Handle guest token / session initialization when not connected to internet

cmd/twitter/main.go

@@ -129,7 +129,12 @@ func main() {
 		scraper.InitApi(profile.LoadSession(scraper.UserHandle(*session_name)))
 		// fmt.Printf("Operating as user: @%s\n", scraper.the_api.UserHandle)
 	} else {
-		scraper.InitApi(scraper.NewGuestSession())
+		session, err := scraper.NewGuestSession()
+		if err != nil {
+			log.Warnf("Unable to initialize guest session!  Might be a network issue")
+		} else {
+			scraper.InitApi(session)
+		}
 	}
 
 	switch operation {
@@ -222,7 +227,10 @@ func main() {
 // - password: twitter account password
 func login(username string, password string) {
 	// Skip the scraper.the_api variable, just use a local one since no scraping is happening
-	api := scraper.NewGuestSession()
+	api, err := scraper.NewGuestSession()
+	if err != nil {
+		die(fmt.Sprintf("Unable to create session: %s", err.Error()), false, 1)
+	}
 	challenge := api.LogIn(username, password)
 	if challenge != nil {
 		fmt.Printf("Secondary challenge issued:\n")

internal/webserver/handler_login.go

@@ -42,7 +42,10 @@ func (app *Application) Login(w http.ResponseWriter, r *http.Request) {
 		panic_if(json.Unmarshal(data, &form)) // TODO: HTTP 400 not 500
 		form.Validate()
 		if len(form.FormErrors) == 0 {
-			api := scraper.NewGuestSession()
+			api, err := scraper.NewGuestSession()
+			if err != nil {
+				panic(err.Error()) // Return it as a toast
+			}
 			challenge := api.LogIn(form.Username, form.Password)
 			if challenge != nil {
 				panic( // Middleware will trap this panic and return an HTMX error toast

internal/webserver/server.go

@@ -62,7 +62,6 @@ func (app *Application) WithMiddlewares() http.Handler {
 
 func (app *Application) SetActiveUser(handle scraper.UserHandle) error {
 	if handle == "no account" {
-		scraper.InitApi(scraper.NewGuestSession())
 		app.ActiveUser = get_default_user()
 		app.IsScrapingDisabled = true // API requests will fail b/c not logged in
 	} else {

pkg/scraper/api_errors.go

@@ -11,5 +11,8 @@ var (
 	ErrorIsTombstone   = errors.New("tweet is a tombstone")
 	ErrRateLimited     = errors.New("rate limited")
 	ErrorDMCA          = errors.New("video is DMCAed, unable to download (HTTP 403 Forbidden)")
-	ErrRequestTimeout  = errors.New("request timed out")
+
+	// These are not API errors, but network errors generally
+	ErrNoInternet     = errors.New("no internet connection")
+	ErrRequestTimeout = errors.New("request timed out")
 )

pkg/scraper/api_request_utils.go

@@ -111,10 +111,10 @@ func (api API) add_authentication_headers(req *http.Request) {
 	}
 }
 
-func NewGuestSession() API {
+func NewGuestSession() (API, error) {
-	guestAPIString, err := GetGuestToken()
+	guestAPIString, err := GetGuestTokenWithRetries(3, 1*time.Second)
 	if err != nil {
-		panic(err)
+		return API{}, err
 	}
 
 	jar, err := cookiejar.New(nil)
@@ -129,7 +129,7 @@ func NewGuestSession() API {
 			Jar:     jar,
 		},
 		CSRFToken: "",
-	}
+	}, nil
 }
 
 func (api *API) update_csrf_token() {

pkg/scraper/guest_token.go

@@ -2,8 +2,11 @@ package scraper
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
+	"log"
+	"net"
 	"net/http"
 	"time"
 )
@@ -15,7 +18,20 @@ type GuestTokenResponse struct {
 
 var guestToken GuestTokenResponse
 
+func GetGuestTokenWithRetries(n int, sleep time.Duration) (ret string, err error) {
+	for i := 0; i < n; i++ {
+		ret, err = GetGuestToken()
+		if err == nil {
+			return
+		}
+		log.Printf("Failed to get guest token: %s\nRetrying...", err.Error())
+		time.Sleep(sleep)
+	}
+	return
+}
+
 func GetGuestToken() (string, error) {
+	// Guest token is still valid; no need for new one
 	if time.Since(guestToken.RefreshedAt).Hours() < 1 {
 		return guestToken.Token, nil
 	}
@@ -29,6 +45,11 @@ func GetGuestToken() (string, error) {
 
 	resp, err := client.Do(req)
 	if err != nil {
+		var dnsErr *net.DNSError
+		if errors.As(err, &dnsErr) && dnsErr.Err == "server misbehaving" && dnsErr.Temporary() {
+			return "", ErrNoInternet
+		}
+
 		return "", fmt.Errorf("Error executing HTTP request:\n  %w", err)
 	}
 

pkg/scraper/user.go

@@ -175,7 +175,11 @@ func ParseSingleUser(apiUser APIUser) (ret User, err error) {
 
 // Calls API#GetUser and returns the parsed result
 func GetUser(handle UserHandle) (User, error) {
-	apiUser, err := NewGuestSession().GetUser(handle)
+	session, err := NewGuestSession() // This endpoint works better if you're not logged in
+	if err != nil {
+		return User{}, err
+	}
+	apiUser, err := session.GetUser(handle)
 	if apiUser.ScreenName == "" {
 		if apiUser.IsBanned || apiUser.DoesntExist {
 			ret := GetUnknownUserWithHandle(handle)