initiall commit

apps/backend/internal/validation/validator.go

@@ -0,0 +1,178 @@
+package validation
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+var (
+	// SlugRegex matches valid slugs (lowercase alphanumeric with hyphens)
+	SlugRegex = regexp.MustCompile(`^[a-z0-9]+(?:-[a-z0-9]+)*$`)
+	
+	// EmailRegex matches valid email addresses
+	EmailRegex = regexp.MustCompile(`^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`)
+	
+	// BucketNameRegex matches valid bucket names
+	BucketNameRegex = regexp.MustCompile(`^[a-z0-9][a-z0-9-]*[a-z0-9]$`)
+)
+
+// ValidationError represents a validation error
+type ValidationError struct {
+	Field   string `json:"field"`
+	Message string `json:"message"`
+}
+
+// Error implements the error interface
+func (ve ValidationError) Error() string {
+	return fmt.Sprintf("%s: %s", ve.Field, ve.Message)
+}
+
+// ValidationErrors is a collection of validation errors
+type ValidationErrors []ValidationError
+
+// Error implements the error interface
+func (ve ValidationErrors) Error() string {
+	if len(ve) == 0 {
+		return ""
+	}
+	
+	var messages []string
+	for _, err := range ve {
+		messages = append(messages, err.Error())
+	}
+	return strings.Join(messages, "; ")
+}
+
+// Validator provides validation functions
+type Validator struct {
+	errors ValidationErrors
+}
+
+// New creates a new validator
+func New() *Validator {
+	return &Validator{
+		errors: make(ValidationErrors, 0),
+	}
+}
+
+// Required checks if a field is not empty
+func (v *Validator) Required(field, value string) *Validator {
+	if strings.TrimSpace(value) == "" {
+		v.errors = append(v.errors, ValidationError{
+			Field:   field,
+			Message: "is required",
+		})
+	}
+	return v
+}
+
+// MinLength checks if a field meets minimum length
+func (v *Validator) MinLength(field, value string, min int) *Validator {
+	if len(value) < min {
+		v.errors = append(v.errors, ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("must be at least %d characters", min),
+		})
+	}
+	return v
+}
+
+// MaxLength checks if a field doesn't exceed maximum length
+func (v *Validator) MaxLength(field, value string, max int) *Validator {
+	if len(value) > max {
+		v.errors = append(v.errors, ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("must not exceed %d characters", max),
+		})
+	}
+	return v
+}
+
+// Email checks if a field is a valid email
+func (v *Validator) Email(field, value string) *Validator {
+	if value != "" && !EmailRegex.MatchString(value) {
+		v.errors = append(v.errors, ValidationError{
+			Field:   field,
+			Message: "must be a valid email address",
+		})
+	}
+	return v
+}
+
+// Slug checks if a field is a valid slug
+func (v *Validator) Slug(field, value string) *Validator {
+	if value != "" && !SlugRegex.MatchString(value) {
+		v.errors = append(v.errors, ValidationError{
+			Field:   field,
+			Message: "must be a valid slug (lowercase letters, numbers, and hyphens)",
+		})
+	}
+	return v
+}
+
+// BucketName checks if a field is a valid bucket name
+func (v *Validator) BucketName(field, value string) *Validator {
+	if value != "" {
+		if !BucketNameRegex.MatchString(value) {
+			v.errors = append(v.errors, ValidationError{
+				Field:   field,
+				Message: "must be a valid bucket name (lowercase letters, numbers, and hyphens, cannot start or end with hyphen)",
+			})
+		}
+		if len(value) < 3 || len(value) > 63 {
+			v.errors = append(v.errors, ValidationError{
+				Field:   field,
+				Message: "must be between 3 and 63 characters",
+			})
+		}
+	}
+	return v
+}
+
+// OneOf checks if a field value is one of the allowed values
+func (v *Validator) OneOf(field, value string, allowed []string) *Validator {
+	if value != "" {
+		found := false
+		for _, a := range allowed {
+			if value == a {
+				found = true
+				break
+			}
+		}
+		if !found {
+			v.errors = append(v.errors, ValidationError{
+				Field:   field,
+				Message: fmt.Sprintf("must be one of: %s", strings.Join(allowed, ", ")),
+			})
+		}
+	}
+	return v
+}
+
+// Custom adds a custom validation error
+func (v *Validator) Custom(field, message string) *Validator {
+	v.errors = append(v.errors, ValidationError{
+		Field:   field,
+		Message: message,
+	})
+	return v
+}
+
+// Valid returns true if there are no validation errors
+func (v *Validator) Valid() bool {
+	return len(v.errors) == 0
+}
+
+// Errors returns all validation errors
+func (v *Validator) Errors() ValidationErrors {
+	return v.errors
+}
+
+// FirstError returns the first validation error or nil
+func (v *Validator) FirstError() error {
+	if len(v.errors) > 0 {
+		return v.errors[0]
+	}
+	return nil
+}