get lead from cookie

using variable to idenfity cookie name.

create cookie based on lead id.

crmpixel.go

 	"encoding/json"
 	"errors"
 	"fmt"
+	"log"
 	"math/rand"
 	"net/http"
 	"net/url"
 	"time"
 )
 
+var cookLeadID = "biukop_cl"
+
 func crmpixelImage() (pixel []byte, err error) {
 	b64pixel := "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAABmJLR0QA/wD/AP+gvaeTAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH4QcIBzEJ3JY/6wAAAAh0RVh0Q29tbWVudAD2zJa/AAAADUlEQVQI12NgYGBgAAAABQABXvMqOgAAAABJRU5ErkJggg=="
 	pixel, err = base64.StdEncoding.DecodeString(b64pixel)
 }
 
 func crmpixelCookie(r *http.Request) (ret http.Cookie) {
-	cookie, leadok := r.Cookie("biukop_cl") //crm lead
+	cookie, leadok := r.Cookie(cookLeadID) //crm lead
 
 	if leadok != nil {
 		ret, _ = createNewCookie(r)
 	return
 }
 
+func getLeadIDFromCookie(r *http.Request) (leadID string, ok bool) {
+	ok = false
+	cookie, leadok := r.Cookie(cookLeadID) //crm lead
+	if leadok != nil {
+		return
+	}
+	valid := isValidCookieBiukopCL(cookie.Value)
+	if !valid {
+		return
+	}
+
+	//correctly split string
+	s := strings.Split(cookie.Value, "|")
+	if len(s) != 4 || s[0] == "" {
+		return
+	}
+	ok = true
+	leadID = s[0]
+	return
+}
+
 func createNewCookie(r *http.Request) (ret http.Cookie, info crmdLead) {
-	expiration := time.Now().Add(10 * 365 * 24 * time.Hour)
 	info = crmCreateNewAnonymousLeadByHTTPRequest(r)
-	cookieValue := buildBiukopCLValue(info.ID)
-	ret = http.Cookie{Name: "biukop_cl", Value: cookieValue, Expires: expiration}
+	ret = createNewCookieByLeadID(info.ID)
+	return
+}
+
+func createNewCookieByLeadID(leadID string) (ret http.Cookie) {
+	expiration := time.Now().Add(10 * 365 * 24 * time.Hour)
+	cookieValue := buildBiukopCLValue(leadID)
+	ret = http.Cookie{Name: cookLeadID, Value: cookieValue, Expires: expiration}
 	return
 }
 
 //
 func setTrackingCookieAndRecirect(w http.ResponseWriter, r *http.Request) {
 
-	cookie := crmpixelCookie(r)
-	http.SetCookie(w, &cookie)
-
 	rq := r.URL.RawQuery
 	m, _ := url.ParseQuery(rq)
 
+	//set cookie if any
+	leadID, ok := m["lid"]
+	if ok {
+		log.Println("setlead cookie :" + leadID[0])
+		cookie := createNewCookieByLeadID(leadID[0])
+		http.SetCookie(w, &cookie)
+	} else {
+		cookie := crmpixelCookie(r)
+		http.SetCookie(w, &cookie)
+	}
+
 	url, ok := m["url"]
 	if ok {
 		http.Redirect(w, r, url[0], 307) //302 temp redirect