// Helper function to replace characters in a string
@function str-replace($string, $search, $replace: '') {
    $index: str-index($string, $search);
    @return if($index,
        str-slice($string, 1, $index - 1) + $replace +
        str-replace(str-slice($string, $index +
        str-length($search)), $search, $replace),
        $string);
}

// Encode svg function by http://codepen.io/jakob-e/pen/doMoML
@function svg-encode($svg){
    // Chunk up string in order to avoid "stack level too deep" error
    $encoded:'';
    $slice: 2000;
    $index: 0;
    $loops: ceil(divide(str-length($svg), $slice));
    @for $i from 1 through $loops {
        $chunk: str-slice($svg, $index, $index + $slice - 1);
        // Encode
        $chunk: str-replace($chunk, '"', '\'');
        $chunk: str-replace($chunk, '%', '%25');
        $chunk: str-replace($chunk, '#', '%23');
        $chunk: str-replace($chunk, '{', '%7B');
        $chunk: str-replace($chunk, '}', '%7D');
        $chunk: str-replace($chunk, '<', '%3C');
        $chunk: str-replace($chunk, '>', '%3E');

        $encoded: #{$encoded}#{$chunk};
        $index: $index + $slice;
    }
    @return "data:image/svg+xml,#{$encoded}";
}

@function checkmark($color) {
    $start: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1 1">';
    $content: '<path style="fill:#{$color}" d="M 0.04038059,0.6267767 0.14644661,0.52071068 0.42928932,0.80355339 0.3232233,0.90961941 z M 0.21715729,0.80355339 0.85355339,0.16715729 0.95961941,0.2732233 0.3232233,0.90961941 z"></path>';
    $end: '</svg>';

    @return svg-encode("#{$start}#{$content}#{$end}");
}

@function indeterminate($color) {
    $start: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1 1">';
    $content: '<rect style="fill:#{$color}" width="0.7" height="0.2" x=".15" y=".4"></rect>';
    $end: '</svg>';

    @return svg-encode("#{$start}#{$content}#{$end}");
}