feat: storage, language rules and migration

internal/domain/article/articleDomain.go

@@ -17,7 +17,7 @@ var (
 	ErrArticleOffline  = errors.New("article is offline")
 
 	ErrInvalidSlug         = errors.New("invalid slug")
-	ErrSlugTaken           = errors.New("another article on this site already uses that slug")
+	ErrSlugTaken           = errors.New("another article on this site in that language already uses that slug")
 	ErrInvalidCanonicalURL = errors.New("invalid canonical url")
 )
 
@@ -134,6 +134,9 @@ type Article struct {
 	SEODismissed      []string        `json:"seo_dismissed"`
 	CreatedAt         time.Time       `json:"created_at"`
 	UpdatedAt         time.Time       `json:"updated_at"`
+	Lang              string          `json:"lang"`
+	StoryID           uint32          `json:"story_id"`
+	ContentRevision   uint32          `json:"-"`
 }
 
 func (a Article) UsesImage(imageID uint32) bool {

internal/domain/article/articleRepositoryInterface.go

@@ -102,7 +102,7 @@ type Repository interface {
 	Delete(id uint32) error
 	FindByBodyContaining(filename string) ([]Article, error)
 	FindByImage(imageID uint32) ([]Article, error)
-	SlugTaken(siteID uint32, slug string, exceptID uint32) (bool, error)
+	SlugTaken(siteID uint32, lang string, slug string, exceptID uint32) (bool, error)
 	ClearImage(imageID uint32) (ImageReferences, error)
 	RestoreImage(references ImageReferences, imageID uint32) error
 	RepointImage(fromImageIDs []uint32, toImageID uint32) ([]uint32, error)

internal/domain/language/languageDomain.go

@@ -0,0 +1,74 @@
+package language
+
+import (
+	"errors"
+	"regexp"
+	"slices"
+	"strings"
+)
+
+var (
+	ErrInvalidLanguage     = errors.New("invalid language tag")
+	ErrUnsupportedLanguage = errors.New("unsupported language")
+	ErrNoDefaultLanguage   = errors.New("the site has no default language")
+)
+
+const (
+	Unassigned   = ""
+	MaxTagLength = 35
+)
+
+var supported = []string{"en", "en-GB", "en-US", "fr", "fr-CA", "pt", "pt-BR", "es", "de", "ar"}
+
+var tagPattern = regexp.MustCompile(`^([A-Za-z]{2,3})(?:-([A-Za-z]{2}))?$`)
+
+func Supported() []string {
+	return slices.Clone(supported)
+}
+
+func Normalize(tag string) (string, error) {
+	parts := tagPattern.FindStringSubmatch(strings.TrimSpace(tag))
+	if parts == nil {
+		return "", ErrInvalidLanguage
+	}
+	normalized := strings.ToLower(parts[1])
+	if parts[2] != "" {
+		normalized += "-" + strings.ToUpper(parts[2])
+	}
+	if !slices.Contains(supported, normalized) {
+		return "", ErrUnsupportedLanguage
+	}
+	return normalized, nil
+}
+
+type Suggestion struct {
+	Tag         string
+	Found       bool
+	Substituted bool
+}
+
+func Suggest(locale *string) Suggestion {
+	if locale == nil {
+		return Suggestion{}
+	}
+	tag, err := Normalize(*locale)
+	if err == nil {
+		return Suggestion{Tag: tag, Found: true}
+	}
+	if !errors.Is(err, ErrUnsupportedLanguage) {
+		return Suggestion{}
+	}
+	base, _, _ := strings.Cut(strings.TrimSpace(*locale), "-")
+	if fallback, err := Normalize(base); err == nil {
+		return Suggestion{Tag: fallback, Found: true, Substituted: true}
+	}
+	return Suggestion{}
+}
+
+type SiteLanguage struct {
+	SiteID    uint32
+	Tag       string
+	IsDefault bool
+	Enabled   bool
+	Confirmed bool
+}

internal/domain/language/languageRepositoryInterface.go

@@ -0,0 +1,7 @@
+package language
+
+type Repository interface {
+	ListBySite(siteID uint32) ([]SiteLanguage, error)
+	LockStartingLanguage(siteID uint32) (string, error)
+	ConfirmDefault(siteID uint32) error
+}

internal/domain/transaction/transactionDomain.go

@@ -5,16 +5,18 @@ import (
 	"RenewCMS/internal/domain/author"
 	"RenewCMS/internal/domain/entry"
 	"RenewCMS/internal/domain/image"
+	"RenewCMS/internal/domain/language"
 	"RenewCMS/internal/domain/site"
 	"context"
 )
 
 type Repositories struct {
-	Articles article.Repository
-	Sites    site.Repository
-	Authors  author.Repository
-	Entries  entry.Repository
-	Images   image.Repository
+	Articles  article.Repository
+	Sites     site.Repository
+	Authors   author.Repository
+	Entries   entry.Repository
+	Images    image.Repository
+	Languages language.Repository
 }
 
 type Transactor interface {