<?php
/**
 * Archives shortcode
 *
 * @author bubel & nickmomrik
 * [archives limit=10]
 *
 * @package automattic/jetpack
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit( 0 );
}

add_shortcode( 'archives', 'archives_shortcode' );

/**
 * Display Archives shortcode.
 *
 * @param array $atts Shortcode attributes.
 */
function archives_shortcode( $atts ) {
	if ( is_feed() ) {
		return '[archives]';
	}

	global $allowedposttags;

	$default_atts = array(
		'type'      => 'postbypost',
		'limit'     => '',
		'format'    => 'html',
		'showcount' => false,
		'before'    => '',
		'after'     => '',
		'order'     => 'desc',
	);

	$attr = shortcode_atts( $default_atts, $atts, 'archives' );

	if ( ! in_array( $attr['type'], array( 'yearly', 'monthly', 'daily', 'weekly', 'postbypost' ), true ) ) {
		$attr['type'] = 'postbypost';
	}

	if ( ! in_array( $attr['format'], array( 'html', 'option', 'custom' ), true ) ) {
		$attr['format'] = 'html';
	}

	$limit = (int) $attr['limit'];
	// A Limit of 0 makes no sense so revert back to the default.
	if ( empty( $limit ) ) {
		$limit = '';
	}

	/*
	 * The `postbypost` type (also the default) lists one entry per published
	 * post. Left unbounded, wp_get_archives() materializes the entire post table
	 * in a single request, which can exhaust PHP memory and fatal on large sites.
	 * Apply a sane, filterable default cap when no explicit limit was supplied.
	 */
	if ( 'postbypost' === $attr['type'] && '' === $limit ) {
		/**
		 * Filter the default number of entries listed by the [archives] shortcode
		 * when using the unbounded `postbypost` type with no explicit `limit`.
		 *
		 * Set to 0 to restore the previous (unlimited) behavior, though this is
		 * not recommended on sites with a large number of posts.
		 *
		 * @module shortcodes
		 *
		 * @since 16.0
		 *
		 * @param int $limit Default maximum number of posts to list. Default 100.
		 */
		$default_limit = (int) apply_filters( 'jetpack_archives_shortcode_default_limit', 100 );

		if ( $default_limit > 0 ) {
			$limit = $default_limit;
		}
	}

	$showcount = false !== $attr['showcount'] && 'false' !== $attr['showcount'];
	$before    = wp_kses( $attr['before'], $allowedposttags );
	$after     = wp_kses( $attr['after'], $allowedposttags );

	// Get the archives.
	$archives = wp_get_archives(
		array(
			'type'            => $attr['type'],
			'limit'           => $limit,
			'format'          => $attr['format'],
			'echo'            => false,
			'show_post_count' => $showcount,
			'before'          => $before,
			'after'           => $after,
		)
	);

	if ( 'asc' === $attr['order'] ) {
		$archives = implode( "\n", array_reverse( explode( "\n", $archives ) ) );
	}

	// Check to see if there are any archives.
	if ( empty( $archives ) ) {
		$archives = '<p>' . __( 'Your blog does not currently have any published posts.', 'jetpack' ) . '</p>';
	} elseif ( 'option' === $attr['format'] ) {
		$is_amp           = class_exists( 'Jetpack_AMP_Support' ) && Jetpack_AMP_Support::is_amp_request();
		$change_attribute = $is_amp ? 'on="change:AMP.navigateTo(url=event.value)"' : 'onchange="document.location.href=this.options[this.selectedIndex].value;"';
		$archives         = '<select name="archive-dropdown" ' . $change_attribute . '><option value="' . get_permalink() . '">--</option>' . $archives . '</select>';
	} elseif ( 'html' === $attr['format'] ) {
		$archives = '<ul>' . $archives . '</ul>';
	}

	return $archives;
}
