEnumerable<IFormFile>? letterFiles, string? metaData, Guid? idCode)
    {
        try
        {
            if (metaData == null)
                return await Save(letterFiles);

            var chunkData = JsonSerializer.Deserialize<ChunkMetaDataModel>(metaData)!;

            if (letterFiles != null)
            {
                foreach (var file in letterFiles) AppendToFile(Path.Combine(hostEnvironment.WebRootPath, Constants.FileUploadPath, chunkData!.FileName), file, idCode?.ToString());
            }

            var fileBlob = new FileResultModel
            {
                uploaded = chunkData!.TotalChunks - 1 <= chunkData.ChunkIndex,
                fileUid  = chunkData.UploadUid
            };

            return Json(fileBlob);
        }
        catch (Exception ex)
        {
            Logger.LogError(ex, $"{nameof(UploadController)} => {nameof(ChunkSave)}: Error: {ex.Message}");
            throw;
        }
    }

    public ActionResult Remove(string[]? fileNames)
    {
        try
        {
            if (fileNames == null) return Content("");

            foreach (var fullName in fileNames)
            {
                var fileName     = Path.GetFileName(fullName);
                var physicalPath = Path.Combine(hostEnvironment.WebRootPath, Constants.FileUploadPath, fileName);

                if (System.IO.File.Exists(physicalPath)) System.IO.File.Delete(physicalPath);
            }

            return Content("");
        }
        catch (Exception ex)
        {
            Logger.LogError(ex, $"{nameof(UploadController)} => {nameof(Remove)}: Error: {ex.Message}");
            throw;
        }
    }

    private void AppendToFile(string fullPath, IFormFile content, string? idCode)
    {
        try
        {
            var basePath = Path.Combine(hostEnvironment.WebRootPath, Constants.FileUploadPath);

            if (!Directory.Exists(basePath)) Directory.CreateDirectory(basePath);

            var letterPath = Path.Combine(basePath, idCode!);

            if (!Directory.Exists(letterPath)) Directory.CreateDirectory(letterPath);

            using var stream = new FileStream(fullPath, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
            content.CopyTo(stream);
        }
        catch (IOException ex)
        {
            Logger.LogError(ex, $"{nameof(UploadController)} => {nameof(AppendToFile)}: Error: {ex.Message}");
            throw;
        }
        catch (Exception ex)
        {
            Logger.LogError(ex, $"{nameof(UploadController)} => {nameof(AppendToFile)}: Error: {ex.Message}");
            throw;
        }
    }

    private async Task<ActionResult> Save([Bind(Prefix = "IdCode.letterFiles")] IEnumerable<IFormFile>? letterFiles)
    {
        try
        {
            if (letterFiles == null) return Content("");

            foreach (var file in letterFiles)
            {
                var fileContent  = ContentDispositionHeaderValue.Parse(file.ContentDisposition);
                var fileName     = Path.GetFileName(fileContent.FileName!.Trim('"'));
                var physicalPath = Path.Combine(hostEnvironment.WebRootPath, Constants.FileUploadPath, fileName);

                await using var fileStream = new FileStream(physicalPath, FileMode.Create);
                await file.CopyToAsync(fileStream);
            }

            return Content("");
        }
        catch (Exception ex)
        {
            Logger.LogError(ex, $"{nameof(UploadController)} => {nameof(Save)}: Error: {ex.Message}");
            throw;
        }
    }

}

var chunkData = JsonSerializer.Deserialize<ChunkMetaDataModel>(metaData)!;

columns.Template("my anchor tag html goes here with template syntax for #:SomePropValue#")

columns.Command(action => {action.Custom("View Application").Click("myJavaScriptFunction")