GODT-1657: Stable sync (still needs more tests)

internal/user/sync_build.go

@@ -0,0 +1,88 @@
+package user
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/ProtonMail/gluon/imap"
+	"github.com/ProtonMail/proton-bridge/v2/pkg/message"
+	"github.com/bradenaw/juniper/xslices"
+	"gitlab.protontech.ch/go/liteapi"
+	"golang.org/x/exp/slices"
+)
+
+type buildRes struct {
+	messageID string
+	addressID string
+	update    *imap.MessageCreated
+}
+
+func defaultJobOpts() message.JobOptions {
+	return message.JobOptions{
+		IgnoreDecryptionErrors: true, // Whether to ignore decryption errors and create a "custom message" instead.
+		SanitizeDate:           true, // Whether to replace all dates before 1970 with RFC822's birthdate.
+		AddInternalID:          true, // Whether to include MessageID as X-Pm-Internal-Id.
+		AddExternalID:          true, // Whether to include ExternalID as X-Pm-External-Id.
+		AddMessageDate:         true, // Whether to include message time as X-Pm-Date.
+		AddMessageIDReference:  true, // Whether to include the MessageID in References.
+	}
+}
+
+func (user *User) buildRFC822(ctx context.Context, metadata liteapi.MessageMetadata) (*buildRes, error) {
+	msg, err := user.client.GetMessage(ctx, metadata.ID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get message %s: %w", metadata.ID, err)
+	}
+
+	attData, err := user.attPool.ProcessAll(ctx, xslices.Map(msg.Attachments, func(att liteapi.Attachment) string { return att.ID }))
+	if err != nil {
+		return nil, fmt.Errorf("failed to get attachments for message %s: %w", metadata.ID, err)
+	}
+
+	literal, err := message.BuildRFC822(user.addrKRs[msg.AddressID], msg, attData, defaultJobOpts())
+	if err != nil {
+		return nil, fmt.Errorf("failed to build message %s: %w", metadata.ID, err)
+	}
+
+	update, err := newMessageCreatedUpdate(metadata, literal)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create IMAP update for message %s: %w", metadata.ID, err)
+	}
+
+	return &buildRes{
+		messageID: metadata.ID,
+		addressID: metadata.AddressID,
+		update:    update,
+	}, nil
+}
+
+func newMessageCreatedUpdate(message liteapi.MessageMetadata, literal []byte) (*imap.MessageCreated, error) {
+	parsedMessage, err := imap.NewParsedMessage(literal)
+	if err != nil {
+		return nil, err
+	}
+
+	flags := imap.NewFlagSet()
+
+	if !message.Unread {
+		flags = flags.Add(imap.FlagSeen)
+	}
+
+	if slices.Contains(message.LabelIDs, liteapi.StarredLabel) {
+		flags = flags.Add(imap.FlagFlagged)
+	}
+
+	imapMessage := imap.Message{
+		ID:    imap.MessageID(message.ID),
+		Flags: flags,
+		Date:  time.Unix(message.Time, 0),
+	}
+
+	return &imap.MessageCreated{
+		Message:       imapMessage,
+		Literal:       literal,
+		LabelIDs:      mapTo[string, imap.LabelID](xslices.Filter(message.LabelIDs, wantLabelID)),
+		ParsedMessage: parsedMessage,
+	}, nil
+}