/* Keep short Russian prepositions with the following word in displayed UI text. */
(function () {
    'use strict';
    if (window.fiRussianTypography) return;
    window.fiRussianTypography = true;
    var excluded = 'script,style,textarea,input,select,option,pre,code,svg,math,[contenteditable]:not([contenteditable="false"]),[data-no-typography]';
    var pattern = /(^|[^\p{L}\p{N}_])(в|во|к|ко|с|со|у|о|об|обо|на|по|из|от|до|за|без|для|при|под|над|из-за|из-под)[ \t]+(?=[\p{L}\p{N}])/giu;
    function format(value) {
        // Repeat once to handle adjacent prepositions without leaving a hanging one.
        return value.replace(pattern, '$1$2\u00a0').replace(pattern, '$1$2\u00a0');
    }
    function visit(root) {
        if (!root || !root.isConnected) return;
        if (root.nodeType === 3) {
            if (root.parentElement && !root.parentElement.closest(excluded)) {
                var value = format(root.nodeValue);
                if (value !== root.nodeValue) root.nodeValue = value;
            }
            return;
        }
        if (root.nodeType !== 1 || root.closest(excluded)) return;
        var walker = document.createTreeWalker(root, NodeFilter.SHOW_TEXT);
        var node;
        while ((node = walker.nextNode())) visit(node);
    }
    function start() {
        visit(document.body);
        new MutationObserver(function (changes) {
            changes.forEach(function (change) {
                if (change.type === 'characterData') visit(change.target);
                else change.addedNodes.forEach(visit);
            });
        }).observe(document.body, {childList:true,subtree:true,characterData:true});
    }
    if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', start);
    else start();
})();