send: move code to lib for reuse

Move the code which handles the preparation of a sender into which the
message can be written into lib to allow for reuse. Also hide the
sending backend a bit more from the `:send` command code by introducing
a NewSender function which determines which backend should be used and
invokes the appropriate sender factory function.

Rename send() to sendHelper() to avoid collision.

Signed-off-by: Karel Balej <balejk@matfyz.cz>
Acked-by: Robin Jarry <robin@jarry.cc>

1 files changed, 77 insertions, 0 deletions

diff --git a/lib/send/sasl.go b/lib/send/sasl.go
new file mode 100644
index 00000000..01e006e3
--- /dev/null
+++ b/lib/send/sasl.go
@@ -0,0 +1,77 @@
+package send
+
+import (
+	"fmt"
+	"net/url"
+
+	"github.com/emersion/go-sasl"
+	"golang.org/x/oauth2"
+
+	"git.sr.ht/~rjarry/aerc/lib"
+)
+
+func newSaslClient(auth string, uri *url.URL) (sasl.Client, error) {
+	var saslClient sasl.Client
+	switch auth {
+	case "":
+		fallthrough
+	case "none":
+		saslClient = nil
+	case "login":
+		password, _ := uri.User.Password()
+		saslClient = sasl.NewLoginClient(uri.User.Username(), password)
+	case "plain":
+		password, _ := uri.User.Password()
+		saslClient = sasl.NewPlainClient("", uri.User.Username(), password)
+	case "oauthbearer":
+		q := uri.Query()
+		oauth2 := &oauth2.Config{}
+		if q.Get("token_endpoint") != "" {
+			oauth2.ClientID = q.Get("client_id")
+			oauth2.ClientSecret = q.Get("client_secret")
+			oauth2.Scopes = []string{q.Get("scope")}
+			oauth2.Endpoint.TokenURL = q.Get("token_endpoint")
+		}
+		password, _ := uri.User.Password()
+		bearer := lib.OAuthBearer{
+			OAuth2:  oauth2,
+			Enabled: true,
+		}
+		if bearer.OAuth2.Endpoint.TokenURL != "" {
+			token, err := bearer.ExchangeRefreshToken(password)
+			if err != nil {
+				return nil, err
+			}
+			password = token.AccessToken
+		}
+		saslClient = sasl.NewOAuthBearerClient(&sasl.OAuthBearerOptions{
+			Username: uri.User.Username(),
+			Token:    password,
+		})
+	case "xoauth2":
+		q := uri.Query()
+		oauth2 := &oauth2.Config{}
+		if q.Get("token_endpoint") != "" {
+			oauth2.ClientID = q.Get("client_id")
+			oauth2.ClientSecret = q.Get("client_secret")
+			oauth2.Scopes = []string{q.Get("scope")}
+			oauth2.Endpoint.TokenURL = q.Get("token_endpoint")
+		}
+		password, _ := uri.User.Password()
+		bearer := lib.Xoauth2{
+			OAuth2:  oauth2,
+			Enabled: true,
+		}
+		if bearer.OAuth2.Endpoint.TokenURL != "" {
+			token, err := bearer.ExchangeRefreshToken(password)
+			if err != nil {
+				return nil, err
+			}
+			password = token.AccessToken
+		}
+		saslClient = lib.NewXoauth2Client(uri.User.Username(), password)
+	default:
+		return nil, fmt.Errorf("Unsupported auth mechanism %s", auth)
+	}
+	return saslClient, nil
+}