/**
 * Variables & Settings
 */
$state-symbol: '\\+';
$state: null !default;
$parent: null !default;
$placeholder-list: ();

@function get-selector-list($_parent) {
  $_selector-list: ();
  $_whitespace-index: str-index($_parent, ' ');

  @if ($_whitespace-index != null) {
    $_first-segment: str-slice($_parent, 1, $_whitespace-index - 1);
    $_second-segment: str-slice($_parent, $_whitespace-index + 1, str-length($_parent));
    $_selector-list: unquote('#{$_first-segment}#{$_second-segment}');
    $_selector-list: simple-selectors($_selector-list);
  } @else {
    $_selector-list: simple-selectors($_parent);
  }

  @return $_selector-list;
}

@function create-selector($_selector) {
  $_final-selector: null;

  @if ($state != null) {
    $_final-selector: selector-nest($state, $_selector);
  } @else {
    $_final-selector: $_selector;
  }

  @return $_final-selector;
}

@function extender-generator($_block) {
  $_extender: null;
  $_extender: $_block;
  @return $_extender;
}

@mixin block($_block) { // BEM Mixin For BLOCK
  $_extender: extender-generator($_block);

  @at-root %#{$_extender} {
    @content;
  }

  @at-root .#{$_extender} {
    @extend %#{$_extender} !optional;
  }

}

@mixin element($_element) { // BEM Mixin For ELEMENT
  $_extender: null;
  $_selector-list: get-selector-list(unquote('#{&}'));

  @each $_selector-item in $_selector-list {
    @if (str-index($_selector-item, $state-symbol) == null) {
      $_extender: str-slice($_selector-item, 2, str-length($_selector-item));
    } @else {
      $state: $_selector-item !global;
    }
  }

  $_extender: unquote('#{$_extender}__#{$_element}');
  @if (index($placeholder-list, $_extender) == null) { //we check if the placeholder is already present
    $placeholder-list: append($placeholder-list, #{$_extender}) !global;

    @at-root %#{$_extender} {
      @content;
    }
  }

  $_selector: unquote('.#{$_extender}');

  @at-root #{create-selector($_selector)} {
    @extend %#{$_extender} !optional;
    @if ($state != null) {
      @content;
    }
  }
}

@mixin modifier($_modifier) { // BEM Mixin For MODIFIER
  $_extender: null;
  $_selector-list: get-selector-list(unquote('#{&}'));

  @each $_selector-item in $_selector-list {
    @if (str-index($_selector-item, $state-symbol) == null) {
      $_extender: str-slice($_selector-item, 2, str-length($_selector-item));
    }
  }

  $_selector: unquote('.#{$_extender}--#{$_modifier}');

  @at-root #{create-selector($_selector)} {
    @extend %#{$_extender} !optional;
    @content;
  }
}

@mixin state($_state, $is-angular-state: false) { // BEM Mixin For STATE
  $_selector: null;
  @if ($is-angular-state == false) {
    $_selector: selector-unify(&, str-insert(unquote('#{$state-symbol}#{$_state}'), '.', 1));
  } @else {

  }

  @at-root #{$_selector} {
    @content;
  }
}