////
/// (c) hidoo | MIT License
/// @group placeholder features
////

@use "sass:list";
@use "sass:meta";
@use "../../../settings";

/// defined placeholders.
/// @access private
/// @type List
///
$_already-defined: () !default;

/// define placeholder class.
/// @param {String} $name - name of placeholder class
///
/// @example scss - scss inputs
///   .selector {
///     $name: unique-id();
///
///     @include mixin.placeholder-define($name: $name) {
///       font-size: 16px;
///     }
///
///     &__child-1 {
///       @extend %#{$name};
///     }
///
///     &__child-2 {
///       @extend %#{$name};
///     }
///   }
///
/// @example css - css outputs
///   .selector__child-1, .selector__child-2 {
///      font-size: 16px;
///   }
///
@mixin define($name) {
  @if meta.type-of($name) != "string" or $name == "" {
    @error "@mixin mixin.placeholder-define: Argument $name is not valid string.";
  }

  // define placeholder if not already defined
  @if list.index($_already-defined, $name) {
    @if settings.$verbose {
      @warn "@mixin mixin.placeholder-define: '%#{$name}' placeholder is already defined and cannot be redefined.";
    }
  } @else {
    @at-root {
      %#{$name} {
        @content;
      }
    }

    // cache defined placeholder
    $_already-defined: list.append($_already-defined, $name) !global;
  }
}