// this function returns some specific signature of a selection
// so it can be easy found to get data quickly next time
func getSelectionSignature(s *goquery.Selection) string {
	var signature string

	tag, _ := goquery.OuterHtml(s)

	pos := strings.Index(tag, ">")

	if pos > -1 {
		tag = tag[1:pos]
	} else {
		return ""
	}

	signature = convertTagToJqueryFormat(tag, s)

	s.Parents().Each(func(i int, sec *goquery.Selection) {
		ohtml, _ := goquery.OuterHtml(sec)

		pos := strings.Index(ohtml, ">")

		if pos > -1 {
			ohtml = ohtml[1:pos]
		}

		tag := convertTagToJqueryFormat(ohtml, sec)

		signature = tag + " " + signature
	})

	return signature
}

//checks the density of links within a node, is there not much text and most of it contains bad links?
//if so it's no good
func (this *contentExtractor) isHighLinkDensity(node *goquery.Selection) bool {
	links := node.Find("a")
	if links == nil || links.Size() == 0 {
		return false
	}
	text := node.Text()
	words := strings.Split(text, " ")
	nwords := len(words)
	sb := make([]string, 0)
	links.Each(func(i int, s *goquery.Selection) {
		linkText := s.Text()
		sb = append(sb, linkText)
	})
	linkText := strings.Join(sb, "")
	linkWords := strings.Split(linkText, " ")
	nlinkWords := len(linkWords)
	nlinks := links.Size()
	linkDivisor := float64(nlinkWords) / float64(nwords)
	score := linkDivisor * float64(nlinks)

	if this.config.debug {
		logText := ""
		if len(node.Text()) >= 51 {
			logText = node.Text()[0:50]
		} else {
			logText = node.Text()
		}
		log.Printf("Calculated link density score as %1.5f for node %s\n", score, logText)
	}
	if score > 1.0 {
		return true
	}
	return false
}

func (b baiduNews) commonPrase(ctx *Context) (infoStr string) {
	body := ctx.GetDom().Find("body")

	var info *goquery.Selection

	if h1s := body.Find("h1"); len(h1s.Nodes) != 0 {
		for i := 0; i < len(h1s.Nodes); i++ {
			info = b.findP(h1s.Eq(i))
		}
	} else if h2s := body.Find("h2"); len(h2s.Nodes) != 0 {
		for i := 0; i < len(h2s.Nodes); i++ {
			info = b.findP(h2s.Eq(i))
		}
	} else if h3s := body.Find("h3"); len(h3s.Nodes) != 0 {
		for i := 0; i < len(h3s.Nodes); i++ {
			info = b.findP(h3s.Eq(i))
		}
	} else {
		info = body.Find("body")
	}
	infoStr, _ = info.Html()

	// 清洗HTML
	infoStr = CleanHtml(infoStr, 5)
	return
}

func parseColors(s *goquery.Selection) string {
	colors := ""
	s.Each(func(i int, s *goquery.Selection) {
		colors += s.Text()
	})
	return colors
}

// attributeOrDefault reads an attribute and returns it or the default value when it's empty.
func (bow *Browser) attrOrDefault(name, def string, sel *goquery.Selection) string {
	a, ok := sel.Attr(name)
	if ok {
		return a
	}
	return def
}

func (b baiduNews) commonPrase(resp *context.Response) (infoStr string) {
	body := resp.GetDom().Find("body")

	var info *goquery.Selection

	if h1s := body.Find("h1"); len(h1s.Nodes) != 0 {
		for i := 0; i < len(h1s.Nodes); i++ {
			info = b.findP(h1s.Eq(i))
		}
	} else if h2s := body.Find("h2"); len(h2s.Nodes) != 0 {
		for i := 0; i < len(h2s.Nodes); i++ {
			info = b.findP(h2s.Eq(i))
		}
	} else if h3s := body.Find("h3"); len(h3s.Nodes) != 0 {
		for i := 0; i < len(h3s.Nodes); i++ {
			info = b.findP(h3s.Eq(i))
		}
	} else {
		info = body.Find("body")
	}
	// 去除标签
	// info.RemoveFiltered("script")
	// info.RemoveFiltered("style")
	infoStr, _ = info.Html()

	// 清洗HTML
	infoStr = CleanHtml(infoStr, 5)
	return
}

func scrapPayload(s *goquery.Selection, n int) string {
	url, ok := s.Find("a").Attr("href")
	if !ok {
		die("unable to find URL for scrapping")
	}
	return scrapPayloadURL("https://developer.github.com"+url, n)
}

func JoinNodesWithSpace(s *goquery.Selection) string {
	texts := []string{}
	s.Each(func(i int, s *goquery.Selection) {
		texts = append(texts, s.Text())
	})
	return strings.Join(texts, " ")
}

func (this *parser) dropTag(selection *goquery.Selection) {
	selection.Each(func(i int, s *goquery.Selection) {
		node := s.Get(0)
		node.Data = s.Text()
		node.Type = html.TextNode
	})
}

func parseGamePosition(selection *goquery.Selection) (position int) {
	positionString := strings.TrimSpace(selection.Children().First().Text())
	var err error
	position, err = strconv.Atoi(strings.TrimSpace(positionString))
	helper.HandleFatalError("parsing game position failed:", err)
	return
}

func ScrapeExamples(s *goquery.Selection) []string {
	examples := []string{}
	s.Find("span.h").Each(func(i int, s *goquery.Selection) {
		examples = append(examples, s.Text())
	})
	return examples
}

func extractCredits(selection *goquery.Selection) string {
	if result := trim(selection.Find(".credits").Text()); strings.Contains(result, "#") {
		return "0"
	} else {
		return result
	}
}

func extractCourseDescription(selection *goquery.Selection) string {
	url := trim(fmt.Sprintln(selection.Find(".catalogdescription a").AttrOr("href", "")))
	fmt.Println("LOGGING URL", url)
	client := http.Client{}
	req, _ := http.NewRequest("GET", "http://catalog.njit.edu/ribbit/index.cgi?format=html&page=fsinjector.rjs&fullpage=true", nil)
	req.Header.Add("Referer", url)
	resp, err := client.Do(req)
	if err != nil {

		return ""
	}
	if resp != nil {
		defer resp.Body.Close()
	}

	body, _ := ioutil.ReadAll(resp.Body)
	//checkError(err)
	result := substringAfter(string(body), "courseblockdesc")
	if len(result) < 4 {
		return ""
	}
	result = substringBefore(result[3:], "<b")
	if string(result[0]) == "<" || strings.Contains(result, "at SISConnxService") {
		return ""
	}
	result = strings.Replace(result, "\\\"", "\"", -1)
	doc, _ := goquery.NewDocumentFromReader(strings.NewReader(result))

	return trim(doc.Text())
}

func convertTagToJqueryFormat(tag string, s *goquery.Selection) string {
	tagitself := tag

	pos := strings.Index(tag, " ")

	if pos > -1 {
		tagitself = tag[0:pos]
	} else {

		return tag
	}

	class, found := s.Attr("class")

	if found && class != "" {
		pos := strings.Index(class, " ")
		// leave only a first class from a list
		if pos > -1 {
			class = class[0:pos]
		}

		tagitself = tagitself + "." + class
	}

	return tagitself
}

func testList(t *testing.T, list *goquery.Selection) {
	list.Find("ul").Each(func(_ int, items *goquery.Selection) {
		testList(t, items)
		items.RemoveFiltered("ul")
	})
	checkAlphabeticOrder(t, list)
}

func (this *parser) delAttr(selection *goquery.Selection, attr string) {
	idx := this.indexOfAttribute(selection, attr)
	if idx > -1 {
		node := selection.Get(0)
		node.Attr = append(node.Attr[:idx], node.Attr[idx+1:]...)
	}
}

// toPage is a helper function that accepts an anchor
// tag referencing a markdown file, parsing the markdown
// file and returning a page to be included in our docs.
func toPage(site *Site, el *goquery.Selection) (*Page, error) {

	// follow the link to see if this is a page
	// that should be added to our documentation.
	href, ok := el.Attr("href")
	if !ok || href == "#" {
		return nil, nil
	}

	// read the markdown file, convert to html and
	// read into a dom element.
	doc, err := toDocument(filepath.Join(site.base, href))
	if err != nil {
		return nil, err
	}

	// convert the extension from markdown to
	// html, in preparation for type conversion.
	href = strings.Replace(href, ".md", ".html", -1)
	el.SetAttr("href", href)

	page := &Page{}
	page.Href = href
	page.html, err = doc.Html()
	return page, err
}

func (this *parser) name(selector string, selection *goquery.Selection) string {
	value, exists := selection.Attr(selector)
	if exists {
		return value
	}
	return ""
}

func (d *Document) classWeight(s *goquery.Selection) int {
	weight := 0
	if !d.WeightClasses {
		return weight
	}

	class, _ := s.Attr("class")
	id, _ := s.Attr("id")

	if class != "" {
		if negativeRegexp.MatchString(class) {
			weight -= 25
		}

		if positiveRegexp.MatchString(class) {
			weight += 25
		}
	}

	if id != "" {
		if negativeRegexp.MatchString(id) {
			weight -= 25
		}

		if positiveRegexp.MatchString(id) {
			weight += 25
		}
	}

	return weight
}

func parseTranslations(elements *goquery.Selection) (results []Translation) {
	elements.Each(func(index int, element *goquery.Selection) {
		results = append(results, Translation{parseMeaning(element), parseHref(element), parsePhrase(element)})
	})

	return
}