Implement domain change via Sites API

cc @ukutaht

lib/plausible/site/domain.ex

@@ -43,15 +43,15 @@ defmodule Plausible.Site.Domain do
 
   @spec change(Site.t(), String.t(), Keyword.t()) ::
           {:ok, Site.t()} | {:error, Ecto.Changeset.t()}
-  def change(site = %Site{}, new_domain, opts \\ []) when is_binary(new_domain) do
+  def change(site = %Site{}, new_domain, opts \\ []) do
     changeset = Site.update_changeset(site, %{domain: new_domain}, opts)
 
     changeset =
-      if Enum.empty?(changeset.changes) do
+      if Enum.empty?(changeset.changes) and is_nil(changeset.errors[:domain]) do
         Ecto.Changeset.add_error(
           changeset,
           :domain,
-          "New domain must be different than your current one."
+          "New domain must be different than the current one"
         )
       else
         changeset

lib/plausible_web/controllers/api/external_sites_controller.ex

@@ -49,6 +49,25 @@ defmodule PlausibleWeb.Api.ExternalSitesController do
     end
   end
 
+  def update_site(conn, %{"site_id" => site_id} = params) do
+    # for now this only allows to change the domain
+    site = Sites.get_for_user(conn.assigns[:current_user].id, site_id, [:owner, :admin])
+
+    if site && Plausible.v2?() do
+      case Plausible.Site.Domain.change(site, params["domain"]) do
+        {:ok, site} ->
+          json(conn, site)
+
+        {:error, changeset} ->
+          conn
+          |> put_status(400)
+          |> json(serialize_errors(changeset))
+      end
+    else
+      H.not_found(conn, "Site could not be found")
+    end
+  end
+
   defp expect_param_key(params, key) do
     case Map.fetch(params, key) do
       :error -> {:missing, key}

lib/plausible_web/router.ex

@@ -98,11 +98,12 @@ defmodule PlausibleWeb.Router do
     pipe_through [:public_api, PlausibleWeb.AuthorizeSitesApiPlug]
 
     post "/", ExternalSitesController, :create_site
-    get "/:site_id", ExternalSitesController, :get_site
-    delete "/:site_id", ExternalSitesController, :delete_site
     put "/shared-links", ExternalSitesController, :find_or_create_shared_link
     put "/goals", ExternalSitesController, :find_or_create_goal
     delete "/goals/:goal_id", ExternalSitesController, :delete_goal
+    get "/:site_id", ExternalSitesController, :get_site
+    put "/:site_id", ExternalSitesController, :update_site
+    delete "/:site_id", ExternalSitesController, :delete_site
   end
 
   scope "/api", PlausibleWeb do

test/plausible_web/controllers/api/external_sites_controller_test.exs

@@ -481,6 +481,7 @@ defmodule PlausibleWeb.Api.ExternalSitesControllerTest do
   describe "GET /api/v1/sites/:site_id" do
     setup :create_new_site
 
+    @tag :v2_only
     test "get a site by its domain", %{conn: conn, site: site} do
       conn = get(conn, "/api/v1/sites/" <> site.domain)
 
@@ -499,6 +500,7 @@ defmodule PlausibleWeb.Api.ExternalSitesControllerTest do
       assert json_response(conn, 200) == %{"domain" => new_domain, "timezone" => site.timezone}
     end
 
+    @tag :v2_only
     test "is 404 when site cannot be found", %{conn: conn} do
       conn = get(conn, "/api/v1/sites/foobar.baz")
 

test/plausible_web/controllers/site_controller_test.exs

@@ -1177,7 +1177,7 @@ defmodule PlausibleWeb.SiteControllerTest do
         })
 
       resp = html_response(conn, 200)
-      assert resp =~ "New domain must be different than your current one."
+      assert resp =~ "New domain must be different than the current one"
     end
 
     @tag :v2_only