using System;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace Sozsoft.Platform;

public class BackgroundWorkerStartupService : IHostedService
{
    private readonly IServiceProvider _serviceProvider;
    private readonly IHostApplicationLifetime _applicationLifetime;
    private readonly ILogger<BackgroundWorkerStartupService> _logger;

    public BackgroundWorkerStartupService(
        IServiceProvider serviceProvider,
        IHostApplicationLifetime applicationLifetime,
        ILogger<BackgroundWorkerStartupService> logger)
    {
        _serviceProvider = serviceProvider;
        _applicationLifetime = applicationLifetime;
        _logger = logger;
    }

    public Task StartAsync(CancellationToken cancellationToken)
    {
        _applicationLifetime.ApplicationStarted.Register(() =>
        {
            _ = Task.Run(InitializeBackgroundWorkersAsync);
        });

        return Task.CompletedTask;
    }

    public Task StopAsync(CancellationToken cancellationToken)
    {
        return Task.CompletedTask;
    }

    private async Task InitializeBackgroundWorkersAsync()
    {
        const int maxAttempts = 5;

        for (var attempt = 1; attempt <= maxAttempts; attempt++)
        {
            try
            {
                _logger.LogInformation(
                    "Background worker startup initialization started. Attempt {Attempt}/{MaxAttempts}.",
                    attempt,
                    maxAttempts);

                using var scope = _serviceProvider.CreateScope();
                var abpRecurringJobInitializer = scope.ServiceProvider.GetRequiredService<AbpBackgroundWorkerRecurringJobInitializer>();
                await abpRecurringJobInitializer.RunAsync();

                var initializer = scope.ServiceProvider.GetRequiredService<BackgroundWorkerInitializer>();
                await initializer.RunAsync();

                _logger.LogInformation("Background worker startup initialization completed.");
                return;
            }
            catch (Exception ex)
            {
                if (attempt == maxAttempts)
                {
                    _logger.LogError(ex, "Background worker initialization failed.");
                    return;
                }

                _logger.LogWarning(
                    ex,
                    "Background worker initialization failed. It will be retried.");

                await Task.Delay(TimeSpan.FromSeconds(3));
            }
        }
    }
}