<?php
/**
 *  Extends the generic task manager to manage smush related queues
 */

if (!defined('ABSPATH')) die('Access denied.');

if (!class_exists('Updraft_Task_Manager_1_4')) require_once(WPO_PLUGIN_MAIN_PATH . 'vendor/team-updraft/common-libs/src/updraft-tasks/class-updraft-task-manager.php');

if (!class_exists('Updraft_Smush_Manager')) :

class Updraft_Smush_Manager extends Updraft_Task_Manager_1_4 {

	static protected $_instance = null;

	/**
	 * Options used for smush jobs
	 *
	 * @var array
	 */
	public $options;

	/**
	 * The service provider to use
	 *
	 * @var string
	 */
	public $webservice;

	/**
	 * The logger for this instance
	 *
	 * @var mixed
	 */
	public $logger;

	/**
	 * Require task-level locking
	 *
	 * @var integer
	 */
	protected $use_per_task_lock = 60;
	
	/**
	 * The Task Manager constructor
	 */
	public function __construct() {
		parent::__construct();


		$this->commands = new Updraft_Smush_Manager_Commands($this);
		$this->options = WP_Optimize()->get_options();

		// we set default options when compression server is false - it means that options was not saved before
		if (!$this->options->get_option('compression_server')) {
			$this->set_default_options();
		}

		$this->webservice = $this->options->get_option('compression_server', 'resmushit');

		// Ensure the saved service is valid
		if (!in_array($this->webservice, $this->get_allowed_services())) {
			$this->webservice = $this->get_default_webservice();
		}
		$this->logger = new Updraft_File_Logger($this->get_logfile_path());
		$this->add_logger($this->logger);

		add_action('wp_ajax_updraft_smush_ajax', array($this, 'updraft_smush_ajax'));
		add_action('admin_enqueue_scripts', array($this, 'admin_enqueue_scripts'), 9);
		add_action('elementor/editor/before_enqueue_scripts', array($this, 'admin_enqueue_scripts'));
		add_action('add_attachment', array($this, 'autosmush_create_task'));
		add_action('ud_task_initialised', array($this, 'set_task_logger'));
		add_action('ud_task_started', array($this, 'set_task_logger'));
		add_action('ud_task_completed', array($this, 'record_stats'));
		add_action('ud_task_failed', array($this, 'record_stats'));
		add_action('prune_smush_logs', array($this, 'prune_smush_logs'));
		add_action('process_smush_tasks', array($this, 'process_smush_tasks'));
		if ('show' == $this->options->get_option('show_smush_metabox', 'show')) {
			add_action('add_meta_boxes_attachment', array($this, 'add_smush_metabox'), 10, 2);
			add_filter('attachment_fields_to_edit', array($this, 'add_compress_button_to_media_modal' ), 10, 2);
		}
		add_action('delete_attachment', array($this, 'unscheduled_original_file_deletion'));

		add_filter('manage_media_columns', array($this, 'manage_media_columns'));
		add_action('manage_media_custom_column', array($this, 'manage_media_custom_column'), 10, 2);

		// clean backup images cron action.
		add_action('wpo_smush_clear_backup_images', array($this, 'clear_backup_images'));

		// add filter for already compressed images by EWWW Image Optimizer.
		add_filter('wpo_get_uncompressed_images_args', array($this, 'ewww_image_optimizer_compressed_images_args'));

		// schedule or unschedule clear backup images cron if need
		$scheduled = wp_next_scheduled('wpo_smush_clear_backup_images');
		if ($this->options->get_option('back_up_delete_after', true)) {
			if (!$scheduled) {
				wp_schedule_event(time(), 'daily', 'wpo_smush_clear_backup_images');
			}
		} else {
			if ($scheduled) {
				wp_unschedule_event($scheduled, 'wpo_smush_clear_backup_images');
			}
		}

		// Schedule CRON job for deleting failed smush tasks
		add_action('wpo_smush_clear_failed_tasks', array($this, 'clear_failed_tasks'));
		if (!wp_next_scheduled('wpo_smush_clear_failed_tasks')) {
			wp_schedule_event(time(), 'wpo_monthly', 'wpo_smush_clear_failed_tasks');
		}
	}

	/**
	 * Add custom column to Media Library.
	 *
	 * @param array $columns
	 * @return mixed
	 */
	public function manage_media_columns($columns) {
		$columns['wpo_smush'] = 'WP-Optimize';

		return $columns;
	}

	/**
	 * Display content in the custom column.
	 *
	 * @param string $column
	 * @param int    $attachment_id
	 */
	public function manage_media_custom_column($column, $attachment_id) {
		if ('wpo_smush' !== $column) return;
		echo $this->get_smush_details($attachment_id); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- Output already escaped when generating smush details
	}
	
	/**
	 * Get smush details of given image ID
	 *
	 * @param int $attachment_id
	 *
	 * @return string smush details
	 */
	public function get_smush_details($attachment_id) {
		$info = '<div class="wpo-smush-media-library-column" data-blog="'.esc_attr(get_current_blog_id()).'" data-id="'.esc_attr($attachment_id).'">';
		$info .= $this->get_media_smush_column_content($attachment_id);
		$info .= '</div>';

		return $info;
	}

	/**
	 * Get content for Media Library column.
	 *
	 * @param int  $attachment_id
	 *
	 * @return string
	 */
	public function get_media_smush_column_content($attachment_id) {
		$file = get_attached_file($attachment_id);
		$ext = WPO_Image_Utils::get_extension($file);
		$allowed_extensions = WPO_Image_Utils::get_allowed_extensions();

		$compressed = get_post_meta($attachment_id, 'smush-complete', true) ? true : false;
		$has_backup = get_post_meta($attachment_id, 'original-file', true) ? true : false;

		$smush_info = get_post_meta($attachment_id, 'smush-info', true);
		$smush_stats = get_post_meta($attachment_id, 'smush-stats', true);
		$marked = get_post_meta($attachment_id, 'smush-marked', false);

		$extract = array(
			'blog_id'			=> get_current_blog_id(),
			'post_id' 			=> $attachment_id,
			'smush_info_display'=> $compressed ? "display:inline-block;" : "display:none;",
			'smush_display'		=> $compressed ? "display:none;" : "display:inline-block;",
			'before_smush_sep'  => !$compressed ? '<span class="wpo-action-separator"> | </span>' : '',
			'restore_action'	=> $has_backup && $compressed ? "display:block;" : "display:none;",
			'smush_mark'		=> !$compressed && !$marked ? "display:inline-block;" : "display:none;",
			'smush_unmark'      => $marked ? "display:inline-block;" : "display:none;",
			'smush_info'		=> $smush_info ? $smush_info : ' ',
			'smush_details'		=> '',
			'restore_tooltip' 	=> $this->get_restore_image_tooltip_text(),
			'smush_marked'		=> $marked,
		);

		if (!empty($smush_stats['sizes-info'])) {
			$extract['smush_details'] = WP_Optimize()->include_template('images/smush-details.php', true, array('sizes_info' => $smush_stats['sizes-info']));
		}

		$extract['compressed_by_another_plugin'] = $this->is_image_compressed_by_another_plugin($attachment_id);

		$output = '';

		if (WPO_Image_Utils::is_supported_extension($ext, $allowed_extensions)) {
			$output .= WP_Optimize()->include_template('admin-medialibrary-smush-column.php', true, $extract);
		} else {
			$message = __('Compressing this file type extension is not supported', 'wp-optimize');
			$output .= sprintf("<p>%s</p>", esc_html($message));

		}

		if (WPO_Image_Utils::is_supported_extension($ext, array_diff($allowed_extensions, array('gif'))) && file_exists($file) && !file_exists($file . '.webp')) {
			if (WPO_WebP_Utils::can_do_webp_conversion()) {
				$link_text = __('Convert to WebP', 'wp-optimize');
				$output .= sprintf('<a href="#" class="convert-to-webp" data-attachment-id="%d">%s</a><br>', esc_attr($attachment_id), esc_html($link_text));
			}
		}

		return $output;
	}

	/**
	 * The Task Manager AJAX handler
	 */
	public function updraft_smush_ajax() {

		$nonce = empty($_REQUEST['nonce']) ? '' : $_REQUEST['nonce'];

		if (!wp_verify_nonce($nonce, 'updraft-task-manager-ajax-nonce') || empty($_REQUEST['subaction']))
			die('Security check failed');

		if (!current_user_can(WP_Optimize()->capability_required())) {
			die('You are not allowed to run this command.');
		}

		$subaction = $_REQUEST['subaction'];

		$allowed_commands = Updraft_Smush_Manager_Commands::get_allowed_ajax_commands();
		
		if (in_array($subaction, $allowed_commands)) {

			if (isset($_REQUEST['data'])) {
				$data = $_REQUEST['data'];
				$results = call_user_func(array($this->commands, $subaction), $data);
			} else {
				$results = call_user_func(array($this->commands, $subaction));
			}
			
			if (is_wp_error($results)) {
				$results = array(
					'status' => true,
					'result' => false,
					'error_code' => $results->get_error_code(),
					'error_message' => $results->get_error_message(),
					'error_data' => $results->get_error_data(),
				);
			}
			
			echo json_encode($results);
		} else {
			echo json_encode(array('error' => 'No such command found'));
		}
		die();
	}

	/**
	 * Creates a task to auto compress an image on  upload
	 *
	 * @param int $post_id - id of the post
	 */
	public function autosmush_create_task($post_id) {

		$post = get_post($post_id);
		$file = get_attached_file($post_id);
		$ext = WPO_Image_Utils::get_extension($file);
		$allowed_extensions = WPO_Image_Utils::get_allowed_extensions();

		if(!in_array($ext, $allowed_extensions)) return;

		if (!$this->options->get_option('autosmush', false))
			return;

		if (!'image' == substr($post->post_mime_type, 0, 5))
			return;

		if ($this->task_exists($post_id))
			return;
		
		$options = array(
			'attachment_id' => $post_id,
			'blog_id'	   => get_current_blog_id(),
			'image_quality' => $this->options->get_option('image_quality', 92),
			'keep_original' => $this->options->get_option('back_up_original', true),
			'preserve_exif' => $this->options->get_option('preserve_exif', true),
			'lossy_compression' => $this->options->get_option('lossy_compression', false)
		);

		if (filesize($file) > 5242880) {
			$options['request_timeout'] = 180;
		}

		$server = $this->options->get_option('compression_server', $this->webservice);
		$task_name = $this->get_associated_task($server);

		$blog_info   = is_multisite() ? ', blog ID : '.get_current_blog_id() : '';
		$description = "$task_name with attachment ID : ".$post_id . $blog_info .", autocreated on : ".date("F d, Y h:i:s", time());

		$task = call_user_func(array($task_name, 'create_task'), 'smush', $description, $options, $task_name);

		if ($task) $this->set_task_logger($task);
		$this->log($description);

		if (!wp_next_scheduled('process_smush_tasks')) {
			wp_schedule_single_event(time() + 300, 'process_smush_tasks');
		}
	}

	/**
	 * Processes the smush tasks in the queue, then cleans up the completed tasks.
	 *
	 * Before processing the queue, it first schedules a cron job to re-initiate the process after a certain
	 * interval, ensuring that the process will be completed later in case the current processing fails
	 * or is interrupted. This method can be invoked directly or scheduled as a cron job.
	 */
	public function process_smush_tasks() {
		/*
		 * Only add log header when called as a cron job, assuming the log header is already added by the caller
		 * when called directly. This is to avoid duplicate log headers in the log file.
		 */
		if (defined('DOING_CRON') && DOING_CRON) {
			$this->write_log_header();
		}

		// If there are no pending tasks, nothing to process. In that case, attempt to clean up old tasks and return
		if ($this->is_queue_processed()) {
			$this->clean_up_old_tasks('smush');
			return;
		}

		if (!wp_next_scheduled('process_smush_tasks')) {
			wp_schedule_single_event(time() + 600, 'process_smush_tasks');
		}

		// Process the queue
		$this->clear_cached_data();
		$this->process_queue('smush');
		$this->clean_up_old_tasks('smush');
	}

	/**
	 * Process the compression of a single image
	 *
	 * @param int	 $image   - ID of image
	 * @param array  $options - options to use
	 * @param string $server  - the server to process with
	 *
	 * @return boolean - Status of the task
	 */
	public function compress_single_image($image, $options, $server) {
		$task_name = $this->get_associated_task($server);
		$blog_info = is_multisite() ? ', blog ID : '.get_current_blog_id() : '';
		$description = "$task_name - attachment ID : ". $image . $blog_info. ", started on : ". date("F d, Y h:i:s", time());

		$task = call_user_func(array($task_name, 'create_task'), 'smush', $description, $options, $task_name);
		if ($task) $this->set_task_logger($task);
		$this->clear_cached_data();

		if (!wp_next_scheduled('prune_smush_logs')) {
			wp_schedule_single_event(time() + 7200, 'prune_smush_logs');
		}

		return $this->process_task($task);
	}

	/**
	 * Restores a single image if a backup is available
	 *
	 * @param int $image_id - The id of the image
	 * @param int $blog_id  - The id of the blog
	 *
	 * @return bool|WP_Error - success or failure
	 */
	public function restore_single_image($image_id, $blog_id) {

		$switched_blog = false;
		if (is_multisite() && current_user_can('manage_network_options')) {
			switch_to_blog($blog_id);
			$switched_blog = true;
		} elseif (is_multisite() && get_current_blog_id() != $blog_id) {
			return new WP_Error('restore_backup_wrong_blog_id', __('The blog ID provided does not match the current blog.', 'wp-optimize'));
		}

		$error = false;

		$image_path = get_attached_file($image_id);
		$backup_path = get_post_meta($image_id, 'original-file', true);
		
		// If the file doesn't exist, check if it's relative
		if (!is_file($backup_path)) {
			$uploads_dir = wp_upload_dir();
			$uploads_basedir = trailingslashit($uploads_dir['basedir']);

			if (is_file($uploads_basedir . $backup_path)) {
				$backup_path = $uploads_basedir . $backup_path;
			}
		}

		// If the file still doesn't exist, the record could be an absolute path from a migrated site
		// Use the current Uploads path
		if (!is_file($backup_path)) {
			$current_uploads_dir_folder = trailingslashit(substr($uploads_basedir, strlen(ABSPATH)));
			// A strict operator (!==) needs to be used, as 0 is a positive result.
			if (false !== strpos($backup_path, $current_uploads_dir_folder)) {
				$temp_relative_backup_path = substr($backup_path, strpos($backup_path, $current_uploads_dir_folder) + strlen($current_uploads_dir_folder));
				if (is_file($uploads_basedir . $temp_relative_backup_path)) {
					$backup_path = $uploads_basedir . $temp_relative_backup_path;
				}
			}


		}

		// If the file still doesn't exist, the record could be an absolute path from a migrated site
		// The current Uploads path failed, so try with the default uploads directory value
		if (!is_file($backup_path)) {
			// A strict operator (!==) needs to be used, as 0 is a positive result.
			if (false !== strpos($backup_path, 'wp-content/uploads/')) {
				$backup_path = substr($backup_path, strpos($backup_path, 'wp-content/uploads/') + strlen('wp-content/uploads/'));
				$backup_path = $uploads_basedir . $backup_path;
			}
		}

		if (!is_file($backup_path)) {
			// Delete information about backup.
			delete_post_meta($image_id, 'original-file');
			$error = new WP_Error('restore_backup_not_found', __('The backup was not found; it may have been deleted or was already restored', 'wp-optimize'));
		} elseif (!is_writable($image_path)) {
			$error =  new WP_Error('restore_failed', __('The destination could not be written to.', 'wp-optimize').' '.__("Please check your folder's permissions", 'wp-optimize'));
		} elseif (!copy($backup_path, $image_path)) {
			$error =  new WP_Error('restore_failed', __('The file could not be copied; check your PHP error logs for details', 'wp-optimize'));
		} elseif (!unlink($backup_path)) {
			$error =  new WP_Error('restore_failed', sprintf(__('The backup file %s could not be deleted.', 'wp-optimize'), $backup_path));
		}

		if (!$error) {
			// if backup image deleted successfully
			// then delete from attachment meta associated smush data
			delete_post_meta($image_id, 'smush-complete');
			delete_post_meta($image_id, 'smush-stats');
			delete_post_meta($image_id, 'original-file');
			delete_post_meta($image_id, 'smush-info');
		}

		if ($switched_blog) {
			restore_current_blog();
		}

		if (is_wp_error($error)) return $error;

		$this->delete_from_cache('uncompressed_images');

		if (!wp_next_scheduled('prune_smush_logs')) {
			wp_schedule_single_event(time() + 7200, 'prune_smush_logs');
		}

		return true;
	}

	/**
	 * Restore compressed images for selected blog.
	 *
	 * @param bool $restore_backup 			 if true then restore images from backup otherwise just delete meta.
	 * @param int  $blog_id        			 blog id.
	 * @param int  $images_limit   			 how many images process per time.
	 * @param bool $delete_only_backups_meta meta fields will deleted only for images those will restored from backup.
	 *
	 * @return array ['completed' => (bool), 'message' => (string), 'error' => (string)]
	 */
	public function bulk_restore_compressed_images($restore_backup, $blog_id = 1, $images_limit = 100, $delete_only_backups_meta = false) {
		global $wpdb;

		if (is_multisite()) {
			switch_to_blog($blog_id);
		}

		$result = array(
			'completed' => false,
			'message' => '',
			'smushed_images_count' => 0,
		);

		$processed = 0;

		if ($restore_backup) {
			// get post ids those have backup meta field.
			$image_ids = $wpdb->get_results($wpdb->prepare("SELECT post_id FROM {$wpdb->postmeta} WHERE meta_key = 'original-file' LIMIT %d;", $images_limit), ARRAY_A);

			if (!empty($image_ids)) {
				// run restore function for each found image.
				foreach ($image_ids as $image) {
					$restore_result = $this->restore_single_image($image['post_id'], $blog_id);

					// if we get an error then we stop the work, except situation when "backup already restored'.
					if (is_wp_error($restore_result) && 'restore_backup_not_found' != $restore_result->get_error_code()) {
						// we need to stop the work as we haven't restored the backup.
						$result['error'] = $restore_result->get_error_message();
						$this->options->delete_option('smush_images_restored');
						break;
					}

					$processed++;
				}
			}

			$images_count = count($image_ids);

			// if all images processed then set flag completed to true.
			if ($processed == $images_count && $images_count < $images_limit) {
				$this->options->delete_option('smush_images_restored');
				$result['completed'] = true;
			} else {
				// save into options total processed count.
				$processed += $this->options->get_option('smush_images_restored', 0);
				$this->options->update_option('smush_images_restored', $processed);

				if (is_multisite()) {
					$result['message'] = sprintf(__('%s compressed images were restored from their backup for the site %s', 'wp-optimize'), $processed, get_site_url($blog_id));
				} else {
					$result['message'] = sprintf(__('%s compressed images were restored from their backup', 'wp-optimize'), $processed);
				}
			}

		} else {
			// if we just delete compressed images meta then set complete flag to true.
			$result['completed'] = true;
		}

		if ($result['completed']) {

			$smushed_images_count = $wpdb->get_var("SELECT COUNT(*) FROM {$wpdb->postmeta} WHERE meta_key='smush-complete' AND meta_value=1");
			$result['smushed_images_count'] = $smushed_images_count;

			if ($delete_only_backups_meta) {
				if (is_multisite()) {
					if ($smushed_images_count > 0) {
						$result['message'] = sprintf(__('All the compressed images for site %s with backup copies of their original files were successfully restored.', 'wp-optimize'), get_site_url($blog_id));
						$result['message'] .= ' '.sprintf(_n('Unable to restore %s image without backup files.', 'Unable to restore %s images without backup files.', $smushed_images_count, 'wp-optimize'), $smushed_images_count);
					} else {
						$result['message'] = sprintf(__('All the compressed images for the site %s were successfully restored.', 'wp-optimize'), get_site_url($blog_id));
					}
				} else {
					if ($smushed_images_count > 0) {
						$result['message'] = __('All the compressed images with backup copies of their original files were successfully restored.', 'wp-optimize');
						$result['message'] .= ' '.sprintf(_n('Unable to restore %s image without backup files.', 'Unable to restore %s images without backup files.', $smushed_images_count, 'wp-optimize'), $smushed_images_count);
					} else {
						$result['message'] = __('All the compressed images were successfully restored.', 'wp-optimize');
					}
				}
			} else {
				if (is_multisite()) {
					$result['message'] = sprintf(__('All the compressed images for the site %s were successfully marked as uncompressed.', 'wp-optimize'), get_site_url($blog_id));
				} else {
					$result['message'] = __('All the compressed images were successfully marked as uncompressed.', 'wp-optimize');
				}
			}

			// clear all metas for smushed images after work completed.
			// if $delete_only_backup_meta set to true then all meta fields was deleted in restore_single_image()
			// and we don't need delete metas for other images.
			if (!$delete_only_backups_meta) {
				$wpdb->query("DELETE FROM {$wpdb->postmeta} WHERE meta_key IN ('smush-complete', 'smush-stats', 'original-file', 'smush-info');");
			}
		}

		if (is_multisite()) {
			restore_current_blog();
		}

		return $result;
	}

	/**
	 * Process bulk smushing operation
	 *
	 * @param array $images - the array of images to process
	 * @return bool - true if processing complete
	 */
	public function process_bulk_smush($images = array()) {

		// Get a list of pending tasks so we can exclude those
		$pending_tasks = $this->get_pending_tasks();
		$queued_images = array();

		$this->write_log_header();

		if (!empty($pending_tasks)) {
			foreach ($pending_tasks as $task) {
				$queued_images[] = array(
					'attachment_id' => $task->get_option('attachment_id'),
					'blog_id' => $task->get_option('blog_id')
				);
			}
		}

		foreach ($images as $image) {
			// Skip if already in the queue
			if (in_array($image, $queued_images)) continue;

			$options = array(
				'attachment_id' => intval($image['attachment_id']),
				'blog_id'	   => intval($image['blog_id']),
				'image_quality' => $this->options->get_option('image_quality', 92),
				'keep_original' => $this->options->get_option('back_up_original', true),
				'preserve_exif' => $this->options->get_option('preserve_exif', true),
				'lossy_compression' => $this->options->get_option('lossy_compression', false)
			);

			$server = $this->options->get_option('compression_server', $this->webservice);
			$task_name = $this->get_associated_task($server);

			$blog_info = is_multisite() ? ', Blog ID : '.intval($image['blog_id']) : '';
			$description = "$task_name - Attachment ID : ". intval($image['attachment_id']) . $blog_info . ", Started on : ". date("F d, Y h:i:s", time());
			$task = call_user_func(array($task_name, 'create_task'), 'smush', $description, $options, $task_name);
			if ($task) $this->set_task_logger($task);
		}

		$this->process_smush_tasks();

		if (!wp_next_scheduled('prune_smush_logs')) {
			wp_schedule_single_event(time() + 7200, 'prune_smush_logs');
		}

		return true;
	}


	/**
	 * Check if a specified server online
	 *
	 * @param string $server - the server to test
	 * @return bool - true if yes, false otherwise
	 */
	public function check_server_online($server = 'resmushit') {
		$task = $this->get_associated_task($server);
		$online = call_user_func(array($task, 'is_server_online'));
			
		if ($online) {
			update_option($task, strtotime('now'));
		} else {
			$this->log(get_option($task));
		}

		$this->log(sprintf('%s server status: %s', $task, $online ? 'Online' : 'Offline'));
		return $online;
	}
	
	/**
	 * Checks if the queue for smushing is complete
	 *
	 * @return bool - true if processed, false otherwise
	 */
	public function is_queue_processed() {

		$active = $this->get_pending_tasks();
		if ($active && 0 != count($active)) return false;

		return true;
	}

	/**
	 * Logs useful data once a smush task completes or if it fails
	 *
	 * @param mixed $task - A task object
	 */
	public function record_stats($task) {

		$attachment_id	= $task->get_option('attachment_id');
		$completed_task_count = $this->options->get_option('completed_task_count', false);
		$failed_task_count = $this->options->get_option('failed_task_count', 0);
		$total_bytes_saved = $this->options->get_option('total_bytes_saved', false);
		$total_percent_saved = $this->options->get_option('total_percent_saved', 0);

		if ('ud_task_failed' == current_action()) {
			$this->options->update_option('failed_task_count', ++$failed_task_count);
			return;
		}

		if (false === $completed_task_count) {
			$completed_task_count = $total_bytes_saved = 0;
		}

		if (!$total_bytes_saved) {
			$total_bytes_saved = 0;
		}

		if (is_multisite()) {
			switch_to_blog($task->get_option('blog_id', 1));
			$stats = get_post_meta($attachment_id, 'smush-stats', true);
			restore_current_blog();
		} else {
			$stats = get_post_meta($attachment_id, 'smush-stats', true);
		}

		if (isset($stats['sizes-info'])) {
		
			$original_size = 0;
			$compressed_size = 0;

			foreach ($stats['sizes-info'] as $info) {
				$original_size += $info['original'];
				$compressed_size += $info['compressed'];
			}

			$percent = round((($original_size - $compressed_size) / $original_size * 100), 2);
		} else {
			$original_size = isset($stats['original-size']) ? $stats['original-size'] : 0;
			$compressed_size = isset($stats['smushed-size']) ? $stats['smushed-size'] : 0;
			$percent = isset($stats['savings-percent']) ? $stats['savings-percent'] : 0;
		}

		$saved = $original_size - $compressed_size;
		$completed_task_count++;

		$total_bytes_saved += $saved;
		$total_percent_saved = (($total_percent_saved * ($completed_task_count - 1)) + $percent) / $completed_task_count;

		$this->options->update_option('completed_task_count', $completed_task_count);
		$this->options->update_option('total_bytes_saved', $total_bytes_saved);
		$this->options->update_option('total_percent_saved', $total_percent_saved);
	}

	/**
	 * Get current smush options.
	 *
	 * @return array
	 */
	public function get_smush_options() {
		static $smush_options = array();
		if (empty($smush_options)) {
			$smush_options = array(
				'compression_server' => $this->options->get_option('compression_server', $this->get_default_webservice()),
				'image_quality' => $this->options->get_option('image_quality', 92),
				'lossy_compression' => $this->options->get_option('lossy_compression', false),
				'back_up_original' => $this->options->get_option('back_up_original', true),
				'back_up_delete_after' => $this->options->get_option('back_up_delete_after', true),
				'back_up_delete_after_days' => $this->options->get_option('back_up_delete_after_days', 50),
				'preserve_exif' => $this->options->get_option('preserve_exif', false),
				'autosmush' => $this->options->get_option('autosmush', false),
				'show_smush_metabox' => $this->options->get_option('show_smush_metabox', 'show') == 'show' ? true : false,
				'webp_conversion' => $this->options->get_option('webp_conversion', false)
			);
		}
		return $smush_options;
	}

	/**
	 * Updates global smush options
	 *
	 * @param array $options - sent in via AJAX
	 * @return bool - status of the update
	 */
	public function update_smush_options($options) {
		
		foreach ($options as $option => $value) {
			$this->options->update_option($option, $value);
		}

		return true;
	}

	/**
	 * Clears smush related stats
	 *
	 * @return bool - status of the update
	 */
	public function clear_smush_stats() {
		$this->options->update_option('failed_task_count', 0);
		$this->options->update_option('completed_task_count', false);
		$this->options->update_option('total_bytes_saved', false);
		$this->options->update_option('total_percent_saved', 0);

		return true;
	}

	/**
	 * Returns array of translations used in javascript code.
	 *
	 * @return array - translations used in JS
	 */
	public function smush_js_translations() {
		$resmushit_article_link = WP_Optimize()->wp_optimize_url('https://resmush.it/api/', __('resmushIt', 'wp-optimize'), '', '', true);

		return apply_filters('updraft_smush_js_translations', array(
			'all_images_compressed' 		  => __('No uncompressed images were found.', 'wp-optimize'),
			'error_unexpected_response' 	  => __('An unexpected response was received from the server.', 'wp-optimize') . ' ' . __('More information has been logged in the browser console.', 'wp-optimize'),
			'compress_single_image_dialog'	  => __('Please wait: compressing the selected image.', 'wp-optimize'),
			'error_try_again_later'			  => __('Please try again later.', 'wp-optimize'),
			'server_check'					  => __('Connecting to the Smush API server, please wait', 'wp-optimize'),
			'please_wait'					  => __('Please wait while the request is being processed', 'wp-optimize'),
			'server_error'					  => __('There was an error connecting to the image compression server.', 'wp-optimize') .
				'<br>' . __('This could mean either the server is temporarily unavailable or there are connectivity issues with your internet connection.', 'wp-optimize') . ' ' .
					'<i>' . sprintf(__('(Also ensure IPs listed at the bottom of this %s page are whitelisted by your webserver).', 'wp-optimize'), $resmushit_article_link) . '</i>' .
				'<br>' . __('Please try later.', 'wp-optimize'),
			'please_select_images'		  	  => __('Please select the images you want compressed from the "Uncompressed images" panel first', 'wp-optimize'),
			'please_updating_images_info'	  => __('Please wait: updating information about the selected image.', 'wp-optimize'),
			'please_select_compressed_images' => __('Please select the images you want to mark as already compressed from the "Uncompressed images" panel first', 'wp-optimize'),
			'view_image'					  => __('View Image', 'wp-optimize'),
			'delete_image_backup_confirm'	=> __('Do you really want to delete all backup images now?', 'wp-optimize') . ' ' . __('This action is irreversible.', 'wp-optimize'),
			'mark_all_images_uncompressed'	=> __('Do you really want to mark all the images as uncompressed?', 'wp-optimize') . ' ' . __('This action is irreversible.', 'wp-optimize'),
			'restore_images_from_backup'	=> __('Do you want to restore the original images from the backup (where they exist?)', 'wp-optimize'),
			'restore_all_compressed_images'	=> __('Do you really want to restore all the compressed images?', 'wp-optimize'),
			'webp_conversion_tool_error' => __('No WebP conversion tools are available on your web-server.', 'wp-optimize'),
			'webp_conversion_tool_how_to' => __('How to get the WebP conversion tools to work?', 'wp-optimize'),
			'more' => __('More', 'wp-optimize'),
			'less' => __('Less', 'wp-optimize'),
			'converting_to_webp' => __('Converting image to WebP format, please wait', 'wp-optimize'),
			'compress_image' => __('Compress Image', 'wp-optimize'),
			'compress' => __('Compress', 'wp-optimize'),
			'cancel' => __('Cancel', 'wp-optimize'),
			'close' => __('Close', 'wp-optimize'),
		));
	}

	/**
	 * Adds a smush metabox on the post edit screen for images
	 *
	 * @param WP_Post $post - a post object
	 */
	public function add_smush_metabox($post) {

		if (!wp_attachment_is_image($post->ID)) return;

		if (!file_exists(get_attached_file($post->ID))) {
			return;
		}

		add_meta_box('smush-metabox', __('Compress Image', 'wp-optimize'), array($this, 'render_smush_metabox'), 'attachment', 'side');
	}

	/**
	 * Renders a metabox on the post edit screen for images
	 *
	 * @param WP_Post $post - a post object
	 */
	public function render_smush_metabox($post) {

		$compressed = get_post_meta($post->ID, 'smush-complete', true) ? true : false;
		$has_backup = get_post_meta($post->ID, 'original-file', true) ? true : false;

		$smush_info = get_post_meta($post->ID, 'smush-info', true);
		$smush_stats = get_post_meta($post->ID, 'smush-stats', true);
		$marked = get_post_meta($post->ID, 'smush-marked', false);
		
		$options = Updraft_Smush_Manager()->get_smush_options();
		
		$file = get_attached_file($post->ID);
		$ext = WPO_Image_Utils::get_extension($file);
		$allowed_extensions = WPO_Image_Utils::get_allowed_extensions();
		$file_size = ($file && is_file($file)) ? filesize($file) : 0;

		$extract = array(
			'post_id' 			=> $post->ID,
			'smush_display'		=> $compressed ? "display:none;" : "display:block;",
			'restore_display' 	=> $compressed ? "display:block;" : "display:none;",
			'restore_action'	=> $has_backup ? "display:block;" : "display:none;",
			'smush_mark'		=> !$compressed && !$marked ? "display:block;" : "display:none;",
			'smush_unmark'      => $marked ? "display:block;" : "display:none;",
			'smush_info'		=> $smush_info ? $smush_info : ' ',
			'file_size'			=> $file_size,
			'smush_options'     => $options,
			'custom'            => 90 >= $options['image_quality'] && 65 <= $options['image_quality'],
			'smush_details'		=> '',
			'restore_tooltip'   => $this->get_restore_image_tooltip_text(),
			'smush_marked'      => $marked,
		);

		if (!empty($smush_stats['sizes-info'])) {
			$extract['smush_details'] = WP_Optimize()->include_template('images/smush-details.php', true, array('sizes_info' => $smush_stats['sizes-info']));
		}

		$extract['smush_settings_form'] = WP_Optimize()->include_template('admin-metabox-smush-settings.php', true, $extract);
		$extract['compressed_by_another_plugin'] = $this->is_image_compressed_by_another_plugin($post->ID);
		if (WPO_Image_Utils::is_supported_extension($ext, $allowed_extensions)) {
			WP_Optimize()->include_template('admin-metabox-smush.php', false, $extract);
		} else {
			printf("<p>%s</p>", __('Compressing this file type extension is not supported', 'wp-optimize'));
		}
	}

	/**
	 * Get text for restrore image tooltip.
	 *
	 * @return string
	 */
	private function get_restore_image_tooltip_text() {
		$text = __('Only the original image will be restored.', 'wp-optimize');
		$text .= ' ';
		$text .= __('In order to restore the other sizes, you should use a plugin such as "Regenerate Thumbnails".', 'wp-optimize');
		
		return $text;
	}

	/**
	 * Check if a single image compressed by another plugin.
	 *
	 * @param int $image_id
	 * @return bool
	 */
	private function is_image_compressed_by_another_plugin($image_id) {
		global $wpdb;

		$meta = $wpdb->get_results("SELECT meta_key, meta_value FROM {$wpdb->postmeta} WHERE `post_id`={$image_id}", ARRAY_A);

		if (is_array($meta)) {
			foreach ($meta as $row) {
				// Smush, Imagify, Compress JPEG & PNG images by TinyPNG.
				if (in_array($row['meta_key'], array('wp-smpro-smush-data', '_imagify_optimization_level', 'tiny_compress_images'))) return true;
				// ShortPixel Image Optimizer
				if ('_shortpixel_status' == $row['meta_key'] && 2 <= $row['meta_key'] && 3 > $row['meta_key']) return true;
			}
		}

		if (WP_Optimize()->get_db_info()->table_exists('ewwwio_images')) {
			$old_show_errors = $wpdb->show_errors(false);
			// EWWW Image Optimizer.
			$ewww_image = $wpdb->get_col("SELECT attachment_id FROM {$wpdb->prefix}ewwwio_images WHERE attachment_id={$image_id} AND gallery='media' LIMIT 1");
			if (!empty($ewww_image)) return true;
			$wpdb->show_errors($old_show_errors);
		}

		return apply_filters('wpo_image_compressed_by_another_plugin', false);
	}

	/**
	 * Get attachment ids for images those already compressed with EWWW Image Optimizer.
	 * Used with filter `wpo_get_uncompressed_images_args`.
	 *
	 * @param array $args WP_Query arguments.
	 * @return array
	 */
	public function ewww_image_optimizer_compressed_images_args($args) {
		global $wpdb;

		if (!WP_Optimize()->get_db_info()->table_exists('ewwwio_images')) return $args;

		$old_show_errors = $wpdb->show_errors(false);
		$compressed_images = $wpdb->get_col("SELECT DISTINCT(attachment_id) FROM {$wpdb->prefix}ewwwio_images WHERE gallery='media'");
		$wpdb->show_errors($old_show_errors);

		if (isset($args['post__not_in'])) {
			$args['post__not_in'] = array_merge($args['post__not_in'], $compressed_images);
		} else {
			$args['post__not_in'] = $compressed_images;
		}

		return $args;
	}

	/**
	 * Returns a list of images for smush (from cache if available)
	 *
	 * @param string $use_cache
	 * @return array - uncompressed images
	 */
	public function get_uncompressed_images($use_cache = "true") {
		if ("true" == $use_cache) {
			$uncompressed_images = $this->get_from_cache('uncompressed_images');
			if ($uncompressed_images) return $uncompressed_images;
		}

		$uncompressed_images = array();
		$accepted_mimes = array('image/jpeg', 'image/gif', 'image/png');

		$args = array(
			'post_type'		=> 'attachment',
			'post_mime_type' => $accepted_mimes,
			'post_status'	=> 'inherit',
			'posts_per_page' => apply_filters('updraft_smush_posts_per_page', 1000),
			'meta_query' => $this->get_uncompressed_images_meta_query(),
			'no_found_rows' => true,
			'fields' => 'ids'
		);

		$allowed_extensions = WPO_Image_Utils::get_allowed_extensions();

		if (is_multisite()) {

			$sites = WP_Optimize()->get_sites();

			foreach ($sites as $site) {
				
				switch_to_blog($site->blog_id);

				$args = apply_filters('wpo_get_uncompressed_images_args', $args);
				$images = new WP_Query($args);

				foreach ($images->posts as $image) {
					// If `field` is removed from $args it returns a WP_Post obj
					$image_id = is_int($image) ? $image : $image->ID;

					$file = get_attached_file($image_id);
					$ext = WPO_Image_Utils::get_extension($file);
					if (file_exists($file)) {
						if (WPO_Image_Utils::is_supported_extension($ext, $allowed_extensions)) {
							$uncompressed_images[$site->blog_id][] = array(
								'id' => $image_id,
								'thumb_url' => wp_get_attachment_thumb_url($image_id),
								'filesize'  => filesize(get_attached_file($image_id))
							);
						} else {
							$this->log("Blog_id={$site->blog_id}, ID={$image_id}, File={$file} This image type is not supported.");
						}
					} else {
						$this->log("Could not find file for image: blog_id={$site->blog_id}, ID={$image_id}, file={$file}");
					}
				}

				restore_current_blog();
			}

		} else {
			$args = apply_filters('wpo_get_uncompressed_images_args', $args);
			$images = new WP_Query($args);
			foreach ($images->posts as $image) {
				// If `field` is removed from $args it returns a WP_Post obj
				$image_id = is_int($image) ? $image : $image->ID;

				$file = get_attached_file($image_id);
				$ext = WPO_Image_Utils::get_extension($file);

				if (file_exists($file)) {
					if (WPO_Image_Utils::is_supported_extension($ext, $allowed_extensions)) {
						$uncompressed_images[1][] = array(
							'id' => $image_id,
							'thumb_url' => wp_get_attachment_thumb_url($image_id),
							'filesize'  => filesize(get_attached_file($image_id))
						);
					} else {
						$this->log("Image ID={$image_id}, File={$file} This image type is not supported.");
					}
				} else {
						$this->log("Could not find file for image: ID={$image_id}, file={$file}");
				}
			}
		}

		$this->save_to_cache('uncompressed_images', $uncompressed_images);
		return $uncompressed_images;
	}

	/**
	 * Returns a list of admin URLs. This is to prevent unnecessary bloat in the output of get_uncompressed_images() (and thus better performance over the network on sites with huge numbers of images)
	 *
	 * @return array - list of admin URLs
	 */
	public function get_admin_urls() {
		
		$admin_urls = $this->get_from_cache('admin_urls');

		if ($admin_urls) return $admin_urls;

		$admin_urls = array();

		if (is_multisite()) {
		
			$sites = WP_Optimize()->get_sites();

			foreach ($sites as $site) {
				switch_to_blog($site->blog_id);
				$admin_urls[$site->blog_id] = admin_url();
				restore_current_blog();
			}

		} else {
			// The pseudo-blog_id here (1) matches (and must match) what is used in get_uncompressed_images
			$admin_urls[1] = admin_url();
		}

		$this->save_to_cache('admin_urls', $admin_urls);
		return $admin_urls;
	}
	
	/**
	 * Check if a task exists for a given image
	 *
	 * @param string $image - The attachment ID of the image
	 * @return bool - true if yes, false otherwise
	 */
	public function task_exists($image) {
		
		$blog_id	   = get_current_blog_id();
		$pending_tasks = $this->get_active_tasks('smush');

		if (!empty($pending_tasks)) {
			foreach ($pending_tasks as $task) {
				$task_attachment_id = $task->get_option('attachment_id');
				$task_blog_id = $task->get_option('blog_id');

				if ($image === $task_attachment_id && $blog_id === $task_blog_id) {
					return true;
				}
			}
		}
		return false;
	}

	/**
	 * Returns the status of images compressed in this iteration of the bulk compress
	 *
	 * @param array $images - List of images in the current session
	 *
	 * @return array - status of the operation
	 */
	public function get_session_stats($images) {
		$stats = array();

		foreach ($images as $image) {
			if (is_multisite()) {
				switch_to_blog($image['blog_id'], 1);
				$stats[] = get_post_meta($image['attachment_id'], 'smush-complete', true) ? 'success' : 'fail';
				restore_current_blog();
			} else {
				$stats[] = get_post_meta($image['attachment_id'], 'smush-complete', true) ? 'success' : 'fail';
			}
		}

		return array_count_values($stats);
	}

	/**
	 * Returns a list of images for smush (from cache if available)
	 *
	 * @return array - List of task objects with uncompressed images
	 */
	public function get_pending_tasks() {
		return $this->get_active_tasks('smush');
	}

	/**
	 * Deletes and removes any pending tasks from queue
	 */
	public function clear_pending_images() {

		$pending_tasks = $this->get_active_tasks('smush');

		if (!empty($pending_tasks)) {
			foreach ($pending_tasks as $task) {
				$task->delete_meta();
				$task->delete();
			}
		}
		
		return true;
	}


	/**
	 * Returns a count of failed tasks
	 *
	 * @return int -  failed tasks
	 */
	public function get_failed_task_count() {
		return $this->options->get_option('failed_task_count', 0);
	}

	/**
	 * Adds the required scripts and styles
	 */
	public function admin_enqueue_scripts() {
		$current_screen = get_current_screen();
		if (null === $current_screen) return;
		// load scripts and styles only on WP-Optimize pages
		if (!preg_match('/wp\-optimize|attachment|upload/i', $current_screen->id)) return;

		$enqueue_version = WP_Optimize()->get_enqueue_version();
		$min_or_not = WP_Optimize()->get_min_or_not_string();
		$min_or_not_internal = WP_Optimize()->get_min_or_not_internal_string();

		$js_variables = $this->smush_js_translations();
		$js_variables['ajaxurl'] = admin_url('admin-ajax.php');
		$js_variables['features'] = $this->get_features();

		$js_variables['smush_ajax_nonce'] = wp_create_nonce('updraft-task-manager-ajax-nonce');
		$js_variables['smush_settings'] = $this->get_smush_options();
		$js_variables['blog_id'] = get_current_blog_id();
		$js_variables['compress'] = esc_html__('Compress', 'wp-optimize');
		$js_variables['cancel'] = esc_html__('Cancel', 'wp-optimize');
		$js_variables['cancelling'] = esc_html__('Cancelling...', 'wp-optimize');
		$js_variables['images_restored_successfully'] = esc_html__('The images were restored successfully', 'wp-optimize');

		wp_enqueue_script('block-ui-js', WPO_PLUGIN_URL.'includes/blockui/jquery.blockUI'.$min_or_not.'.js', array('jquery'), $enqueue_version);
		wp_enqueue_script('wp-optimize-heartbeat-js', WPO_PLUGIN_URL.'js/heartbeat'.$min_or_not_internal.'.js', array('jquery'), $enqueue_version);
		wp_localize_script('wp-optimize-heartbeat-js', 'wpo_heartbeat_ajax', array(
			'ajaxurl' => admin_url('admin-ajax.php'),
			'nonce' => wp_create_nonce('heartbeat-nonce'),
			'interval' => WPO_Ajax::HEARTBEAT_INTERVAL
		));
		wp_enqueue_script('smush-js', WPO_PLUGIN_URL.'js/wposmush'.$min_or_not_internal.'.js', array('jquery', 'block-ui-js', 'wp-optimize-send-command', 'wp-optimize-heartbeat-js'), $enqueue_version);
		wp_enqueue_style('smush-css', WPO_PLUGIN_URL.'css/smush'.$min_or_not_internal.'.css', array(), $enqueue_version);
		wp_localize_script('smush-js', 'wposmush', $js_variables);
	}

	/**
	 * Gets default service provider for smush
	 *
	 * @return string - service name
	 */
	public function get_default_webservice() {
		return 'resmushit';
	}

	/**
	 * Sets default options for smush
	 */
	public function set_default_options() {

		$options = array(
			'compression_server' => $this->get_default_webservice(),
			'image_quality'		 => 92,
			'lossy_compression'	 => false,
			'back_up_original'	 => true,
			'preserve_exif'		 => false,
			'autosmush'			 => false,
			'back_up_delete_after' => $this->options->get_option('back_up_delete_after', true),
			'back_up_delete_after_days' => $this->options->get_option('back_up_delete_after_days', 50),
			'webp_conversion'	 => false,
		);
		
		$this->update_smush_options($options);
	}

	/**
	 * Gets default service provider for smush
	 *
	 * @param string $server - The name of the server
	 * @return string - associated task type, default if none found
	 */
	public function get_associated_task($server) {
		$allowed = $this->get_allowed_services();

		if (key_exists($server, $allowed))
			return $allowed[$server];

		$default = $this->get_default_webservice();
		return $allowed[$default];
	}

	/**
	 * Gets allowed service providers for smush
	 *
	 * @return array - key value pair of service name => task name
	 */
	public function get_allowed_services() {
		return array(
			'resmushit'  => 'Re_Smush_It_Task',
		);
	}

	/**
	 * Gets allowed service provider features smush
	 *
	 * @return array - key value pair of service name => features exposed
	 */
	public function get_features() {
		$features = array();
		foreach ($this->get_allowed_services() as $service => $class_name) {
			$features[$service] = call_user_func(array($class_name, 'get_features'));
		}
		return $features;
	}

	/**
	 * Returns the path to the logfile
	 *
	 * @return string - file path
	 */
	public function get_logfile_path() {
		return WP_Optimize_Utils::get_log_file_path('smush');
	}

	/**
	 * Delete all smush log files
	 *
	 * @deprecated 3.5.0
	 */
	public function delete_log_files() {
		_deprecated_function(__METHOD__, '3.5.0');
	}

	/**
	 * Adds a logger to the task
	 *
	 * @param Mixed $task - a task object
	 */
	public function set_task_logger($task) {
		if (!$this->logger) {
			$this->logger = new Updraft_File_Logger($this->get_logfile_path());
		}
		
		if (!$task->get_loggers()) {
			$task->add_logger($this->logger);
		}
	}

	/**
	 * Writes a standardised header to the log file
	 */
	public function write_log_header() {
		global $wpdb;
		
		// phpcs:disable
		$wp_version = $this->get_wordpress_version();
		$mysql_version = $wpdb->db_version();
		$disabled_functions = ini_get('disable_functions');
		$max_execution_time = (int) @ini_get("max_execution_time");

		$memory_limit = ini_get('memory_limit');
		$memory_usage = round(@memory_get_usage(false)/1048576, 1);
		$total_memory_usage = round(@memory_get_usage(true)/1048576, 1);

		// Attempt to raise limit
		@set_time_limit(330);

		$log_header = array();

		// phpcs:enable
		$log_header[] = "\n";
		$log_header[] = "Header for logs at time:  ".date('r')." on ".network_site_url();
		$log_header[] = "WP: ".$wp_version;
		$php_uname = '';
		if (function_exists('php_uname')) {
			$php_uname = ", " . php_uname();
		}
		$log_header[] = "PHP: ".phpversion()." (".PHP_SAPI.$php_uname.")";
		$log_header[] = "MySQL: $mysql_version";
		$log_header[] = "WPLANG: ".get_locale();
		$log_header[] = "Server: ".$_SERVER["SERVER_SOFTWARE"];
		$log_header[] = "Outbound connections: ".(defined('WP_HTTP_BLOCK_EXTERNAL') ? 'Y' : 'N');
		$log_header[] = "Disabled Functions: $disabled_functions";
		$log_header[] = "max_execution_time: $max_execution_time";
		$log_header[] = "memory_limit: $memory_limit (used: {$memory_usage}M | {$total_memory_usage}M)";
		$log_header[] = "multisite: ".(is_multisite() ? 'Y' : 'N');
		$log_header[] = "openssl: ".(defined('OPENSSL_VERSION_TEXT') ? OPENSSL_VERSION_TEXT : 'N');

		if (apply_filters("wpo_write_server_info_in_smush_log", false)) {
			foreach ($log_header as $log_entry) {
				$this->log($log_entry);
			}
		}

		$memlim = $this->memory_check_current();

		if ($memlim<65 && $memlim>0) {
			$this->log(sprintf('The amount of memory (RAM) allowed for PHP is very low (%s Mb) - you should increase it to avoid failures due to insufficient memory (consult your web hosting company for more help)', round($memlim, 1)), 'warning');
		}

		if ($max_execution_time>0 && $max_execution_time<20) {
			$this->log(sprintf('The amount of time allowed for WordPress plugins to run is very low (%s seconds) - you should increase it to avoid failures due to time-outs (consult your web hosting company for more help - it is the max_execution_time PHP setting; the recommended value is %s seconds or more)', $max_execution_time, 90), 'warning');
		}
	}

	/**
	 * Prunes the log file
	 */
	public function prune_smush_logs() {
		$this->log("Pruning the smush log file");
		$this->logger->prune_logs();
	}

	/**
	 * Get the WordPress version
	 *
	 * @return String - the version
	 */
	public function get_wordpress_version() {
		static $got_wp_version = false;
		
		if (!$got_wp_version) {
			global $wp_version;
			@include(ABSPATH.WPINC.'/version.php');// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress warning if `version.php` does not exists
			$got_wp_version = $wp_version;
		}

		return $got_wp_version;
	}

	/**
	 * Get the current memory limit
	 *
	 * @return String - memory limit in megabytes
	 */
	public function memory_check_current($memory_limit = false) {
		// Returns in megabytes
		if (false == $memory_limit) $memory_limit = ini_get('memory_limit');
		$memory_limit = rtrim($memory_limit);
		$memory_unit = $memory_limit[strlen($memory_limit)-1];
		if (0 == (int) $memory_unit && '0' !== $memory_unit) {
			$memory_limit = substr($memory_limit, 0, strlen($memory_limit)-1);
		} else {
			$memory_unit = '';
		}
		switch ($memory_unit) {
			case '':
			$memory_limit = floor($memory_limit/1048576);
				break;
			case 'K':
			case 'k':
			$memory_limit = floor($memory_limit/1024);
				break;
			case 'G':
			$memory_limit = $memory_limit*1024;
				break;
			case 'M':
			// assumed size, no change needed
				break;
		}
		return $memory_limit;
	}

	/**
	 * Saves a value to the cache.
	 *
	 * @param string $key
	 * @param mixed  $value
	 * @param int	$blog_id
	 */
	public function save_to_cache($key, $value, $blog_id = 1) {
		$transient_limit = 3600 * 48;
		$key = 'wpo_smush_cache_' . $blog_id . '_'. $key;

		WP_Optimize_Transients_Cache::get_instance()->set_transient($key, $value, $transient_limit);
	}

	/**
	 * Gets value from the cache.
	 *
	 * @param string $key
	 * @param int	$blog_id
	 * @return mixed
	 */
	public function get_from_cache($key, $blog_id = 1) {
		$key = 'wpo_smush_cache_' . $blog_id . '_'. $key;

		return WP_Optimize_Transients_Cache::get_instance()->get($key);
	}

	/**
	 * Deletes a value from the cache.
	 *
	 * @param string $key
	 * @param int	$blog_id
	 */
	public function delete_from_cache($key, $blog_id = 1) {
		$key = 'wpo_smush_cache_' . $blog_id . '_'. $key;

		WP_Optimize_Transients_Cache::get_instance()->delete($key);

		$this->delete_transient($key);
	}

	/**
	 * Wrapper for deleting a transient
	 *
	 * @param string $key
	 */
	public function delete_transient($key) {
		if ($this->is_multisite_mode()) {
			delete_site_transient($key);
		} else {
			delete_transient($key);
		}
	}

	/**
	 * Removes all cached data
	 */
	public function clear_cached_data() {
		global $wpdb;

		// get list of cached data by optimization.
		if ($this->is_multisite_mode()) {
			$keys = $wpdb->get_col("SELECT meta_key FROM {$wpdb->sitemeta} WHERE meta_key LIKE '%wpo_smush_cache_%'");
		} else {
			$keys = $wpdb->get_col("SELECT option_name FROM {$wpdb->options} WHERE option_name LIKE '%wpo_smush_cache_%'");
		}

		if (!empty($keys)) {
			$transient_keys = array();
			foreach ($keys as $key) {
				preg_match('/wpo_smush_cache_.+/', $key, $option_name);
				$option_name = $option_name[0];
				$transient_keys[] = $option_name;
			}

			// get unique keys.
			$transient_keys = array_unique($transient_keys);

			// delete transients.
			foreach ($transient_keys as $key) {
				$this->delete_transient($key);
			}
		}
	}

	/**
	 * Delete recursively all smush backup files created more that $days_ago days.
	 *
	 * @param string $directory upload directory
	 * @param int    $days_ago
	 */
	public function clear_backup_images_directory($directory, $days_ago = 30) {

		$directory = trailingslashit($directory);
		$current_time = time();

		if (preg_match('/(\d{4})\/(\d{2})\/$/', $directory, $match)) {

			$check_date = false;

			if ($days_ago > 0) {
				// check if it is end directory then scan for backup images.
				$year = (int) $match[1];
				$month = (int) $match[2];

				$limit = strtotime('-'.$days_ago.' '.(($days_ago > 1) ? 'days' : 'day'));
				$year_limit = (int) date('Y', $limit);
				$month_limit = (int) date('m', $limit);
				$day_limit = (int) date('j', $limit);

				// if current directory is newer than needed then we skip it.
				if ($year_limit < $year || ($year_limit == $year && $month_limit < $month)) {
					return;
				}

				// we will check dates only in directory that contain limit date.
				$check_date = ($year_limit == $year && $month_limit == $month);
			}

			// GLOB_BRACE isn't defined on some systems (Solaris, SunOS and more) > https://www.php.net/manual/en/function.glob.php
			$files = glob($directory . '*-updraft-pre-smush-original.*', (defined('GLOB_BRACE') ? GLOB_BRACE : 0));

			foreach ($files as $file) {
				if ($check_date) {
					$filedate_day = (int) date('j', filectime($file));
					if ($filedate_day >= $day_limit) continue;
				}

				unlink($file);
			}

		} else {
			// scan directories recursively.
			$handle = opendir($directory);

			if (false === $handle) return;

			$file = readdir($handle);

			while (false !== $file) {

				if ('.' == $file || '..' == $file) {
					$file = readdir($handle);
					continue;
				}

				if (is_dir($directory . $file)) {
					$this->clear_backup_images_directory($directory . $file, $days_ago);
				} elseif (is_file($directory . $file) && preg_match('/^.+-updraft-pre-smush-original\.\S{3,4}/i', $file)) {
					// check the file time and compare with $days_ago.
					$filedate_day = (int) filectime($directory . $file);
					if ($filedate_day > 0 && ($current_time - $filedate_day) / 86400 >= $days_ago) unlink($directory . $file);
				}

				$file = readdir($handle);
			}
		}

	}

	/**
	 * Clean backup smush images according to saved options.
	 */
	public function clear_backup_images() {
		$back_up_delete_after = $this->options->get_option('back_up_delete_after', false);

		if (!$back_up_delete_after) return;

		$back_up_delete_after_days = $this->options->get_option('back_up_delete_after_days', 50);

		$upload_dir = wp_upload_dir(null, false);
		$base_dir = $upload_dir['basedir'];

		$this->clear_backup_images_directory($base_dir, $back_up_delete_after_days);
	}

	/**
	 * Check if attachment already compressed.
	 *
	 * @param int $attachment_id
	 *
	 * @return bool
	 */
	public function is_compressed($attachment_id) {
		return (true == get_post_meta($attachment_id, 'smush-complete', true));
	}

	/**
	 * @param array   $form_fields
	 * @param WP_Post $post
	 *
	 * @return array
	 */
	public function add_compress_button_to_media_modal($form_fields, $post) {

		if (!is_admin() || !function_exists('get_current_screen')) return $form_fields;
	
		/**
		 * In media modal get_current_screen() return null or id = 'async-upload' We don't need add smush fields elsewhere.
		 */
		$current_screen = get_current_screen();
		if (null !== $current_screen && 'async-upload' != $current_screen->id) return $form_fields;

		/**
		 * Don't show additional fields for non-image attachments.
		 */
		if (!wp_attachment_is_image($post->ID)) return $form_fields;

		ob_start();
		$this->render_smush_metabox($post);
		$smush_metabox = ob_get_contents();
		ob_end_clean();

		$form_fields['wpo_compress_image'] = array(
			'value'			=> '',
			'label'         => __('Compress image', 'wp-optimize'),
			'input'         => 'html',
			'html'          => $smush_metabox,
		);

		return $form_fields;
	}

	/**
	 * Returns true if multisite
	 *
	 * @return bool
	 */
	public function is_multisite_mode() {
		return WP_Optimize()->is_multisite_mode();
	}

	/**
	 * This callback function is triggered due to delete_attachment action (wp-includes/post.php) and is executed prior to deletion of post-type attachment
	 *
	 * @param int $post_id - WordPress Post ID
	 */
	public function unscheduled_original_file_deletion($post_id) {
		$the_original_file = get_post_meta($post_id, 'original-file', true);
		$uploads_dir = wp_get_upload_dir();
		$the_original_file = trailingslashit($uploads_dir['basedir'])  . $the_original_file;
		if ('' != $the_original_file && file_exists($the_original_file)) {
			@unlink($the_original_file);// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress warning because of file permission issues
		}
	}

	/**
	 * Remove failed smush tasks from the wp_tm_tasks table
	 */
	public function clear_failed_tasks() {
		$failed_tasks = $this->get_tasks('failed', 'smush');
		if (empty($failed_tasks)) return;

		foreach ($failed_tasks as $task) {
			$task->delete_meta();
			$task->delete();
		}
	}

	/**
	 * Instance of WP_Optimize_Page_Cache_Preloader.
	 *
	 * @return self
	 */
	public static function instance() {
		if (empty(self::$_instance)) {
			self::$_instance = new self();
		}

		return self::$_instance;
	}
	
	/**
	 * Meta query array for getting uncompressed images
	 *
	 * @return array
	 */
	public function get_uncompressed_images_meta_query() {
		return array(
			'relation' => 'AND',
			array(
				'relation' => 'OR',
				array(
					'key'	 => 'smush-complete',
					'compare' => '!=',
					'value'   => '1',
				),
				array(
					'key'	 => 'smush-complete',
					'compare' => 'NOT EXISTS',
					'value'   => '',
				),
			),
			// ShortPixel Image Optimizer plugin
			array(
				'relation' => 'OR',
				array(
					'key'    => '_shortpixel_status',
					'compare' => '<',
					'value'   => '2',
				),
				array(
					'key'    => '_shortpixel_status',
					'compare' => '>=',
					'value'   => '3',
				),
				array(
					'key'	 => '_shortpixel_status',
					'compare' => 'NOT EXISTS',
					'value'   => '',
				),
			),
			// Smush plugin
			array(
				'key'	 => 'wp-smpro-smush-data',
				'compare' => 'NOT EXISTS',
				'value'   => '',
			),
			// Imagify
			array(
				'key'	 => '_imagify_optimization_level',
				'compare' => 'NOT EXISTS',
				'value'   => '',
			),
			// Compress JPEG & PNG images by TinyPNG
			array(
				'key'	 => 'tiny_compress_images',
				'compare' => 'NOT EXISTS',
				'value'   => '',
			),
		);
	}
}

/**
 * Returns a Updraft_Smush_Manager instance
 */
function Updraft_Smush_Manager() {
	return Updraft_Smush_Manager::instance();
}

endif;
