using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Net.Mail;
using System.Threading;
using System.Threading.Tasks;
using AsbCloudApp.Data;
using AsbCloudApp.Exceptions;
using AsbCloudApp.Repositories;
using AsbCloudApp.Services.Notifications;
using AsbCloudInfrastructure.Background;
using AsbCloudInfrastructure.Background.PeriodicWorks;
using DocumentFormat.OpenXml.Presentation;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace AsbCloudInfrastructure.Services.Email
{

    public class EmailNotificationTransportService : INotificationTransportService
    {
        private readonly BackgroundWorker backgroundWorker;
        private readonly bool IsConfigured;
        private readonly string sender;
        private readonly string smtpServer;
        private readonly string smtpPassword;
        private IConfiguration configuration;

        public EmailNotificationTransportService(BackgroundWorker backgroundWorker, 
            IConfiguration configuration)
        {
            sender = configuration.GetValue("email:sender", string.Empty);
            smtpPassword = configuration.GetValue("email:password", string.Empty);
            smtpServer = configuration.GetValue("email:smtpServer", string.Empty);


            var configError = string.IsNullOrEmpty(sender) ||
                string.IsNullOrEmpty(smtpPassword) ||
                string.IsNullOrEmpty(smtpServer);

            IsConfigured = !configError;

            this.backgroundWorker = backgroundWorker;
        }

        public int IdTransportType => 1;
        
        public Task SendAsync(NotificationDto notification, CancellationToken cancellationToken)
        {
            //if (!IsConfigured)
            //{
            //    Trace.TraceWarning("smtp is not configured");
            //    return Task.CompletedTask;
            //}

            var workId = MakeWorkId(notification.IdUser, notification.Title, notification.Message);
            if (!backgroundWorker.Works.Any(w=>w.Id==workId))
            {
                var work = new WorkToSendEmail(workId, notification, sender, smtpPassword, smtpServer);
                backgroundWorker.Enqueue(work);

            }

            return Task.CompletedTask;
        }

        public Task SendRangeAsync(IEnumerable<NotificationDto> notifications, CancellationToken cancellationToken)
        {
            var tasks = notifications
                .Select(notification => SendAsync(notification, cancellationToken));

            return Task.WhenAll(tasks);
        }
        
        private static string MakeWorkId(int idUser, string subject, string content)
        {
            var hash = idUser.GetHashCode();
            hash ^= subject.GetHashCode();
            hash ^= content.GetHashCode();
            return hash.ToString("x");
        }
    }
}