//
// Copyright 2024 Google LLC
// SPDX-License-Identifier: Apache-2.0
//

// go/keep-sorted start
@use 'sass:list';
@use 'sass:map';
@use 'sass:meta';
// go/keep-sorted end

/// Returns a map of 4 logical tokens (start-start, start-end, end-end,
/// and end-start) for each of the given shape tokens in the provided token
/// map.
///
/// @example scss
///   $tokens: ('container-shape': 16px 16px 0px 0px);
///   $new-tokens: shape.get-new-logical-shape-tokens(
///     $tokens,
///     'container-shape'
///   );
///   // (
///   //   'container-shape-start-start': 16px,
///   //   'container-shape-start-end': 16px,
///   //   'container-shape-end-end': 0px,
///   //   'container-shape-end-start': 0px,
///   // )
///
/// @param $tokens A Map of tokens.
/// @param $shape-tokens One or more shape tokens in the provided map. Each
///     shape token will add 4 logical shape tokens to the returned map.
/// @return A map with 4 logical tokens for each provided shape token.
@function get-new-logical-shape-tokens($tokens, $shape-tokens...) {
  $new-logical-tokens: ();
  $logical-suffixes: (
    // top-left
    'start-start',
    // top-right
    'start-end',
    // bottom-right
    'end-end',
    // bottom-left
    'end-start'
  );

  @each $shape-token in $shape-tokens {
    $shorthand-value: _expand-shorthand-to-list(map.get($tokens, $shape-token));

    @each $logical-suffix in $logical-suffixes {
      $logical-token: '#{$shape-token}-#{$logical-suffix}';
      $logical-index: list.index($logical-suffixes, $logical-suffix);

      $new-logical-tokens: map.set(
        $new-logical-tokens,
        $logical-token,
        list.nth($shorthand-value, $logical-index)
      );
    }
  }

  @return $new-logical-tokens;
}

@function _expand-shorthand-to-list($shorthand) {
  @if meta.type-of($shorthand) != 'list' or list.length($shorthand) == 1 {
    @return ($shorthand, $shorthand, $shorthand, $shorthand);
  }

  @if list.length($shorthand) == 2 {
    $top-left-and-bottom-right: list.nth($shorthand, 1);
    $top-right-and-bottom-left: list.nth($shorthand, 2);
    @return (
      $top-left-and-bottom-right,
      $top-right-and-bottom-left,
      $top-left-and-bottom-right,
      $top-right-and-bottom-left
    );
  }

  @if list.length($shorthand) == 3 {
    $top-left: list.nth($shorthand, 1);
    $top-right-and-bottom-left: list.nth($shorthand, 2);
    $bottom-right: list.nth($shorthand, 3);
    @return (
      $top-left,
      $top-right-and-bottom-left,
      $bottom-right,
      $top-right-and-bottom-left
    );
  }

  @return $shorthand;
}