<?php
/**
 * Temporary compatibility shims for features present in Gutenberg, pending
 * upstream commit to the WordPress core source repository. Functions here
 * exist only as long as necessary for corresponding WordPress support, and
 * each should be associated with a Trac ticket.
 *
 * @package gutenberg
 */

/**
 * Filters allowed CSS attributes to include `flex-basis`, included in saved
 * markup of the Column block.
 *
 * This can be removed when plugin support requires WordPress 5.3.0+.
 *
 * @see https://core.trac.wordpress.org/ticket/47281
 * @see https://core.trac.wordpress.org/changeset/45363
 *
 * @since 5.7.0
 *
 * @param string[] $attr Array of allowed CSS attributes.
 *
 * @return string[] Filtered array of allowed CSS attributes.
 */
function gutenberg_safe_style_css_column_flex_basis( $attr ) {
	$attr[] = 'flex-basis';

	return $attr;
}
add_filter( 'safe_style_css', 'gutenberg_safe_style_css_column_flex_basis' );

/**
 * Shim that hooks into `pre_render_block` so as to override `render_block`
 * with a function that passes `render_callback` the block object as the
 * argument.
 *
 * @see https://core.trac.wordpress.org/ticket/48104
 *
 * @param string $pre_render The pre-rendered content. Default null.
 * @param array  $block The block being rendered.
 *
 * @return string String of rendered HTML.
 */
function gutenberg_provide_render_callback_with_block_object( $pre_render, $block ) {
	global $post;

	$source_block = $block;

	/** This filter is documented in src/wp-includes/blocks.php */
	$block = apply_filters( 'render_block_data', $block, $source_block );

	$block_type    = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );
	$is_dynamic    = $block['blockName'] && null !== $block_type && $block_type->is_dynamic();
	$block_content = '';
	$index         = 0;

	foreach ( $block['innerContent'] as $chunk ) {
		$block_content .= is_string( $chunk ) ? $chunk : render_block( $block['innerBlocks'][ $index++ ] );
	}

	if ( ! is_array( $block['attrs'] ) ) {
		$block['attrs'] = array();
	}

	if ( $is_dynamic ) {
		$global_post = $post;

		$prepared_attributes = $block_type->prepare_attributes_for_render( $block['attrs'] );
		$block_content       = (string) call_user_func( $block_type->render_callback, $prepared_attributes, $block_content, $block );

		$post = $global_post;
	}

	/** This filter is documented in src/wp-includes/blocks.php */
	return apply_filters( 'render_block', $block_content, $block );
}
add_filter( 'pre_render_block', 'gutenberg_provide_render_callback_with_block_object', 10, 2 );

/**
 * Sets the current post for usage in template blocks.
 *
 * @return WP_Post|null The post if any, or null otherwise.
 */
function gutenberg_get_post_from_context() {
	// TODO: Without this temporary fix, an infinite loop can occur where
	// posts with post content blocks render themselves recursively.
	if ( is_admin() || defined( 'REST_REQUEST' ) ) {
		return null;
	}
	if ( ! in_the_loop() ) {
		rewind_posts();
		the_post();
	}
	return get_post();
}