using BotPages.Core;
using Telegram.Bot;
using Telegram.Bot.Types;

namespace BotPages.Telegram
{
    /// <summary>
    /// Утилиты для извлечения контекста из Telegram Update.
    /// </summary>
    public static class TelegramUpdateMapper
    {
        /// <summary>
        /// Преобразует Telegram Update в универсальный UpdateContext.
        /// </summary>
        public static UpdateContext Map(ITelegramBotClient bot, INavigationService nav, IStateStore store, Update update)
        {
            var chat = update.Message?.Chat ?? update.CallbackQuery?.Message?.Chat;
            var user = update.Message?.From ?? update.CallbackQuery?.From;

            var text = update.Message?.Text ?? update.CallbackQuery?.Data;

            var files = new List<FileDescriptor>();
            if (update.Message?.Document is { } doc)
            {
                files.Add(new FileDescriptor(doc.FileId, doc.FileName ?? "file", doc.MimeType ?? "application/octet-stream"));
            }
            if (update.Message?.Photo is { } photos && photos.Count() > 0)
            {
                var largest = photos.OrderBy(p => p.FileSize).Last();
                files.Add(new FileDescriptor(largest.FileId, "photo.jpg", "image/jpeg"));
            }

            return new UpdateContext
            {
                Client = new TelegramClientAdapter(bot),
                Chat = new ChatContext { Id = chat!.Id, Title = chat.Title },
                User = new UserContext { Id = user!.Id, DisplayName = $"{user.FirstName} {user.LastName}" },
                Text = text,
                IncomingFiles = files,
                RawUpdate = update,
                Nav = nav,
                State = store
            };
        }
    }
}