////
/// @group utils.typography
////

// Based on this: https://codepen.io/jakob-e/pen/LVVXjO

@function __gf__list-unique($list) {
    $result: ();
    @each $item in $list {
        @if not index($result, $item + '') {
            $result: append($result, $item + '');
        }
    }
    @each $item in $result {
        $result: set-nth($result, index($result, $item), unquote($item));
    }
    @return $result;
}
@function __gf__str-replace($string, $search, $replace: '') {
    $index: str-index($string, $search);
    @return if(
        $index,
        str-slice($string, 1, $index - 1) + $replace +
            __gf__str-replace(str-slice($string, $index + str-length($search)), $search, $replace),
        $string
    );
}
@function __gf__str-explode($string) {
    $list: ();
    @for $i from 1 through str-length($string) {
        $list: append($list, str-slice($string, $i, $i));
    }
    @return $list;
}

/// The font subset to loaded. Note that the latin subset is always included if
/// available and need not be specified. Also, if a client browser supports
/// supports unicode-range then this subset parameter is igored and the browser
/// will select from the subsets supported by the font to get what it needs to
/// render the text.

$google-font-subsets: (
    'arabic': false,
    'bengali': false,
    'cyrillic': false,
    'cyrillic-ext': false,
    'devanagari': false,
    'greek': false,
    'greek-ext': false,
    'gujarati': false,
    'hebrew': false,
    'khmer': false,
    'latin': false,
    'latin-ext': false,
    'tamil': false,
    'telugu': false,
    'thai': false,
    'vietnamese': false,
) !default;

/// Mixin for loading google fonts.
///
/// @param {string} $name [null] Name of the font (must match google)
///
/// @param {list or number} $weights [400]  A list of weights to be loaded (or
/// single weight)
///
/// @param {list or string} $styles [normal] A list of styles to be loaded (or
/// single style)
///
/// @param {*} $text [null] Subsetting text
///
/// @example
/// %%include google-font(Lato, 300);
///
/// @example
/// %%include google-font(Open Sans, 400, italic)
///
/// @example
/// %%include google-font(Slapo 27px, 400 200, $text: 'Lorem ipsum dolor sit amet');
///
/// @example
/// // By placing google-font includes inside a google-font include (without arguments nested includes will be merged into a single import
/// %%include google-font {
///     %%include google-font(Material Icons);
///     %%include google-font(Open Sans, 300 400 700, normal);
///     %%include google-font(Open Sans, 300 400 700, italic normal);
///     %%include google-font(Lato, 300 400i 700i);
///     %%include google-font(Lato, 300 700, italic normal);
/// }
///
/// => @import url("//fonts.googleapis.com/css?family=Material+Icons:400|Open+Sans:300,400,700,300i,400i,700i|Lato:300,400")

@mixin google-font($name: null, $weights: 400, $styles: normal, $text: null) {
    //  base url
    $URL: 'https://fonts.googleapis.com/css?family=';

    //  create global variables
    @if not variable-exists(__gf__combine) {
        $__gf__combine: false !global;
    }
    @if not variable-exists(__gf__map) {
        $__gf__map: () !global;
    }
    @if not variable-exists(google-font-subsets) {
        $google-font-subsets: () !global;
    }

    //  append italic to weights
    @if index($styles, italic) and not str-index($weights + '', i) {
        $wgt: if(index($styles, normal), $weights, ());
        @each $weight in $weights {
            $wgt: append($wgt, $weight + i);
        }
        $weights: $wgt;
    }

    //  reduce and encode text
    @if $text {
        $list: __gf__list-unique(__gf__str-explode($text));
        $text: '&text=';
        $encode: (
            '!': '%21',
            '#': '%23',
            '$': '%24',
            '&': '%26',
            "'": '%27',
            '(': '%28',
            ')': '%29',
            '*': '%2A',
            '+': '%2B',
            ',': '%2C',
            '/': '%2F',
            ':': '%3A',
            ';': '%3B',
            '=': '%3D',
            '?': '%3F',
            '@': '%40',
            '[': '%5B',
            ']': '%5D',
            ' ': '%20',
        );
        @for $i from 1 through length($list) {
            $char: map-get($encode, nth($list, $i)) or nth($list, $i);
            $text: $text + $char;
        }
    }

    //  subsets from config
    $subset: '';
    @each $set, $enabled in $google-font-subsets {
        @if $enabled {
            $subset: $subset + if($subset == '', '', ',') + $set;
        }
    }
    $subset: if(str-length($subset) > 0 and $subset != latin, '&subset=' + $subset, '');

    @if $name {
        //  replace name whitespaces
        $name: if(type-of($name) == string, unquote($name), $name);
        $name: __gf__str-replace(inspect($name), ' ', '+');
        @if $__gf__combine and not $text {
            //  add weights to combine map
            $wgt: map-get($__gf__map, $name) or ();
            $wgt: __gf__list-unique(join($wgt, $weights, comma));
            $__gf__map: map-merge(
                $__gf__map,
                (
                    $name: $wgt,
                )
            ) !global;
        } @else {
            //  create query
            $query: '';
            @each $weight in $weights {
                $query: $query + if($query != '', ',', '') + $weight;
            }
            $query: __gf__str-replace($query, ' ');
            $query: $name + if(str-length($query) > 0 and $query != '400', ':' + $query, '');

            //  create single immport
            @at-root {
                /* url(#{$URL}+#{$query}+#{if($text, $text, '')}+#{$subset}) */
                @import url($URL + $query + if($text, $text, '') + $subset);
            }
        }
    } @else {
        //  set combine flag
        $__gf__combine: true !global;

        //  nested includes
        @content;

        //  convert combine map to query
        //  (remove weights if just 400)
        $query: '';
        @each $font, $weights in $__gf__map {
            $query: $query +
                if($query != '', '|', '') +
                $font +
                if(
                    length($weights) == 1 and (nth($weights, 1) == '400'),
                    '',
                    ':' + join((), $weights, comma)
                );
        }

        //  remove query whitespaces
        $query: __gf__str-replace($query, ' ');

        //  create combined immport
        @at-root {
            @import url($URL + $query + $subset);
        }

        //  reset combine flag
        $__gf__combine: false !global;
    }
}