namespace Yes.Application.Core.HostedServices
{
    public class RssGenerationJob
    {
        private readonly BlogSettings _settings;
        private readonly BlogDbContext _db;
        private readonly ILogger<RssGenerationJob> _logger;
        private readonly IWebHostEnvironment _env;
        public RssGenerationJob(
            IOptionsMonitor<BlogSettings> options,
            BlogDbContext db,
            IWebHostEnvironment env,
            ILogger<RssGenerationJob> logger)
        {
            _settings = options.CurrentValue;
            _db = db;
            _env = env;
            _logger = logger;
        }

        public async Task Execute()
        {
            try
            {
                var queryArticle = _db.Articles.Where(x => x.Type == ArticleTypeEnum.Article && x.Status == ArticleStatusEnum.Normal).AsQueryable();
                var pubDate = queryArticle.Any() ? _db.Articles.Min(x => x.PublishDate) : DateTime.MinValue;

                var channel = new Channel
                {
                    Title = _settings.Name,
                    Link = _settings.Url,
                    Description = _settings.Description,
                    Language = "zh-CN",
                    FeedUrl = $"{_settings.Url}/feed/",
                    PubDate = pubDate
                };

                // 添加扩展元素（示例）
                channel.Extensions.Add(new XElement("generator", _settings.Name));
                channel.Extensions.Add(new XElement("docs", "http://www.rssboard.org/rss-specification"));

                var query = from article in queryArticle
                            join categoryTemp in _db.Categories.AsNoTracking() on article.CategoryId equals categoryTemp.Id into tempCategory
                            from category in tempCategory.DefaultIfEmpty()
                            join userTemp in _db.Users.AsNoTracking() on article.UserId equals userTemp.Id into tempUser
                            from user in tempUser.DefaultIfEmpty()
                            orderby article.Id descending
                            select new ArticleModel
                            {
                                Id = article.Id,
                                CanComment = article.CanComment,
                                CommentCount = article.CommentCount,
                                CategoryId = article.CategoryId,
                                ModifyDate = article.ModifyDate.ToSafeTime(),
                                PublishDate = article.PublishDate.ToSafeTime(),
                                CreateDate = article.CreateDate.ToSafeTime(),
                                Content = article.Content,
                                CoverUrl = article.CoverUrl,
                                Slug = article.Slug,
                                ReadCount = article.ReadCount,
                                Title = article.Title,
                                Summary = article.Summary,
                                UserId = article.UserId,
                                Category = new CategoryModel
                                {
                                    CoverUrl = category.CoverUrl,
                                    Description = category.Description,
                                    Id = category.Id,
                                    Name = category.Name,
                                    Slug = category.Slug
                                }
                            };

                var items = query.Select(x => new Item
                {
                    Content = x.Content,
                    Title = x.Title,
                    Url = $"{_settings.Url}/{_settings.ArticleRoute.ToRoute(x.Category, x)}",
                    Description = x.Summary,
                    CommentsCount = x.CommentCount,
                    Creator = x.UserId.ToString(),
                    PublishDate = x.PublishDate,
                    CommentsUrl = $"{_settings.Url}/{_settings.ArticleRoute.ToRoute(x.Category, x)}#comments",
                    CommentRssUrl = $"{_settings.Url}/feed/"
                });


                var generator = new RssGenerator();
                string xml = generator.GenerateRss(channel, items);


                File.WriteAllText(Path.Combine(_env.WebRootPath, "feed.xml"), xml);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "RSS generation failed");
            }
        }
    }
}