create CMS error handling

internal/cms/validation.go

@@ -0,0 +1,136 @@
+package cms
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/asaskevich/govalidator"
+	"github.com/labstack/echo/v4"
+)
+
+var (
+	objectIDPattern = regexp.MustCompile(`^[a-fA-F0-9]{24}$`)
+	filePathPattern = regexp.MustCompile(`^/[^/]*/v\d+/files/[a-fA-F0-9]{24}(/download)?$`)
+)
+
+// ValidationService registers CMS-specific govalidator rules.
+type ValidationService struct{}
+
+// NewValidationService registers custom validators used by CMS forms.
+func NewValidationService() ValidationService {
+	govalidator.CustomTypeTagMap.Set("mediaRef", govalidator.CustomTypeValidator(func(i interface{}, _ interface{}) bool {
+		value, ok := i.(string)
+		if !ok {
+			return false
+		}
+		return isMediaReference(value)
+	}))
+
+	return ValidationService{}
+}
+
+func isMediaReference(value string) bool {
+	if value == "" {
+		return true
+	}
+	if govalidator.IsURL(value) {
+		return true
+	}
+	if objectIDPattern.MatchString(value) {
+		return true
+	}
+	return filePathPattern.MatchString(value)
+}
+
+// ValidateCMSForm validates a CMS create/update payload.
+func ValidateCMSForm(form *CMSForm) error {
+	_, err := govalidator.ValidateStruct(form)
+	return err
+}
+
+// ParseForm binds and validates a CMS form from the request.
+func ParseForm(c echo.Context) (*CMSForm, error) {
+	var form CMSForm
+	if err := c.Bind(&form); err != nil {
+		return nil, fmt.Errorf("invalid request format: %w", err)
+	}
+	if err := ValidateCMSForm(&form); err != nil {
+		return nil, err
+	}
+	return &form, nil
+}
+
+// FormatValidationErrors converts govalidator errors into user-facing messages.
+func FormatValidationErrors(err error) string {
+	if err == nil {
+		return ""
+	}
+
+	errs, ok := err.(govalidator.Errors)
+	if !ok {
+		return humanizeValidationError(err.Error())
+	}
+
+	messages := make([]string, 0, len(errs))
+	for _, item := range errs {
+		messages = append(messages, humanizeValidationError(item.Error()))
+	}
+	return strings.Join(messages, "; ")
+}
+
+func humanizeValidationError(raw string) string {
+	field, rule, ok := parseGovalidatorError(raw)
+	if !ok {
+		return raw
+	}
+
+	label := fieldLabel(field)
+	lowerRule := strings.ToLower(rule)
+
+	switch {
+	case strings.Contains(lowerRule, "mediaref"):
+		return label + " must be a valid URL or uploaded file"
+	case strings.Contains(lowerRule, "url"):
+		return label + " must be a valid URL"
+	case strings.Contains(lowerRule, "email"):
+		return label + " must be a valid email address"
+	case strings.Contains(lowerRule, "length"):
+		return label + " has an invalid length"
+	case strings.Contains(lowerRule, "range"):
+		return label + " is out of the allowed range"
+	case strings.Contains(lowerRule, "in("):
+		return label + " has an invalid value"
+	default:
+		return label + " is invalid"
+	}
+}
+
+func parseGovalidatorError(raw string) (field, rule string, ok bool) {
+	parts := strings.SplitN(raw, ": ", 2)
+	if len(parts) != 2 {
+		return "", "", false
+	}
+	return parts[0], parts[1], true
+}
+
+func fieldLabel(field string) string {
+	field = strings.TrimPrefix(field, "CMSForm.")
+	replacer := strings.NewReplacer(
+		"Hero.", "Hero section: ",
+		"Chart.", "Chart section: ",
+		"Features.", "Features section: ",
+		"Challenges.", "Challenges section: ",
+		"Advantages.", "Advantages section: ",
+		"Contact.", "Contact section: ",
+		"Footer.", "Footer section: ",
+		".", " ",
+	)
+	label := replacer.Replace(field)
+	label = strings.ReplaceAll(label, "Cards 0", "card 1")
+	label = strings.ReplaceAll(label, "Cards 1", "card 2")
+	label = strings.ReplaceAll(label, "Cards 2", "card 3")
+	label = strings.ReplaceAll(label, "Cards 3", "card 4")
+	label = strings.ReplaceAll(label, "Cards 4", "card 5")
+	return label
+}