package getelementbyid

import (
	"golang.org/x/net/html"
)

func GetAttribute(n *html.Node, key string) (string, bool) {
	for _, attr := range n.Attr {
		if attr.Key == key {
			return attr.Val, true
		}
	}
	return "", false
}

func checkId(n *html.Node, id string) bool {
	if n.Type == html.ElementNode {
		s, ok := GetAttribute(n, "id")
		if ok && s == id {
			return true
		}
	}
	return false
}

func traverse(n *html.Node, id string) *html.Node {
	if checkId(n, id) {
		return n
	}

	for c := n.FirstChild; c != nil; c = c.NextSibling {
		result := traverse(c, id)
		if result != nil {
			return result
		}
	}

	return nil
}

func getElementById(n *html.Node, id string) *html.Node {
	return traverse(n, id)
}