From 91a1b078d28908341e20671de7f062bd4e9d551d Mon Sep 17 00:00:00 2001
From: Jonny Harris <jon@spacedmonkey.co.uk>
Date: Thu, 27 Oct 2022 20:05:43 +0100
Subject: [PATCH] Prepare links method.

---
 ...gutenberg-rest-template-revision-count.php | 85 +++++++++++--------
 packages/edit-site/src/store/selectors.js     |  4 +-
 2 files changed, 50 insertions(+), 39 deletions(-)

diff --git a/lib/experimental/class-gutenberg-rest-template-revision-count.php b/lib/experimental/class-gutenberg-rest-template-revision-count.php
index 44bfc34a6060d8..00ea9a50476f8e 100644
--- a/lib/experimental/class-gutenberg-rest-template-revision-count.php
+++ b/lib/experimental/class-gutenberg-rest-template-revision-count.php
@@ -8,7 +8,7 @@
  * @package gutenberg
  */
 
- class Gutenberg_REST_Template_Revision_Count extends WP_REST_Templates_Controller {
+class Gutenberg_REST_Template_Revision_Count extends WP_REST_Templates_Controller {
 	/**
 	 * Add revisions to the response.
 	 *
@@ -19,54 +19,65 @@ class Gutenberg_REST_Template_Revision_Count extends WP_REST_Templates_Controlle
 	public function prepare_item_for_response( $item, $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
 		$template = $item;
 
-		$response = parent::prepare_item_for_response( $item, $request );
-		$data = $response->get_data();
 		$fields = $this->get_fields_for_response( $request );
 
-		if ( ! empty( $template->wp_id ) && $template->wp_id > 0 ) {
-			$revisions = wp_get_latest_revision_id_and_total_count( $template->wp_id );
-		} else {
-			// TODO: Should this be included if it's a file-based template?
-			$revisions = array(
-				'count' => 0,
-				'latest_id' => 0,
-			);
-		}
-
-		if ( rest_is_field_included( 'revision_count', $fields ) ) {
-			$data['revision_count'] = (int) $revisions['count'];
-		}
+		$response = parent::prepare_item_for_response( $item, $request );
 
-		if ( rest_is_field_included( 'latest_revision_id', $fields ) ) {
-			$data['latest_revision_id'] = (int) $revisions['latest_id'];
+		if ( rest_is_field_included( '_links', $fields ) || rest_is_field_included( '_embedded', $fields ) ) {
+			$links = $this->prepare_links( $template );
+			$response->add_links( $links );
+			if ( ! empty( $links['self']['href'] ) ) {
+				$actions = $this->get_available_actions();
+				$self    = $links['self']['href'];
+				foreach ( $actions as $rel ) {
+					$response->add_link( $rel, $self );
+				}
+			}
 		}
 
-		$response->set_data( $data );
 		return $response;
 	}
 
 	/**
-	 * Adds revision_count and latest_revision_id to the template schema.
+	 * Prepares links for the request.
+	 *
+	 * @since 6.2.0
 	 *
-	 * @return array Item schema data.
+	 * @param WP_Block_Template $template    Template instance.
+	 * @return array Links for the given post.
 	 */
-	public function get_item_schema() {
-		$schema = parent::get_item_schema();
-
-		$schema['properties']['revision_count'] = array(
-			'description' => __( 'The number of revisions of the template.' ),
-			'type'        => 'integer',
-			'context'     => array( 'edit', 'embed' ),
-			'readonly'    => true,
+	protected function prepare_links( $template ) {
+		$base  = sprintf( '%s/%s', $this->namespace, $this->rest_base );
+		$links = array(
+			'self'       => array(
+				'href' => rest_url( trailingslashit( $base ) . $template->id ),
+			),
+			'collection' => array(
+				'href' => rest_url( rest_get_route_for_post_type_items( $this->post_type ) ),
+			),
+			'about'      => array(
+				'href' => rest_url( 'wp/v2/types/' . $this->post_type ),
+			),
 		);
 
-		$schema['properties']['latest_revision_id'] = array(
-			'description' => __( 'The id of the latest revision of the template.' ),
-			'type'        => 'integer',
-			'context'     => array( 'edit', 'embed' ),
-			'readonly'    => true,
-		);
+		if ( post_type_supports( $this->post_type, 'revisions' ) && (int) $template->wp_id ) {
+			$revisions       = wp_get_latest_revision_id_and_total_count( (int) $template->wp_id );
+			$revisions_count = ! is_wp_error( $revisions ) ? $revisions['count'] : 0;
+			$revisions_base  = sprintf( '/%s/%s/%s/revisions', $this->namespace, $this->rest_base, $template->id );
+
+			$links['version-history'] = array(
+				'href'  => rest_url( $revisions_base ),
+				'count' => $revisions_count,
+			);
+
+			if ( $revisions_count > 0 ) {
+				$links['predecessor-version'] = array(
+					'href' => rest_url( $revisions_base . '/' . $revisions['latest_id'] ),
+					'id'   => $revisions['latest_id'],
+				);
+			}
+		}
 
-		return $schema;
+		return $links;
 	}
-}
\ No newline at end of file
+}
diff --git a/packages/edit-site/src/store/selectors.js b/packages/edit-site/src/store/selectors.js
index d2ed050f16c475..d3e0f32ce63ef1 100644
--- a/packages/edit-site/src/store/selectors.js
+++ b/packages/edit-site/src/store/selectors.js
@@ -429,7 +429,7 @@ export function getCurrentTemplateRevisionsCount( state ) {
 	if ( template.source === 'theme' ) {
 		return 0;
 	}
-	return ( template.revision_count ?? 0 ) + 1;
+	return ( template?._links?.['version-history']?.[ 0 ]?.count ?? 0 ) + 1;
 }
 
 /**
@@ -441,5 +441,5 @@ export function getCurrentTemplateRevisionsCount( state ) {
  * @return {?number} ID of the last revision.
  */
 export function getCurrentTemplateLastRevisionId( state ) {
-	return getCurrentTemplate( state ).latest_revision_id ?? null;
+	return getCurrentTemplate( state )?._links?.['predecessor-version']?.[ 0 ]?.id ?? null;
 }