refactor: use controller approach in handlers

internal/controller/oauth_controller.go

@@ -0,0 +1,185 @@
+package controller
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+	"tinyauth/internal/auth"
+	"tinyauth/internal/providers"
+	"tinyauth/internal/types"
+	"tinyauth/internal/utils"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/go-querystring/query"
+)
+
+type OAuthRequest struct {
+	Provider string `uri:"provider" binding:"required"`
+}
+
+type OAuthControllerConfig struct {
+	CSRFCookieName     string
+	RedirectCookieName string
+	SecureCookie       bool
+	AppURL             string
+}
+
+type OAuthController struct {
+	Config    OAuthControllerConfig
+	Router    *gin.RouterGroup
+	Auth      *auth.Auth
+	Providers *providers.Providers
+}
+
+func NewOAuthController(config OAuthControllerConfig, router *gin.RouterGroup, auth *auth.Auth, providers *providers.Providers) *OAuthController {
+	return &OAuthController{
+		Config:    config,
+		Router:    router,
+		Auth:      auth,
+		Providers: providers,
+	}
+}
+
+func (controller *OAuthController) SetupRoutes() {
+	oauthGroup := controller.Router.Group("/oauth")
+	oauthGroup.GET("/url/:provider", controller.oauthURLHandler)
+	oauthGroup.GET("/callback/:provider", controller.oauthCallbackHandler)
+}
+
+func (controller *OAuthController) oauthURLHandler(c *gin.Context) {
+	var req OAuthRequest
+
+	err := c.BindUri(&req)
+	if err != nil {
+		c.JSON(400, gin.H{
+			"status":  400,
+			"message": "Bad Request",
+		})
+		return
+	}
+
+	provider := controller.Providers.GetProvider(req.Provider)
+
+	if provider == nil {
+		c.JSON(404, gin.H{
+			"status":  404,
+			"message": "Not Found",
+		})
+		return
+	}
+
+	state := provider.GenerateState()
+	authURL := provider.GetAuthURL(state)
+	c.SetCookie(controller.Config.CSRFCookieName, state, int(time.Hour.Seconds()), "/", "", controller.Config.SecureCookie, true)
+
+	redirectURI := c.Query("redirect_uri")
+
+	if redirectURI != "" {
+		c.SetCookie(controller.Config.RedirectCookieName, redirectURI, int(time.Hour.Seconds()), "/", "", controller.Config.SecureCookie, true)
+	}
+
+	c.JSON(200, gin.H{
+		"status":  200,
+		"message": "OK",
+		"url":     authURL,
+	})
+}
+
+func (controller *OAuthController) oauthCallbackHandler(c *gin.Context) {
+	var req OAuthRequest
+
+	err := c.BindUri(&req)
+	if err != nil {
+		c.JSON(400, gin.H{
+			"status":  400,
+			"message": "Bad Request",
+		})
+		return
+	}
+
+	state := c.Query("state")
+	csrfCookie, err := c.Cookie(controller.Config.CSRFCookieName)
+
+	if err != nil || state != csrfCookie {
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.Config.AppURL))
+		return
+	}
+
+	c.SetCookie(controller.Config.CSRFCookieName, "", -1, "/", "", controller.Config.SecureCookie, true)
+
+	code := c.Query("code")
+	provider := controller.Providers.GetProvider(req.Provider)
+
+	if provider == nil {
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.Config.AppURL))
+		return
+	}
+
+	_, err = provider.ExchangeToken(code)
+	if err != nil {
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.Config.AppURL))
+		return
+	}
+
+	user, err := controller.Providers.GetUser(req.Provider)
+
+	if err != nil {
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.Config.AppURL))
+		return
+	}
+
+	if user.Email == "" {
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.Config.AppURL))
+		return
+	}
+
+	if !controller.Auth.EmailWhitelisted(user.Email) {
+		queries, err := query.Values(types.UnauthorizedQuery{
+			Username: user.Email,
+		})
+
+		if err != nil {
+			c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.Config.AppURL))
+			return
+		}
+
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/unauthorized?%s", controller.Config.AppURL, queries.Encode()))
+		return
+	}
+
+	var name string
+
+	if user.Name != "" {
+		name = user.Name
+	} else {
+		name = fmt.Sprintf("%s (%s)", utils.Capitalize(strings.Split(user.Email, "@")[0]), strings.Split(user.Email, "@")[1])
+	}
+
+	controller.Auth.CreateSessionCookie(c, &types.SessionCookie{
+		Username:    user.Email,
+		Name:        name,
+		Email:       user.Email,
+		Provider:    req.Provider,
+		OAuthGroups: utils.CoalesceToString(user.Groups),
+	})
+
+	redirectURI, err := c.Cookie(controller.Config.RedirectCookieName)
+
+	if err != nil {
+		c.Redirect(http.StatusTemporaryRedirect, controller.Config.AppURL)
+		return
+	}
+
+	queries, err := query.Values(types.RedirectQuery{
+		RedirectURI: redirectURI,
+	})
+
+	if err != nil {
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.Config.AppURL))
+		return
+	}
+
+	c.SetCookie(controller.Config.RedirectCookieName, "", -1, "/", "", controller.Config.SecureCookie, true)
+	c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/login?%s", controller.Config.AppURL, queries.Encode()))
+}