@page "/docs/{Page}"

@using Markdig
@inject HttpClient Http
@inject NavigationManager Nav
@inject IJSRuntime JS
@implements IDisposable

<PageTitle>Docs: @Page</PageTitle>

<div class="min-h-screen bg-zinc-950 text-zinc-200 font-mono p-6 space-y-6">

    <!-- Header -->
    <div class="space-y-2">
        <h1 class="text-lg text-zinc-100">
            Docs:
            <span class="text-emerald-400">@Page</span>
        </h1>
    </div>

    @if (_isLoading)
    {
        <div class="text-zinc-500">loading documentation…</div>
    }
    else if (_notFound)
    {
        <div class="text-zinc-500">document not found</div>
    }
    else
    {
        <div class="markdown">
            @((MarkupString)_htmlContent!)
        </div>
    }

</div>

@code {

    [Parameter]
    public string Page { get; set; } = string.Empty;

    private string? _htmlContent;
    private bool _isLoading = true;
    private bool _notFound;

    private static readonly MarkdownPipeline Pipeline =
        new MarkdownPipelineBuilder()
            .UseAdvancedExtensions()
            .UseAutoIdentifiers()
            .Build();

    private bool _pendingScroll;

    protected override void OnInitialized()
    {
        Nav.LocationChanged += HandleLocationChanged;
    }

    private void HandleLocationChanged(object? sender, LocationChangedEventArgs e)
    {
        // Trigger re-render so OnAfterRenderAsync runs again
        _pendingScroll = true;
        InvokeAsync(StateHasChanged);
    }

    protected override async Task OnParametersSetAsync()
    {
        _isLoading = true;
        _notFound = false;
        _pendingScroll = true;

        try
        {
            var decoded = Uri.UnescapeDataString(Page);

            if (!decoded.EndsWith(".md", StringComparison.OrdinalIgnoreCase))
                decoded += ".md";

            var url = $"_content/Shared.Rcl/raw_docs/{decoded}";

            var markdown = await Http.GetStringAsync(url);

            _htmlContent = Markdown.ToHtml(markdown, Pipeline);
        }
        catch
        {
            _notFound = true;
            _htmlContent = null;
        }
        finally
        {
            _isLoading = false;
        }
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (_pendingScroll && !_isLoading && !_notFound)
        {
            _pendingScroll = false;
            await ScrollToFragmentAsync();
        }
    }

    private async Task ScrollToFragmentAsync()
    {
        var uri = new Uri(Nav.Uri);
        var fragment = uri.Fragment;

        if (!string.IsNullOrWhiteSpace(fragment))
        {
            var anchor = fragment.TrimStart('#');
            await JS.InvokeVoidAsync("scrollToAnchor", anchor);
        }
    }

    public void Dispose()
    {
        Nav.LocationChanged -= HandleLocationChanged;
    }
}