Add support for import/export of profile icon

profile/icon.go

@@ -1,9 +1,16 @@
 package profile
 
 import (
+	"errors"
+	"fmt"
 	"strings"
+	"sync"
 
+	"github.com/vincent-petithory/dataurl"
 	"golang.org/x/exp/slices"
+
+	"github.com/safing/portbase/database"
+	"github.com/safing/portbase/database/record"
 )
 
 // Icon describes an icon.
@@ -58,3 +65,68 @@ func sortAndCompactIcons(icons []Icon) []Icon {
 
 	return icons
 }
+
+// GetIconAsDataURL returns the icon data as a data URL.
+func (icon *Icon) GetIconAsDataURL() (bloburl string, err error) {
+	switch icon.Type {
+	case IconTypeFile:
+		return "", errors.New("getting icon from file is not supported")
+
+	case IconTypeDatabase:
+		if !strings.HasPrefix(icon.Value, "cache:icons/") {
+			return "", errors.New("invalid icon db key")
+		}
+		r, err := iconDB.Get(icon.Value)
+		if err != nil {
+			return "", err
+		}
+		dbIcon, err := EnsureIconInDatabase(r)
+		if err != nil {
+			return "", err
+		}
+		return dbIcon.IconData, nil
+
+	case IconTypeAPI:
+		data, err := GetProfileIcon(icon.Value)
+		if err != nil {
+			return "", err
+		}
+		return dataurl.EncodeBytes(data), nil
+
+	default:
+		return "", errors.New("unknown icon type")
+	}
+}
+
+var iconDB = database.NewInterface(&database.Options{
+	Local:    true,
+	Internal: true,
+})
+
+type IconInDatabase struct {
+	sync.Mutex
+	record.Base
+
+	IconData string `json:"iconData,omitempty"` // DataURL
+}
+
+// EnsureIconInDatabase ensures that the given record is a *IconInDatabase, and returns it.
+func EnsureIconInDatabase(r record.Record) (*IconInDatabase, error) {
+	// unwrap
+	if r.IsWrapped() {
+		// only allocate a new struct, if we need it
+		newIcon := &IconInDatabase{}
+		err := record.Unwrap(r, newIcon)
+		if err != nil {
+			return nil, err
+		}
+		return newIcon, nil
+	}
+
+	// or adjust type
+	newIcon, ok := r.(*IconInDatabase)
+	if !ok {
+		return nil, fmt.Errorf("record not of type *IconInDatabase, but %T", r)
+	}
+	return newIcon, nil
+}

profile/icons.go

@@ -17,6 +17,11 @@ var profileIconStoragePath = ""
 
 // GetProfileIcon returns the profile icon with the given ID and extension.
 func GetProfileIcon(name string) (data []byte, err error) {
+	// Check if enabled.
+	if profileIconStoragePath == "" {
+		return nil, errors.New("api icon storage not configured")
+	}
+
 	// Build storage path.
 	iconPath := filepath.Clean(
 		filepath.Join(profileIconStoragePath, name),