using System.Net.Mail;
using MailKit;
using MailKit.Net.Imap;
using MailKit.Net.Smtp;
using MimeKit;

namespace NejAccountingAPI.Services.Email;

public class SMTPService : IEmailService
{
    public record SMTPSettings(string From, string Host, int Port, int ImapPort, string Username, string Password);

    private readonly SMTPSettings _settings;

    private readonly ILogger<SMTPService> Logger;

    public SMTPService(ILogger<SMTPService> logger, SMTPSettings settings)
    {
        _settings = settings;
        Logger = logger;
    }

    public async Task SendEmailAsync(string recipient, string subject, string message, List<Attachment>? attachments = null)
    {
        var mess = new MimeMessage();
        mess.From.Add(MailboxAddress.Parse(_settings.From));
        mess.To.Add(MailboxAddress.Parse(recipient));
        mess.Subject = subject;

        var bodyBuilder = new BodyBuilder();
        bodyBuilder.HtmlBody = message;
        bodyBuilder.TextBody = "";

        foreach (var attachment in attachments ?? new List<Attachment>())
            bodyBuilder.Attachments.Add(attachment.Name, attachment.ContentStream, ContentType.Parse(attachment.ContentType.ToString()));

        mess.Body = bodyBuilder.ToMessageBody();

        using (var client = new MailKit.Net.Smtp.SmtpClient())
        {
            await client.ConnectAsync(_settings.Host, _settings.Port);

            // Note: only needed if the SMTP server requires authentication
            await client.AuthenticateAsync(_settings.Username, _settings.Password);

            await client.SendAsync(mess);
            await client.DisconnectAsync(true);

            using (var imap = new MailKit.Net.Imap.ImapClient())
            {
                await imap.ConnectAsync(_settings.Host, _settings.ImapPort);     // or ConnectSSL for SSL
                await imap.AuthenticateAsync(_settings.Username, _settings.Password);

                //get the sent folder
                IMailFolder sent = null;
                if (imap.Capabilities.HasFlag(ImapCapabilities.SpecialUse))
                    sent = imap.GetFolder(SpecialFolder.Sent);

                if (sent == null)
                {
                    // get the default personal namespace root folder
                    var personal = imap.GetFolder(imap.PersonalNamespaces[0]);

                    // This assumes the sent folder's name is "Sent", but use whatever the real name is
                    sent = await personal.GetSubfolderAsync("Sent").ConfigureAwait(false);
                }

                if (sent != null)
                {
                    await sent.AppendAsync(mess, MessageFlags.Seen);
                }

                await imap.DisconnectAsync(true);
            }
            Logger.LogInformation("Email {0} sent to {1} - {2} attachments", subject, recipient, attachments?.Count ?? 0);
        }
    }
}