feat: Authors feature backend (and upgraded deprecated mods)

internal/domain/author/authorDomain.go

@@ -0,0 +1,216 @@
+package author
+
+import (
+	"errors"
+	"net/url"
+	"regexp"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+var (
+	ErrAuthorNotFound      = errors.New("author not found")
+	ErrSlugTaken           = errors.New("an author with that slug already exists")
+	ErrAuthorHasArticles   = errors.New("the author is still credited on articles")
+	ErrUserAlreadyLinked   = errors.New("the user already has an author")
+	ErrAuthorAlreadyLinked = errors.New("the author is already linked to a user")
+	ErrAuthorRights        = errors.New("only an owner or admin can change this author")
+	ErrBioTooLong          = errors.New("the bio is too long")
+	ErrInvalidURL          = errors.New("invalid url")
+	ErrTooManyLinks        = errors.New("too many social links")
+	ErrInvalidSlug         = errors.New("invalid slug")
+	ErrInvalidReassign     = errors.New("invalid reassign destination")
+	ErrInvalidSocialType   = errors.New("invalid social link type")
+)
+
+const (
+	MinNameRunes = 1
+	MaxNameRunes = 100
+	MaxSlugRunes = 100
+	MaxBioRunes  = 280
+	MaxURLLength = 2048
+	MaxLinks     = 5
+
+	FallbackSlug = "author"
+
+	SocialX        = "x"
+	SocialLinkedIn = "linkedin"
+	SocialGitHub   = "github"
+	SocialMastodon = "mastodon"
+	SocialCustom   = "custom"
+)
+
+var slugPattern = regexp.MustCompile(`^[a-z0-9]+(-[a-z0-9]+)*$`)
+
+var nonSlugRun = regexp.MustCompile(`[^a-z0-9]+`)
+
+var diacriticFolder = strings.NewReplacer(
+	"à", "a", "á", "a", "â", "a", "ã", "a", "ä", "a", "å", "a", "ā", "a", "ă", "a", "ą", "a",
+	"æ", "ae",
+	"ç", "c", "ć", "c", "č", "c", "ĉ", "c",
+	"ď", "d", "đ", "d",
+	"è", "e", "é", "e", "ê", "e", "ë", "e", "ē", "e", "ė", "e", "ę", "e", "ě", "e",
+	"ğ", "g",
+	"ì", "i", "í", "i", "î", "i", "ï", "i", "ī", "i", "į", "i", "ı", "i",
+	"ł", "l", "ľ", "l",
+	"ñ", "n", "ń", "n", "ň", "n",
+	"ò", "o", "ó", "o", "ô", "o", "õ", "o", "ö", "o", "ø", "o", "ō", "o", "ő", "o",
+	"œ", "oe",
+	"ř", "r",
+	"ś", "s", "š", "s", "ş", "s", "ș", "s",
+	"ß", "ss",
+	"ť", "t", "ț", "t", "ţ", "t",
+	"ù", "u", "ú", "u", "û", "u", "ü", "u", "ū", "u", "ů", "u", "ű", "u", "ų", "u",
+	"ý", "y", "ÿ", "y",
+	"ź", "z", "ż", "z", "ž", "z",
+)
+
+type SocialLink struct {
+	Type string `json:"type"`
+	URL  string `json:"url"`
+}
+
+type Author struct {
+	ID           uint32       `json:"id"`
+	Name         string       `json:"name"`
+	Slug         string       `json:"slug"`
+	Bio          string       `json:"bio"`
+	AvatarID     *uint32      `json:"avatar_id"`
+	Website      *string      `json:"website"`
+	SocialLinks  []SocialLink `json:"social_links"`
+	UserID       *uint32      `json:"user_id"`
+	IsLinked     bool         `json:"is_linked"`
+	ArticleCount int          `json:"article_count"`
+	UserEmail    *string      `json:"user_email,omitempty"`
+}
+
+type Byline struct {
+	ID          uint32       `json:"id"`
+	Name        string       `json:"name"`
+	Slug        string       `json:"slug"`
+	Bio         string       `json:"bio"`
+	AvatarID    *uint32      `json:"avatar_id"`
+	Website     *string      `json:"website"`
+	SocialLinks []SocialLink `json:"social_links"`
+}
+
+func (a Author) Byline() Byline {
+	links := a.SocialLinks
+	if links == nil {
+		links = []SocialLink{}
+	}
+	return Byline{ID: a.ID, Name: a.Name, Slug: a.Slug, Bio: a.Bio, AvatarID: a.AvatarID, Website: a.Website, SocialLinks: links}
+}
+
+type Nullable[T any] struct {
+	Set   bool
+	Value *T
+}
+
+type Patch struct {
+	Name        *string
+	Slug        *string
+	Bio         *string
+	AvatarID    Nullable[uint32]
+	Website     Nullable[string]
+	SocialLinks *[]SocialLink
+	UserID      Nullable[uint32]
+}
+
+type ListQuery struct {
+	Q    string
+	Page int
+	Size int
+}
+
+type Page struct {
+	Items []Author
+	Total int
+}
+
+func IsValidSlug(slug string) bool {
+	length := utf8.RuneCountInString(slug)
+	return length >= 1 && length <= MaxSlugRunes && slugPattern.MatchString(slug)
+}
+
+func IsValidName(name string) bool {
+	length := utf8.RuneCountInString(strings.TrimSpace(name))
+	return length >= MinNameRunes && length <= MaxNameRunes
+}
+
+func ValidateBio(bio string) error {
+	if utf8.RuneCountInString(bio) > MaxBioRunes {
+		return ErrBioTooLong
+	}
+	return nil
+}
+
+func ValidateURL(raw string) error {
+	if raw == "" || len(raw) > MaxURLLength {
+		return ErrInvalidURL
+	}
+	parsed, err := url.Parse(raw)
+	if err != nil || parsed.Scheme != "https" || parsed.Hostname() == "" {
+		return ErrInvalidURL
+	}
+	return nil
+}
+
+func NormalizeWebsite(website *string) (*string, error) {
+	if website == nil || *website == "" {
+		return nil, nil
+	}
+	if err := ValidateURL(*website); err != nil {
+		return nil, err
+	}
+	return website, nil
+}
+
+func IsValidSocialType(linkType string) bool {
+	switch linkType {
+	case SocialX, SocialLinkedIn, SocialGitHub, SocialMastodon, SocialCustom:
+		return true
+	}
+	return false
+}
+
+func ValidateLinks(links []SocialLink) error {
+	if len(links) > MaxLinks {
+		return ErrTooManyLinks
+	}
+	for _, link := range links {
+		if !IsValidSocialType(link.Type) {
+			return ErrInvalidSocialType
+		}
+		if err := ValidateURL(link.URL); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func GenerateSlug(name string) string {
+	folded := diacriticFolder.Replace(strings.ToLower(name))
+	slug := strings.Trim(nonSlugRun.ReplaceAllString(folded, "-"), "-")
+	slug = truncateSlug(slug, MaxSlugRunes)
+	if slug == "" {
+		return FallbackSlug
+	}
+	return slug
+}
+
+func truncateSlug(slug string, limit int) string {
+	if len(slug) <= limit {
+		return slug
+	}
+	return strings.TrimRight(slug[:limit], "-")
+}
+
+func SlugWithSuffix(base string, attempt int) string {
+	if attempt <= 1 {
+		return base
+	}
+	suffix := "-" + strconv.Itoa(attempt)
+	return truncateSlug(base, MaxSlugRunes-len(suffix)) + suffix
+}