package copier

import "reflect"

func (c *copier) lookupAndCopyWithConverter(dst, src reflect.Value, fieldName string) (bool, error) {
	if cnv, ok := c.opt.convertByName[fieldName]; ok {
		return convert(dst, src, cnv)
	}

	if len(c.opt.converters) > 0 {
		pair := converterPair{
			SrcType: src.Type(),
			DstType: dst.Type(),
		}

		if cnv, ok := c.opt.converters[pair]; ok {
			return convert(dst, src, cnv)
		}
	}

	return false, nil
}

func convert(dst, src reflect.Value, fn convertFunc) (bool, error) {
	result, err := fn(src.Interface())
	if err != nil {
		return false, err
	}

	if result != nil {
		dst.Set(reflect.ValueOf(result))
	} else {
		dst.Set(reflect.Zero(dst.Type()))
	}

	return true, nil

}