using FabApprovalWorkerService.Models;
using FabApprovalWorkerService.Services;

using Infineon.Monitoring.MonA;

using Quartz;

using System.Text;

namespace FabApprovalWorkerService.Workers;

public class CertificationTrainingGroupWorker : IJob {
    private static readonly int MAX_RETRIES = 3;
    private static readonly int BACKOFF_SECONDS = 30;
    
    private readonly ILogger<CertificationTrainingGroupWorker> _logger;
    private readonly ITrainingService _trainingService;
    private readonly IMonInClient _monInClient;

    public CertificationTrainingGroupWorker(ILogger<CertificationTrainingGroupWorker> logger,
                                   ITrainingService trainingService,
                                   IMonInClient monInClient) {
        _logger = logger ?? throw new ArgumentNullException("ILogger not injected");
        _trainingService = trainingService ?? throw new ArgumentNullException("ITrainingService not injected");
        _monInClient = monInClient ?? throw new ArgumentNullException("IMonInClient not injected");
    }

    public async Task Execute(IJobExecutionContext context) {
        DateTime start = DateTime.Now;
        bool isInternalError = false;
        string metricName = "CertificationTrainingGroupWorker";

        try {
            int remainingRetries = MAX_RETRIES;
            bool isSuccessful = false;

            while (!isSuccessful && remainingRetries > 0) {
                await Task.Delay((MAX_RETRIES - remainingRetries--) * BACKOFF_SECONDS);

                _logger.LogInformation($"Attempting to update certification training group membership. Remaining retries: {remainingRetries}");

                IEnumerable<UserCertificationRecord> certRecords = await _trainingService.GetUserCertificationRecords();
                isSuccessful = await _trainingService.UpdateTrainingGroupMembership(certRecords);
            }

            if (isSuccessful) {
                _logger.LogInformation("Successfully updated certification training group membership.");
            } else {
                throw new Exception("Unable to update certification training group membership.");
            }
        } catch (Exception ex) {
            StringBuilder errMsgBuilder = new();
            errMsgBuilder.Append("An exception occurred when attempting to update certification training group membership. ");
            errMsgBuilder.Append($"Exception: {ex.Message}");
            _logger.LogError(errMsgBuilder.ToString());
            isInternalError = true;
        } finally {
            DateTime end = DateTime.Now;
            double latencyInMS = (end - start).TotalMilliseconds;
            _monInClient.PostMetric(metricName + "Latency", latencyInMS);

            if (isInternalError) {
                _monInClient.PostStatus(metricName, State.Critical);
            } else {
                _monInClient.PostStatus(metricName, State.Ok);
            }
        }
    }
}