using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Telegram.Bot;
using Telegram.Bot.Polling;
using Telegram.Bot.Types.Enums;

namespace GymLogAI.TelegramBot;

public sealed class TelegramBotHostedService(
    ITelegramBotClient botClient,
    IServiceProvider serviceProvider,
    IOptions<TelegramBotOptions> options,
    ILogger<TelegramBotHostedService> logger) : BackgroundService
{
    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        if (string.IsNullOrWhiteSpace(options.Value.BotToken))
        {
            logger.LogWarning("Telegram bot token is not configured. Bot polling is disabled.");
            return;
        }

        var receiverOptions = new ReceiverOptions
        {
            AllowedUpdates = [UpdateType.Message]
        };

        botClient.StartReceiving(
            async (client, update, cancellationToken) =>
            {
                await using var scope = serviceProvider.CreateAsyncScope();
                var handler = scope.ServiceProvider.GetRequiredService<UpdateHandler>();
                await handler.HandleUpdateAsync(client, update, cancellationToken);
            },
            async (client, exception, cancellationToken) =>
            {
                await using var scope = serviceProvider.CreateAsyncScope();
                var handler = scope.ServiceProvider.GetRequiredService<UpdateHandler>();
                await handler.HandleErrorAsync(client, exception, cancellationToken);
            },
            receiverOptions,
            stoppingToken);

        logger.LogInformation("Telegram bot long polling started.");

        while (!stoppingToken.IsCancellationRequested)
        {
            await Task.Delay(TimeSpan.FromSeconds(options.Value.PollingTimeoutSeconds), stoppingToken);
        }
    }
}