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

namespace Elternbeirat.Web.Features.Posts;

public partial class PostDetail
{
    [LoggerMessage(
        Level = LogLevel.Error,
        Message = "Could not load post '{Slug}' from PocketBase; content source is unavailable.")]
    private static partial void LogSourceUnavailable(
        ILogger logger,
        string slug,
        Exception exception);

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

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

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

    [Inject]
    private NavigationManager Navigation { get; set; } = null!;

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

    private Post? _post;

    // Set when the content source could not be reached or read. The markup then
    // shows a "temporarily unavailable" note instead of a not-found page, matching
    // the 503 this sets on the response.
    private bool _unavailable;

    // The post body rendered from Markdown to HTML, ready to emit as a
    // MarkupString in the markup.
    private MarkupString Body => (MarkupString)Markdown.ToHtml(_post?.Body);

    protected override async Task OnParametersSetAsync()
    {
        try
        {
            var posts = await PocketBase.GetPostsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
            _post = posts.FirstOrDefault(
                post => string.Equals(post.Slug, Slug, StringComparison.OrdinalIgnoreCase));
        }
        catch (PocketBaseUnavailableException exception)
        {
            // The site works, its data store is down: 503, not 404.
            LogSourceUnavailable(Logger, Slug, exception);
            _unavailable = true;
            SourceUnavailable.SetStatus(HttpContext);
            return;
        }

        if (_post is null)
        {
            // The source answered, but there is no post with this slug: a genuine 404.
            Navigation.NotFound();
        }
    }
}