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, 35 insertions, 0 deletions

diff --git a/lib/send/sender.go b/lib/send/sender.go
new file mode 100644
index 00000000..a1e03da5
--- /dev/null
+++ b/lib/send/sender.go
@@ -0,0 +1,35 @@
+package send
+
+import (
+	"fmt"
+	"io"
+	"net/url"
+
+	"github.com/emersion/go-message/mail"
+
+	"git.sr.ht/~rjarry/aerc/worker/types"
+)
+
+// NewSender returns an io.WriterCloser into which the caller can write
+// contents of a message. The caller must invoke the Close() method on the
+// sender when finished.
+func NewSender(
+	worker *types.Worker, uri *url.URL, domain string,
+	from *mail.Address, rcpts []*mail.Address,
+) (io.WriteCloser, error) {
+	protocol, auth, err := parseScheme(uri)
+	if err != nil {
+		return nil, err
+	}
+
+	switch protocol {
+	case "smtp", "smtp+insecure", "smtps":
+		return newSmtpSender(protocol, auth, uri, domain, from, rcpts)
+	case "jmap":
+		return newJmapSender(worker, from, rcpts)
+	case "":
+		return newSendmailSender(uri, rcpts)
+	default:
+		return nil, fmt.Errorf("unsupported protocol %s", protocol)
+	}
+}