feat: add github oauth

server/app/auth/oauth_github.go

@@ -0,0 +1,124 @@
+package auth
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+
+	"github.com/gofiber/fiber/v2"
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/github"
+	"gorm.io/gorm"
+	"rul.sh/vaulterm/server/models"
+	"rul.sh/vaulterm/server/utils"
+)
+
+var config *oauth2.Config
+
+func getGithubConfig() *oauth2.Config {
+	if config != nil {
+		return config
+	}
+
+	config = &oauth2.Config{
+		ClientID:     os.Getenv("GITHUB_CLIENT_ID"),
+		ClientSecret: os.Getenv("GITHUB_CLIENT_SECRET"),
+		Endpoint:     github.Endpoint,
+		RedirectURL:  "http://localhost:3000/auth/oauth/github/callback",
+		Scopes:       []string{"read:user"},
+	}
+	return config
+}
+
+func githubRedir(c *fiber.Ctx) error {
+	// Redirect to GitHub login page
+	url := getGithubConfig().AuthCodeURL("state", oauth2.AccessTypeOffline)
+	return c.Redirect(url)
+}
+
+func githubCallback(c *fiber.Ctx) error {
+	code := c.Query("code")
+	if code == "" {
+		return c.Status(fiber.StatusBadRequest).SendString("Missing code")
+	}
+
+	// Exchange code for a token
+	cfg := getGithubConfig()
+	token, err := cfg.Exchange(c.Context(), code)
+	if err != nil {
+		return c.Status(fiber.StatusInternalServerError).SendString("Failed to exchange token")
+	}
+
+	// Retrieve user info
+	client := cfg.Client(c.Context(), token)
+	resp, err := client.Get("https://api.github.com/user")
+	if err != nil {
+		return c.Status(fiber.StatusInternalServerError).SendString("Failed to get user info")
+	}
+	defer resp.Body.Close()
+
+	body, _ := io.ReadAll(resp.Body)
+	if resp.StatusCode != 200 {
+		return c.Status(fiber.StatusInternalServerError).
+			SendString(fmt.Sprintf("GitHub API error: %s", string(body)))
+	}
+
+	// Parse user info
+	var user struct {
+		Login     string `json:"login"`
+		ID        int    `json:"id"`
+		Name      string `json:"name"`
+		AvatarURL string `json:"avatar_url"`
+		Email     string `json:"email"`
+	}
+
+	if err := json.Unmarshal(body, &user); err != nil {
+		return c.Status(fiber.StatusInternalServerError).SendString("Failed to parse user info")
+	}
+
+	repo := NewRepository()
+	accountId := strconv.Itoa(user.ID)
+	userAccount, err := repo.FindUserAccount("github", accountId)
+
+	// Register the user if the account not yet registered
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		acc := models.UserAccount{
+			Type:      "github",
+			AccountID: accountId,
+			Username:  user.Login,
+			Email:     user.Email,
+		}
+		user := models.User{
+			Name:     user.Name,
+			Role:     models.UserRoleUser,
+			Image:    user.AvatarURL,
+			Accounts: []*models.UserAccount{&acc},
+		}
+
+		sessionId, err := repo.CreateUser(&user)
+		if err != nil {
+			return utils.ResponseError(c, err, 500)
+		}
+
+		return c.JSON(fiber.Map{
+			"user":      user,
+			"sessionId": sessionId,
+		})
+	}
+
+	if err != nil {
+		return utils.ResponseError(c, err, 500)
+	}
+	sessionId, err := repo.CreateUserSession(&userAccount.User)
+	if err != nil {
+		return utils.ResponseError(c, err, 500)
+	}
+
+	return c.JSON(fiber.Map{
+		"user":      userAccount.User,
+		"sessionId": sessionId,
+	})
+}

server/app/auth/repository.go

@@ -23,6 +23,12 @@ func (r *Auth) FindUser(username string, email string) (*models.User, error) {
 	return &user, ret.Error
 }
 
+func (r *Auth) FindUserAccount(accountType string, accountId string) (*models.UserAccount, error) {
+	var user models.UserAccount
+	ret := r.db.Where("type = ? AND account_id = ?", accountType, accountId).Joins("User").First(&user)
+	return &user, ret.Error
+}
+
 func (r *Auth) CreateUserSession(user *models.User) (string, error) {
 	sessionId, err := lib.GenerateSessionID(20)
 	if err != nil {

server/app/auth/router.go

@@ -15,6 +15,10 @@ func Router(app *fiber.App) {
 	router.Get("/user", middleware.Protected(), getUser)
 	router.Post("/register", register)
 	router.Post("/logout", middleware.Protected(), logout)
+
+	oauth := router.Group("/oauth")
+	oauth.Get("/github", githubRedir)
+	oauth.Get("/github/callback", githubCallback)
 }
 
 func login(c *fiber.Ctx) error {