feat: redirect user back to where they were after login redirect

Signed-off-by: brookjeynes <[e-mail]>

internal/server/middleware/middleware.go

···
 
 import (
 	"context"
+	"fmt"
 	"log"
 	"net/http"
+	"net/url"
 	"slices"
 	"strings"
 
···
 func AuthMiddleware(a *oauth.OAuth) middlewareFunc {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			redirectFunc := func(w http.ResponseWriter, r *http.Request) {
-				http.Redirect(w, r, "/login", http.StatusTemporaryRedirect)
+			returnURL := "/"
+			if u, err := url.Parse(r.Header.Get("Referer")); err == nil {
+				returnURL = u.RequestURI()
 			}
 
+			loginURL := fmt.Sprintf("/login?return_url=%s", url.QueryEscape(returnURL))
+
+			redirectFunc := func(w http.ResponseWriter, r *http.Request) {
+				http.Redirect(w, r, loginURL, http.StatusTemporaryRedirect)
+			}
 			if r.Header.Get("HX-Request") == "true" {
 				redirectFunc = func(w http.ResponseWriter, _ *http.Request) {
-					w.Header().Set("HX-Redirect", "/login")
+					w.Header().Set("HX-Redirect", loginURL)
 					w.WriteHeader(http.StatusOK)
 				}
 			}
···
 				next.ServeHTTP(w, r)
 				return
 			}
+
+			didOrHandle = strings.TrimPrefix(didOrHandle, "@")
 
 			id, err := mw.idResolver.ResolveIdent(r.Context(), didOrHandle)
 			if err != nil {

internal/server/views/login.templ

···
 					</div>
 					<div class="flex flex-col gap-2">
 						<label for="handle">Handle or DID</label>
-						<input type="text" id="handle" name="handle" placeholder="username.bsky.social" class="input" autocomplete="username"/>
+						<input
+							type="text"
+							id="handle"
+							name="handle"
+							placeholder="username.bsky.social"
+							class="input"
+							autocomplete="username"
+						/>
 						<p class="text-xs text-text-muted">Enter your Bluesky handle (e.g., alice.bsky.social) or full DID</p>
 					</div>
+					<input type="hidden" name="return_url" value={ params.ReturnUrl }/>
 					<button class="btn btn-primary" type="submit" id="login-button">
 						<span>Log in with AT Protocol</span>
 						<i class="w-4 h-4" data-lucide="arrow-right"></i>

internal/server/views/views.go

···
 
 type LoginPageParams struct {
 	// The current logged in user.
-	User *types.User
+	User      *types.User
+	ReturnUrl string
 }
 
 type ProfilePageParams struct {