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 IUserService _userService;
    private readonly IMonInClient _monInClient;

    private readonly string _siProductionGroupName;
    private readonly string _cleansTrainingGroupName;
    private readonly string _asmHtrTrainingGroupName;
    private readonly string _epiProTrainingGroupName;
    private readonly string _fqaTrainingGroupName;
    private readonly string _packagingAndLabelingTrainingGroupName;

    public CertificationTrainingGroupWorker(ILogger<CertificationTrainingGroupWorker> logger,
                                   ITrainingService trainingService,
                                   IUserService userService,
                                   IMonInClient monInClient) {
        _logger = logger ?? throw new ArgumentNullException("ILogger not injected");
        _trainingService = trainingService ?? throw new ArgumentNullException("ITrainingService not injected");
        _userService = userService ?? throw new ArgumentNullException("IUserService not injected");
        _monInClient = monInClient ?? throw new ArgumentNullException("IMonInClient not injected");
        _siProductionGroupName = Environment.GetEnvironmentVariable("SiProductionTrainingGroupName") ??
            throw new ArgumentNullException("SiProductionTrainingGroupName environment variable not found");
        _asmHtrTrainingGroupName = Environment.GetEnvironmentVariable("AsmHtrTrainingGroupName") ??
            throw new ArgumentNullException("AsmHtrTrainingGroupName environment variable not found");
        _cleansTrainingGroupName = Environment.GetEnvironmentVariable("CleansTrainingGroupName") ??
            throw new ArgumentNullException("CleansTrainingGroupName environment variable not found");
        _epiProTrainingGroupName = Environment.GetEnvironmentVariable("EpiProTrainingGroupName") ??
            throw new ArgumentNullException("EpiProTrainingGroupName environment variable not found");
        _fqaTrainingGroupName = Environment.GetEnvironmentVariable("FqaTrainingGroupName") ??
            throw new ArgumentNullException("FqaTrainingGroupName environment variable not found");
        _packagingAndLabelingTrainingGroupName = Environment.GetEnvironmentVariable("PackagingAndLabelingTrainingGroupName") ??
            throw new ArgumentNullException("PackagingAndLabelingTrainingGroupName environment variable not found");
    }

    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}");

                _logger.LogInformation("Deleting ASM/HTR training group members");
                int asmHtrGroupId = await _trainingService.GetTrainingGroupIdByName(_asmHtrTrainingGroupName);
                await _trainingService.DeleteAllUsersFromTrainingGroup(asmHtrGroupId);

                _logger.LogInformation("Deleting EpiPro training group members");
                int epiProGroupId = await _trainingService.GetTrainingGroupIdByName(_epiProTrainingGroupName);
                await _trainingService.DeleteAllUsersFromTrainingGroup(epiProGroupId);

                _logger.LogInformation("Deleting FQA training group members");
                int fqaGroupId = await _trainingService.GetTrainingGroupIdByName(_fqaTrainingGroupName);
                await _trainingService.DeleteAllUsersFromTrainingGroup(fqaGroupId);

                _logger.LogInformation("Deleting Packaging & Labeling training group members");
                int packagingAndLabelingGroupId = await _trainingService.GetTrainingGroupIdByName(_packagingAndLabelingTrainingGroupName);
                await _trainingService.DeleteAllUsersFromTrainingGroup(packagingAndLabelingGroupId);

                _logger.LogInformation("Deleting Cleans training group members");
                int cleansGroupId = await _trainingService.GetTrainingGroupIdByName(_cleansTrainingGroupName);
                await _trainingService.DeleteAllUsersFromTrainingGroup(cleansGroupId);

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

                if (certRecords is null || certRecords.Count() == 0)
                    throw new ArgumentNullException("certRecords cannot be null or empty");

                int siProductionTrainingGroupId = await _trainingService.GetTrainingGroupIdByName(_siProductionGroupName);

                List<Task> queryTasks = new();
                foreach (UserCertificationRecord record in certRecords) {
                    _logger.LogInformation($"Processing cert record {{{record}}}");

                    if (record is not null) {
                        User? user;
                        try {
                            user = await _userService.GetUserByEmail(record.Email);
                        } catch (Exception ex) {
                            user = null;
                            StringBuilder errMsgBuilder = new();
                            errMsgBuilder.Append($"An exception occurred when attempting to get user for email {record.Email}. ");
                            errMsgBuilder.Append($"Exception: {ex.Message}");
                        }

                        if (user is not null && user.IsActive) {
                            bool userIsInSiProduction = await _trainingService.IsUserMemberOfTrainingGroup(user.UserID, siProductionTrainingGroupId);
                            if (userIsInSiProduction) {
                                if (record.IsEpiProCertified) queryTasks.Add(_trainingService.AddUserToTrainingGroup(epiProGroupId, user));
                                if (record.IsPackagingLabelingCertified) queryTasks.Add(_trainingService.AddUserToTrainingGroup(packagingAndLabelingGroupId, user));
                                if (record.IsCleansCertified) queryTasks.Add(_trainingService.AddUserToTrainingGroup(cleansGroupId, user));
                                if (record.IsFqaCertified) queryTasks.Add(_trainingService.AddUserToTrainingGroup(fqaGroupId, user));
                                if (record.IsAnyLevelCertified) queryTasks.Add(_trainingService.AddUserToTrainingGroup(asmHtrGroupId, user));
                            }
                        }
                    }
                }

                await Task.WhenAll(queryTasks);

                isSuccessful = true;
            }

            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);
            }
        }
    }
}