<?php

/**

 * Server-side rendering of the `core/comments` block.

 *

 * @package WordPress

 */

/**

 * Renders the `core/comments` block on the server.

 *

 * This render callback is mainly for rendering a dynamic, legacy version of

 * this block (the old `core/post-comments`). It uses the `comments_template()`

 * function to generate the output, in the same way as classic PHP themes.

 *

 * As this callback will always run during SSR, first we need to check whether

 * the block is in legacy mode. If not, the HTML generated in the editor is

 * returned instead.

 *

 * @since 6.1.0

 *

 * @global WP_Post $post Global post object.

 *

 * @param array    $attributes Block attributes.

 * @param string   $content    Block default content.

 * @param WP_Block $block      Block instance.

 * @return string Returns the filtered post comments for the current post wrapped inside "p" tags.

 */

function render_block_core_comments( $attributes, $content, $block ) {

	global $post;

	$post_id = $block->context['postId'];

	if ( ! isset( $post_id ) ) {

		return '';

	}

	// Return early if there are no comments and comments are closed.

	if ( ! comments_open( $post_id ) && (int) get_comments_number( $post_id ) === 0 ) {

		return '';

	}

	// If this isn't the legacy block, we need to render the static version of this block.

	$is_legacy = 'core/post-comments' === $block->name || ! empty( $attributes['legacy'] );

	if ( ! $is_legacy ) {

		return $block->render( array( 'dynamic' => false ) );

	}

	$post_before = $post;

	$post        = get_post( $post_id );

	setup_postdata( $post );

	ob_start();

	/*

	 * There's a deprecation warning generated by WP Core.

	 * Ideally this deprecation is removed from Core.

	 * In the meantime, this removes it from the output.

	 */

	add_filter( 'deprecated_file_trigger_error', '__return_false' );

	comments_template();

	remove_filter( 'deprecated_file_trigger_error', '__return_false' );

	$output = ob_get_clean();

	$post   = $post_before;

	$classnames = array();

	// Adds the old class name for styles' backwards compatibility.

	if ( isset( $attributes['legacy'] ) ) {

		$classnames[] = 'wp-block-post-comments';

	}

	if ( isset( $attributes['textAlign'] ) ) {

		$classnames[] = 'has-text-align-' . $attributes['textAlign'];

	}

	$wrapper_attributes = get_block_wrapper_attributes(

		array( 'class' => implode( ' ', $classnames ) )

	);

	/*

	 * Enqueues scripts and styles required only for the legacy version. That is

	 * why they are not defined in `block.json`.

	 */

	wp_enqueue_script( 'comment-reply' );

	enqueue_legacy_post_comments_block_styles( $block->name );

	return sprintf( '<div %1$s>%2$s</div>', $wrapper_attributes, $output );

}

/**

 * Registers the `core/comments` block on the server.

 *

 * @since 6.1.0

 */

function register_block_core_comments() {

	register_block_type_from_metadata(

		__DIR__ . '/comments',

		array(

			'render_callback'   => 'render_block_core_comments',

			'skip_inner_blocks' => true,

		)

	);

}

add_action( 'init', 'register_block_core_comments' );

/**

 * Use the button block classes for the form-submit button.

 *

 * @since 6.1.0

 *

 * @param array $fields The default comment form arguments.

 *

 * @return array Returns the modified fields.

 */

function comments_block_form_defaults( $fields ) {

	if ( wp_is_block_theme() ) {

		$fields['submit_button'] = '<input name="%1$s" type="submit" id="%2$s" class="%3$s wp-block-button__link ' . wp_theme_get_element_class_name( 'button' ) . '" value="%4$s" />';

		$fields['submit_field']  = '<p class="form-submit wp-block-button">%1$s %2$s</p>';

	}

	return $fields;

}

add_filter( 'comment_form_defaults', 'comments_block_form_defaults' );

/**

 * Enqueues styles from the legacy `core/post-comments` block. These styles are

 * required only by the block's fallback.

 *

 * @since 6.1.0

 *

 * @param string $block_name Name of the new block type.

 */

function enqueue_legacy_post_comments_block_styles( $block_name ) {

	static $are_styles_enqueued = false;

	if ( ! $are_styles_enqueued ) {

		$handles = array(

			'wp-block-post-comments',

			'wp-block-buttons',

			'wp-block-button',

		);

		foreach ( $handles as $handle ) {

			wp_enqueue_block_style( $block_name, array( 'handle' => $handle ) );

		}

		$are_styles_enqueued = true;

	}

}

/**

 * Ensures backwards compatibility for any users running the Gutenberg plugin

 * who have used Post Comments before it was merged into Comments Query Loop.

 *

 * The same approach was followed when core/query-loop was renamed to

 * core/post-template.

 *

 * @since 6.1.0

 *

 * @see https://github.com/WordPress/gutenberg/pull/41807

 * @see https://github.com/WordPress/gutenberg/pull/32514

 */

function register_legacy_post_comments_block() {

	$registry = WP_Block_Type_Registry::get_instance();

	/*

	 * Remove the old `post-comments` block if it was already registered, as it

	 * is about to be replaced by the type defined below.

	 */

	if ( $registry->is_registered( 'core/post-comments' ) ) {

		unregister_block_type( 'core/post-comments' );

	}

	// Recreate the legacy block metadata.

	$metadata = array(

		'name'              => 'core/post-comments',

		'category'          => 'theme',

		'attributes'        => array(

			'textAlign' => array(

				'type' => 'string',

			),

		),

		'uses_context'      => array(

			'postId',

			'postType',

		),

		'supports'          => array(

			'html'       => false,

			'align'      => array( 'wide', 'full' ),

			'typography' => array(

				'fontSize'                      => true,

				'lineHeight'                    => true,

				'__experimentalFontStyle'       => true,

				'__experimentalFontWeight'      => true,

				'__experimentalLetterSpacing'   => true,

				'__experimentalTextTransform'   => true,

				'__experimentalDefaultControls' => array(

					'fontSize' => true,

				),

			),

			'color'      => array(

				'gradients'                     => true,

				'link'                          => true,

				'__experimentalDefaultControls' => array(

					'background' => true,

					'text'       => true,

				),

			),

			'inserter'   => false,

		),

		'style'             => array(

			'wp-block-post-comments',

			'wp-block-buttons',

			'wp-block-button',

		),

		'render_callback'   => 'render_block_core_comments',

		'skip_inner_blocks' => true,

	);

	/*

	 * Filters the metadata object, the same way it's done inside

	 * `register_block_type_from_metadata()`. This applies some default filters,

	 * like `_wp_multiple_block_styles`, which is required in this case because

	 * the block has multiple styles.

	 */

	/** This filter is documented in wp-includes/blocks.php */

	$metadata = apply_filters( 'block_type_metadata', $metadata );

	register_block_type( 'core/post-comments', $metadata );

}

add_action( 'init', 'register_legacy_post_comments_block', 21 );