using FabApprovalWorkerService.Models;
using FabApprovalWorkerService.Services;

using Infineon.Monitoring.MonA;

using Quartz;

using System.Net.Mail;
using System.Text;

namespace FabApprovalWorkerService.Workers;

public class TrainingNotificationWorker : IJob {
    private readonly ILogger<TrainingNotificationWorker> _logger;
    private readonly ITrainingService _trainingService;
    private readonly IUserService _userService;
    private readonly IECNService _ecnService;
    private readonly ISmtpService _smtpService;
    private readonly IMonInClient _monInClient;
    private readonly string _baseUrl;

    public TrainingNotificationWorker(ILogger<TrainingNotificationWorker> logger,
                                      ITrainingService trainingService,
                                      IUserService userService,
                                      IECNService ecnService,
                                      ISmtpService smtpService,
                                      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");
        _ecnService = ecnService ?? throw new ArgumentNullException("IECNService not injected");
        _smtpService = smtpService ?? throw new ArgumentNullException("ISmtpService not injected");
        _monInClient = monInClient ?? throw new ArgumentNullException("IMonInClient not injected");
        _baseUrl = Environment.GetEnvironmentVariable("FabApprovalBaseUrl") ??
            throw new ArgumentNullException("FabApprovalBaseUrl environment variable not found");
    }

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

        try {
            _logger.LogInformation("Attempting to send training notifications");

            IEnumerable<TrainingAssignment> trainingAssignments = await _trainingService.GetActiveTrainingAssignments();

            _logger.LogInformation($"There are {trainingAssignments.Count()} active training assignments");

            foreach (TrainingAssignment trainingAssignment in trainingAssignments) {
                int ecnNumber = await _trainingService.GetEcnNumberByTrainingId(trainingAssignment.TrainingID);
                ECN ecn = await _ecnService.GetEcnByNumber(ecnNumber);

                bool ecnIsExpired = _ecnService.EcnIsExpired(ecn);
                if (ecnIsExpired) {
                    _logger.LogInformation($"ECN {ecn.ECNNumber} is expired. Cancelling all training.");

                    await _trainingService.DeleteTrainingAssignmentsByTrainingId(trainingAssignment.TrainingID);
                    await _trainingService.DeleteDocAssignment(trainingAssignment.ID);
                    await _trainingService.MarkTrainingAsComplete(trainingAssignment.TrainingID);
                }

                User user = await _userService.GetUserById(trainingAssignment.UserID);
                bool userIsActive = user.IsActive;
                if (!userIsActive) {
                    _logger.LogInformation($"User {user.UserID} is inactive. Cancelling all training.");

                    IEnumerable<int> userTrainingAssignmentIds = await _trainingService.GetTrainingAssignmentIdsByUserId(user.UserID);
                    
                    foreach (int trainingAssignmentId in userTrainingAssignmentIds) {
                        await _trainingService.DeleteTrainingAssignmentById(trainingAssignmentId);
                        await _trainingService.DeleteDocAssignment(trainingAssignmentId);
                    }
                }

                if (!ecnIsExpired && userIsActive && !user.OOO) {
                    bool lastNotificationMoreThanFourDaysAgo = (DateTime.Now.Date - trainingAssignment.LastNotification).Days >= 5;
                    bool dateAssignedMoreThanFourDaysAgo = (DateTime.Now.Date - trainingAssignment.DateAssigned).Days >= 5;

                    bool notificationSent = false;
                    if (lastNotificationMoreThanFourDaysAgo && dateAssignedMoreThanFourDaysAgo) {
                        await SendTrainingReminder(ecn, user);
                        notificationSent = true;
                        await _trainingService.UpdateTrainingAssignmentLastNotification(trainingAssignment.ID);
                    }

                    if (!notificationSent) {
                        DateTime latestExpirationDate = (ecn.ExtensionDate > ecn.ExpirationDate ? ecn.ExtensionDate : ecn.ExpirationDate);
                        int daysTillExpiration = (latestExpirationDate - DateTime.Now.Date).Days;
                        if (daysTillExpiration > 0 && daysTillExpiration <= 5) {
                            await SendTrainingReminder(ecn, user);
                            await _trainingService.UpdateTrainingAssignmentLastNotification(trainingAssignment.ID);
                        }
                    }
                }
            }

            _logger.LogInformation("Successfully sent training notifications");
        } catch (Exception ex) {
            StringBuilder errMsgBuilder = new();
            errMsgBuilder.Append("An exception occurred when attempting to send training notifications. ");
            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);
            }
        }
    }

    private async Task SendTrainingReminder(ECN ecn, User user) {
        _logger.LogInformation($"Attempting to send training reminder for ECN {ecn.ECNNumber} to user {user.UserID}");

        IEnumerable<MailAddress> recipients = new List<MailAddress>() {
            new MailAddress(user.Email)
        };

        IEnumerable<MailAddress> ccRecipients = new List<MailAddress>();
        
        StringBuilder bodyBuilder = new();
        bodyBuilder.Append("Hello, you have open training assignments in Fab Approval. This is a reminder to ");
        bodyBuilder.Append("finish your training assignments. <br /> View your open training assignments ");
        bodyBuilder.Append($"<a href='{_baseUrl}/Training/ViewMyTrainingAssignments'>here. </a>");

        string subject = $"Fab Approval Training Reminder - ECN# {ecn.ECNNumber} - {ecn.Title}";

        await _smtpService.SendEmail(recipients, ccRecipients, subject, bodyBuilder.ToString());
    }
}