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

namespace Elternbeirat.Web.Features.Embeds;

public partial class EventsEmbed
{
    // Number of upcoming events shown in the teaser; the full list is one link away.
    private const int TeaserCount = 3;

    [LoggerMessage(
        Level = LogLevel.Warning,
        Message = "Could not load events for an embed from PocketBase; the teaser is omitted.")]
    private static partial void LogSourceUnavailable(
        ILogger logger,
        Exception exception);

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

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

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

    private IReadOnlyList<Event> _upcoming = [];

    protected override async Task OnInitializedAsync()
    {
        IReadOnlyList<Event> events;
        try
        {
            events = await PocketBase.GetEventsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
        }
        catch (PocketBaseUnavailableException exception)
        {
            // Only part of the page fails: omit the teaser, keep the page (and its
            // 200) intact. A missing teaser is degraded, not broken.
            LogSourceUnavailable(Logger, exception);
            return;
        }

        // Teaser: the soonest upcoming events, earliest first. An event earlier
        // today still counts as upcoming.
        var today = DateOnly.FromDateTime(DateTime.Today);
        _upcoming =
        [
            .. events
                .Where(@event => DateOnly.FromDateTime(@event.Start) >= today)
                .OrderBy(@event => @event.Start)
                .Take(TeaserCount)
        ];
    }
}