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

namespace Inventory.Agent
{
    public class Worker : BackgroundService
    {
        private readonly ILogger<Worker> _logger;
        private readonly IConfiguration _configuration;
        private readonly IServiceProvider _serviceProvider;

        public Worker(ILogger<Worker> logger, IConfiguration configuration, IServiceProvider serviceProvider)
        {
            _logger = logger;
            _configuration = configuration;
            _serviceProvider = serviceProvider;
        }

        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            _logger.LogInformation("Inventory Agent starting.");

            // Perform an initial run on startup
            await DoWork(stoppingToken);

            var updateIntervalMinutes = _configuration.GetValue<int>("UPDATE_INTERVAL_MINUTES");
            if (updateIntervalMinutes <= 0)
            {
                updateIntervalMinutes = 60; // Default to 60 minutes if not configured or invalid
            }
            _logger.LogInformation("Update interval set to {Minutes} minutes.", updateIntervalMinutes);
            using var timer = new PeriodicTimer(TimeSpan.FromMinutes(updateIntervalMinutes));

            while (await timer.WaitForNextTickAsync(stoppingToken))
            {
                await DoWork(stoppingToken);
            }
        }

        private async Task DoWork(CancellationToken stoppingToken)
        {
            _logger.LogInformation("Starting inventory update workflow.");
            try
            {
                using var scope = _serviceProvider.CreateScope();
                var updateWorkflow = scope.ServiceProvider.GetRequiredService<Inventory.Core.UpdateWorkflow>();
                await updateWorkflow.Run();
                _logger.LogInformation("Inventory update completed successfully.");
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "An error occurred during the inventory update.");
            }
        }
    }
}