First working version

internal/naming/naming.go

@@ -0,0 +1,227 @@
+package naming
+
+import (
+	"strings"
+	"unicode"
+)
+
+// ToSnakeCase converts a string to snake_case
+func ToSnakeCase(s string) string {
+	var result []rune
+	for i, r := range s {
+		if unicode.IsUpper(r) {
+			if i > 0 {
+				result = append(result, '_')
+			}
+			result = append(result, unicode.ToLower(r))
+		} else {
+			result = append(result, r)
+		}
+	}
+	return string(result)
+}
+
+// ToPascalCase converts snake_case to PascalCase
+func ToPascalCase(s string) string {
+	parts := strings.Split(s, "_")
+	for i, part := range parts {
+		if len(part) > 0 {
+			parts[i] = strings.ToUpper(part[:1]) + part[1:]
+		}
+	}
+	return strings.Join(parts, "")
+}
+
+// Singularize converts a plural word to singular
+// Uses common English pluralization rules
+func Singularize(word string) string {
+	// Handle empty string
+	if word == "" {
+		return word
+	}
+
+	// Common irregular plurals
+	irregulars := map[string]string{
+		"people":     "person",
+		"men":        "man",
+		"women":      "woman",
+		"children":   "child",
+		"teeth":      "tooth",
+		"feet":       "foot",
+		"mice":       "mouse",
+		"geese":      "goose",
+		"oxen":       "ox",
+		"sheep":      "sheep",
+		"fish":       "fish",
+		"deer":       "deer",
+		"series":     "series",
+		"species":    "species",
+		"quizzes":    "quiz",
+		"analyses":   "analysis",
+		"diagnoses":  "diagnosis",
+		"oases":      "oasis",
+		"theses":     "thesis",
+		"crises":     "crisis",
+		"phenomena":  "phenomenon",
+		"criteria":   "criterion",
+		"data":       "datum",
+	}
+
+	lower := strings.ToLower(word)
+	if singular, ok := irregulars[lower]; ok {
+		return preserveCase(word, singular)
+	}
+
+	// Handle words ending in 'ies' -> 'y'
+	if strings.HasSuffix(lower, "ies") && len(word) > 3 {
+		return word[:len(word)-3] + "y"
+	}
+
+	// Handle words ending in 'ves' -> 'fe' or 'f'
+	if strings.HasSuffix(lower, "ves") && len(word) > 3 {
+		base := word[:len(word)-3]
+		// Common words that end in 'fe'
+		if strings.HasSuffix(strings.ToLower(base), "li") ||
+		   strings.HasSuffix(strings.ToLower(base), "wi") ||
+		   strings.HasSuffix(strings.ToLower(base), "kni") {
+			return base + "fe"
+		}
+		return base + "f"
+	}
+
+	// Handle words ending in 'xes', 'ses', 'shes', 'ches' -> remove 'es'
+	if strings.HasSuffix(lower, "xes") ||
+	   strings.HasSuffix(lower, "ses") ||
+	   strings.HasSuffix(lower, "shes") ||
+	   strings.HasSuffix(lower, "ches") {
+		if len(word) > 2 {
+			return word[:len(word)-2]
+		}
+	}
+
+	// Handle words ending in 'oes' -> 'o'
+	if strings.HasSuffix(lower, "oes") && len(word) > 3 {
+		return word[:len(word)-2]
+	}
+
+	// Handle simple 's' suffix
+	if strings.HasSuffix(lower, "s") && len(word) > 1 {
+		// Don't remove 's' from words that naturally end in 's'
+		if !strings.HasSuffix(lower, "ss") &&
+		   !strings.HasSuffix(lower, "us") &&
+		   !strings.HasSuffix(lower, "is") {
+			return word[:len(word)-1]
+		}
+	}
+
+	return word
+}
+
+// Pluralize converts a singular word to plural
+func Pluralize(word string) string {
+	if word == "" {
+		return word
+	}
+
+	// Common irregular plurals
+	irregulars := map[string]string{
+		"person":     "people",
+		"man":        "men",
+		"woman":      "women",
+		"child":      "children",
+		"tooth":      "teeth",
+		"foot":       "feet",
+		"mouse":      "mice",
+		"goose":      "geese",
+		"ox":         "oxen",
+		"sheep":      "sheep",
+		"fish":       "fish",
+		"deer":       "deer",
+		"series":     "series",
+		"species":    "species",
+		"quiz":       "quizzes",
+		"analysis":   "analyses",
+		"diagnosis":  "diagnoses",
+		"oasis":      "oases",
+		"thesis":     "theses",
+		"crisis":     "crises",
+		"phenomenon": "phenomena",
+		"criterion":  "criteria",
+		"datum":      "data",
+	}
+
+	lower := strings.ToLower(word)
+	if plural, ok := irregulars[lower]; ok {
+		return preserveCase(word, plural)
+	}
+
+	// Already plural (ends in 's' and not special case)
+	if strings.HasSuffix(lower, "s") && !strings.HasSuffix(lower, "us") {
+		return word
+	}
+
+	// Handle words ending in 'y' -> 'ies'
+	if strings.HasSuffix(lower, "y") && len(word) > 1 {
+		prevChar := rune(lower[len(lower)-2])
+		if !isVowel(prevChar) {
+			return word[:len(word)-1] + "ies"
+		}
+	}
+
+	// Handle words ending in 'f' or 'fe' -> 'ves'
+	if strings.HasSuffix(lower, "f") {
+		return word[:len(word)-1] + "ves"
+	}
+	if strings.HasSuffix(lower, "fe") {
+		return word[:len(word)-2] + "ves"
+	}
+
+	// Handle words ending in 'o' -> 'oes'
+	if strings.HasSuffix(lower, "o") && len(word) > 1 {
+		prevChar := rune(lower[len(lower)-2])
+		if !isVowel(prevChar) {
+			return word + "es"
+		}
+	}
+
+	// Handle words ending in 'x', 's', 'sh', 'ch' -> add 'es'
+	if strings.HasSuffix(lower, "x") ||
+	   strings.HasSuffix(lower, "s") ||
+	   strings.HasSuffix(lower, "sh") ||
+	   strings.HasSuffix(lower, "ch") {
+		return word + "es"
+	}
+
+	// Default: just add 's'
+	return word + "s"
+}
+
+// preserveCase preserves the case pattern of the original word
+func preserveCase(original, replacement string) string {
+	if len(original) == 0 {
+		return replacement
+	}
+
+	if unicode.IsUpper(rune(original[0])) {
+		return strings.ToUpper(replacement[:1]) + replacement[1:]
+	}
+	return replacement
+}
+
+// isVowel checks if a rune is a vowel
+func isVowel(r rune) bool {
+	vowels := "aeiouAEIOU"
+	return strings.ContainsRune(vowels, r)
+}
+
+// SingularizeTableName converts a table name to its singular form
+// Handles snake_case table names
+func SingularizeTableName(tableName string) string {
+	parts := strings.Split(tableName, "_")
+	if len(parts) > 0 {
+		// Only singularize the last part
+		lastIdx := len(parts) - 1
+		parts[lastIdx] = Singularize(parts[lastIdx])
+	}
+	return strings.Join(parts, "_")
+}