<%-
import 'context'
import 'fmt'
import model.package

validation_error = packages.type_for('ValidationError')
raise "ValidationError not found" unless validation_error
import validation_error.package
-%>

func (s *<%= type.name %>) ValidateUniqueness(ctx context.Context, m *<%= model.qualified_name %>) error {
	conditions := map[string]interface{}{
<%- model.fields.select(&:unique).each do |field| -%>
		"<%= field.name %>": m.<%= field.name %>,
<%- end -%>
  }
	for field, value := range conditions {
		q := s.Query().Filter(field+" =", value)
		c, err := s.CountBy(ctx, q)
		if err != nil {
			return err
		}
		b := 0
		if m.IsPersisted() {
			b = 1
		}
		if c > b {
			return &<%= validation_error.qualified_name %>{
				Field:   field,
				Message: fmt.Sprintf("%v has already been taken", value),
			}
		}
	}
	return nil
}