Auto-create player lists in SportsPress

sp_create_player_lists.php

<?php

/**
 * Auto-create player lists in SportsPress.
 *
 * This code will generate player lists for teams without one.
 * It's useful if your SportsPress site has a lot of teams and you don't
 * want to create player lists one by one.
 *
 * The code will only work when the parameter `sp_create_player_lists` is
 * detected in the URL, @example, http://sp.box/?sp_create_player_lists=1.
 * 
 * @license GPLv3+
 */
add_action( 'init', function() {

	/**
	 * Settings.
	 */
	$settings = [ 
		'sp_columns' => [
			'goals',
			'assists',
			// 'yellowcards',
			// 'redcards',
			// 'etc...',
		],
		'sp_grouping' => '', // You can use 'position'
	];

	/**
	 * Verify that you're an admin.
	 */
	if ( ! current_user_can( 'manage_options' ) ) {
		return;
	}

	/**
	 * Verify that sp_create_player_lists is set in the URL. 
	 */
	if ( ! array_key_exists( 'sp_create_player_lists', $_GET ) ) {
		return;
	}

	/**
	 * Verifies that the team doesn't have a player list already.
	 *
	 * @param  $team_post_id  The team post ID.
	 */
	$team_has_player_list = function( $team_post_id ) {
		return ( bool ) get_posts( [
			'post_type' => 'sp_list',
			'numberposts' => -1,
			'posts_per_page' => -1,
			'meta_key' => 'sp_team',
			'meta_value' => $team_post_id,
		] );
	};

	/**
	 * Creates player list.
	 *
	 * @param  $team      Team post object.
	 * @param  $settings  Settings (e.g. columns).
	 */
	$create_team_player_list = function( $team, $settings ) {		
		return wp_insert_post( [
			/**
			 * Post attribtues.
			 */
			'post_status' => 'publish',
			'post_title' => $team->post_title,
			'post_type' => 'sp_list',
			/**
			 * Metadata.
			 */
			'meta_input' => [
				'sp_columns' => $settings[ 'sp_columns' ],
				'sp_grouping' => $settings[ 'sp_grouping' ],
				'sp_era' => 'current',
				'sp_team' => $team->ID,
			],
		], true );
	};

	/**
	 * Loop through teams and create player lists where missing.
	 */
	$teams = get_posts( [
		'post_type' => 'sp_team',
		'numberposts' => -1,
	] );
	foreach ( $teams as $team ) {
		if ( ! $team_has_player_list( $team->ID ) ) {
			$create_team_player_list( $team, $settings );
		}
	}

	/**
	 * All done! Let's redirect you to the player lists page.
	 */
	wp_safe_redirect( admin_url( 'edit.php?post_type=sp_list' ) );
	exit;
} );