init push

internal/transport/http/validators/validator.go

@@ -0,0 +1,95 @@
+package validators
+
+import (
+	"fmt"
+	"reflect"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/go-playground/validator/v10"
+
+	"wucher/internal/transport/http/jsonapi"
+)
+
+type Validator struct {
+	validate *validator.Validate
+}
+
+var hoursPattern = regexp.MustCompile(`^\d+(\.\d+)?$`)
+
+// validateHoursOrDate accepts an hours value (e.g. "1200" or "1200.5") or a calendar
+// date "YYYY-MM-DD". Anything else (e.g. "1200 FH") is rejected.
+func validateHoursOrDate(fl validator.FieldLevel) bool {
+	s := strings.TrimSpace(fl.Field().String())
+	if s == "" {
+		return true
+	}
+	if hoursPattern.MatchString(s) {
+		return true
+	}
+	_, err := time.Parse("2006-01-02", s)
+	return err == nil
+}
+
+func New() *Validator {
+	v := validator.New()
+	v.RegisterTagNameFunc(func(fld reflect.StructField) string {
+		name := fld.Tag.Get("json")
+		if name == "" {
+			return fld.Name
+		}
+		if idx := strings.Index(name, ","); idx != -1 {
+			return name[:idx]
+		}
+		return name
+	})
+	_ = v.RegisterValidation("hours_or_date", validateHoursOrDate)
+	return &Validator{validate: v}
+}
+
+func (v *Validator) ValidateStruct(s any) []jsonapi.ErrorObject {
+	if err := v.validate.Struct(s); err != nil {
+		if ve, ok := err.(validator.ValidationErrors); ok {
+			return toJSONAPIErrors(ve)
+		}
+		return []jsonapi.ErrorObject{{
+			Status: "400",
+			Title:  "Invalid request",
+			Detail: err.Error(),
+		}}
+	}
+	return nil
+}
+
+func toJSONAPIErrors(ve validator.ValidationErrors) []jsonapi.ErrorObject {
+	errs := make([]jsonapi.ErrorObject, 0, len(ve))
+	for _, fe := range ve {
+		field := fe.Field()
+		jsonPath := "/data/attributes/" + strings.ReplaceAll(field, ".", "/")
+		errs = append(errs, jsonapi.ErrorObject{
+			Status: "422",
+			Title:  "Validation error",
+			Detail: validationMessage(field, fe),
+			Source: &jsonapi.ErrorSource{Pointer: jsonPath},
+		})
+	}
+	return errs
+}
+
+func validationMessage(field string, fe validator.FieldError) string {
+	switch fe.Tag() {
+	case "required":
+		return field + " is required"
+	case "uuid":
+		return field + " must be a valid UUID"
+	case "email":
+		return field + " must be a valid email address"
+	case "hours_or_date":
+		return field + " must be flight hours (e.g. 1200) or a date in YYYY-MM-DD format"
+	case "oneof":
+		return field + " must be one of: " + fe.Param()
+	default:
+		return fmt.Sprintf("%s is invalid (%s)", field, fe.Tag())
+	}
+}