package vouch

import (
	"fmt"
	"reflect"
)

type Schema map[string][]Rule

func (s Schema) Validate(v any) error {
	val := reflect.ValueOf(v)

	if val.Kind() == reflect.Ptr {
		val = val.Elem()
	}

	if val.Kind() != reflect.Struct {
		panic("expected a struct")
	}

	for i := range val.NumField() {
		field := val.Field(i)
		fieldType := val.Type().Field(i)
		fieldName := fieldType.Name

		if rules, exists := s[fieldName]; exists {
			for _, rule := range rules {
				if err := rule(field.Interface(), field.Kind()); err != nil {
					return fmt.Errorf("field '%s' %s", fieldName, err)
				}
			}
		}
	}

	return nil
}