/**
 * Removes the element's gutter margin, regardless of its position in the grid hierarchy or display property. It can target a specific element, or every `nth-child` occurrence. Works only with `block` layouts.
 *
 * @param {List} $query (block)
 *   List of arguments. Supported arguments are `nth-child` selectors (targets a specific pseudo element) and `auto` (targets `last-child`).
 *
 *   When passed an `nth-child` argument of type `*n` with `block` display, the omega mixin automatically adds a clear to the `*n+1` th element. Note that composite arguments such as `2n+1` do not support this feature.
 *
 *   **Deprecation warning**: The omega mixin will no longer take a `$direction` argument. To change the layout direction, use `row($direction)` or set `$default-layout-direction` instead.
 *
 * @example scss - Usage
 *   .element {
 *     @include omega;
 *   }
 *
 *   .nth-element {
 *     @include omega(4n);
 *   }
 *
 * @example css - CSS Output
 *   .element {
 *     margin-right: 0;
 *   }
 *
 *   .nth-element:nth-child(4n) {
 *     margin-right: 0;
 *   }
 *
 *   .nth-element:nth-child(4n+1) {
 *     clear: left;
 *   }
 */
@mixin omega($query: block, $direction: default) {
  $table: belongs-to(table, $query);
  $auto: belongs-to(auto, $query);

  @if $direction != default {
    @include -neat-warn("The omega mixin will no longer take a $direction argument. To change the layout direction, use the direction(){...} mixin.");
  } @else {
    $direction: get-direction($layout-direction, $default-layout-direction);
  }

  @if $table {
    @include -neat-warn("The omega mixin no longer removes padding in table layouts.");
  }

  @if length($query) == 1 {
    @if $auto {
      &:last-child {
        margin-#{$direction}: 0;
      }
    }

    @else if contains-display-value($query) and $table == false {
      margin-#{$direction}: 0;
    }

    @else {
      @include nth-child($query, $direction);
    }
  }

  @else if length($query) == 2 {
    @if $auto {
      &:last-child {
        margin-#{$direction}: 0;
      }
    }

    @else {
      @include nth-child(nth($query, 1), $direction);
    }
  }

  @else {
    @include -neat-warn("Too many arguments passed to the omega() mixin.");
  }
}

@mixin nth-child($query, $direction) {
  $opposite-direction: get-opposite-direction($direction);

  &:nth-child(#{$query}) {
    margin-#{$direction}: 0;
  }

  @if type-of($query) == number {
    &:nth-child(#{$query}+1) {
      clear: $opposite-direction;
    }
  }
}