func (u *UniterAPIV3) charmModifiedVersion(tagStr string, canAccess func(names.Tag) bool) (int, error) {
tag, err := names.ParseTag(tagStr)
if err != nil {
return -1, common.ErrPerm
}
if !canAccess(tag) {
return -1, common.ErrPerm
}
unitOrService, err := u.st.FindEntity(tag)
if err != nil {
return -1, err
}
var service *state.Service
switch entity := unitOrService.(type) {
case *state.Service:
service = entity
case *state.Unit:
service, err = entity.Service()
if err != nil {
return -1, err
}
default:
return -1, errors.BadRequestf("type %t does not have a CharmModifiedVersion", entity)
}
return service.CharmModifiedVersion(), nil
}