package main

import (
	"log"
	"strconv"

	"github.com/emersion/go-imap/v2/imapclient"
	"github.com/emersion/go-sasl"
	"github.com/emersion/go-smtp"
	"github.com/zalando/go-keyring"
	"gorm.io/gorm"
)

type MailAccountConnection struct {
	gorm.Model
	Email        string `gorm:"uniqueIndex"`
	ImapServer   string
	ImapPort     int
	ImapUsername string
	SmtpServer   string
	SmtpPort     int
	SmtpUsername string
	Password     string             `gorm:"-:all"`
	ImapClient   *imapclient.Client `gorm:"-:all"`
	SmtpClient   *smtp.Client       `gorm:"-:all"`
	SmtpSasl     *sasl.Client       `gorm:"-:all"`
}

var mailConnections = make(map[string]MailAccountConnection)

func (app *App) GetMailConnections() ([]MailAccountConnection, error) {
	userContact := app.GetUserContact()
	connections := make([]MailAccountConnection, len(userContact.Emails))
	for index, email := range userContact.Emails {
		if err := app.DB.
			Where("email = ?", email.Value).
			First(&connections[index]).
			Error; err != nil {
			connections[index].Email = email.Value
			connections[index].ImapUsername = email.Value
			connections[index].ImapPort = 993
			connections[index].SmtpUsername = email.Value
			connections[index].SmtpPort = 465
			continue
		}
		mailPassword, err := keyring.Get(
			app.GetMailPasswordKeyringService(),
			email.Value,
		)
		if err != nil {
			continue
		}
		connections[index].Password = mailPassword

		if connections[index].Email != "" &&
			connections[index].ImapServer != "" &&
			connections[index].ImapPort != 0 &&
			connections[index].ImapUsername != "" &&
			connections[index].SmtpServer != "" &&
			connections[index].SmtpPort != 0 &&
			connections[index].SmtpUsername != "" &&
			connections[index].Password != "" {
			mailConnections[email.Value] = connections[index]
		}
	}

	return connections, nil
}

func (app *App) SaveMailConnection(conn MailAccountConnection) error {
	keyring.Set(
		app.GetMailPasswordKeyringService(),
		conn.Email,
		conn.Password,
	)
	return app.DB.Save(&conn).Error
}

func RemoveMailConnection(address string) {
	if conn, ok := mailConnections[address]; ok {
		if conn.ImapClient != nil {
			conn.ImapClient.Close()
		}
		if conn.SmtpClient != nil {
			conn.SmtpClient.Close()
		}
		delete(mailConnections, address)
	}
}

func (app *App) EstablishMailConnections() {
	_, _ = app.GetMailConnections()
	for key, conn := range mailConnections {
		log.Printf("Attempting to connect to %s...\n", conn.Email)
		var err error

		if conn.ImapClient != nil {
			conn.ImapClient.Close()
		}
		switch conn.ImapPort {
		case 143:
			conn.ImapClient, err = imapclient.DialStartTLS(
				conn.ImapServer+":"+strconv.Itoa(conn.ImapPort),
				nil,
			)
			break
		case 993:
			conn.ImapClient, err = imapclient.DialTLS(
				conn.ImapServer+":"+strconv.Itoa(conn.ImapPort),
				nil,
			)
			break
		default:
			conn.ImapClient, err = imapclient.DialTLS(
				conn.ImapServer+":"+strconv.Itoa(conn.ImapPort),
				nil,
			)
			break
		}
		if err != nil {
			RemoveMailConnection(conn.Email)
			log.Print(err.Error())
			continue
		}

		if err := conn.ImapClient.Login(conn.ImapUsername, conn.Password).Wait(); err != nil {
			RemoveMailConnection(conn.Email)
			log.Print(err.Error())
			continue
		}

		if conn.SmtpClient != nil {
			conn.SmtpClient.Close()
		}
		switch conn.SmtpPort {
		case 25:
			conn.SmtpClient, err = smtp.Dial(conn.SmtpServer + ":" + strconv.Itoa(conn.SmtpPort))
			break
		case 587:
			conn.SmtpClient, err = smtp.DialStartTLS(
				conn.SmtpServer+":"+strconv.Itoa(conn.SmtpPort),
				nil,
			)
			break
		case 465:
			conn.SmtpClient, err = smtp.DialTLS(
				conn.SmtpServer+":"+strconv.Itoa(conn.SmtpPort),
				nil,
			)
			break
		default:
			conn.SmtpClient, err = smtp.DialTLS(
				conn.SmtpServer+":"+strconv.Itoa(conn.SmtpPort),
				nil,
			)
			break
		}
		if err != nil {
			RemoveMailConnection(conn.Email)
			log.Print(err.Error())
			continue
		}

		auth := sasl.NewPlainClient("", conn.SmtpUsername, conn.Password)
		if err := conn.SmtpClient.Auth(auth); err != nil {
			RemoveMailConnection(conn.Email)
			log.Print(err.Error())
			continue
		}
		conn.SmtpSasl = &auth

		mailConnections[key] = conn
		log.Printf("Successfully connected %s!\n", conn.Email)
	}
}

func CloseMailConnections() {
	for key, _ := range mailConnections {
		RemoveMailConnection(key)
	}
}