Import/Export backend prep

internal/transfer/message.go

@@ -0,0 +1,100 @@
+// 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 transfer
+
+import (
+	"fmt"
+	"mime"
+	"net/mail"
+	"time"
+)
+
+// Message is data holder passed between import and export.
+type Message struct {
+	ID      string
+	Unread  bool
+	Body    []byte
+	Source  Mailbox
+	Targets []Mailbox
+}
+
+// MessageStatus holds status for message used by progress manager.
+type MessageStatus struct {
+	eventTime time.Time // Time of adding message to the process.
+	rule      *Rule     // Rule with source and target mailboxes.
+	SourceID  string    // Message ID at the source.
+	targetID  string    // Message ID at the target (if any).
+	bodyHash  string    // Hash of the message body.
+
+	exported  bool
+	imported  bool
+	exportErr error
+	importErr error
+
+	// Info about message displayed to user.
+	// This is needed only for failed messages, but we cannot know in advance
+	// which message will fail. We could clear it once the message passed
+	// without any error. However, if we say one message takes about 100 bytes
+	// in average, it's about 100 MB per million of messages, which is fine.
+	Subject string
+	From    string
+	Time    time.Time
+}
+
+func (status *MessageStatus) setDetailsFromHeader(header mail.Header) {
+	dec := &mime.WordDecoder{}
+
+	status.Subject = header.Get("subject")
+	if subject, err := dec.Decode(status.Subject); err == nil {
+		status.Subject = subject
+	}
+
+	status.From = header.Get("from")
+	if from, err := dec.Decode(status.From); err == nil {
+		status.From = from
+	}
+
+	if msgTime, err := header.Date(); err == nil {
+		status.Time = msgTime
+	}
+}
+
+func (status *MessageStatus) hasError(includeMissing bool) bool {
+	return status.exportErr != nil || status.importErr != nil || (includeMissing && !status.imported)
+}
+
+// GetErrorMessage returns error message.
+func (status *MessageStatus) GetErrorMessage() string {
+	return status.getErrorMessage(true)
+}
+
+func (status *MessageStatus) getErrorMessage(includeMissing bool) string {
+	if status.exportErr != nil {
+		return fmt.Sprintf("failed to export: %s", status.exportErr)
+	}
+	if status.importErr != nil {
+		return fmt.Sprintf("failed to import: %s", status.importErr)
+	}
+	if includeMissing && !status.imported {
+		if !status.exported {
+			return "failed to import: lost before read"
+		}
+		return "failed to import: lost in the process"
+	}
+	return ""
+}