update github oauth callback api

api/auth.go

@@ -1,8 +1,14 @@
 package api
 
 import (
+	"bytes"
+	"database/sql"
 	"encoding/json"
+	"fmt"
+	"io/ioutil"
 	"memos/api/e"
+	"memos/common"
+	"memos/config"
 	"memos/store"
 	"net/http"
 
@@ -88,10 +94,131 @@ func handleUserSignOut(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+func handleGithubAuthCallback(w http.ResponseWriter, r *http.Request) {
+	code := r.URL.Query().Get("code")
+
+	requestBody := map[string]string{
+		"client_id":     config.GITHUB_CLIENTID,
+		"client_secret": config.GITHUB_SECRET,
+		"code":          code,
+	}
+
+	requestJSON, _ := json.Marshal(requestBody)
+
+	// POST request to get access_token
+	req, err := http.NewRequest(
+		"POST",
+		"https://github.com/login/oauth/access_token",
+		bytes.NewBuffer(requestJSON),
+	)
+
+	if err != nil {
+		e.ErrorHandler(w, "REQUEST_BODY_ERROR", "Error in request github api")
+		return
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		e.ErrorHandler(w, "REQUEST_BODY_ERROR", "Error in request github api")
+		return
+	}
+
+	// Response body converted to stringified JSON
+	respBody, _ := ioutil.ReadAll(resp.Body)
+
+	// Represents the response received from Github
+	type GithubAccessTokenResponse struct {
+		AccessToken string `json:"access_token"`
+		TokenType   string `json:"token_type"`
+		Scope       string `json:"scope"`
+	}
+
+	ghResp := GithubAccessTokenResponse{}
+	json.Unmarshal(respBody, &ghResp)
+
+	githubAccessToken := ghResp.AccessToken
+
+	// Get request to a set URL
+	req, err = http.NewRequest(
+		"GET",
+		"https://api.github.com/user",
+		nil,
+	)
+	if err != nil {
+		e.ErrorHandler(w, "REQUEST_BODY_ERROR", "Error in request github api")
+		return
+	}
+
+	authorizationHeaderValue := fmt.Sprintf("token %s", githubAccessToken)
+	req.Header.Set("Authorization", authorizationHeaderValue)
+
+	resp, err = http.DefaultClient.Do(req)
+
+	if err != nil {
+		e.ErrorHandler(w, "REQUEST_BODY_ERROR", "Error in request github api")
+		return
+	}
+
+	respBody, _ = ioutil.ReadAll(resp.Body)
+
+	githubData := string(respBody)
+
+	type GithubUser struct {
+		Login string `json:"login"`
+		Name  string `json:"name"`
+	}
+
+	githubUser := GithubUser{}
+	json.Unmarshal([]byte(githubData), &githubUser)
+
+	session, _ := SessionStore.Get(r, "session")
+	userId := fmt.Sprintf("%v", session.Values["user_id"])
+
+	if userId != "" {
+		githubNameUsable, err := store.CheckGithubNameUsable(githubUser.Login)
+
+		if err != nil {
+			e.ErrorHandler(w, "DATABASE_ERROR", "Error in CheckGithubNameUsable")
+			return
+		}
+
+		if !githubNameUsable {
+			e.ErrorHandler(w, "DATABASE_ERROR", "Error in CheckGithubNameUsable")
+			return
+		}
+
+		userPatch := store.UserPatch{
+			GithubName: &githubUser.Login,
+		}
+
+		store.UpdateUser(userId, &userPatch)
+	}
+
+	user, err := store.GetUserByGithubName(githubUser.Login)
+
+	if err == sql.ErrNoRows {
+		username := githubUser.Name
+		usernameUsable, _ := store.CheckUsernameUsable(username)
+		if !usernameUsable {
+			username = username + common.GenUUID()
+		}
+		user, _ = store.CreateNewUser(username, username, githubUser.Login, "")
+	}
+
+	session.Values["user_id"] = user.Id
+	session.Save(r, w)
+
+	http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
+}
+
 func RegisterAuthRoutes(r *mux.Router) {
 	authRouter := r.PathPrefix("/api/auth").Subrouter()
 
 	authRouter.HandleFunc("/signup", handleUserSignUp).Methods("POST")
 	authRouter.HandleFunc("/signin", handleUserSignIn).Methods("POST")
 	authRouter.HandleFunc("/signout", handleUserSignOut).Methods("POST")
+	authRouter.HandleFunc("/github", handleGithubAuthCallback).Methods("GET")
 }