add frontend template + GET /users/{userRef} route

backend/routes/auth/routes.go

@@ -3,7 +3,9 @@ package auth
 import (
 	"net/http"
 
+	"emperror.dev/errors"
 	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/render"
 	"gitlab.com/1f320/pronouns/backend/server"
 )
 
@@ -13,15 +15,46 @@ type Server struct {
 
 func Mount(srv *server.Server, r chi.Router) {
 	s := &Server{srv}
-	_ = s
 
-	r.Route("/auth/discord", func(r chi.Router) {
-		r.Get("/authorize", nil) // generate csrf token, returns URL
-		r.Get("/callback", nil)  // takes code + state, validates it, returns token OR discord signup ticket
-		r.Get("/signup", nil)    // takes discord signup ticket to register account
+	r.Route("/auth", func(r chi.Router) {
+		// generate csrf token, returns all supported OAuth provider URLs
+		r.Get("/urls", server.WrapHandler(s.oauthURLs))
 
-		r.Get("/test", func(w http.ResponseWriter, r *http.Request) {
-			w.Write([]byte("hello world!"))
+		r.Route("/discord", func(r chi.Router) {
+			// takes code + state, validates it, returns token OR discord signup ticket
+			r.Post("/callback", nil)
+			// takes discord signup ticket to register account
+			r.Post("/signup", nil)
 		})
 	})
 }
+
+type oauthURLsRequest struct {
+	CallbackURL string `json:"callback_url"`
+}
+
+type oauthURLsResponse struct {
+	Discord string `json:"discord"`
+}
+
+func (s *Server) oauthURLs(w http.ResponseWriter, r *http.Request) error {
+	req, err := Decode[oauthURLsRequest](r)
+	if err != nil {
+		return server.APIError{Code: server.ErrBadRequest}
+	}
+
+	// generate CSRF state
+	state, err := s.setCSRFState(r.Context())
+	if err != nil {
+		return errors.Wrap(err, "setting CSRF state")
+	}
+
+	// copy Discord config and set redirect url
+	discordCfg := discordOAuthConfig
+	discordCfg.RedirectURL = req.CallbackURL
+
+	render.JSON(w, r, oauthURLsResponse{
+		Discord: discordCfg.AuthCodeURL(state),
+	})
+	return nil
+}