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

@use 'sass:list';
@use 'sass:map';
@use 'sass:meta';

/// 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: ('start-start', 'start-end', 'end-end', '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;
}