[WordPress] Ask me anything on post #42. Auto-approves comments and replies automatically on post ID 42 until a given date. CUSTOM EDITS REQUIRED!

ama-42.php

<?php
/**
 * Plugin Name: AMA 42
 * Description: Ask me anything on post 42.
 * Version:     2017-02-08
 * Author:      Caspar Hübinger
 * Author URI:  https://profiles.wordpress.org/glueckpress
 * License:     GNU General Public License v3 or later
 * License URI: http://www.gnu.org/licenses/gpl-3.0.html
 */

defined( 'ABSPATH' ) or die( 'You know better.' );

/**
 * Author slug to exclude from auto-replies.
 *
 * EDIT THIS TO YOUR OWN USER NAME!!!
 * If you leave this as is, you’re in for a comment flood.
 */
if ( ! defined( 'AMA42_AUTHOR' ) )
	define( 'AMA42_AUTHOR', 'caspar' );

/**
 * Date/time to end all plugin functionality.
 *
 * EDIT THIS TO ANY SUITABLE DATE IN THE FUTURE.
 * If you’re in a different timezone than Europe/Berlin, the function where
 * this gets applied will need another parameter.
 */
if ( ! defined( 'AMA42_END_DATE' ) )
	define( 'AMA42_END_DATE', '2017-02-09 00:00:00' );

/**
 * Target this post ID only.
 */
if ( ! defined( 'AMA42_TARGET_POST_ID' ) )
	define( 'AMA42_TARGET_POST_ID', 42 );


/* NO MORE EDITS REQUIRED BELOW THIS LINE. */


/**
 * Do stuff, or not.
 *
 * @return bool  False when bailing out, else true.
 */
function ama42() {

	// Late to the party? Stop here.
	if ( ama42__is_it_yet( AMA42_END_DATE  ) )
		return false;

	// Auto-approve comments.
	add_filter( 'pre_comment_approved', 'ama42__auto_approve_comments', 10, 2 );

	// Post replies.
	add_action( 'comment_post', 'ama42__post_reply', 10, 3 );

	return true;
}
add_action( 'plugins_loaded', 'ama42' );

/**
 * Auto-post a reply to any incoming comment.
 *
 * @param  int    $comment_id       Incoming comment ID
 * @param  int    $comment_approved Incoming comment approved status
 * @param  array  $commentdata      Incoming comment data
 * @return int                      Comment ID
 */
function ama42__post_reply( $comment_id, $comment_approved, $commentdata ) {

	if ( AMA42_TARGET_POST_ID !== absint( $commentdata['comment_post_ID'] )  )
		return $comment_id;

	if ( AMA42_AUTHOR === $commentdata['comment_author'] )
		return $comment_id;

	$reply_author_data = get_user_by( 'slug', AMA42_AUTHOR );

	$reply_data = array(
		'comment_post_ID'      => AMA42_TARGET_POST_ID,
		'comment_approved'     => 1,
		'comment_author'       => AMA42_AUTHOR,
		'comment_author_email' => $reply_author_data->user_email,
		'comment_content'      => ama42__reply_content( $commentdata ),
		'comment_parent'       => $comment_id
	);

	wp_insert_comment( $reply_data );

	return $comment_id;
}

/**
 * Auto-approve incoming comments for this specific post.
 *
 * @param  int     $approved    Incoming comment approved status
 * @param  array   $commentdata Incoming comment data
 * @return int                  Comment approved status
 */
function ama42__auto_approve_comments( $approved, $commentdata ) {

	if ( AMA42_TARGET_POST_ID === absint( $commentdata['comment_post_ID'] ) )
		return 1;

	return $approved;
}

/**
 * Automatic replies.
 * Essentially Hello Dolly, with some minor tweaks.
 *
 * @param  array $commentdata Incoming comment data
 * @return string             Comment content to reply with
 */
function ama42__reply_content( $commentdata ) {

	$comment_content = $commentdata['comment_content'];

	preg_match('/(.*)(w?)\?/', $comment_content, $questions );

	if ( empty( $questions ) )
		return 'Is that’ a question?';

	$replies = array();
	$replies[] = '42.';
	$replies[] = '42!';
	$replies[] = '42!!';
	$replies[] = 'Well, 42.';
	$replies[] = '42 afaik.';
	$replies[] = 'Forty-two.';
	$replies[] = 'Clearly 42.';
	$replies[] = 'For. Ty. Two.';
	$replies[] = 'How about 42?';
	$replies[] = 'This is so 42.';
	$replies[] = 'Heck yeah, 42!!';
	$replies[] = '42, essentially.';
	$replies[] = 'Hmmm, I’’d say… 42?';
	$replies[] = 'Good question! But 42.';
	$replies[] = '42——you knew it, didn’t you?';
	$replies[] = 'Have you actually… well, 42.';
	$replies[] = 'Hey, you here! :) 42 for sure!';
	$replies[] = '42. Who would have thought so?';
	$replies[] = 'I wonder sometimes, but mostly 42.';
	$replies[] = 'Would you be mad at me if I said 42?';
	$replies[] = 'Is that even a question? 42, obviously!';
	$replies[] = 'Glad you’’re asking. Once and for all: 42.';
	$replies[] = 'This is even beyond 42. Wait, it can’’t be.';
	$replies[] = 'Can’’t think of anything but 42 for this one.';
	$replies[] = 'If you don’’t know, who would? 42, of course!';
	$replies[] = 'I’ would have thought otherwise myself, but 42.';
	$replies[] = 'Tough one.<br>&#160;<br>&#160;<br>&#160;<br>42?';
	$replies[] = 'Not sure if I understand the question, but let’’s go with 42. :)';

	shuffle( $replies );

	$reply = wptexturize( $replies[ mt_rand( 0, count( $replies ) - 1 ) ] );

	return $reply;
}

/**
 * Check if we’re at a given date yet.
 * 
 * Could probably be done in more WordPress-ish fashion.
 * (Truth is, I had this in my cupboard and didn’t feel like putting in
 * any extra work to fluff it up WordPress-style.)
 *
 * @param  string $is_it_yet Timestamp to figure out
 * @param  string $time_zone Time zone to be applied
 * @return bool              TRUE if $is_it_yet is in the past, FALSE otherwise
 */
function ama42__is_it_yet( $is_it_yet = '2016-01-01 00:00:01', $time_zone = 'Europe/Berlin' ) {

	date_default_timezone_set( $time_zone );

	$earliest = new DateTime( $is_it_yet );
	$current  = new DateTime();

	$diff = date_diff( $earliest, $current );

	// DateInterval->invert is 1 if the interval represents a negative time period; 0 otherwise.
	return ( 0 === $diff->invert ) ? true : false;
}