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

/**
* Renders the `core/calendar` block on server.
*
* @since 5.2.0
*
* @global int $monthnum.
* @global int $year.
*
* @param array $attributes The block attributes.
*
* @return string Returns the block content.
*/
function render_block_core_calendar( $attributes ) {
global $monthnum, $year;

// Calendar shouldn't be rendered
// when there are no published posts on the site.
if ( ! block_core_calendar_has_published_posts() ) {
if ( is_user_logged_in() ) {
return '<div>' . __( 'The calendar block is hidden because there are no published posts.' ) . '</div>';
}
return '';
}

$previous_monthnum = $monthnum;
$previous_year = $year;

if ( isset( $attributes['month'] ) && isset( $attributes['year'] ) ) {
$permalink_structure = get_option( 'permalink_structure' );
if (
str_contains( $permalink_structure, '%monthnum%' ) &&
str_contains( $permalink_structure, '%year%' )
) {
$monthnum = $attributes['month'];
$year = $attributes['year'];
}
}

$color_block_styles = array();

// Text color.
$preset_text_color = array_key_exists( 'textColor', $attributes ) ? "var:preset|color|{$attributes['textColor']}" : null;
$custom_text_color = $attributes['style']['color']['text'] ?? null;
$color_block_styles['text'] = $preset_text_color ? $preset_text_color : $custom_text_color;

// Background Color.
$preset_background_color = array_key_exists( 'backgroundColor', $attributes ) ? "var:preset|color|{$attributes['backgroundColor']}" : null;
$custom_background_color = $attributes['style']['color']['background'] ?? null;
$color_block_styles['background'] = $preset_background_color ? $preset_background_color : $custom_background_color;

// Generate color styles and classes.
$styles = wp_style_engine_get_styles( array( 'color' => $color_block_styles ), array( 'convert_vars_to_classnames' => true ) );
$inline_styles = empty( $styles['css'] ) ? '' : sprintf( ' style="%s"', esc_attr( $styles['css'] ) );
$classnames = empty( $styles['classnames'] ) ? '' : ' ' . esc_attr( $styles['classnames'] );
if ( isset( $attributes['style']['elements']['link']['color']['text'] ) ) {
$classnames .= ' has-link-color';
}
// Apply color classes and styles to the calendar.
$calendar = str_replace( '<table', '<table' . $inline_styles, get_calendar( true, false ) );
$calendar = str_replace( 'class="wp-calendar-table', 'class="wp-calendar-table' . $classnames, $calendar );

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

$monthnum = $previous_monthnum;
$year = $previous_year;

return $output;
}

/**
* Registers the `core/calendar` block on server.
*
* @since 5.2.0
*/
function register_block_core_calendar() {
register_block_type_from_metadata(
__DIR__ . '/calendar',
array(
'render_callback' => 'render_block_core_calendar',
)
);
}

add_action( 'init', 'register_block_core_calendar' );

/**
* Returns whether or not there are any published posts.
*
* Used to hide the calendar block when there are no published posts.
* This compensates for a known Core bug: https://core.trac.wordpress.org/ticket/12016
*
* @since 5.9.0
*
* @return bool Has any published posts or not.
*/
function block_core_calendar_has_published_posts() {
// Multisite already has an option that stores the count of the published posts.
// Let's use that for multisites.
if ( is_multisite() ) {
return 0 < (int) get_option( 'post_count' );
}

// On single sites we try our own cached option first.
$has_published_posts = get_option( 'wp_calendar_block_has_published_posts', null );
if ( null !== $has_published_posts ) {
return (bool) $has_published_posts;
}

// No cache hit, let's update the cache and return the cached value.
return block_core_calendar_update_has_published_posts();
}

/**
* Queries the database for any published post and saves
* a flag whether any published post exists or not.
*
* @since 5.9.0
*
* @global wpdb $wpdb WordPress database abstraction object.
*
* @return bool Has any published posts or not.
*/
function block_core_calendar_update_has_published_posts() {
global $wpdb;
$has_published_posts = (bool) $wpdb->get_var( "SELECT 1 as test FROM {$wpdb->posts} WHERE post_type = 'post' AND post_status = 'publish' LIMIT 1" );
update_option( 'wp_calendar_block_has_published_posts', $has_published_posts );
return $has_published_posts;
}

// We only want to register these functions and actions when
// we are on single sites. On multi sites we use `post_count` option.
if ( ! is_multisite() ) {
/**
* Handler for updating the has published posts flag when a post is deleted.
*
* @since 5.9.0
*
* @param int $post_id Deleted post ID.
*/
function block_core_calendar_update_has_published_post_on_delete( $post_id ) {
$post = get_post( $post_id );

if ( ! $post || 'publish' !== $post->post_status || 'post' !== $post->post_type ) {
return;
}

block_core_calendar_update_has_published_posts();
}

/**
* Handler for updating the has published posts flag when a post status changes.
*
* @since 5.9.0
*
* @param string $new_status The status the post is changing to.
* @param string $old_status The status the post is changing from.
* @param WP_Post $post Post object.
*/
function block_core_calendar_update_has_published_post_on_transition_post_status( $new_status, $old_status, $post ) {
if ( $new_status === $old_status ) {
return;
}

if ( 'post' !== get_post_type( $post ) ) {
return;
}

if ( 'publish' !== $new_status && 'publish' !== $old_status ) {
return;
}

block_core_calendar_update_has_published_posts();
}

add_action( 'delete_post', 'block_core_calendar_update_has_published_post_on_delete' );
add_action( 'transition_post_status', 'block_core_calendar_update_has_published_post_on_transition_post_status', 10, 3 );
}