<?php
/**
 * Image Optimization check.
 *
 * @package advanced-analytics
 *
 * @since 4.9.0
 */

declare(strict_types=1);

namespace ADVAN\Checks\Speed;

use ADVAN\Checks\Abstract_Check;
use ADVAN\Helpers\Plugin_Theme_Helper;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( 'ADVAN\Checks\Speed\Image_Optimization_Check' ) ) {

	/**
	 * Checks for image optimization plugins and WebP support.
	 *
	 * @since 4.9.0
	 */
	class Image_Optimization_Check extends Abstract_Check {

		/**
		 * Check identifier.
		 *
		 * @var string Check identifier.
		 *
		 * @since 4.9.0
		 */
		protected static string $id = 'image-optimization';

		/**
		 * Check category.
		 *
		 * @var string Check category.
		 *
		 * @since 4.9.0
		 */
		protected static string $category = 'speed';

		/**
		 * Check weight (1-10).
		 *
		 * @var int Check weight.
		 *
		 * @since 4.9.0
		 */
		protected static int $weight = 8;

		/**
		 * Check title (translatable).
		 *
		 * @return string Check title.
		 *
		 * @since 4.9.0
		 */
		public static function get_title(): string {
			return \__( 'Image Optimization', '0-day-analytics' );
		}

		/**
		 * Check description (translatable).
		 *
		 * @return string Check description.
		 *
		 * @since 4.9.0
		 */
		public static function get_description(): string {
			return \__( 'Checks for image optimization plugins and WebP support.', '0-day-analytics' );
		}

		/**
		 * Run the check.
		 *
		 * @return array Check result.
		 *
		 * @since 4.9.0
		 */
		public static function run(): array {
			// Image optimization plugins.
			$image_plugins = array(
				'imagify/imagify.php'               => 'Imagify',
				'wp-smushit/wp-smush.php'           => 'Smush',
				'shortpixel-image-optimiser/wp-shortpixel.php' => 'ShortPixel',
				'ewww-image-optimizer/ewww-image-optimizer.php' => 'EWWW Image Optimizer',
				'tiny-compress-images/tiny-compress-images.php' => 'TinyPNG',
				'optimus/optimus.php'               => 'Optimus',
				'kraken-image-optimizer/kraken.php' => 'Kraken.io',
				'webp-express/webp-express.php'     => 'WebP Express',
				'converter-for-media/converter-for-media.php' => 'Converter for Media',
			);

			$active_optimizer = null;

			foreach ( $image_plugins as $plugin_path => $plugin_name ) {
				if ( Plugin_Theme_Helper::is_plugin_active( $plugin_path ) ) {
					$active_optimizer = $plugin_name;
					break;
				}
			}

			// Check for WebP support.
			$webp_support = static::check_webp_support();

			// Count large images in media library (sample check).
			$large_images = static::count_large_images();

			$details = array(
				'active_plugin' => $active_optimizer,
				'webp_support'  => $webp_support,
				'large_images'  => $large_images,
			);

			if ( $active_optimizer && $webp_support ) {
				return static::pass(
					sprintf(
					/* translators: %s: plugin name */
						\__( 'Image optimization is active with %s and WebP format is supported. Your images are being served in modern, efficient formats.', '0-day-analytics' ),
						$active_optimizer
					),
					$details
				);
			}

			if ( $active_optimizer ) {
				if ( ! $webp_support ) {
					return static::warning(
						sprintf(
						/* translators: %s: plugin name */
							\__( '%s is optimizing your images, but WebP format is not being used. WebP can reduce image sizes by an additional 25-35%% compared to JPEG/PNG.', '0-day-analytics' ),
							$active_optimizer
						),
						\__( 'Enable WebP conversion in your image optimization plugin settings, or use a dedicated WebP plugin.', '0-day-analytics' ),
						$details
					);
				}

				return static::pass(
					sprintf(
					/* translators: %s: plugin name */
						\__( 'Image optimization is active with %s. Your images are being compressed to reduce file sizes.', '0-day-analytics' ),
						$active_optimizer
					),
					$details
				);
			}

			if ( $large_images > 10 ) {
				return static::fail(
					'medium',
					sprintf(
					/* translators: %d: number of images */
						\__( 'No image optimization detected and you have approximately %d unoptimized images. Images are often the largest files on a webpage and unoptimized images significantly slow down your site.', '0-day-analytics' ),
						$large_images
					),
					\__( 'Install an image optimization plugin like Imagify, ShortPixel, or EWWW Image Optimizer. These can compress existing images and automatically optimize new uploads.', '0-day-analytics' ),
					$details
				);
			}

			return static::warning(
				\__( 'No image optimization plugin detected. As your site grows, unoptimized images can significantly slow down page load times.', '0-day-analytics' ),
				\__( 'Consider installing an image optimization plugin to compress images and serve them in modern formats like WebP.', '0-day-analytics' ),
				$details
			);
		}

		/**
		 * Check for WebP support.
		 *
		 * @return bool
		 *
		 * @since 4.9.0
		 */
		private static function check_webp_support() {
			// Check if there are any WebP files in uploads.
			$uploads_dir = wp_upload_dir();
			$uploads     = $uploads_dir['basedir'];

			// Sample only the current month's upload directory to avoid
			// expensive glob() on sites with millions of media files (R-04).
			$month_dir = isset( $uploads_dir['path'] ) ? $uploads_dir['path'] : $uploads;
			$webp_files = glob( $month_dir . '/*.webp' );

			if ( ! empty( $webp_files ) ) {
				return true;
			}

			// Check if WebP conversion is configured.
			$webp_options = array(
				'ewww_image_optimizer_webp',
				'imagify_auto_webp',
				'shortpixel_webp_create',
			);

			foreach ( $webp_options as $option ) {
				if ( get_option( $option ) ) {
					return true;
				}
			}

			return false;
		}

		/**
		 * Count potentially unoptimized images (estimate).
		 *
		 * Note: This provides a rough estimate since checking actual file sizes
		 * for all images would be too resource-intensive. The count returned
		 * is an approximation based on typical WordPress media library statistics.
		 *
		 * @return int Estimated count of potentially unoptimized images.
		 *
		 * @since 4.9.0
		 */
		private static function count_large_images() {
			global $wpdb;

			// Count total images in the media library.
			$total_images = (int) $wpdb->get_var(
				"SELECT COUNT(*)
			FROM {$wpdb->posts} p
			INNER JOIN {$wpdb->postmeta} pm ON p.ID = pm.post_id
			WHERE p.post_type = 'attachment'
			AND p.post_mime_type LIKE 'image/%'
			AND pm.meta_key = '_wp_attached_file'"
			);

			// Return 0 if no images found.
			if ( $total_images <= 0 ) {
				return 0;
			}

			// Estimate: Without an optimization plugin, approximately 30% of images
			// in a typical media library are larger than optimal for web delivery.
			// This is a conservative estimate based on common WordPress usage patterns.
			return (int) ceil( $total_images * 0.3 );
		}
	}
}