Import/Export backend prep

internal/transfer/provider_local.go

@@ -0,0 +1,68 @@
+// 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
+
+// LocalProvider implements import from local EML and MBOX file structure.
+type LocalProvider struct {
+	root         string
+	emlProvider  *EMLProvider
+	mboxProvider *MBOXProvider
+}
+
+func NewLocalProvider(root string) *LocalProvider {
+	return &LocalProvider{
+		root:         root,
+		emlProvider:  NewEMLProvider(root),
+		mboxProvider: NewMBOXProvider(root),
+	}
+}
+
+// ID is used for generating transfer ID by combining source and target ID.
+// We want to keep the same rules for import from or export to local files
+// no matter exact path, therefore it returns constant.
+// The same as EML and MBOX.
+func (p *LocalProvider) ID() string {
+	return "local" //nolint[goconst]
+}
+
+// Mailboxes returns all available folder names from root of EML and MBOX files.
+func (p *LocalProvider) Mailboxes(includeEmpty, includeAllMail bool) ([]Mailbox, error) {
+	mailboxes, err := p.emlProvider.Mailboxes(includeEmpty, includeAllMail)
+	if err != nil {
+		return nil, err
+	}
+
+	mboxMailboxes, err := p.mboxProvider.Mailboxes(includeEmpty, includeAllMail)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, mboxMailbox := range mboxMailboxes {
+		found := false
+		for _, mailboxes := range mailboxes {
+			if mboxMailbox.Name == mailboxes.Name {
+				found = true
+				break
+			}
+		}
+		if !found {
+			mailboxes = append(mailboxes, mboxMailbox)
+		}
+	}
+	return mailboxes, nil
+}