@page "/filelist"

<h1>Blazor.LocalFiles - File Select List</h1>

<FileSelectList @ref="fileSelectList" IsMultiple="true" FilesSelected="FilesSelectedHandler"></FileSelectList>

<div class="row">
    <div class="col-sm-6">
        <div>
            <button class="btn btn-primary" @onclick="@SelectFiles">Select Files</button>
        </div>
        @if (errorMessage != null)
        {

            <div class="alert alert-warning" role="alert">
                @errorMessage
                <button type="button" class="close" aria-label="Close" @onclick="@CloseErrorAlert">
                    <span aria-hidden="true">&times;</span>
                </button>
            </div>
        }
    </div>
</div>

@if (fileSelectList?.HasSelectedFiles == true)
{
    <hr />
    <table class="table table-condensed table-borderless">
        <thead>
            <tr>
                <th>Name</th>
                <th>Last Modified</th>
                <th>Size</th>
                <th>Is Loaded</th>
                <th>Loaded Size</th>
                <th></th>
            </tr>
        </thead>
        <tbody>
            @foreach (var selectedFile in fileSelectList.SelectedFiles)
            {
                var fileLoad = loadFiles[selectedFile.Name];
                <tr>
                    <td>@selectedFile.Name</td>
                    <td>@selectedFile.LastModified.ToLocalTime()</td>
                    <td>@selectedFile.Size</td>
                    <td>@fileLoad.IsLoaded</td>
                    <td>@fileLoad.LoadedSize</td>
                    <td>
                        <button class="btn btn-primary" @onclick="@(async () => await LoadFile(fileLoad))">Load File</button>
                        <button class="btn btn-outline-danger" @onclick="@(() => RemoveFile(selectedFile.Name))">Remove File</button>
                    </td>
                </tr>
            }
        </tbody>
    </table>
}

@code
{
    FileSelectList fileSelectList;

    Dictionary<string, LoadFile> loadFiles = new Dictionary<string, LoadFile>(StringComparer.OrdinalIgnoreCase);

    string errorMessage;

    void SelectFiles()
    {
        ResetErrorState();

        // Trigger the file selection dialog
        fileSelectList.SelectFiles();
    }

    Task FilesSelectedHandler(SelectedFile[] selectedFiles)
    {
        var newSelectedFiles = selectedFiles.Select(file => new LoadFile()
        {
            SelectedFile = file,
            IsLoaded = false,
            LoadedSize = 0
        }).ToArray();

        foreach(var file in newSelectedFiles)
        {
            loadFiles[file.SelectedFile.Name] = file;
        }

        return Task.CompletedTask;
    }

    async Task LoadFile(LoadFile file)
    {
        try
        {
            using (var fileStream = await fileSelectList.OpenFileStreamAsync(file.SelectedFile.Name))
            {
                var buffer = new System.IO.MemoryStream();
                await fileStream.CopyToAsync(buffer);
                file.IsLoaded = true;
                file.LoadedSize = (int)buffer.Length;
            }
        }
        catch(Exception ex)
        {
            errorMessage = ex.Message;
        }
    }

    void RemoveFile(string fileName)
    {
        fileSelectList.RemoveFile(fileName);
    }

    void CloseErrorAlert()
    {
        ResetErrorState();
    }

    void ResetErrorState()
    {
        errorMessage = null;
    }
}