We build too many walls and not enough bridges

pkg/message/envelope.go

@@ -0,0 +1,48 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package message
+
+import (
+	"net/mail"
+	"time"
+
+	"github.com/ProtonMail/proton-bridge/pkg/pmapi"
+	"github.com/emersion/go-imap"
+)
+
+func GetEnvelope(m *pmapi.Message) *imap.Envelope {
+	messageID := m.ExternalID
+	if messageID == "" {
+		messageID = m.Header.Get("Message-Id")
+	} else {
+		messageID = "<" + messageID + ">"
+	}
+
+	return &imap.Envelope{
+		Date:      time.Unix(m.Time, 0),
+		Subject:   m.Subject,
+		From:      getAddresses([]*mail.Address{m.Sender}),
+		Sender:    getAddresses([]*mail.Address{m.Sender}),
+		ReplyTo:   getAddresses(m.ReplyTos),
+		To:        getAddresses(m.ToList),
+		Cc:        getAddresses(m.CCList),
+		Bcc:       getAddresses(m.BCCList),
+		InReplyTo: m.Header.Get("In-Reply-To"),
+		MessageId: messageID,
+	}
+}