package main

import (
	"github.com/PuerkitoBio/goquery"
	"github.com/gin-gonic/gin"
	"github.com/gorilla/websocket"
	"log"
	"net/http"
	"time"
)

type fetchData struct {
	url   string
	title string
	desc  string
	date  string
}
type fetchHandler struct {
	fetchUrl      string
	hadFetchData  []fetchData
	cronTime      time.Duration
	keyword       string
	hadFetchedMap map[string]int
	reloadCron    chan int
	isOff         chan int
	ws            *websocket.Conn
	rMsgChan      chan message
	newFetchItem  chan []fetchData
}

type message struct {
	Status  bool
	Action  string
	Message string
	Data    interface{}
}

func newFetchHandler(fetchUrl, keyword string) *fetchHandler {
	return &fetchHandler{
		fetchUrl:      fetchUrl,
		keyword:       keyword,
		hadFetchedMap: make(map[string]int),
		cronTime:      60 * time.Second,
		reloadCron:    make(chan int),
		isOff:         make(chan int),
		rMsgChan:      make(chan message, 10),
		newFetchItem:  make(chan []fetchData, 10),
	}
}

func (f *fetchHandler) handle() {
	f.parsesDom(f.fetch(f.fetchUrl + f.keyword))
}

func (f *fetchHandler) receiveMsg() {
	for {
		r := <-f.rMsgChan
		switch r.Action {
		case "search":
			f.handle()
		case "timeStepSet":
			if t, ok := r.Data.(int); ok {
				f.reloadCron <- t
			}

		}
	}
}

func (f *fetchHandler) fetch(url string) *http.Response {
	client := http.Client{
		Transport:     nil,
		CheckRedirect: nil,
		Jar:           nil,
		Timeout:       10 * time.Second,
	}
	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9")
	req.Header.Add("accept-language", "zh-CN,zh;q=0.9")
	req.Header.Add("cache-control", "no-cache")
	req.Header.Add("connection", "keep-alive")
	req.Header.Add("cookie", "BIDUPSID=844E3DCAA2EEBF5C872DC99B967B6B7B; PSTM=1655872163; BAIDUID=844E3DCAA2EEBF5CB3E1D79750162204:FG=1; BD_UPN=123353; ORIGIN=2; ISSW=1; ISSW=1; BAIDUID_BFESS=844E3DCAA2EEBF5CB3E1D79750162204:FG=1; ZFY=jWFAySgO:AoQfb6emY9vnmEdptVao:Anj0FFkp028wFws:C; BD_HOME=1; delPer=0; BD_CK_SAM=1; PSINO=3; COOKIE_SESSION=42_0_2_2_3_0_1_0_2_0_0_0_18_0_51_0_1655888428_0_1655888377%7C3%230_0_1655888377%7C1; BAIDU_WISE_UID=wapp_1655902298617_702; ZD_ENTRY=google; channel=baidusearch; baikeVisitId=b3b23509-9330-4d33-82ae-b8eb37895917; BA_HECTOR=8k2g2g218ga40181ak1hbgg1n14; BDRCVFR[C0p6oIjvx-c]=mbxnW11j9Dfmh7GuZR8mvqV; BDSVRTM=1011; H_PS_PSSID=36550_36459_36673_36455_36453_36692_36165_36695_36697_36569_36075_36467_36316_36651")
	req.Header.Add("referer", "http://news.baidu.com/")
	req.Header.Add("sec-fetch-dest", "document")
	req.Header.Add("sec-fetch-mode", "navigate")
	req.Header.Add("sec-fetch-site", "cross-site")
	req.Header.Add("sec-fetch-user", "?1")
	req.Header.Add("upgrade-insecure-requests", "1")
	req.Header.Add("user-agent", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36")
	req.Header.Add("#sec-ch-ua", "\".Not/A)Brand\";v=\"99\", \"Google Chrome\";v=\"103\", \"Chromium\";v=\"103\"")
	req.Header.Add("sec-ch-ua-mobile", "?0")
	req.Header.Add("sec-ch-ua-platform", "\"Linux\"")
	req.Header.Add("postman-token", "81407fbc-2b96-54a7-0193-f640156714ab")

	response, err := client.Do(req)
	if err != nil {
		panic(err)
	}
	return response
}

func (f *fetchHandler) parsesDom(html *http.Response) {
	doc, err := goquery.NewDocumentFromReader(html.Body)
	if err != nil {
		panic(err)
	}
	doc.Find("div[class=\"result-op c-container xpath-log new-pmd\"]").Each(func(i int, selection *goquery.Selection) {
		data := fetchData{}
		data.url, _ = selection.Attr("mu")
		t := selection.Find(".news-title-font_1xS-F").First()
		data.title = t.Text()
		data.desc = selection.Find(".c-row .c-color-text").First().Text()
		k := data.url + "_" + data.title
		var newFetch []fetchData
		if _, ok := f.hadFetchedMap[k]; !ok {
			f.hadFetchData = append(f.hadFetchData, data)
			f.hadFetchedMap[k] = 1
			newFetch = append(newFetch, data)
		}
		f.newFetchItem <- newFetch
	})

	err = html.Body.Close()
	if err != nil {
		panic(err)
	}
}

func (f *fetchHandler) sendFetchData() {
	for {
		data := <-f.newFetchItem
		err := f.ws.WriteJSON(message{
			Status:  true,
			Action:  "newData",
			Message: "",
			Data:    data,
		})
		if err != nil {
			log.Println(err)
		}
	}
}

func (f *fetchHandler) cronFetch() {
	t := time.NewTicker(f.cronTime)
	defer t.Stop()
	for {
		select {
		case <-t.C:
			f.handle()
		case tt := <-f.reloadCron:
			f.cronTime = time.Duration(tt) * time.Second
			go f.cronFetch()
			return
		case <-f.isOff:
			return
		}
	}
}

func main() {
	h := newFetchHandler("https://www.baidu.com/s?rtt=1&bsst=1&cl=2&tn=news&rsv_dl=ns_pc&word=", "纪检")
	router := gin.Default()
	var upgrader = websocket.Upgrader{}
	router.LoadHTMLGlob("templates/*")
	//router.LoadHTMLFiles("templates/template1.html", "templates/template2.html")
	router.GET("/index", func(c *gin.Context) {
		c.HTML(http.StatusOK, "index.gohtml", gin.H{
			"title":    "爬虫",
			"keyword":  h.keyword,
			"timeStep": h.cronTime.Seconds(),
		})
	})
	router.GET("ws", func(c *gin.Context) {
		conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
		if err != nil {
			c.JSON(201, message{
				Status:  false,
				Message: err.Error(),
				Data:    nil,
				Action:  "upgradeWs",
			})
			return
		}
		h.ws = conn
		msg := message{}
		for {
			err := conn.ReadJSON(msg)
			if err != nil {
				return
			}
			h.rMsgChan <- msg
		}
	})
	router.Run(":8080")
}