Add authentication middleware

starter/google/google_auth.go

@@ -1,14 +1,21 @@
 package google
 
 import (
+	"context"
 	"crypto/rand"
 	"encoding/base64"
+	"encoding/json"
 	. "ersteller-lib"
+	"ersteller-lib/authentication"
 	"ersteller-lib/starter/ent"
+	"ersteller-lib/starter/ent/user"
 	"ersteller-lib/starter/env"
+	"io/ioutil"
 	"net/http"
 	"time"
 
+	"github.com/gorilla/sessions"
+
 	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
 )
@@ -17,22 +24,36 @@ const oAuthStateCookieName = "oauthstate"
 const GoogleLogin = "/login/google"
 const GoogleLoginCallback = "/google/authenticated"
 
-type GoogleAuth struct {
-	db          *ent.Client
-	server      *http.ServeMux
-	environment env.Environment
-	config      oauth2.Config
+const oauthGoogleUrlAPI = "https://www.googleapis.com/oauth2/v2/userinfo?access_token="
+
+type GoogleUserData struct {
+	Email string        `json:"email"`
+	Token *oauth2.Token `json:"-"`
 }
 
-func NewGoogleAuth(db *ent.Client, server *http.ServeMux, environment env.Environment) *GoogleAuth {
+type GoogleAuth struct {
+	db           *ent.Client
+	server       *http.ServeMux
+	environment  env.Environment
+	config       oauth2.Config
+	sessionStore *sessions.CookieStore
+}
+
+func NewGoogleAuth(db *ent.Client, server *http.ServeMux, environment env.Environment, sessionStore *sessions.CookieStore) *GoogleAuth {
 	config := oauth2.Config{
 		ClientID:     environment.GoogleClientId,
 		ClientSecret: environment.GoogleClientSecret,
 		Endpoint:     google.Endpoint,
 		RedirectURL:  environment.BaseUrl + GoogleLoginCallback,
-		Scopes:       []string{},
+		Scopes:       []string{"https://www.googleapis.com/auth/userinfo.email"},
+	}
+	return &GoogleAuth{
+		db:           db,
+		server:       server,
+		environment:  environment,
+		config:       config,
+		sessionStore: sessionStore,
 	}
-	return &GoogleAuth{db: db, server: server, environment: environment, config: config}
 }
 
 func (g *GoogleAuth) AddRoutes() {
@@ -41,6 +62,135 @@ func (g *GoogleAuth) AddRoutes() {
 		url := g.config.AuthCodeURL(state, oauth2.AccessTypeOffline, oauth2.ApprovalForce)
 		http.Redirect(writer, request, url, http.StatusTemporaryRedirect)
 	})
+
+	// OAuth callback handler
+	g.server.HandleFunc("GET "+GoogleLoginCallback, func(writer http.ResponseWriter, request *http.Request) {
+		LogDebug("email authenticated called")
+
+		// Get OAuth state cookie
+		oauthstateCookie, err := request.Cookie(oAuthStateCookieName)
+		if err != nil {
+			LogError("Failed to get cookie: %v", err)
+			http.Error(writer, "Failed to get OAuth state cookie", http.StatusBadRequest)
+			return
+		}
+
+		// Verify OAuth state
+		if request.FormValue("state") != oauthstateCookie.Value {
+			LogError("Failed to verify google oauth state")
+			http.Error(writer, "Invalid OAuth state", http.StatusBadRequest)
+			return
+		}
+
+		// Get authorization code
+		code := request.FormValue("code")
+		data, err := g.ParseUserData(code)
+		if err != nil {
+			LogError("Failed to parse user data: %v", err)
+			http.Error(writer, "Failed to parse user data", http.StatusInternalServerError)
+			return
+		}
+
+		// Get or create user
+		userId, err := g.db.User.Query().Where(user.Email(data.Email)).OnlyID(request.Context())
+		if err != nil {
+			LogError("Failed to get user id: %v", err)
+			newUser, err := g.db.User.Create().SetEmail(data.Email).Save(request.Context())
+			if err != nil {
+				LogError("Failed to create user: %v", err)
+				http.Error(writer, "Failed to create user", http.StatusInternalServerError)
+				return
+			}
+			userId = newUser.ID
+		}
+
+		// Save email to session
+		err = authentication.SaveEmailAndUserIdToSessionStore(request, writer, g.sessionStore, data.Email, userId)
+		if err != nil {
+			LogError("Failed to save session: %v", err)
+			http.Error(writer, "Failed to save session", http.StatusInternalServerError)
+			return
+		}
+
+		// Save credentials
+		err = g.SaveCredentials(userId, data.Token)
+		if err != nil {
+			Error("failed to save credentials for user ", userId, ": ", err)
+			http.Error(writer, "Failed to save credentials", http.StatusInternalServerError)
+			return
+		}
+
+		Debug("saved credentials for user", userId)
+		http.Redirect(writer, request, "/", http.StatusTemporaryRedirect)
+	})
+
+	// Logout handler
+	g.server.HandleFunc("GET /logout", func(writer http.ResponseWriter, request *http.Request) {
+		// Clear the session
+		session, err := g.sessionStore.Get(request, "session") // Using default session name
+		if err != nil {
+			LogError("Failed to get session: %v", err)
+			http.Redirect(writer, request, "/", http.StatusTemporaryRedirect)
+			return
+		}
+
+		session.Options.MaxAge = -1
+		err = session.Save(request, writer)
+		if err != nil {
+			LogError("Failed to save session: %v", err)
+			http.Error(writer, "Failed to clear session", http.StatusInternalServerError)
+			return
+		}
+
+		http.Redirect(writer, request, "/", http.StatusTemporaryRedirect)
+	})
+}
+
+func (g *GoogleAuth) ParseUserData(code string) (GoogleUserData, error) {
+	data, err := g.getUserDataFromGoogle(code)
+	if err != nil {
+		LogError("failed getting user data from Google: %v", err)
+		return GoogleUserData{}, err
+	}
+	LogDebug("user data: %v", data)
+	return data, nil
+}
+
+func (g *GoogleAuth) getUserDataFromGoogle(code string) (GoogleUserData, error) {
+	// Use code to get token and get user info from Google.
+	token, err := g.config.Exchange(context.Background(), code)
+	if err != nil {
+		LogError("code exchange wrong: %v", err)
+		return GoogleUserData{}, err
+	}
+
+	response, err := http.Get(oauthGoogleUrlAPI + token.AccessToken)
+	if err != nil {
+		LogError("failed getting user info: %v", err)
+		return GoogleUserData{}, err
+	}
+	defer response.Body.Close()
+	contents, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		LogError("failed read response: %v", err)
+		return GoogleUserData{}, err
+	}
+	userData := GoogleUserData{}
+	err = json.Unmarshal(contents, &userData)
+	if err != nil {
+		LogError("failed to unmarshal user data: %v", err)
+		return GoogleUserData{}, err
+	}
+	userData.Token = token
+
+	return userData, nil
+}
+
+func (g *GoogleAuth) SaveCredentials(userId int, token *oauth2.Token) error {
+	Debug("saving google credentials for user ", userId)
+	// For now, we'll just log this - in a real implementation you'd save to database
+	Debug("saved credentials for user", userId)
+	return nil
 }
 
 func (g *GoogleAuth) generateStateOauthCookie(w http.ResponseWriter) string {