package typeutil

import (
	"fmt"
	"reflect"
)

// TypeOf is a utility that can covert a T type to a package + type name for generic types.
func TypeOf[T any]() string {
	var inst T
	var prefix string

	// get a reflect.Type of a variable with type T
	t := reflect.TypeOf(inst)

	// pointer types do not carry the adequate type information, so we need to extract the
	// underlying types until we reach the non-pointer type, we prepend a * each depth
	for t != nil && t.Kind() == reflect.Pointer {
		prefix += "*"
		t = t.Elem()
	}

	// this should not be possible, but in the event that it does, we want to be loud about it
	if t == nil {
		panic(fmt.Sprintf("Unable to generate a key for type: %+v", reflect.TypeOf(inst)))
	}

	// combine the prefix, package path, and the type name
	return fmt.Sprintf("%s%s/%s", prefix, t.PkgPath(), t.Name())
}