fix: Handle Unicode/emoji in plain text CV with proper centering

- Fix infinite loop caused by byte-based string slicing on multi-byte chars
- Use rune-based operations for proper Unicode handling
- Add template functions: center, separator, box
- Box function creates rounded corners with dynamic width
- Account for emoji display width (2 chars) in calculations
- Make line width configurable via plainTextLineWidth constant

internal/handlers/cv_text.go

@@ -10,6 +10,9 @@ import (
 	"text/template"
 )
 
+// Plain text configuration
+const plainTextLineWidth = 80
+
 // Text-based browsers and CLI tools that should get plain text
 var textBrowsers = []string{
 	"curl",
@@ -80,13 +83,63 @@ func (h *CVHandler) PlainText(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Add base URL and icons setting
+	// Add base URL, icons setting, and line width
 	data["BaseURL"] = h.serverAddr
 	data["Icons"] = showIcons
+	data["LineWidth"] = plainTextLineWidth
 
-	// Load and parse the plain text template
+	// Template functions for text formatting
+	funcMap := template.FuncMap{
+		// center centers text within the line width
+		"center": func(text string) string {
+			runes := []rune(text)
+			textLen := len(runes)
+			if textLen >= plainTextLineWidth {
+				return text
+			}
+			padding := (plainTextLineWidth - textLen) / 2
+			return strings.Repeat(" ", padding) + text
+		},
+		// separator creates a centered separator line
+		"separator": func(char string, length int) string {
+			line := strings.Repeat(char, length)
+			padding := (plainTextLineWidth - length) / 2
+			return strings.Repeat(" ", padding) + line
+		},
+		// box creates a centered box frame with rounded corners around text
+		"box": func(text string) string {
+			// Calculate visual width (emojis display as 2 chars wide)
+			visualWidth := 0
+			for _, r := range text {
+				if r > 0x1F000 { // Emoji range
+					visualWidth += 2
+				} else {
+					visualWidth++
+				}
+			}
+
+			innerPadding := 3 // spaces on each side inside the box
+			boxWidth := visualWidth + (innerPadding * 2) + 2 // padding both sides + 2 border chars
+			topBottom := "╭" + strings.Repeat("─", boxWidth-2) + "╮"
+			middle := "│" + strings.Repeat(" ", innerPadding) + text + strings.Repeat(" ", innerPadding) + "│"
+			bottom := "╰" + strings.Repeat("─", boxWidth-2) + "╯"
+
+			// Center each line (using visual width for proper alignment)
+			centerLine := func(line string, lineVisualWidth int) string {
+				if lineVisualWidth >= plainTextLineWidth {
+					return line
+				}
+				padding := (plainTextLineWidth - lineVisualWidth) / 2
+				return strings.Repeat(" ", padding) + line
+			}
+
+			return centerLine(topBottom, boxWidth) + "\n" + centerLine(middle, boxWidth) + "\n" + centerLine(bottom, boxWidth)
+		},
+	}
+
+	// Load and parse the plain text template with custom functions
 	tmplPath := filepath.Join("templates", "cv-text.txt")
-	tmpl, err := template.New("cv-text.txt").ParseFiles(tmplPath)
+	tmpl, err := template.New("cv-text.txt").Funcs(funcMap).ParseFiles(tmplPath)
 	if err != nil {
 		log.Printf("PlainText: Failed to load template: %v", err)
 		http.Error(w, "Failed to load template", http.StatusInternalServerError)
@@ -142,8 +195,11 @@ func cleanPlainText(text string) string {
 }
 
 // wrapLine wraps a single line to maxLength, preserving leading whitespace
+// Uses runes for proper Unicode/emoji handling
 func wrapLine(line string, maxLength int) []string {
-	if len(line) <= maxLength {
+	runes := []rune(line)
+
+	if len(runes) <= maxLength {
 		return []string{line}
 	}
 
@@ -154,7 +210,7 @@ func wrapLine(line string, maxLength int) []string {
 
 	// Detect leading whitespace for continuation lines
 	indent := ""
-	for _, r := range line {
+	for _, r := range runes {
 		if r == ' ' || r == '\t' {
 			indent += string(r)
 		} else {
@@ -169,7 +225,7 @@ func wrapLine(line string, maxLength int) []string {
 	}
 
 	var wrapped []string
-	remaining := line
+	remaining := runes
 
 	for len(remaining) > maxLength {
 		// Find last space before maxLength
@@ -182,16 +238,25 @@ func wrapLine(line string, maxLength int) []string {
 		}
 
 		// If no space found, force break at maxLength
-		if breakPoint == maxLength && !strings.Contains(remaining[:maxLength], " ") {
-			breakPoint = maxLength
+		if breakPoint == maxLength {
+			hasSpace := false
+			for i := 0; i < maxLength; i++ {
+				if remaining[i] == ' ' {
+					hasSpace = true
+					break
+				}
+			}
+			if !hasSpace {
+				breakPoint = maxLength
+			}
 		}
 
-		wrapped = append(wrapped, remaining[:breakPoint])
-		remaining = indent + strings.TrimLeft(remaining[breakPoint:], " ")
+		wrapped = append(wrapped, string(remaining[:breakPoint]))
+		remaining = []rune(indent + strings.TrimLeft(string(remaining[breakPoint:]), " "))
 	}
 
 	if len(remaining) > 0 {
-		wrapped = append(wrapped, remaining)
+		wrapped = append(wrapped, string(remaining))
 	}
 
 	return wrapped

templates/cv-text.txt

@@ -1,14 +1,14 @@
 ================================================================================
-{{if .Icons}}                              📄 CURRICULUM VITAE
-{{else}}                                CURRICULUM VITAE
+{{if .Icons}}{{center "📄 CURRICULUM VITAE"}}
+{{else}}{{center "CURRICULUM VITAE"}}
 {{end}}================================================================================
 
-{{if .Icons}}                         👤 {{.CV.Personal.Name}}
-{{else}}                            {{.CV.Personal.Name}}
+{{if .Icons}}{{center (printf "👤 %s" .CV.Personal.Name)}}
+{{else}}{{center .CV.Personal.Name}}
+{{end}}
+{{if .Icons}}{{box (printf "💼 %s" .CV.Personal.Title)}}
+{{else}}{{box .CV.Personal.Title}}
 {{end}}
-                ┌─────────────────────────────────────────────┐
-                │    {{.CV.Personal.Title}}    │
-                └─────────────────────────────────────────────┘
 
 - {{if .Icons}}📍{{else}}Location:{{end}} {{.CV.Personal.Location}}