refactor(showcase): decompose formatGemtext and guard zero totals (oq)

2 files changed, 197 insertions, 135 deletions

diff --git a/internal/showcase/showcase.go b/internal/showcase/showcase.go
index 7b80de6..90a4dc7 100644
--- a/internal/showcase/showcase.go
+++ b/internal/showcase/showcase.go
@@ -860,10 +860,29 @@ func (g *Generator) generateProjectSummary(repoName string, forceRegenerate bool
 	return projectSummary, nil
 }
 
-// formatGemtext formats the summaries as Gemini Gemtext
+type showcaseOverviewStats struct {
+	totalProjects int
+	totalCommits  int
+	totalLOC      int
+	totalDocs     int
+	releasedCount int
+	languageStats []LanguageStats
+	docStats      []LanguageStats
+}
+
+// formatGemtext formats the summaries as Gemini Gemtext.
 func (g *Generator) formatGemtext(summaries []ProjectSummary) string {
 	var builder strings.Builder
 
+	writeGemtextHeader(&builder)
+	stats := collectShowcaseOverviewStats(summaries)
+	writeShowcaseOverviewStats(&builder, stats)
+	g.writeProjectsGemtext(&builder, summaries)
+
+	return builder.String()
+}
+
+func writeGemtextHeader(builder *strings.Builder) {
 	// Header
 	builder.WriteString("# Project Showcase\n\n")
 
@@ -879,192 +898,195 @@ func (g *Generator) formatGemtext(summaries []ProjectSummary) string {
 
 	// Template inline TOC
 	builder.WriteString("<< template::inline::toc\n\n")
+}
 
-	// Calculate total stats
-	totalProjects := len(summaries)
-	totalCommits := 0
-	totalLOC := 0
-	totalDocs := 0
-	releasedCount := 0
+func collectShowcaseOverviewStats(summaries []ProjectSummary) showcaseOverviewStats {
+	stats := showcaseOverviewStats{
+		totalProjects: len(summaries),
+	}
 	languageTotals := make(map[string]int)
 	docTotals := make(map[string]int)
 
 	for _, summary := range summaries {
-		if summary.Metadata != nil {
-			totalCommits += summary.Metadata.CommitCount
-			totalLOC += summary.Metadata.LinesOfCode
-			totalDocs += summary.Metadata.LinesOfDocs
+		if summary.Metadata == nil {
+			continue
+		}
 
-			// Count projects with releases
-			if summary.Metadata.HasReleases {
-				releasedCount++
-			}
+		stats.totalCommits += summary.Metadata.CommitCount
+		stats.totalLOC += summary.Metadata.LinesOfCode
+		stats.totalDocs += summary.Metadata.LinesOfDocs
 
-			// Aggregate language statistics
-			for _, lang := range summary.Metadata.Languages {
-				languageTotals[lang.Name] += lang.Lines
-			}
+		if summary.Metadata.HasReleases {
+			stats.releasedCount++
+		}
 
-			// Aggregate documentation statistics
-			for _, doc := range summary.Metadata.Documentation {
-				docTotals[doc.Name] += doc.Lines
-			}
+		for _, lang := range summary.Metadata.Languages {
+			languageTotals[lang.Name] += lang.Lines
 		}
-	}
 
-	// Calculate language percentages
-	var languageStats []LanguageStats
-	for name, lines := range languageTotals {
-		percentage := 0.0
-		if totalLOC > 0 {
-			percentage = float64(lines) * 100.0 / float64(totalLOC)
+		for _, doc := range summary.Metadata.Documentation {
+			docTotals[doc.Name] += doc.Lines
 		}
-		languageStats = append(languageStats, LanguageStats{
-			Name:       name,
-			Lines:      lines,
-			Percentage: percentage,
-		})
 	}
 
-	// Sort languages by percentage
-	sort.Slice(languageStats, func(i, j int) bool {
-		return languageStats[i].Percentage > languageStats[j].Percentage
-	})
+	stats.languageStats = buildSortedPercentageStats(languageTotals, stats.totalLOC)
+	stats.docStats = buildSortedPercentageStats(docTotals, stats.totalDocs)
+	return stats
+}
 
-	// Calculate documentation percentages
-	var docStats []LanguageStats
-	for name, lines := range docTotals {
+func buildSortedPercentageStats(lineTotalsByName map[string]int, totalLines int) []LanguageStats {
+	stats := make([]LanguageStats, 0, len(lineTotalsByName))
+	for name, lines := range lineTotalsByName {
 		percentage := 0.0
-		if totalDocs > 0 {
-			percentage = float64(lines) * 100.0 / float64(totalDocs)
+		if totalLines > 0 {
+			percentage = float64(lines) * 100.0 / float64(totalLines)
 		}
-		docStats = append(docStats, LanguageStats{
+		stats = append(stats, LanguageStats{
 			Name:       name,
 			Lines:      lines,
 			Percentage: percentage,
 		})
 	}
 
-	// Sort documentation by percentage
-	sort.Slice(docStats, func(i, j int) bool {
-		return docStats[i].Percentage > docStats[j].Percentage
+	sort.Slice(stats, func(i, j int) bool {
+		return stats[i].Percentage > stats[j].Percentage
 	})
+	return stats
+}
 
-	// Write total stats section
+func writeShowcaseOverviewStats(builder *strings.Builder, stats showcaseOverviewStats) {
 	builder.WriteString("## Overall Statistics\n\n")
-	builder.WriteString(fmt.Sprintf("* 📦 Total Projects: %d\n", totalProjects))
-	builder.WriteString(fmt.Sprintf("* 📊 Total Commits: %s\n", formatNumber(totalCommits)))
-	builder.WriteString(fmt.Sprintf("* 📈 Total Lines of Code: %s\n", formatNumber(totalLOC)))
-	if totalDocs > 0 {
-		builder.WriteString(fmt.Sprintf("* 📄 Total Lines of Documentation: %s\n", formatNumber(totalDocs)))
+	builder.WriteString(fmt.Sprintf("* 📦 Total Projects: %d\n", stats.totalProjects))
+	builder.WriteString(fmt.Sprintf("* 📊 Total Commits: %s\n", formatNumber(stats.totalCommits)))
+	builder.WriteString(fmt.Sprintf("* 📈 Total Lines of Code: %s\n", formatNumber(stats.totalLOC)))
+	if stats.totalDocs > 0 {
+		builder.WriteString(fmt.Sprintf("* 📄 Total Lines of Documentation: %s\n", formatNumber(stats.totalDocs)))
 	}
-	if len(languageStats) > 0 {
-		builder.WriteString(fmt.Sprintf("* 💻 Languages: %s\n", FormatLanguagesWithPercentages(languageStats)))
+	if len(stats.languageStats) > 0 {
+		builder.WriteString(fmt.Sprintf("* 💻 Languages: %s\n", FormatLanguagesWithPercentages(stats.languageStats)))
 	}
-	if len(docStats) > 0 {
-		builder.WriteString(fmt.Sprintf("* 📚 Documentation: %s\n", FormatLanguagesWithPercentages(docStats)))
+	if len(stats.docStats) > 0 {
+		builder.WriteString(fmt.Sprintf("* 📚 Documentation: %s\n", FormatLanguagesWithPercentages(stats.docStats)))
 	}
-	experimentalCount := totalProjects - releasedCount
+
+	experimentalCount, releasedPercentage, experimentalPercentage := releaseStatusBreakdown(stats.totalProjects, stats.releasedCount)
 	builder.WriteString(fmt.Sprintf("* 🚀 Release Status: %d released, %d experimental (%.1f%% with releases, %.1f%% experimental)\n",
-		releasedCount, experimentalCount,
-		float64(releasedCount)*100/float64(totalProjects),
-		float64(experimentalCount)*100/float64(totalProjects)))
+		stats.releasedCount, experimentalCount, releasedPercentage, experimentalPercentage))
 	builder.WriteString("\n")
+}
+
+func releaseStatusBreakdown(totalProjects, releasedCount int) (experimentalCount int, releasedPercentage, experimentalPercentage float64) {
+	experimentalCount = totalProjects - releasedCount
+	if totalProjects == 0 {
+		return experimentalCount, 0, 0
+	}
+	releasedPercentage = float64(releasedCount) * 100 / float64(totalProjects)
+	experimentalPercentage = float64(experimentalCount) * 100 / float64(totalProjects)
+	return experimentalCount, releasedPercentage, experimentalPercentage
+}
 
-	// Add Projects section
+func (g *Generator) writeProjectsGemtext(builder *strings.Builder, summaries []ProjectSummary) {
 	builder.WriteString("## Projects\n\n")
 
-	// Add each project
 	for i, summary := range summaries {
 		if i > 0 {
 			builder.WriteString("\n---\n\n")
 		}
 
-		builder.WriteString(fmt.Sprintf("### %d. %s%s\n\n", i+1, summary.Name, formatRankHistoryForHeader(summary.RankHistory)))
+		g.writeProjectGemtext(builder, i, summary)
+	}
+}
 
-		// Add metadata if available
-		if summary.Metadata != nil {
-			if len(summary.Metadata.Languages) > 0 {
-				builder.WriteString(fmt.Sprintf("* 💻 Languages: %s\n", FormatLanguagesWithPercentages(summary.Metadata.Languages)))
-			}
-			if len(summary.Metadata.Documentation) > 0 {
-				builder.WriteString(fmt.Sprintf("* 📚 Documentation: %s\n", FormatLanguagesWithPercentages(summary.Metadata.Documentation)))
-			}
-			builder.WriteString(fmt.Sprintf("* 📊 Commits: %d\n", summary.Metadata.CommitCount))
-			builder.WriteString(fmt.Sprintf("* 📈 Lines of Code: %d\n", summary.Metadata.LinesOfCode))
-			if summary.Metadata.LinesOfDocs > 0 {
-				builder.WriteString(fmt.Sprintf("* 📄 Lines of Documentation: %d\n", summary.Metadata.LinesOfDocs))
-			}
-			builder.WriteString(fmt.Sprintf("* 🏷️ Tags: %d\n", summary.Metadata.TagCount))
-			builder.WriteString(fmt.Sprintf("* 📅 Development Period: %s to %s\n", summary.Metadata.FirstCommitDate, summary.Metadata.LastCommitDate))
-			builder.WriteString(fmt.Sprintf("* 🏆 Score: %.1f (combines recent activity, code size, tags, and release status)\n", summary.Metadata.Score))
-			builder.WriteString(fmt.Sprintf("* ⚖️ License: %s\n", summary.Metadata.License))
-
-			// Add release information or experimental status
-			if summary.Metadata.HasReleases && summary.Metadata.LatestTag != "" {
-				if summary.Metadata.LatestTagDate != "" {
-					builder.WriteString(fmt.Sprintf("* 🏷️ Latest Release: %s (%s)\n", summary.Metadata.LatestTag, summary.Metadata.LatestTagDate))
-				} else {
-					builder.WriteString(fmt.Sprintf("* 🏷️ Latest Release: %s\n", summary.Metadata.LatestTag))
-				}
-			} else {
-				builder.WriteString("* 🧪 Status: Experimental (no releases yet)\n")
-			}
+func (g *Generator) writeProjectGemtext(builder *strings.Builder, index int, summary ProjectSummary) {
+	builder.WriteString(fmt.Sprintf("### %d. %s%s\n\n", index+1, summary.Name, formatRankHistoryForHeader(summary.RankHistory)))
+	writeProjectMetadata(builder, summary.Metadata)
+	writeProjectSummaryContent(builder, summary)
+	writeProjectLinks(builder, summary)
+}
 
-			// Mark as inactive when the average age of the last 42 commits exceeds
-			// 730 days (~2 years).  A single recent commit (e.g. a deprecation
-			// notice) does not rescue a dormant project — ~42 recent commits are
-			// required to move the average below the threshold.  This matches the
-			// grey-line rule used in the interactive rank-history SVG.
-			if summary.Metadata.AvgCommitAge > 730 {
-				builder.WriteString("\n⚠️  **Notice**: This project appears to be inactive or no longer maintained. The average age of its last 42 commits exceeds 2 years. Use at your own risk.")
-			}
-			builder.WriteString("\n\n")
-		}
+func writeProjectMetadata(builder *strings.Builder, metadata *RepoMetadata) {
+	if metadata == nil {
+		return
+	}
 
-		// Handle images and paragraphs
-		paragraphs := splitSummaryParagraphs(sanitizeSummaryForGemtext(summary.Summary))
+	if len(metadata.Languages) > 0 {
+		builder.WriteString(fmt.Sprintf("* 💻 Languages: %s\n", FormatLanguagesWithPercentages(metadata.Languages)))
+	}
+	if len(metadata.Documentation) > 0 {
+		builder.WriteString(fmt.Sprintf("* 📚 Documentation: %s\n", FormatLanguagesWithPercentages(metadata.Documentation)))
+	}
+	builder.WriteString(fmt.Sprintf("* 📊 Commits: %d\n", metadata.CommitCount))
+	builder.WriteString(fmt.Sprintf("* 📈 Lines of Code: %d\n", metadata.LinesOfCode))
+	if metadata.LinesOfDocs > 0 {
+		builder.WriteString(fmt.Sprintf("* 📄 Lines of Documentation: %d\n", metadata.LinesOfDocs))
+	}
+	builder.WriteString(fmt.Sprintf("* 🏷️ Tags: %d\n", metadata.TagCount))
+	builder.WriteString(fmt.Sprintf("* 📅 Development Period: %s to %s\n", metadata.FirstCommitDate, metadata.LastCommitDate))
+	builder.WriteString(fmt.Sprintf("* 🏆 Score: %.1f (combines recent activity, code size, tags, and release status)\n", metadata.Score))
+	builder.WriteString(fmt.Sprintf("* ⚖️ License: %s\n", metadata.License))
 
-		// If we have images, distribute them nicely
-		if len(summary.Images) > 0 {
-			// First image after metadata, before text
-			builder.WriteString(fmt.Sprintf("=> %s %s screenshot\n\n", summary.Images[0], summary.Name))
+	// Add release information or experimental status.
+	if metadata.HasReleases && metadata.LatestTag != "" {
+		if metadata.LatestTagDate != "" {
+			builder.WriteString(fmt.Sprintf("* 🏷️ Latest Release: %s (%s)\n", metadata.LatestTag, metadata.LatestTagDate))
+		} else {
+			builder.WriteString(fmt.Sprintf("* 🏷️ Latest Release: %s\n", metadata.LatestTag))
+		}
+	} else {
+		builder.WriteString("* 🧪 Status: Experimental (no releases yet)\n")
+	}
 
-			// First paragraph
-			if len(paragraphs) > 0 {
-				builder.WriteString(fmt.Sprintf("%s\n\n", strings.TrimSpace(paragraphs[0])))
-			}
+	// Mark as inactive when the average age of the last 42 commits exceeds
+	// 730 days (~2 years).  A single recent commit (e.g. a deprecation
+	// notice) does not rescue a dormant project — ~42 recent commits are
+	// required to move the average below the threshold.  This matches the
+	// grey-line rule used in the interactive rank-history SVG.
+	if metadata.AvgCommitAge > 730 {
+		builder.WriteString("\n⚠️  **Notice**: This project appears to be inactive or no longer maintained. The average age of its last 42 commits exceeds 2 years. Use at your own risk.")
+	}
+	builder.WriteString("\n\n")
+}
 
-			// Second image after first paragraph (if we have 2 images and multiple paragraphs)
-			if len(summary.Images) > 1 && len(paragraphs) > 1 {
-				builder.WriteString(fmt.Sprintf("=> %s %s screenshot\n\n", summary.Images[1], summary.Name))
-			}
+func writeProjectSummaryContent(builder *strings.Builder, summary ProjectSummary) {
+	paragraphs := splitSummaryParagraphs(sanitizeSummaryForGemtext(summary.Summary))
 
-			// Remaining paragraphs
-			for i := 1; i < len(paragraphs); i++ {
-				builder.WriteString(fmt.Sprintf("%s\n\n", strings.TrimSpace(paragraphs[i])))
-			}
-		} else {
-			// No images - just add all paragraphs
-			for _, para := range paragraphs {
-				builder.WriteString(fmt.Sprintf("%s\n\n", strings.TrimSpace(para)))
-			}
-		}
+	if len(summary.Images) > 0 {
+		// First image after metadata, before text.
+		builder.WriteString(fmt.Sprintf("=> %s %s screenshot\n\n", summary.Images[0], summary.Name))
 
-		// Add links
-		if summary.CodebergURL != "" {
-			builder.WriteString(fmt.Sprintf("=> %s View on Codeberg\n", summary.CodebergURL))
+		// First paragraph.
+		if len(paragraphs) > 0 {
+			builder.WriteString(fmt.Sprintf("%s\n\n", strings.TrimSpace(paragraphs[0])))
 		}
-		if summary.GitHubURL != "" {
-			builder.WriteString(fmt.Sprintf("=> %s View on GitHub\n", summary.GitHubURL))
+
+		// Second image after first paragraph (if we have 2 images and multiple paragraphs).
+		if len(summary.Images) > 1 && len(paragraphs) > 1 {
+			builder.WriteString(fmt.Sprintf("=> %s %s screenshot\n\n", summary.Images[1], summary.Name))
 		}
-		if summary.CgitURL != "" {
-			builder.WriteString(fmt.Sprintf("=> %s View in cgit\n", summary.CgitURL))
+
+		// Remaining paragraphs.
+		for i := 1; i < len(paragraphs); i++ {
+			builder.WriteString(fmt.Sprintf("%s\n\n", strings.TrimSpace(paragraphs[i])))
 		}
+		return
+	}
 
+	// No images - just add all paragraphs.
+	for _, para := range paragraphs {
+		builder.WriteString(fmt.Sprintf("%s\n\n", strings.TrimSpace(para)))
 	}
+}
 
-	return builder.String()
+func writeProjectLinks(builder *strings.Builder, summary ProjectSummary) {
+	if summary.CodebergURL != "" {
+		builder.WriteString(fmt.Sprintf("=> %s View on Codeberg\n", summary.CodebergURL))
+	}
+	if summary.GitHubURL != "" {
+		builder.WriteString(fmt.Sprintf("=> %s View on GitHub\n", summary.GitHubURL))
+	}
+	if summary.CgitURL != "" {
+		builder.WriteString(fmt.Sprintf("=> %s View in cgit\n", summary.CgitURL))
+	}
 }
 
 // showcaseOutputDir returns the canonical directory where showcase output files
diff --git a/internal/showcase/showcase_test.go b/internal/showcase/showcase_test.go
index ca40293..6341e41 100644
--- a/internal/showcase/showcase_test.go
+++ b/internal/showcase/showcase_test.go
@@ -167,6 +167,46 @@ func TestFormatGemtext_IncludesCgitLink(t *testing.T) {
 	}
 }
 
+func TestFormatGemtext_ZeroProjectsReleasePercentagesAreZero(t *testing.T) {
+	t.Parallel()
+
+	g := &Generator{config: &config.Config{}}
+	content := g.formatGemtext(nil)
+
+	if !strings.Contains(content, "* 🚀 Release Status: 0 released, 0 experimental (0.0% with releases, 0.0% experimental)\n") {
+		t.Fatalf("unexpected release status for zero projects: %s", content)
+	}
+	if strings.Contains(content, "NaN") || strings.Contains(content, "Inf") {
+		t.Fatalf("release status should not include NaN/Inf: %s", content)
+	}
+}
+
+func TestFormatGemtext_ReleaseStatusPercentagesForNonEmptySummaries(t *testing.T) {
+	t.Parallel()
+
+	g := &Generator{config: &config.Config{}}
+	content := g.formatGemtext([]ProjectSummary{
+		{
+			Name:    "released",
+			Summary: "released summary",
+			Metadata: &RepoMetadata{
+				HasReleases: true,
+			},
+		},
+		{
+			Name:    "experimental",
+			Summary: "experimental summary",
+			Metadata: &RepoMetadata{
+				HasReleases: false,
+			},
+		},
+	})
+
+	if !strings.Contains(content, "* 🚀 Release Status: 1 released, 1 experimental (50.0% with releases, 50.0% experimental)\n") {
+		t.Fatalf("unexpected release status for non-empty summaries: %s", content)
+	}
+}
+
 func TestFindReadmeContent_UsesRepoPathWithoutChangingCWD(t *testing.T) {
 	t.Parallel()