using MailKit.Net.Smtp;
using MimeKit;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ServiceShared
{
    public class Mail
    {
        /// <summary>
        /// Smtp server for sending mails
        /// </summary>
        private static string SMTPServer = null;

        /// <summary>
        /// Smtp server port for sending mails
        /// </summary>
        private static int SMTPPort = 25;

        /// <summary>
        /// Flag for using ssl for sending mails
        /// </summary>
        public static bool SMTPSSLUse = false;

        /// <summary>
        /// Username for authentification to smtp server
        /// </summary>
        public static string SMTPUsername { get; set; }

        /// <summary>
        /// Password for authentification to smtp server
        /// </summary>
        public static string SMTPPassword { get; set; }

        /// <summary>
        /// Smtp server sender email for sending mails
        /// </summary>
        private static string SMTPSenderEmail = null;

        /// <summary>
        /// Smtp server sender name(Display Name) for sending mails
        /// </summary>
        private static string SMTPSenderName = null;

        /// <summary>
        /// Smpt log recipients, separated by ; for sending mails
        /// </summary>
        private static string LogsRecipients = null;

        /// <summary>
        /// Smpt customer request recipients, separated by ; for sending mails
        /// </summary>
        private static string CustomerRequestsRecipients = null;

        /// <summary>
        /// Sets the smtp data
        /// </summary>
        /// <param name="server">Host/IP for smtp server</param>
        /// <param name="port">Port for Smtp server</param>
        /// <param name="ssl">Flag if Smtp server is using ssl</param>
        /// <param name="senderEmail">Sender Email for Smtp logs</param>
        /// <param name="senderName">Sender Name for Smtp logs</param>
        /// <param name="logsRecipients">Recipients of Smtp logs, separated by ;</param>
        /// <param name="customerRequestsRecipients">Recipients of customer requests, separated by ;</param>
        public static void SetSMTPData(string server, int port, bool ssl, string senderEmail, string senderName, string logsRecipients, string customerRequestsRecipients, string username, string password)
        {
            SMTPServer = server;
            SMTPPort = port;
            SMTPSSLUse = ssl;
            SMTPSenderEmail = senderEmail;
            SMTPSenderName = senderName;
            LogsRecipients = logsRecipients;
            CustomerRequestsRecipients = customerRequestsRecipients;
            SMTPUsername = username;
            SMTPPassword = password;
        }

        /// <summary>
        /// Send the customer request mail with subject and body to the recipients
        /// </summary>
        /// <param name="_subject">subject of mail</param>
        /// <param name="_body">body of mail</param>
        public static bool SendCustomerRequest(string _subject, string _body)
        {
            bool result = false;

            try
            {
                if(!String.IsNullOrEmpty(SMTPServer) && SMTPPort > 0 && !string.IsNullOrEmpty(CustomerRequestsRecipients))
                {
                    string[] recipients = null;

                    if (CustomerRequestsRecipients.Contains(";"))
                    {
                        recipients = CustomerRequestsRecipients.Split(new[] { ";" }, StringSplitOptions.RemoveEmptyEntries);
                    }
                    else
                    {
                        recipients = new string[] { CustomerRequestsRecipients };
                    }

                    result = Send("Customer Request - " + _subject, _body, recipients);
                }
            }
            catch (Exception ex)
            {
                Log.Error(ex, "ServiceShared.Mail", "SendCustomerRequest(string, string)");
            }

            return result;
        }

        /// <summary>
        /// Send log mail with subject and body to the recipients
        /// </summary>
        /// <param name="_subject">subject of mail</param>
        /// <param name="_body">body of mail</param>
        public static void SendLogs(string _subject, string _body)
        {
            try
            {
                if (!String.IsNullOrEmpty(SMTPServer) && SMTPPort > 0 && !string.IsNullOrEmpty(LogsRecipients))
                {
                    string[] recipients = null;

                    if (LogsRecipients.Contains(";"))
                    {
                        recipients = LogsRecipients.Split(new[] { ";" }, StringSplitOptions.RemoveEmptyEntries);
                    }
                    else
                    {
                        recipients = new string[] { LogsRecipients };
                    }

                    Send("LOG - " + _subject, _body, recipients);
                }
            }
            catch (Exception ex)
            {
                Log.Error(ex, "ServiceShared.Mail", "SendCustomerRequest(string, string)");
            }
        }

        /// <summary>
        /// Sends mail to recipients with subject and body
        /// </summary>
        /// <param name="subject">subject of mail</param>
        /// <param name="body">text of maily</param>
        /// <param name="recipients">recipients</param>
        /// <returns></returns>
        private static bool Send(string subject, string body, string[] recipients)
        {
            bool result = false;

            try
            {
                using (SmtpClient client = new SmtpClient())
                {
                    client.ServerCertificateValidationCallback = (s, c, h, e) => true;

                    Log.Debug("Mail connecting to server: " + SMTPServer + ":" + SMTPPort + (SMTPSSLUse ? "(SSL)" : ""));

                    client.Connect(SMTPServer, SMTPPort, SMTPSSLUse);

                    if (!string.IsNullOrEmpty(SMTPUsername) && !string.IsNullOrEmpty(SMTPPassword))
                    {
                        Log.Debug("Mail authentificate to server: " + SMTPServer + ":" + SMTPPort + (SMTPSSLUse ? "(SSL)" : ""));
                        client.Authenticate(SMTPUsername, SMTPPassword);
                    }

                    MimeMessage message = new MimeMessage();
                    message.From.Add(new MailboxAddress((string.IsNullOrEmpty(SMTPSenderName) ? SMTPSenderName : SMTPSenderEmail), SMTPSenderEmail));

                    foreach (string recipient in recipients)
                    {
                        message.To.Add(new MailboxAddress(null, recipient));
                    }

                    message.Subject = subject;

                    BodyBuilder builder = new BodyBuilder();
                    builder.TextBody = body;
                    message.Body = builder.ToMessageBody();

                    Log.Debug("Mail sending: " + subject + ", " + body);
                    client.Send(message);
                    client.Disconnect(true);

                    Log.Debug("Mail sent: " + subject + ", " + body);

                    result = true;
                }
            }
            catch (Exception ex)
            {
                Log.Error(ex, "ServiceShared.Mail", "Send(string, string, string[])");
            }

            return result;
        }
    }
}