using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.DirectoryServices.AccountManagement;
using System.Net.Mail;
using JD.Core.Logging;
using JD.Interfaces.Logging;

namespace JD.Core
{
    public class MailManager : IDisposable
    {
        static MailManager()
        {
            Instance = new MailManager();
        }

        public static MailManager Instance { get; }

        public const string DefaultMailServer = "relay.ubisoft.org";

        private string _mailServer;
        private SmtpClient _mailClient;
        PrincipalContext _principalContext;

        protected MailManager()
        {

        }

        public void Init(string mailServer)
        {
            _mailServer = mailServer;
            _mailClient = new SmtpClient(mailServer) {UseDefaultCredentials = true};
        }

        private void InitLDAP()
        {
            _principalContext = new PrincipalContext(ContextType.Domain, "10.0.0.9");
        }
        
        public bool SendMail(MailInfo mailInfo, string mailServer = null, bool fromMyself = false, bool toMyself = false)
        {
            try
            {
                if (_mailServer == null)
                {
                    Init(mailServer ?? DefaultMailServer);
                }

                var mail = new MailMessage
                {
                    Subject = mailInfo.Subject,
                    Body = mailInfo.Body
                };

                if (fromMyself)
                {
                    if (_principalContext == null)
                        InitLDAP();

                    var user = UserPrincipal.FindByIdentity(_principalContext, System.IO.Path.GetFileName(System.Security.Principal.WindowsIdentity.GetCurrent().Name));
                    if (user == null)
                        return false;

                    mail.From = new MailAddress(user.EmailAddress, user.Name);
                }
                else
                {
                    mail.From = new MailAddress(mailInfo.From.Mail, mailInfo.From.Name);
                }
                foreach (var recipient in mailInfo.To)
                {
                    mail.To.Add(string.IsNullOrEmpty(recipient.Name) ? new MailAddress(recipient.Mail) : new MailAddress(recipient.Mail, recipient.Name));
                }

                if (toMyself)
                {
                    if (_principalContext == null)
                        InitLDAP();

                    var user = UserPrincipal.FindByIdentity(_principalContext, System.IO.Path.GetFileName(System.Security.Principal.WindowsIdentity.GetCurrent().Name));
                    if (user == null)
                        return false;

                    mail.To.Add(new MailAddress(user.EmailAddress, user.Name));
                }

                mail.IsBodyHtml = mailInfo.IsHtml;
                _mailClient.Send(mail);
                return true;
            }
            catch (Exception ex)
            {
                var log = JD.Interfaces.Composition.Objects.GetInstance(typeof(ILog)) as ILog;
                if (log != null)
                {
                    log.Error(LogCategories.Get("Mail"), "Failed to send mail. ");
                    log.Exception(ex);
                }

                return false;
            }
        }

        public struct MailInfo
        {
            public MailInfo(string fromName, string fromMail, string subject, string body, bool isHtml)
            {
                From = new MailRecipient {Name = fromName, Mail = fromMail} ;
                To = new List<MailRecipient>();
                Subject = subject;
                Body = body;
                IsHtml = isHtml;
            }

            public MailRecipient From { get; }

            public List<MailRecipient> To { get; }

            public string Subject { get; }

            public string Body { get; }

            public bool IsHtml { get; }

            public void AddRecipient(string mail)
            {
                To.Add(new MailRecipient { Name = null, Mail = mail });
            }

            public void AddRecipient(string mail, string name)
            {
                To.Add(new MailRecipient { Name = name, Mail = mail });
            }
        }

        public struct MailRecipient
        {
            public string Name { get; set; }
            public string Mail { get; set; }
        }

        [Export(typeof(ILogCategory))]
        public class MailLogCategory : LogCategory { }

        public void Dispose()
        {
            _mailClient?.Dispose();
            _principalContext?.Dispose();
        }
    }
}