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// Не забудьте перед отправкой изменить в module.exports = function(html, css) {
export default function(html, css) {
    
    let css1 = css.map(cssRule => {
        let indexPlus = cssRule.selector.indexOf("+");
        if (indexPlus !== -1) {
            return { 
                tags: cssRule.selector.split("+").map(it => it.trim()), 
                declarations: cssRule.declarations,
                op: "+",
                priority: 3,
            };
        }
        let indexGt = cssRule.selector.indexOf(">");
        if (indexGt !== -1) {
            return { 
                tags: cssRule.selector.split(">").map(it => it.trim()), 
                declarations: cssRule.declarations,
                op: ">",
                priority: 2,
            };
        }
        let indexTilde = cssRule.selector.indexOf("~");
        if (indexTilde !== -1) {
            return { 
                tags: cssRule.selector.split("~").map(it => it.trim()), 
                declarations: cssRule.declarations,
                op: "~",
                priority: 4,
            };
        }
        let indexSpace = cssRule.selector.indexOf(" ");
        if (indexSpace !== -1) {
            return { 
                tags: cssRule.selector.split(" ").map(it => it.trim()), 
                declarations: cssRule.declarations,
                op: " ",
                priority: 1,
            };
        }
        return { 
            tags: [cssRule.selector], 
            declarations: cssRule.declarations,
            op: null,
            priority: 100,
        };
    })
    css1.sort((e1, e2) => e1.priority - e2.priority);
    let applyRule = function(curStyles, cssRule) {
        Object.entries(cssRule.declarations).forEach(([key, value]) => {
            curStyles[key] = value;
          });
    }
    // sibindex cur pos in sibList/
    // siblist all bros in cur level
    function traverseTree(html, css, sibIndex, sibList, styles, parentTags) {
        if (html.type === "TEXT") {
            return;
        }
        const curStyles = Object.assign({}, styles);
        css.forEach(cssRule => {
            if (cssRule.op === null && cssRule.tags[0] === html.tag) {
                applyRule(curStyles, cssRule);
            }
            if (cssRule.op === " " && cssRule.tags[1] === html.tag && parentTags.includes(cssRule.tags[0])) {
                applyRule(curStyles, cssRule);
            }
            if (cssRule.op === ">" && cssRule.tags[1] === html.tag && parentTags[parentTags.length - 1] === cssRule.tags[0]) {
                applyRule(curStyles, cssRule);
            }

            if (cssRule.op === "+" && cssRule.tags[1] === html.tag && sibIndex > 0 && sibList[sibIndex - 1].tag === cssRule.tags[0]) {
                applyRule(curStyles, cssRule);
            }

            if (cssRule.op === "~" && cssRule.tags[1] === html.tag) {
                for (let i = 0; i < sibIndex; i++) {
                    if (cssRule.tags[0] === sibList[i].tag) {
                        applyRule(curStyles, cssRule);
                        break;
                    }
                }
                
            }
        });
        
        html.styles = curStyles;
        parentTags.push(html.tag);
        html.children.forEach((child, i) => traverseTree(child, css, i, html.children, curStyles, parentTags))
        parentTags.pop();
        return;
    }

    traverseTree(html, css1, 0, [html], {}, []);
    return html;
}