source: imaps-frontend/node_modules/nano-css/addon/stylis/plugin-onRule.js

'use strict';

module.exports = function (insertRule) {
    var delimiter = '/*|*/';
    var needle = delimiter + '}';

    function toSheet (block) {
        if (block)
            try {
                insertRule(block + '}');
            } catch (e) {
                // eslint-disable-next-line
            };
    }

    return function ruleSheet (context, content, selectors, parents, line, column, length, ns, depth, at) {
        switch (context) {
        // property
        case 1:
            // @import
            if (depth === 0 && content.charCodeAt(0) === 64)
                return insertRule(content+';'), '';
            break;
        // selector
        case 2:
            if (ns === 0)
                return content + delimiter;
            break;
        // at-rule
        case 3:
            switch (ns) {
            // @font-face, @page
            case 102:
            case 112:
                return insertRule(selectors[0]+content), '';
            default:
                return content + (at === 0 ? delimiter : '');
            }
        case -2:
            content.split(needle).forEach(toSheet);
        }
    };
};