feat(user): use gen auth for users

lib/learning_phoenix_web/controllers/user_session_controller.ex

@@ -0,0 +1,67 @@
+defmodule LearningPhoenixWeb.UserSessionController do
+  use LearningPhoenixWeb, :controller
+
+  alias LearningPhoenix.Accounts
+  alias LearningPhoenixWeb.UserAuth
+
+  def create(conn, %{"_action" => "confirmed"} = params) do
+    create(conn, params, "User confirmed successfully.")
+  end
+
+  def create(conn, params) do
+    create(conn, params, "Welcome back!")
+  end
+
+  # magic link login
+  defp create(conn, %{"user" => %{"token" => token} = user_params}, info) do
+    case Accounts.login_user_by_magic_link(token) do
+      {:ok, {user, tokens_to_disconnect}} ->
+        UserAuth.disconnect_sessions(tokens_to_disconnect)
+
+        conn
+        |> put_flash(:info, info)
+        |> UserAuth.log_in_user(user, user_params)
+
+      _ ->
+        conn
+        |> put_flash(:error, "The link is invalid or it has expired.")
+        |> redirect(to: ~p"/users/log-in")
+    end
+  end
+
+  # email + password login
+  defp create(conn, %{"user" => user_params}, info) do
+    %{"email" => email, "password" => password} = user_params
+
+    if user = Accounts.get_user_by_email_and_password(email, password) do
+      conn
+      |> put_flash(:info, info)
+      |> UserAuth.log_in_user(user, user_params)
+    else
+      # In order to prevent user enumeration attacks, don't disclose whether the email is registered.
+      conn
+      |> put_flash(:error, "Invalid email or password")
+      |> put_flash(:email, String.slice(email, 0, 160))
+      |> redirect(to: ~p"/users/log-in")
+    end
+  end
+
+  def update_password(conn, %{"user" => user_params} = params) do
+    user = conn.assigns.current_scope.user
+    true = Accounts.sudo_mode?(user)
+    {:ok, {_user, expired_tokens}} = Accounts.update_user_password(user, user_params)
+
+    # disconnect all existing LiveViews with old sessions
+    UserAuth.disconnect_sessions(expired_tokens)
+
+    conn
+    |> put_session(:user_return_to, ~p"/users/settings")
+    |> create(params, "Password updated successfully!")
+  end
+
+  def delete(conn, _params) do
+    conn
+    |> put_flash(:info, "Logged out successfully.")
+    |> UserAuth.log_out_user()
+  end
+end