add login_as to admin

app/admin_model.py

@@ -3,7 +3,7 @@ from flask import redirect, url_for, request, flash
 from flask_admin import expose, AdminIndexView
 from flask_admin.actions import action
 from flask_admin.contrib import sqla
-from flask_login import current_user
+from flask_login import current_user, login_user
 
 from app.extensions import db
 from app.models import User, ManualSubscription
@@ -122,6 +122,22 @@ class UserAdmin(SLModelView):
 
         db.session.commit()
 
+    @action(
+        "login_as",
+        "Login as this user",
+        "Login as this user?",
+    )
+    def login_as(self, ids):
+        if len(ids) != 1:
+            flash("only 1 user can be selected", "error")
+            return
+
+        for user in User.query.filter(User.id.in_(ids)):
+            login_user(user)
+            flash(f"Login as user {user}", "success")
+            return redirect("/")
+
+
 
 def manual_upgrade(way: str, ids: [int], is_giveaway: bool):
     query = User.query.filter(User.id.in_(ids))