@charset "UTF-8";

/// Directional-property mixins are shorthands for writing properties like the following
///
/// @ignore You can also use `false` instead of `null`.
///
/// @param {List} $vals
///   List of directional values
///
/// @example scss - Usage
///   .element {
///     @include border-style(dotted null);
///     @include margin(null 0 10px);
///   }
///
/// @example css - CSS Output
///   .element {
///     border-bottom-style: dotted;
///     border-top-style: dotted;
///     margin-bottom: 10px;
///     margin-left: 0;
///     margin-right: 0;
///   }
///
/// @require {function} contains-falsy
///
/// @return {List}

@function collapse-directionals($vals) {
    $output: null;

    $a: nth($vals, 1);
    $b: if(length($vals) < 2, $a, nth($vals, 2));
    $c: if(length($vals) < 3, $a, nth($vals, 3));
    $d: if(length($vals) < 2, $a, nth($vals, if(length($vals) < 4, 2, 4)));

    @if $a == 0 {
        $a: 0;
    }
    @if $b == 0 {
        $b: 0;
    }
    @if $c == 0 {
        $c: 0;
    }
    @if $d == 0 {
        $d: 0;
    }

    @if $a == $b and $a == $c and $a == $d {
        $output: $a;
    } @else if $a == $c and $b == $d {
        $output: $a $b;
    } @else if $b == $d {
        $output: $a $b $c;
    } @else {
        $output: $a $b $c $d;
    }

    @return $output;
}

/// Output directional properties, for instance `margin`.
///
/// @access private
///
/// @param {String} $pre
///   Prefix to use
/// @param {String} $suf
///   Suffix to use
/// @param {List} $vals
///   List of values
///
/// @require {function} collapse-directionals
/// @require {function} contains-falsy

@mixin directional-property($pre, $suf, $vals) {
    // Property Names
    $top: $pre + "-top"    + if($suf, "-#{$suf}", "");
    $bottom: $pre + "-bottom" + if($suf, "-#{$suf}", "");
    $left: $pre + "-left"   + if($suf, "-#{$suf}", "");
    $right: $pre + "-right"  + if($suf, "-#{$suf}", "");
    $all: $pre +             if($suf, "-#{$suf}", "");

    $vals: collapse-directionals($vals);

    @if contains-falsy($vals) {
        @if nth($vals, 1) {
            #{$top}: nth($vals, 1);
        }

        @if length($vals) == 1 {
            @if nth($vals, 1) {
                #{$right}: nth($vals, 1);
            }
        } @else {
            @if nth($vals, 2) {
                #{$right}: nth($vals, 2);
            }
        }

        @if length($vals) == 2 {
            @if nth($vals, 1) {
                #{$bottom}: nth($vals, 1);
            }
            @if nth($vals, 2) {
                #{$left}: nth($vals, 2);
            }
        } @else if length($vals) == 3 {
            @if nth($vals, 3) {
                #{$bottom}: nth($vals, 3);
            }
            @if nth($vals, 2) {
                #{$left}: nth($vals, 2);
            }
        } @else if length($vals) == 4 {
            @if nth($vals, 3) {
                #{$bottom}: nth($vals, 3);
            }
            @if nth($vals, 4) {
                #{$left}: nth($vals, 4);
            }
        }
    } @else {
        #{$all}: $vals;
    }
}