/**
 * Take a transition as parameter and parse it to return the {Map} corresponding
 * The $transition parameter can be either a registered transition name or a custom css transition like : all .2s ease-in-out 2s
 * The $transition argument will be parsed with the [./_s-parse-properties.scss] function.
 *
 * @param 			{List} 				$transition 			The registered transition name or the transition string to transform into map
 * @return 			{Map} 										The corresponding transition map properties
 *
 * @example
 * // register a transition
 * \@include s-setup((
 * 		transitions : (
 * 			fast : all .2s ease-in-out,
 * 			// other transitions...
 * 		)
 * ));
 *
 * // registered transition
 * s-transition-map(fast);
 * // {
 * // 	property : all,
 * // 	duration : .2s,
 * // 	ease : ease-in-out
 * // }
 *
 * // custom transition
 * s-transition-map(fast -delay .5s);
 * // {
 * // 	property : all,
 * // 	duration : .2s,
 * // 	ease : ease-in-out,
 * // 	delay : .5s
 * // }
 *
 * @author 			Olivier Bossel <olivier.bossel@gmail.com> (https://olivierbossel.com)
 */
$_s-default-transition-map: null;
@function s-transition-map($transition) {
  // merge with default transition
  // to avoid recursion
  @if not $_s-default-transition-map {
    $_s-default-transition-map: s-parse-properties(
      s-setting("transitions.default"),
      (
        property: string,
        duration: number,
        ease: string,
        delay: number
      )
    ) !global;
  }

  // parse passed transition
  $tran: s-parse-properties(
    $transition,
    (
      name: map-keys(s-setting("transitions")),
      property: string,
      duration: number,
      ease: string,
      delay: number
    )
  );

  // working transition
  $working_tran: $_s-default-transition-map;

  // if we have a name, mean that we want to merge transitions
  $name: map-get($tran, name);
  @if $name {
    // get the transition
    $named_transition: s-setting("transitions.#{$name}");
    // check the name
    @if not $named_transition {
      @error ('The transition named "#{$name}" does not exist...');
    }
    // transform the named transition in map
    $named_transition: s-transition-map($named_transition);
    // merge the named transition with the actual transition
    $working_tran: map-merge($_s-default-transition-map, $named_transition);
  }

  // merge the actual transition into the working one
  $tran: map-merge($working_tran, $tran);

  // return the transition map
  @return $tran;
}