package web

import (
	"net/http"
	"net/url"
	"strconv"
	"strings"

	"github.com/PuerkitoBio/goquery"
)

var aolURL = urlMustParse("https://search.aol.com/aol/search?rp=&s_chn=prt_bon&s_it=comsearch")

type AOL struct {
	keyword   string
	userAgent string
	page      int
	doc       *goquery.Document
	initDone  bool
	baseSel   *goquery.Selection
}

// SetKeyword sets the keyword for searching
func (a *AOL) SetKeyword(keyword string) {
	a.keyword = keyword
}

// SetPage sets the page number for searching
func (a *AOL) SetPage(page int) {
	a.page = page * 10
	if a.page > 0 {
		a.page++
	}
}

// SetUserAgent sets the user agent to use for the request
func (a *AOL) SetUserAgent(ua string) {
	a.userAgent = ua
}

// Init runs requests for Bing search engine
func (a *AOL) Init() error {
	// Copy URL so it can be changed
	initURL := copyURL(aolURL)
	query := initURL.Query()
	// Set query
	query.Set("q", a.keyword)
	if a.page > 0 {
		query.Set("b", strconv.Itoa(a.page))
	}
	// Update URL query parameters
	initURL.RawQuery = query.Encode()

	// Create new request for modified URL
	req, err := http.NewRequest(
		http.MethodGet,
		initURL.String(),
		nil,
	)
	if err != nil {
		return err
	}
	// If no user agent, use default
	if a.userAgent == "" {
		a.userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36"
	}
	// Set request user agent
	req.Header.Set("User-Agent", a.userAgent)

	// Perform request
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer res.Body.Close()

	// Create new goquery document
	doc, err := goquery.NewDocumentFromReader(res.Body)
	if err != nil {
		return err
	}
	a.doc = doc
	a.baseSel = doc.Find(`h3.title > a[href]`)
	a.initDone = true
	return nil
}

// Each runs eachCb with the index of each search result
func (a *AOL) Each(eachCb func(int) error) error {
	for i := 0; i < a.baseSel.Length(); i++ {
		err := eachCb(i)
		if err != nil {
			return err
		}
	}
	return nil
}

// Title returns the title of the search result corresponding to i
func (a *AOL) Title(i int) (string, error) {
	return get(a.baseSel, i).Text(), nil
}

// Link returns the link to the search result corresponding to i
func (a *AOL) Link(i int) (string, error) {
	href := get(a.baseSel, i).AttrOr("href", "")
	hrefURL, err := url.Parse(href)
	if err != nil {
		return "", err
	}

	var ru string
	splitPath := strings.Split(hrefURL.RawPath, "/")
	for _, item := range splitPath {
		if strings.HasPrefix(item, "RU=") {
			ru = strings.TrimPrefix(item, "RU=")
			break
		}
	}
	if ru == "" {
		return href, nil
	}

	return url.PathUnescape(ru)
}

// Desc returns the description of the search result corresponding to i
func (a *AOL) Desc(i int) (string, error) {
	return a.baseSel.
		First().
		Parent().
		Parent().
		Next().
		Children().
		First().
		Text(), nil
}

// Name returns "aol"
func (*AOL) Name() string {
	return "aol"
}

// https://search.aol.com/aol/search?q=site%3Alinkedin.com%2Fin%2F+%22Senior+Developer%22+%22Nvidia%22&rp=&s_chn=prt_bon&s_it=comsearch