Bash Alias with ternary?

Still dipping my toes in bash coding and trying to crate a 1 liner alias to:

• if 'perms' is entered w/out a parameter, it does a stat -c '%a - %n' *
• else if 'perms' is entered with a parameter it does stat -c '%a - %n' <parameter>
• Goal is if no param added, shows perms for all files/folders, else show perms for specified file/folder.

I've gotten this far with 2 different versions, but they both result in the same thing; WITH a parameter added it works fine; without a parameter it isn't getting the * added and the command says it requires a parameter. So for some reason the "if true" part is not filling the $a var, but the "else" part does fill it.

alias perms="a=$(if [ -z '$@' ]; then *; else $@; fi) stat -c '%a - %n' $a"

alias perms="a=$([[ -z '$1' ]] && '*' || $1) stat -c '%a - %n' $a"

This should be a function. (Most things people try to use aliases for should be functions.)

perms () {
  if [ $# -eq 0 ]; then
    stat -c '%a -%n' *
  else
    stat -c '%a - %n' "$@"
  fi
}