defmodule PhoenixKitWeb.Users.MagicLinkController do
  @moduledoc """
  Controller for handling magic link verification and authentication.

  This controller handles the server-side verification of magic link tokens
  when users click on the links received via email.
  """
  use PhoenixKitWeb, :controller

  alias PhoenixKit.Users.MagicLink
  alias PhoenixKitWeb.Users.Auth, as: UserAuth

  @doc """
  Verifies a magic link token and logs the user in.

  This is the endpoint that magic link URLs point to. It:
  1. Verifies the token is valid and not expired
  2. Logs the user in by creating a session
  3. Redirects to the appropriate post-login destination
  4. Handles invalid/expired tokens gracefully
  """
  def verify(conn, %{"token" => token}) do
    case MagicLink.verify_magic_link(token) do
      {:ok, user} ->
        conn
        |> put_flash(:info, "Successfully logged in with magic link!")
        |> UserAuth.log_in_user(user)

      {:error, :invalid_token} ->
        conn
        |> put_flash(:error, "Magic link is invalid or has expired. Please request a new one.")
        |> redirect(to: ~p"/phoenix_kit/users/log-in")
    end
  end

  def verify(conn, _params) do
    conn
    |> put_flash(:error, "Invalid magic link. Please request a new one.")
    |> redirect(to: ~p"/phoenix_kit/users/log-in")
  end
end