fathom/api/collect.go

package api

import (
  "net/http"
  "strings"
  "github.com/mssola/user_agent"
  "github.com/dannyvankooten/ana/models"
  "github.com/dannyvankooten/ana/db"
  "encoding/base64"
)

func getRequestIp(r *http.Request) string {
  ipAddress := r.RemoteAddr

  headerForwardedFor := r.Header.Get("X-Forwarded-For")
  if( headerForwardedFor != "" ) {
    ipAddress = headerForwardedFor
  }

  return ipAddress
}

func CollectHandler(w http.ResponseWriter, r *http.Request) {
  ua := user_agent.New(r.UserAgent())

  // abort if this is a bot.
  if ua.Bot() {
    return
  }

  q := r.URL.Query()

  // find or insert page
  page := models.Page{
    Path: q.Get("p"),
    Title: q.Get("t"),
    Hostname: q.Get("h"),
  }
  stmt, _ := db.Conn.Prepare("SELECT p.id FROM pages p WHERE p.hostname = ? AND p.path = ? LIMIT 1")
  defer stmt.Close()
  err := stmt.QueryRow(page.Hostname, page.Path).Scan(&page.ID)
  if err != nil {
    page.Save(db.Conn)
  }

  // find or insert visitor.
  // TODO: Mask IP Address
  visitor := models.Visitor{
    IpAddress: getRequestIp(r),
    BrowserLanguage: q.Get("l"),
    ScreenResolution: q.Get("sr"),
    DeviceOS: ua.OS(),
    Country: "",
  }

  // add browser details
  visitor.BrowserName, visitor.BrowserVersion = ua.Browser()
  versionParts := strings.SplitN(visitor.BrowserVersion, ".", 3)
  if len(versionParts) > 1 {
      visitor.BrowserVersion = versionParts[0] + "." + versionParts[1]
  }

  // query by unique visitor key
  visitor.GenerateKey()
  stmt, _ = db.Conn.Prepare("SELECT v.id FROM visitors v WHERE v.visitor_key = ? LIMIT 1")
  defer stmt.Close()
  err = stmt.QueryRow(visitor.Key).Scan(&visitor.ID)
  if err != nil {
    visitor.Save(db.Conn)
  }

  pageview := models.Pageview{
    PageID: page.ID,
    VisitorID: visitor.ID,
    ReferrerUrl: q.Get("ru"),
    ReferrerKeyword: q.Get("rk"),
  }

  // only store referrer URL if not coming from own site
  if strings.Contains(pageview.ReferrerUrl, page.Hostname)  {
    pageview.ReferrerUrl = ""
  }

  pageview.Save(db.Conn)

  // don't you cache this
  w.Header().Set("Content-Type", "image/gif")
  w.Header().Set("Expires", "Mon, 01 Jan 1990 00:00:00 GMT")
  w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
  w.Header().Set("Pragma", "no-cache")
  w.WriteHeader(http.StatusOK)

  // 1x1 px transparent GIF
  b, _ := base64.StdEncoding.DecodeString("R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7")
  w.Write(b)
}