feat: SEO backend output (2/4)

internal/infrastructure/useCases/seoRules.go

@@ -0,0 +1,97 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/article"
+	"RenewCMS/internal/domain/site"
+	"slices"
+	"strings"
+	"unicode/utf8"
+)
+
+func metaTitle(art article.Article) (string, string) {
+	if art.SEOTitle != "" {
+		return art.SEOTitle, article.SEOSourceSEOTitle
+	}
+	return art.Title, article.SEOSourceTitle
+}
+
+func resolveDescription(art article.Article, owner site.Site, facts bodyFacts) (string, string) {
+	if art.SEODescription != "" {
+		return art.SEODescription, article.SEOSourceSEODescription
+	}
+	if art.Excerpt != "" {
+		return art.Excerpt, article.SEOSourceExcerpt
+	}
+	if sentence := firstSentence(facts.spacedText); sentence != "" {
+		return sentence, article.SEOSourceBody
+	}
+	if owner.DefaultDescription != "" {
+		return owner.DefaultDescription, article.SEOSourceSite
+	}
+	return "", article.SEOSourceNone
+}
+
+func suggestion(code string, field string, params map[string]int) article.SEOSuggestion {
+	return article.SEOSuggestion{Code: code, Field: field, Params: params}
+}
+
+func rawSuggestions(art article.Article, owner site.Site, facts bodyFacts) []article.SEOSuggestion {
+	suggestions := []article.SEOSuggestion{}
+	title, _ := metaTitle(art)
+	titleRunes := utf8.RuneCountInString(title)
+	if titleRunes > article.SEOTitleMaxRunes {
+		suggestions = append(suggestions, suggestion(article.DismissTitleLong, article.SEOFieldTitle, map[string]int{"length": titleRunes, "max": article.SEOTitleMaxRunes}))
+	}
+	if strings.TrimSpace(title) == "" {
+		suggestions = append(suggestions, suggestion(article.DismissTitleEmpty, article.SEOFieldTitle, map[string]int{}))
+	}
+	description, _ := resolveDescription(art, owner, facts)
+	descriptionRunes := utf8.RuneCountInString(description)
+	if descriptionRunes < article.SEODescriptionMinRunes {
+		suggestions = append(suggestions, suggestion(article.DismissDescShort, article.SEOFieldDescription, map[string]int{"length": descriptionRunes, "min": article.SEODescriptionMinRunes}))
+	}
+	if descriptionRunes > article.SEODescriptionMaxRunes {
+		suggestions = append(suggestions, suggestion(article.DismissDescLong, article.SEOFieldDescription, map[string]int{"length": descriptionRunes, "max": article.SEODescriptionMaxRunes}))
+	}
+	if art.CoverImageID != nil && strings.TrimSpace(art.CoverImageAlt) == "" {
+		suggestions = append(suggestions, suggestion(article.DismissCoverAlt, article.SEOFieldCoverAlt, map[string]int{}))
+	}
+	if art.CoverImageID == nil {
+		suggestions = append(suggestions, suggestion(article.DismissCoverNone, article.SEOFieldCoverID, map[string]int{}))
+	}
+	slugRunes := utf8.RuneCountInString(art.Slug)
+	if slugRunes > article.SEOSlugMaxRunes {
+		suggestions = append(suggestions, suggestion(article.DismissSlugLong, article.SEOFieldSlug, map[string]int{"length": slugRunes, "max": article.SEOSlugMaxRunes}))
+	}
+	if len(art.Authors) == 0 {
+		suggestions = append(suggestions, suggestion(article.DismissNoAuthor, article.SEOFieldAuthors, map[string]int{}))
+	}
+	if facts.textRunes >= article.SEOHeadingMinTextRunes && !facts.hasSubheading {
+		suggestions = append(suggestions, suggestion(article.DismissNoHeading, article.SEOFieldBody, map[string]int{}))
+	}
+	if facts.imagesWithoutAlt > 0 {
+		suggestions = append(suggestions, suggestion(article.DismissBodyAlt, article.SEOFieldBody, map[string]int{"count": facts.imagesWithoutAlt}))
+	}
+	if facts.textRunes < article.SEOShortBodyRunes {
+		suggestions = append(suggestions, suggestion(article.DismissShort, article.SEOFieldBody, map[string]int{"length": facts.textRunes, "min": article.SEOShortBodyRunes}))
+	}
+	return suggestions
+}
+
+func assessSEO(art article.Article, owner site.Site) article.SEOAssessment {
+	facts := analyzeBody(art.Body)
+	kept := []article.SEOSuggestion{}
+	for _, found := range rawSuggestions(art, owner, facts) {
+		if !slices.Contains(art.SEODismissed, found.Code) {
+			kept = append(kept, found)
+		}
+	}
+	status := article.SEOStatusReady
+	if len(kept) > 0 {
+		status = article.SEOStatusSuggestions
+	}
+	if art.Noindex {
+		status = article.SEOStatusHidden
+	}
+	return article.SEOAssessment{Status: status, Suggestions: kept}
+}