using MailKit.Net.Smtp;
using MimeKit;

namespace qtc_api.Services.EmailService
{
    public class EmailService : IEmailService
    {
        private IConfiguration _configuration;
        private ILogger<EmailService> _logger;
        public EmailService(IConfiguration configuration, ILogger<EmailService> logger)
        {
            _configuration = configuration;
            _logger = logger;
        }

        public async Task SendConfirmationEmail(string email, string name, string confirmUrl)
        {
            // get config entries
            bool confirmationRequired = _configuration.GetValue<bool>("EmailConfig:EmailConfirmationRequired");
            string? host = _configuration.GetValue<string>("EmailConfig:SMTPServer");
            string? username = _configuration.GetValue<string>("EmailConfig:SMTPUsername");
            string? password = _configuration.GetValue<string>("EmailConfig:SMTPPassword");
            string? senderAddress = _configuration.GetValue<string>("EmailConfig:SMTPSenderAddress");

            if (!confirmationRequired)
            {
                _logger.LogInformation("Email Confirmation Is Disabled. For Better Security Of Your Instance, Consider Setting Up An Email Sender Service.");
                return;
            } else if (host == null ||  username == null || password == null || senderAddress == null)
            {
                _logger.LogInformation("Email Confirmation Is Enabled But No SMTP Settings Were Set.");
                return;
            }

            // set email subject
            string emailSubject = "QtC.NET Email Confirmation";

            // build confirmation email body
            StringBuilder emailBody = new();
            emailBody.AppendLine($"<h2>Hello {name},</h2>");
            emailBody.AppendLine("<p>Your receiving this message because you made a QtC.NET Account on a server that requires email confirmation.<br>");
            emailBody.AppendLine(@$"You can confirm your account by clicking <a href=""{confirmUrl}"">here.</a><br>");
            emailBody.AppendLine("NOTE: This Link Is Only Valid For 24 Hours.<br><br>");
            emailBody.AppendLine("If you did not create a QtC.NET account on any server, you may simply ignore this email.</p>");

            // create new client
            using var client = new SmtpClient()
            {
                RequireTLS = true
            };
            
            // connect and authenticate
            await client.ConnectAsync(host, 587);
            await client.AuthenticateAsync(username, password);

            // construct email
            using var message = new MimeMessage();
            message.To.Add(new MailboxAddress(name, email));
            message.From.Add(new MailboxAddress("QtC.NET Server", senderAddress));

            message.Subject = emailSubject;
            message.Body = new TextPart(MimeKit.Text.TextFormat.Html) 
            {
                Text = emailBody.ToString()
            };

            // send email
            await client.SendAsync(message);

            // disconnect
            await client.DisconnectAsync(true);
        }

        public async Task SendPasswordResetEmail(string email, string name, string passwordResetUrl)
        {
            // get config entries
            bool confirmationRequired = _configuration.GetValue<bool>("EmailConfig:EmailConfirmationRequired");
            string? host = _configuration.GetValue<string>("EmailConfig:SMTPServer");
            string? username = _configuration.GetValue<string>("EmailConfig:SMTPUsername");
            string? password = _configuration.GetValue<string>("EmailConfig:SMTPPassword");
            string? senderAddress = _configuration.GetValue<string>("EmailConfig:SMTPSenderAddress");

            if (!confirmationRequired)
            {
                _logger.LogInformation("Email Confirmation Is Disabled. For Better Security Of Your Instance, Consider Setting Up An Email Sender Service.");
                return;
            }
            else if (host == null || username == null || password == null || senderAddress == null)
            {
                _logger.LogInformation("Email Confirmation Is Enabled But No SMTP Settings Were Set.");
                return;
            }

            // set email subject
            string emailSubject = "QtC.NET Email Confirmation";

            // build confirmation email body
            StringBuilder emailBody = new();
            emailBody.AppendLine($"<h2>Hello {name},</h2>");
            emailBody.AppendLine("<p>Your receiving this message because you requested a password reset on a QtC.NET Account.<br>");
            emailBody.AppendLine(@$"You can reset your password by clicking <a href=""{passwordResetUrl}"">here.</a><br>");
            emailBody.AppendLine("NOTE: This Link Is Only Valid For 24 Hours.<br><br>");
            emailBody.AppendLine("If you did not request a password reset on any QtC.NET account on any server, you may simply ignore this email.</p>");

            // create new client
            using var client = new SmtpClient()
            {
                RequireTLS = true
            };

            // connect and authenticate
            await client.ConnectAsync(host, 587);
            await client.AuthenticateAsync(username, password);

            // construct email
            using var message = new MimeMessage();
            message.To.Add(new MailboxAddress(name, email));
            message.From.Add(new MailboxAddress("QtC.NET Server", senderAddress));

            message.Subject = emailSubject;
            message.Body = new TextPart(MimeKit.Text.TextFormat.Html)
            {
                Text = emailBody.ToString()
            };

            // send email
            await client.SendAsync(message);

            // disconnect
            await client.DisconnectAsync(true);
        }
    }
}