@function kf($kf-map, $loop: null) {
  $globals:  _get-globals();
  // nop
  @if not map-get($globals, enabled) { @return (eptv-map: ()); }

  // apply pipeline fn
  $pipeline-fn: map-get($globals, pipeline-fn);
  @if $pipeline-fn != null {
    $kf-map: call($pipeline-fn, $kf-map);
  }

  $eptv-map: _normalize_map-hierarchy($kf-map);
  $total-ms: _calculate-animation-length($eptv-map);
  $seperated: _kf-properties-extractor($eptv-map);
  $eptv-map-seperated:  nth($seperated, 1);
  $eptv-map-seperated: _expand-super-selectors($eptv-map-seperated);
  $eptv-map-seperated: _fill-from-start-and-to-end($eptv-map-seperated, $total-ms);

  @return (
    animation-handle: kf-#{unique-id()},
    total-ms: $total-ms,
    eptv-map: $eptv-map-seperated,
    infinite-loop: if($loop != null, $loop, map-get($globals, infinite-loop)),
    generate-debugger-animation: map-get($kf-map, _kf-debug)
  );
}


@mixin kf($kf-map, $loop: null) {
  $kf-props:         kf($kf-map, $loop);
  $animation-handle: map-get($kf-props, animation-handle);
  $total-ms:         map-get($kf-props, total-ms);
  $eptv-map:         map-get($kf-props, eptv-map);
  $infinite-loop:    map-get($kf-props, infinite-loop);
  $debugger-enabled: map-get($kf-props, generate-debugger-animation);

  @if $debugger-enabled != null { #{$debugger-enabled} { @include _debugger-styles(); } }

  $i: 0;
  @each $selector, $animation-set in $eptv-map {
    $i: $i + 1;
    $selector-animation-name-handle: #{$animation-handle}-#{$i};
    @include _at-root-keyframes($selector-animation-name-handle) {
      $kfs: _make-animation-sets($animation-set, $total-ms);
      @each $set in $kfs {
        #{map-get($set, percent-list)} {
          #{map-get($set, property)}: map-get($set, value);
          @if map-get($set, animation-timing-function) != null {
            animation-timing-function: map-get($set, animation-timing-function);
          }
        }
      }
    }

    #{$selector} {
      animation-fill-mode: forwards;
      animation-iteration-count: if($infinite-loop, infinite, 1);
      animation-name: $selector-animation-name-handle;
      animation-duration: $total-ms;
    }
  }
}