chapter-organizer/WebApp/Components/Shared/Components/PageNoteButton.razor

@namespace WebApp.Components.Shared.Components
@inject INotesService NotesService
@inject IDialogService DialogService
@implements IAsyncDisposable

<div @ref="_anchorElement"
     @onmouseenter="@(() => { if (_hasContent) _popoverOpen = true; })"
     @onmouseleave="@(() => _popoverOpen = false)"
     style="display: inline-block;">
    <MudButton StartIcon="@IconValue"
              OnClick="OpenDialog"
              Variant="@Variant"
              Size="@Size"
              Color="@ButtonColor"
              Tooltip="@TooltipText"
              Class="@MarkdownHelper.GetNoteColorClass(_noteId)">
        @if (!string.IsNullOrEmpty(ButtonText))
        {
            @ButtonText
        }
    </MudButton>
</div>
<MudPopover @bind-Open="_popoverOpen"
            AnchorOrigin="Origin.BottomCenter"
            TransformOrigin="Origin.TopCenter"
            Elevation="8"
            Anchor="@_anchorElement">
    <ChildContent>
        @if (_hasContent && !string.IsNullOrWhiteSpace(_noteContent))
        {
            <MudPaper Elevation="0" 
                     Class="pa-3" 
                     Style="max-width: 500px; max-height: 400px; overflow-y: auto;"
                     @onmouseenter="@(() => _popoverOpen = true)"
                     @onmouseleave="@(() => _popoverOpen = false)">
                <MudText Typo="Typo.subtitle1" Class="mb-2">@PageIdentifier</MudText>
                <MudDivider Class="my-2" />
                <div class="markdown-content" style="max-height: 350px; overflow-y: auto;">
                    @((MarkupString)MarkdownHelper.ToHtml(_noteContent))
                </div>
            </MudPaper>
        }
    </ChildContent>
</MudPopover>

@code {
    [Parameter]
    public string PageIdentifier { get; set; } = null!;

    [Parameter]
    public string? Icon { get; set; }

    [Parameter]
    public Variant Variant { get; set; } = Variant.Outlined;

    [Parameter]
    public Size Size { get; set; } = Size.Medium;

    [Parameter]
    public string? ButtonText { get; set; }

    [Parameter]
    public string? Tooltip { get; set; }

    private string IconValue => Icon ?? Icons.Material.Filled.Note;
    private string TooltipText => Tooltip ?? $"Page notes for {PageIdentifier}";
    private bool _hasContent = false;
    private int _noteId = 0;
    private string _noteContent = string.Empty;
    private bool _popoverOpen = false;
    private ElementReference _anchorElement;
    private Color ButtonColor => _hasContent ? Color.Success : (Variant == Variant.Filled ? Color.Primary : Color.Default);
    private CancellationTokenSource? _cancellationTokenSource;
    private bool _isDisposed = false;

    protected override void OnInitialized()
    {
        _cancellationTokenSource = new CancellationTokenSource();
    }

    protected override async Task OnInitializedAsync()
    {
        await CheckNoteContent();
    }

    private async Task CheckNoteContent()
    {
        if (_isDisposed) return;

        try
        {
            var note = await NotesService.GetPageNoteAsync(PageIdentifier);
            _hasContent = note != null && !string.IsNullOrWhiteSpace(note.Content);
            _noteId = note?.Id ?? 0;
            _noteContent = note?.Content ?? string.Empty;
            
            if (!_isDisposed)
            {
                StateHasChanged();
            }
        }
        catch (TaskCanceledException)
        {
            // Component was disposed, ignore
        }
        catch (JSDisconnectedException)
        {
            // JS connection lost, ignore
        }
        catch (Exception)
        {
            // Error checking note - ignore
        }
    }

    private async Task OpenDialog()
    {
        if (_isDisposed) return;

        try
        {
            var parameters = new DialogParameters
            {
                ["PageIdentifier"] = PageIdentifier
            };

            var options = new DialogOptions
            {
                MaxWidth = MaxWidth.Medium,
                FullWidth = true,
                CloseButton = true
            };

            var dialog = await DialogService.ShowAsync<PageNoteDialog>($"Page Notes: {PageIdentifier}", parameters, options);
            var result = await dialog.Result;
            
            // Always refresh content indicator after dialog closes
            // (content may have been saved even if dialog was closed with Cancel)
            if (!_isDisposed)
            {
                await CheckNoteContent();
            }
        }
        catch (TaskCanceledException)
        {
            // Component was disposed, ignore
        }
        catch (JSDisconnectedException)
        {
            // JS connection lost, ignore
        }
        catch (Exception)
        {
            // Error opening dialog - could show snackbar if we had access
        }
    }

    public async ValueTask DisposeAsync()
    {
        if (!_isDisposed)
        {
            _isDisposed = true;
            _cancellationTokenSource?.Cancel();
            _cancellationTokenSource?.Dispose();
            _cancellationTokenSource = null;
        }
        await ValueTask.CompletedTask;
    }
}