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|
package imap
import (
"fmt"
"net/url"
"strings"
imapClient "github.com/emersion/go-imap/client"
"github.com/Necoro/feed2imap-go/internal/log"
)
const (
imapsPort = "993"
imapPort = "143"
imapsSchema = "imaps"
imapSchema = "imap"
)
func forceTLS(url *url.URL) bool {
return url.Scheme == imapsSchema || url.Port() == imapsPort
}
func setDefaultScheme(url *url.URL) {
switch url.Scheme {
case imapSchema, imapsSchema:
return
default:
oldScheme := url.Scheme
if url.Port() == imapsPort {
url.Scheme = imapsSchema
} else {
url.Scheme = imapSchema
}
if oldScheme != "" {
log.Warnf("Unknown scheme '%s', defaulting to '%s'", oldScheme, url.Scheme)
}
}
}
func setDefaultPort(url *url.URL) {
if url.Port() == "" {
var port string
if url.Scheme == imapsSchema {
port = imapsPort
} else {
port = imapPort
}
url.Host += ":" + port
}
}
func sanitizeUrl(url *url.URL) {
setDefaultScheme(url)
setDefaultPort(url)
}
func Connect(url *url.URL) (*Client, error) {
var c *imapClient.Client
var err error
sanitizeUrl(url)
forceTls := forceTLS(url)
if forceTls {
c, err = imapClient.DialTLS(url.Host, nil)
if err != nil {
return nil, fmt.Errorf("connecting (TLS) to %s: %w", url.Host, err)
}
log.Print("Connected to ", url.Host, " (TLS)")
} else {
c, err = imapClient.Dial(url.Host)
if err != nil {
return nil, fmt.Errorf("connecting to %s: %w", url.Host, err)
}
}
var client = Client{c: c, host: url.Host, folders: folders{}}
defer func() {
if err != nil {
client.Disconnect()
}
}()
if !forceTls {
var hasStartTls bool // explicit to avoid shadowing err
hasStartTls, err = c.SupportStartTLS()
if err != nil {
return nil, fmt.Errorf("checking for starttls for %s: %w", url.Host, err)
}
if hasStartTls {
if err = c.StartTLS(nil); err != nil {
return nil, fmt.Errorf("enabling starttls for %s: %w", url.Host, err)
}
log.Print("Connected to ", url.Host, " (STARTTLS)")
} else {
log.Print("Connected to ", url.Host, " (Plain)")
}
}
pwd, _ := url.User.Password()
if err = c.Login(url.User.Username(), pwd); err != nil {
return nil, fmt.Errorf("login to %s: %w", url.Host, err)
}
if err = client.fetchDelimiter(); err != nil {
return nil, fmt.Errorf("fetching delimiter: %w", err)
}
client.toplevel = url.Path
if client.toplevel[0] == '/' {
client.toplevel = client.toplevel[1:]
}
client.toplevel = client.FolderName(strings.Split(client.toplevel, "/"))
log.Printf("Determined '%s' as toplevel, with '%s' as delimiter", client.toplevel, client.delimiter)
if err = client.EnsureFolder(client.toplevel); err != nil {
return nil, err
}
return &client, nil
}
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