Use mattermost v5 module (#1192)

vendor/github.com/mattermost/go-i18n/i18n/translation/translation.go

@@ -0,0 +1,84 @@
+// Package translation defines the interface for a translation.
+package translation
+
+import (
+	"fmt"
+
+	"github.com/mattermost/go-i18n/i18n/language"
+)
+
+// Translation is the interface that represents a translated string.
+type Translation interface {
+	// MarshalInterface returns the object that should be used
+	// to serialize the translation.
+	MarshalInterface() interface{}
+	MarshalFlatInterface() interface{}
+	ID() string
+	Template(language.Plural) *template
+	UntranslatedCopy() Translation
+	Normalize(language *language.Language) Translation
+	Backfill(src Translation) Translation
+	Merge(Translation) Translation
+	Incomplete(l *language.Language) bool
+}
+
+// SortableByID implements sort.Interface for a slice of translations.
+type SortableByID []Translation
+
+func (a SortableByID) Len() int           { return len(a) }
+func (a SortableByID) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a SortableByID) Less(i, j int) bool { return a[i].ID() < a[j].ID() }
+
+// NewTranslation reflects on data to create a new Translation.
+//
+// data["id"] must be a string and data["translation"] must be either a string
+// for a non-plural translation or a map[string]interface{} for a plural translation.
+func NewTranslation(data map[string]interface{}) (Translation, error) {
+	id, ok := data["id"].(string)
+	if !ok {
+		return nil, fmt.Errorf(`missing "id" key`)
+	}
+	var pluralObject map[string]interface{}
+	switch translation := data["translation"].(type) {
+	case string:
+		tmpl, err := newTemplate(translation)
+		if err != nil {
+			return nil, err
+		}
+		return &singleTranslation{id, tmpl}, nil
+	case map[interface{}]interface{}:
+		// The YAML parser uses interface{} keys so we first convert them to string keys.
+		pluralObject = make(map[string]interface{})
+		for k, v := range translation {
+			kstr, ok := k.(string)
+			if !ok {
+				return nil, fmt.Errorf(`invalid plural category type %T; expected string`, k)
+			}
+			pluralObject[kstr] = v
+		}
+	case map[string]interface{}:
+		pluralObject = translation
+	case nil:
+		return nil, fmt.Errorf(`missing "translation" key`)
+	default:
+		return nil, fmt.Errorf(`unsupported type for "translation" key %T`, translation)
+	}
+
+	templates := make(map[language.Plural]*template, len(pluralObject))
+	for k, v := range pluralObject {
+		pc, err := language.NewPlural(k)
+		if err != nil {
+			return nil, err
+		}
+		str, ok := v.(string)
+		if !ok {
+			return nil, fmt.Errorf(`plural category "%s" has value of type %T; expected string`, pc, v)
+		}
+		tmpl, err := newTemplate(str)
+		if err != nil {
+			return nil, err
+		}
+		templates[pc] = tmpl
+	}
+	return &pluralTranslation{id, templates}, nil
+}