using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using ResourceMonitorService.Configuration;
using ResourceMonitorService.Services;
using ResourceMonitorService.Hubs;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.DependencyInjection;

namespace ResourceMonitorService
{
    public class Worker : BackgroundService
    {
        private readonly ILogger<Worker> _logger;
        private readonly IResourceMonitorService _resourceMonitorService;
        private readonly IGameDetectionService _gameDetectionService;
        private readonly IAlertService _alertService;
        private readonly MonitoringSettings _monitoringSettings;
        private readonly IServiceProvider _serviceProvider;

        public Worker(
            ILogger<Worker> logger,
            IResourceMonitorService resourceMonitorService,
            IGameDetectionService gameDetectionService,
            IAlertService alertService,
            IOptions<MonitoringSettings> monitoringSettings,
            IServiceProvider serviceProvider)
        {
            _logger = logger;
            _resourceMonitorService = resourceMonitorService;
            _gameDetectionService = gameDetectionService;
            _alertService = alertService;
            _monitoringSettings = monitoringSettings.Value;
            _serviceProvider = serviceProvider;
        }

        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            _logger.LogInformation("Resource Monitor background service starting...");
            await BackgroundMonitoringLoop(stoppingToken);
        }

        private async Task BackgroundMonitoringLoop(CancellationToken cancellationToken)
        {
            _logger.LogInformation("Background monitoring started");
            int errorCount = 0;
            int successfulCycles = 0;

            while (!cancellationToken.IsCancellationRequested)
            {
                try
                {
                    // Get current resource usage
                    var resourceUsage = await _resourceMonitorService.GetResourceUsageAsync();

                    // Add current game info if game detection is enabled
                    if (_monitoringSettings.EnableGameDetection)
                    {
                        try
                        {
                            resourceUsage.RunningGame = await _gameDetectionService.GetCurrentlyRunningGameAsync();
                        }
                        catch (Exception ex)
                        {
                            // Only log game detection errors occasionally to avoid spam
                            if (errorCount % 12 == 0) // Every minute if 5-second intervals
                            {
                                _logger.LogDebug("Game detection error (suppressed): {Message}", ex.Message);
                            }
                        }
                    }

                    // Check for alerts
                    if (_monitoringSettings.EnableAlerts)
                    {
                        await _alertService.CheckAndGenerateAlertsAsync(resourceUsage);
                    }

                    // Send real-time updates via SignalR
                    try
                    {
                        using var scope = _serviceProvider.CreateScope();
                        var hubContext = scope.ServiceProvider.GetService<IHubContext<ResourceHub>>();
                        if (hubContext != null)
                        {
                            await hubContext.Clients.All.SendAsync("ResourceUpdate", resourceUsage, cancellationToken);
                        }
                    }
                    catch (Exception ex)
                    {
                        _logger.LogDebug("SignalR broadcast error: {Message}", ex.Message);
                    }

                    successfulCycles++;

                    // Log performance metrics occasionally
                    if (successfulCycles % 4 == 0) // Every 60 seconds with 15-second intervals
                    {
                        _logger.LogDebug("Performance: CPU: {CpuUsage:F1}%, Memory: {MemoryUsage:F1}%, GPU: {GpuUsage}%", 
                            resourceUsage.CPU.Usage, 
                            resourceUsage.Memory.UsagePercentage,
                            resourceUsage.GPU.Usage);
                    }

                    // Log successful monitoring occasionally for health verification
                    if (successfulCycles % 120 == 0) // Every 10 minutes
                    {
                        _logger.LogInformation("Background monitoring healthy - completed {SuccessfulCycles} cycles", successfulCycles);
                    }

                    errorCount = 0; // Reset error count on success
                }
                catch (Exception ex)
                {
                    errorCount++;
                    
                    // Only log errors occasionally to avoid spam, but always log the first few
                    if (errorCount <= 3 || errorCount % 12 == 0)
                    {
                        _logger.LogError(ex, "Error in background monitoring loop (occurrence #{ErrorCount})", errorCount);
                    }
                    
                    // If too many consecutive errors, increase delay
                    if (errorCount > 10)
                    {
                        await Task.Delay(_monitoringSettings.UpdateIntervalMs * 2, cancellationToken);
                        continue;
                    }
                }

                await Task.Delay(_monitoringSettings.UpdateIntervalMs, cancellationToken);
            }

            _logger.LogInformation("Background monitoring stopped after {SuccessfulCycles} successful cycles", successfulCycles);
        }
    }
}