Supply frontend with endpoints and nonce

* the UI needs to fetch the scores for SEO and readability
* those routes are protected by a nonce we need to provide
* introduce endpoint interface -- apply that to the seo scores and readability scores
* refactor the routes slightly to add the namespace
* lazier approach with the nonce

# Conflicts:
#	src/dashboard/user-interface/scores/abstract-scores-route.php
#	src/dashboard/user-interface/scores/readability-scores-route.php
#	src/dashboard/user-interface/scores/seo-scores-route.php

src/dashboard/application/configuration/dashboard-configuration.php

@@ -5,6 +5,8 @@
 namespace Yoast\WP\SEO\Dashboard\Application\Configuration;
 
 use Yoast\WP\SEO\Dashboard\Application\Content_Types\Content_Types_Repository;
+use Yoast\WP\SEO\Dashboard\Application\Endpoints\Endpoints_Repository;
+use Yoast\WP\SEO\Dashboard\Infrastructure\Nonces\Nonce_Repository;
 use Yoast\WP\SEO\Editors\Application\Analysis_Features\Enabled_Analysis_Features_Repository;
 use Yoast\WP\SEO\Editors\Framework\Keyphrase_Analysis;
 use Yoast\WP\SEO\Editors\Framework\Readability_Analysis;
@@ -44,6 +46,20 @@ class Dashboard_Configuration {
 	 */
 	private $enabled_analysis_features_repository;
 
+	/**
+	 * The endpoints repository.
+	 *
+	 * @var Endpoints_Repository
+	 */
+	private $endpoints_repository;
+
+	/**
+	 * The nonce repository.
+	 *
+	 * @var Nonce_Repository
+	 */
+	private $nonce_repository;
+
 	/**
 	 * The constructor.
 	 *
@@ -53,17 +69,23 @@ class Dashboard_Configuration {
 	 * @param User_Helper                          $user_helper                          The user helper.
 	 * @param Enabled_Analysis_Features_Repository $enabled_analysis_features_repository The analysis feature
 	 *                                                                                   repository.
+	 * @param Endpoints_Repository                 $endpoints_repository                 The endpoints repository.
+	 * @param Nonce_Repository                     $nonce_repository                     The nonce repository.
 	 */
 	public function __construct(
 		Content_Types_Repository $content_types_repository,
 		Indexable_Helper $indexable_helper,
 		User_Helper $user_helper,
-		Enabled_Analysis_Features_Repository $enabled_analysis_features_repository
+		Enabled_Analysis_Features_Repository $enabled_analysis_features_repository,
+		Endpoints_Repository $endpoints_repository,
+		Nonce_Repository $nonce_repository
 	) {
 		$this->content_types_repository             = $content_types_repository;
 		$this->indexable_helper                     = $indexable_helper;
 		$this->user_helper                          = $user_helper;
 		$this->enabled_analysis_features_repository = $enabled_analysis_features_repository;
+		$this->endpoints_repository                 = $endpoints_repository;
+		$this->nonce_repository                     = $nonce_repository;
 	}
 
 	/**
@@ -82,6 +104,8 @@ public function get_configuration(): array {
 					Keyphrase_Analysis::NAME,
 				]
 			)->to_array(),
+			'endpoints'               => $this->endpoints_repository->get_all_endpoints()->to_array(),
+			'nonce'                   => $this->nonce_repository->get_rest_nonce(),
 		];
 	}
 }

src/dashboard/application/endpoints/endpoints-repository.php

@@ -0,0 +1,42 @@
+<?php
+// phpcs:disable Yoast.NamingConventions.NamespaceName.TooLong -- Needed in the folder structure.
+namespace Yoast\WP\SEO\Dashboard\Application\Endpoints;
+
+use Yoast\WP\SEO\Dashboard\Domain\Endpoint\Endpoint_Interface;
+use Yoast\WP\SEO\Dashboard\Domain\Endpoint\Endpoint_List;
+
+/**
+ * Repository for endpoints.
+ */
+class Endpoints_Repository {
+
+	/**
+	 * Holds the endpoints.
+	 *
+	 * @var array<Endpoint_Interface>
+	 */
+	private $endpoints;
+
+	/**
+	 * Constructs the repository.
+	 *
+	 * @param Endpoint_Interface ...$endpoints The endpoints to add to the repository.
+	 */
+	public function __construct( Endpoint_Interface ...$endpoints ) {
+		$this->endpoints = $endpoints;
+	}
+
+	/**
+	 * Creates a list with all endpoints.
+	 *
+	 * @return Endpoint_List The list with all endpoints.
+	 */
+	public function get_all_endpoints(): Endpoint_List {
+		$list = new Endpoint_List();
+		foreach ( $this->endpoints as $endpoint ) {
+			$list->add_endpoint( $endpoint );
+		}
+
+		return $list;
+	}
+}

src/dashboard/domain/endpoint/endpoint-interface.php

@@ -0,0 +1,34 @@
+<?php
+// phpcs:disable Yoast.NamingConventions.NamespaceName.TooLong -- Needed in the folder structure.
+namespace Yoast\WP\SEO\Dashboard\Domain\Endpoint;
+
+interface Endpoint_Interface {
+
+	/**
+	 * Gets the name.
+	 *
+	 * @return string
+	 */
+	public function get_name(): string;
+
+	/**
+	 * Gets the namespace.
+	 *
+	 * @return string
+	 */
+	public function get_namespace(): string;
+
+	/**
+	 * Gets the route.
+	 *
+	 * @return string
+	 */
+	public function get_route(): string;
+
+	/**
+	 * Gets the URL.
+	 *
+	 * @return string
+	 */
+	public function get_url(): string;
+}

src/dashboard/domain/endpoint/endpoint-list.php

@@ -0,0 +1,41 @@
+<?php
+// phpcs:disable Yoast.NamingConventions.NamespaceName.TooLong -- Needed in the folder structure.
+namespace Yoast\WP\SEO\Dashboard\Domain\Endpoint;
+
+/**
+ * List of endpoints.
+ */
+class Endpoint_List {
+
+	/**
+	 * Holds the endpoints.
+	 *
+	 * @var array<Endpoint_Interface> $endpoints
+	 */
+	private $endpoints = [];
+
+	/**
+	 * Adds an endpoint to the list.
+	 *
+	 * @param Endpoint_Interface $endpoint An endpoint.
+	 *
+	 * @return void
+	 */
+	public function add_endpoint( Endpoint_Interface $endpoint ): void {
+		$this->endpoints[] = $endpoint;
+	}
+
+	/**
+	 * Converts the list to an array.
+	 *
+	 * @return array<string,string> The array of endpoints.
+	 */
+	public function to_array(): array {
+		$result = [];
+		foreach ( $this->endpoints as $endpoint ) {
+			$result[ $endpoint->get_name() ] = $endpoint->get_url();
+		}
+
+		return $result;
+	}
+}

src/dashboard/infrastructure/endpoints/readability-scores-endpoint.php

@@ -0,0 +1,48 @@
+<?php
+// phpcs:disable Yoast.NamingConventions.NamespaceName.TooLong -- Needed in the folder structure.
+namespace Yoast\WP\SEO\Dashboard\Infrastructure\Endpoints;
+
+use Yoast\WP\SEO\Dashboard\Domain\Endpoint\Endpoint_Interface;
+use Yoast\WP\SEO\Dashboard\User_Interface\Scores\Readability_Scores_Route;
+
+/**
+ * Represents the readability scores endpoint.
+ */
+class Readability_Scores_Endpoint implements Endpoint_Interface {
+
+	/**
+	 * Gets the name.
+	 *
+	 * @return string
+	 */
+	public function get_name(): string {
+		return 'readabilityScores';
+	}
+
+	/**
+	 * Gets the namespace.
+	 *
+	 * @return string
+	 */
+	public function get_namespace(): string {
+		return Readability_Scores_Route::ROUTE_NAMESPACE;
+	}
+
+	/**
+	 * Gets the route.
+	 *
+	 * @return string
+	 */
+	public function get_route(): string {
+		return Readability_Scores_Route::ROUTE_PREFIX;
+	}
+
+	/**
+	 * Gets the URL.
+	 *
+	 * @return string
+	 */
+	public function get_url(): string {
+		return \rest_url( $this->get_namespace() . $this->get_route() );
+	}
+}

src/dashboard/infrastructure/endpoints/seo-scores-endpoint.php

@@ -0,0 +1,48 @@
+<?php
+// phpcs:disable Yoast.NamingConventions.NamespaceName.TooLong -- Needed in the folder structure.
+namespace Yoast\WP\SEO\Dashboard\Infrastructure\Endpoints;
+
+use Yoast\WP\SEO\Dashboard\Domain\Endpoint\Endpoint_Interface;
+use Yoast\WP\SEO\Dashboard\User_Interface\Scores\SEO_Scores_Route;
+
+/**
+ * Represents the SEO scores endpoint.
+ */
+class Seo_Scores_Endpoint implements Endpoint_Interface {
+
+	/**
+	 * Gets the name.
+	 *
+	 * @return string
+	 */
+	public function get_name(): string {
+		return 'seoScores';
+	}
+
+	/**
+	 * Gets the namespace.
+	 *
+	 * @return string
+	 */
+	public function get_namespace(): string {
+		return Seo_Scores_Route::ROUTE_NAMESPACE;
+	}
+
+	/**
+	 * Gets the route.
+	 *
+	 * @return string
+	 */
+	public function get_route(): string {
+		return Seo_Scores_Route::ROUTE_PREFIX;
+	}
+
+	/**
+	 * Gets the URL.
+	 *
+	 * @return string
+	 */
+	public function get_url(): string {
+		return \rest_url( $this->get_namespace() . $this->get_route() );
+	}
+}

src/dashboard/infrastructure/nonces/nonce-repository.php

@@ -0,0 +1,18 @@
+<?php
+// phpcs:disable Yoast.NamingConventions.NamespaceName.TooLong -- Needed in the folder structure.
+namespace Yoast\WP\SEO\Dashboard\Infrastructure\Nonces;
+
+/**
+ * Repository for WP nonces.
+ */
+class Nonce_Repository {
+
+	/**
+	 * Creates the nonce for a WP REST request.
+	 *
+	 * @return string
+	 */
+	public function get_rest_nonce(): string {
+		return \wp_create_nonce( 'wp_rest' );
+	}
+}

src/dashboard/user-interface/scores/abstract-scores-route.php

@@ -23,6 +23,13 @@ abstract class Abstract_Scores_Route implements Route_Interface {
 
 	use No_Conditionals;
 
+	/**
+	 * The namespace of the rout.
+	 *
+	 * @var string
+	 */
+	public const ROUTE_NAMESPACE = Main::API_V1_NAMESPACE;
+
 	/**
 	 * The prefix of the rout.
 	 *
@@ -116,7 +123,7 @@ public function get_route_prefix() {
 	 */
 	public function register_routes() {
 		\register_rest_route(
-			Main::API_V1_NAMESPACE,
+			self::ROUTE_NAMESPACE,
 			$this->get_route_prefix(),
 			[
 				[