using Elternbeirat.Contracts;
using Elternbeirat.PocketBase;
using Elternbeirat.Web.Shared;
using Microsoft.AspNetCore.Components;

namespace Elternbeirat.Web.Features.Faqs;

public partial class FaqList
{
    [LoggerMessage(
        Level = LogLevel.Error,
        Message = "Could not load FAQs from PocketBase; content source is unavailable.")]
    private static partial void LogSourceUnavailable(
        ILogger logger,
        Exception exception);

    [Inject]
    private PocketBaseClient PocketBase { get; set; } = null!;

    [Inject]
    private ILogger<FaqList> Logger { get; set; } = null!;

    [CascadingParameter]
    private HttpContext? HttpContext { get; set; }

    private IReadOnlyList<IGrouping<FaqTopic, Faq>> _groups = [];

    // Set when the content source could not be reached or read. The markup then
    // shows a "temporarily unavailable" note instead of "no questions", matching
    // the 503 this sets on the response.
    private bool _unavailable;

    protected override async Task OnInitializedAsync()
    {
        try
        {
            var faqs = await PocketBase.GetFaqsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);

            // GetFaqsAsync sorts by topic.order first, so grouping in encounter order
            // keeps the topic groups in the order an editor gave the topics. Entries
            // without an expanded topic have no group and are skipped rather than
            // grouped under a null heading.
            _groups = [.. faqs.Where(faq => faq.Topic is not null).GroupBy(faq => faq.Topic!)];
        }
        catch (PocketBaseUnavailableException exception)
        {
            // An empty page would claim there are no questions. The site works, its
            // data store is down: 503 and an honest note.
            LogSourceUnavailable(Logger, exception);
            _unavailable = true;
            SourceUnavailable.SetStatus(HttpContext);
        }
    }
}