<?php
/**
 * Server-side rendering of the `core/tag-cloud` block.
 *
 * @package WordPress
 */

/**
 * Renders the `core/tag-cloud` block on server.
 *
 * @since 5.2.0
 *
 * @param array $attributes The block attributes.
 *
 * @return string Returns the tag cloud for selected taxonomy.
 */
function render_block_core_tag_cloud( $attributes ) {
    $smallest_font_size = $attributes['smallestFontSize'];
    $unit               = ( preg_match( '/^[0-9.]+(?P<unit>[a-z%]+)$/i', $smallest_font_size, $m ) ? $m['unit'] : 'pt' );

    $args      = array(
        'echo'       => false,
        'unit'       => $unit,
        'taxonomy'   => $attributes['taxonomy'],
        'show_count' => $attributes['showTagCounts'],
        'number'     => $attributes['numberOfTags'],
        'smallest'   => floatVal( $attributes['smallestFontSize'] ),
        'largest'    => floatVal( $attributes['largestFontSize'] ),
    );
    $tag_cloud = wp_tag_cloud( $args );

    if ( empty( $tag_cloud ) ) {
        // Display placeholder content when there are no tags only in editor.
        if ( wp_is_serving_rest_request() ) {
            $tag_cloud = __( 'There&#8217;s no content to show here yet.' );
        } else {
            return '';
        }
    }

    $wrapper_attributes = get_block_wrapper_attributes();

    return sprintf(
        '<p %1$s>%2$s</p>',
        $wrapper_attributes,
        $tag_cloud
    );
}

/**
 * Registers the `core/tag-cloud` block on server.
 *
 * @since 5.2.0
 */
function register_block_core_tag_cloud() {
    register_block_type_from_metadata(
        __DIR__ . '/tag-cloud',
        array(
            'render_callback' => 'render_block_core_tag_cloud',
        )
    );
}
add_action( 'init', 'register_block_core_tag_cloud' );