papero/imaputils/connection.go

package imaputils

import (
	"crypto/tls"
	"errors"
	"fmt"
	"os"

	"git.sr.ht/~blallo/papero/config"
	"github.com/emersion/go-imap/client"
)

var ErrUnencrypted = errors.New("the connection is unencrypted")

type IMAPConnection struct {
	config *config.AccountData
	client *client.Client
}

func NewConnection(conf *config.AccountData) *IMAPConnection {
	conn := &IMAPConnection{}
	conn.config = conf
	return conn
}

func (c *IMAPConnection) Start(debug bool) error {
	var err error
	c.client, err = tryConnection(c.config.Host, c.config.Port)
	if err != nil {
		// TODO: allow unencrypted connections
		return err
	}
	if debug {
		c.client.SetDebug(os.Stderr)
	}

	return c.client.Login(c.config.Username, c.config.Password)
}

func (c *IMAPConnection) Close() {
	c.client.Logout()
}

func tryConnection(host string, port int) (*client.Client, error) {
	connString := fmt.Sprintf("%s:%d", host, port)
	c, err := client.DialTLS(connString, nil)
	if err == nil {
		return c, err
	}
	c, err = client.Dial(connString)
	if err != nil {
		return c, err
	}
	err = c.StartTLS(&tls.Config{ServerName: host})
	if err != nil {
		err = ErrUnencrypted
	}
	return c, err
}