@function _convert-animation-into-transition-list($animation-map) {
  $animation-map: _normalize-map-hierarchy($animation-map, eptv);
  $seperated: _kf-properties-extractor($animation-map);

  $transition-list: ();
  $m: nth($seperated, 1);
  @each $e, $ptv in $m {
    @each $p, $tv in $ptv {

      $last-t: null;
      $last-v: null;
      $i: 0;

      @each $t, $v in $tv {
        $duration: 0;
        $from: initial;
        @if $last-t != null { $duration: $t - $last-t; }
        @if $last-v != null { $from: $last-v; }

        // E.g. don't put initial state value, only worried about *transitions*
        @if $i > 0 {
          $transition-list: append($transition-list, (
            property: $p,
            selector: $e,
            start: $last-t,
            duration: $duration,
            from: $from,
            to: $v
          ));
        }

        $i: $i + 1;
        $last-t: $t;
        $last-v: $v;
      }
    }
  }

  @return _filter-function($transition-list, _is-valid-transition);
}

@function _is-valid-transition($item) {
  $duration: map-get($item, duration);
  $from: map-get($item, from);
  $to: map-get($item, to);
  @return $from != $to and $duration > 0;
}

@function _get-start-timings-from-transition-list($transition-list) {
  @return _list-uniq(_map-function($transition-list, map-get, start));
}

@function _map-transition-list-into-content-property($transition-list) {
  $message: "";
  @each $item in $transition-list {
    $selector: map-get($item, selector);
    $start: map-get($item, start);
    $duration: map-get($item, duration);
    $end: $start + $duration;
    $from: map-get($item, from);
    $to: map-get($item, to);
    $property: map-get($item, property);

    @if $from != $to and $duration > 0 {
      $append-line: "#{$selector} [#{$property}]: #{$start}::#{$from} → #{$end}::#{$to} (#{$duration})";
      @if $message == "" {
        $message: "#{$append-line}"
      } @else {
        $message: "#{$message}\a#{$append-line}"
      }
    }
  }
  @return $message;
}


@function _generate-debugger-animation($for-selector, $animation-map) {
  $animation-map: _sort-map-keys-deep($animation-map);
  $transition-list: _convert-animation-into-transition-list($animation-map);
  $start-timings: _sort-list(_get-start-timings-from-transition-list($transition-list));

  $tv-set: ();
  $so-far-transition-stack: ();
  @each $timing in $start-timings {
    $transitions-with-start-timing: _filter-function(
      $transition-list, _map-has-key-with-value, start, $timing
    );
    $so-far-transition-stack: join($so-far-transition-stack, $transitions-with-start-timing);
    $tv-set: map-merge($tv-set, (
      $timing: _map-transition-list-into-content-property($so-far-transition-stack)
    ));
  }

  $duration: _calculate-animation-length($animation-map);
  @return kf-ease(step-end, (
    _kf-duration: $duration,
    $for-selector: ('content': $tv-set)
  ));
}