using Microsoft.Extensions.Options;
using MaksIT.UScheduler.Services;


namespace MaksIT.UScheduler.BackgroundServices;

public sealed class PSScriptBackgroundService : BackgroundService {

  private readonly ILogger<PSScriptBackgroundService> _logger;
  private readonly Configuration _configuration;
  private readonly PSScriptService _psScriptService;

  public PSScriptBackgroundService(
    ILogger<PSScriptBackgroundService> logger,
    IOptions<Configuration> options,
    PSScriptService psScriptService
  ) {
    _logger = logger;
    _configuration = options.Value;
    _psScriptService = psScriptService;
  }

  protected override async Task ExecuteAsync(CancellationToken stoppingToken) {
    _logger.LogInformation("Starting PSScriptBackgroundService");

    try {
      var psScripts = _configuration.Powershell;

      while (!stoppingToken.IsCancellationRequested) {
        _logger.LogInformation("Checking for PowerShell scripts to run");

        foreach (var psScript in psScripts) {
          var scriptPath = psScript.Path;

          if (scriptPath == string.Empty)
            continue;

          _logger.LogInformation($"Running PowerShell script {scriptPath}");
          _psScriptService.RunScript(scriptPath, psScript.IsSigned, stoppingToken);
        }

        await Task.Delay(TimeSpan.FromSeconds(10), stoppingToken);
      }
    }
    catch (OperationCanceledException) {
      // When the stopping token is canceled, for example, a call made from services.msc,
      // we shouldn't exit with a non-zero exit code. In other words, this is expected...
      _logger.LogInformation("Stopping PSScriptBackgroundService due to cancellation request");
    }
    catch (Exception ex) {
      _logger.LogError(ex, "{Message}", ex.Message);

      // Terminates this process and returns an exit code to the operating system.
      // This is required to avoid the 'BackgroundServiceExceptionBehavior', which
      // performs one of two scenarios:
      // 1. When set to "Ignore": will do nothing at all, errors cause zombie services.
      // 2. When set to "StopHost": will cleanly stop the host, and log errors.
      //
      // In order for the Windows Service Management system to leverage configured
      // recovery options, we need to terminate the process with a non-zero exit code.
      Environment.Exit(1);
    }
  }


  public override Task StopAsync(CancellationToken stoppingToken) {
    // Perform cleanup tasks here
    _logger.LogInformation("Stopping PSScriptBackgroundService");

    _logger.LogInformation("PSScriptBackgroundService stopped");

    return Task.CompletedTask;
  }
}