<?php
/**
 * Asset Counter - counts enqueued scripts and styles.
 *
 * @package Asmith_Speed_Optimizer
 */

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

class Asmith_SO_Asset_Counter {

	private static $instance = null;

	/**
	 * Cached counts.
	 *
	 * @var array|null
	 */
	private $counts = null;

	public static function instance() {
		if ( null === self::$instance ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	private function __construct() {
		if ( ! is_admin() ) {
			add_action( 'wp_print_scripts', array( $this, 'count_scripts' ), 999 );
			add_action( 'wp_print_styles', array( $this, 'count_styles' ), 999 );
		}
	}

	/**
	 * Count enqueued scripts and store in transient.
	 */
	public function count_scripts() {
		global $wp_scripts;

		if ( ! ( $wp_scripts instanceof WP_Scripts ) ) {
			return;
		}

		$count = count( $wp_scripts->queue );
		$counts = get_transient( 'asmith_so_asset_counts' );
		if ( ! is_array( $counts ) ) {
			$counts = array();
		}
		$counts['scripts']      = $count;
		$counts['scripts_list'] = $wp_scripts->queue;
		$counts['timestamp']    = time();

		set_transient( 'asmith_so_asset_counts', $counts, HOUR_IN_SECONDS );
	}

	/**
	 * Count enqueued styles and store in transient.
	 */
	public function count_styles() {
		global $wp_styles;

		if ( ! ( $wp_styles instanceof WP_Styles ) ) {
			return;
		}

		$count = count( $wp_styles->queue );
		$counts = get_transient( 'asmith_so_asset_counts' );
		if ( ! is_array( $counts ) ) {
			$counts = array();
		}
		$counts['styles']      = $count;
		$counts['styles_list'] = $wp_styles->queue;
		$counts['timestamp']   = time();

		set_transient( 'asmith_so_asset_counts', $counts, HOUR_IN_SECONDS );
	}

	/**
	 * Get the cached asset counts.
	 *
	 * @return array
	 */
	public function get_counts() {
		if ( null !== $this->counts ) {
			return $this->counts;
		}

		$counts = get_transient( 'asmith_so_asset_counts' );
		if ( ! is_array( $counts ) ) {
			$counts = array(
				'scripts' => 0,
				'styles'  => 0,
			);
		}

		$this->counts = $counts;
		return $this->counts;
	}
}