<?php
/**
 * Plugin Compatibility Class
 *
 * Detects and coordinates with other image optimization plugins.
 *
 * @package Gatewell
 * @subpackage Utilities
 * @since 1.3.0
 */

namespace Gatewell;

defined( 'ABSPATH' ) || exit;

/**
 * Class Plugin_Compatibility
 *
 * Handles detection and coordination with third-party optimization plugins.
 *
 * @since 1.3.0
 */
class Plugin_Compatibility {

	/**
	 * Cached plugin detection results.
	 *
	 * @var array|null
	 */
	private static $detected_plugins = null;

	/**
	 * Detect active image optimization plugins.
	 *
	 * @return array List of active optimization plugins with their capabilities.
	 * @since 1.3.0
	 */
	public static function get_active_optimization_plugins() {
		// Return cached results if available.
		if ( self::$detected_plugins !== null ) {
			return self::$detected_plugins;
		}

		$optimization_plugins = array();

		// ShortPixel Image Optimizer.
		if ( defined( 'SHORTPIXEL_PLUGIN_FILE' ) || class_exists( 'ShortPixel\ShortPixelPlugin' ) || class_exists( 'ShortPixelAPI' ) ) {
			$optimization_plugins[] = array(
				'name'                     => 'ShortPixel Image Optimizer',
				'slug'                     => 'shortpixel',
				'handles_compression'      => true,
				'handles_format_conversion' => true,
				'supports_avif'            => true,
				'supports_webp'            => true,
				'cdn_based'                => false,
				'cloud_service'            => true,
			);
		}

		// Imagify.
		if ( defined( 'IMAGIFY_VERSION' ) || class_exists( 'Imagify' ) ) {
			$optimization_plugins[] = array(
				'name'                     => 'Imagify',
				'slug'                     => 'imagify',
				'handles_compression'      => true,
				'handles_format_conversion' => true,
				'supports_avif'            => false,
				'supports_webp'            => true,
				'cdn_based'                => false,
				'cloud_service'            => true,
			);
		}

		// Smush.
		if ( defined( 'WP_SMUSH_VERSION' ) || class_exists( 'WP_Smush' ) || class_exists( 'Smush\Core\Core' ) ) {
			$optimization_plugins[] = array(
				'name'                     => 'Smush',
				'slug'                     => 'smush',
				'handles_compression'      => true,
				'handles_format_conversion' => true,
				'supports_avif'            => false,
				'supports_webp'            => true,
				'cdn_based'                => false,
				'cloud_service'            => false,
			);
		}

		// EWWW Image Optimizer.
		if ( defined( 'EWWW_IMAGE_OPTIMIZER_VERSION' ) || class_exists( 'EWWW_Image_Optimizer' ) ) {
			$optimization_plugins[] = array(
				'name'                     => 'EWWW Image Optimizer',
				'slug'                     => 'ewww',
				'handles_compression'      => true,
				'handles_format_conversion' => true,
				'supports_avif'            => true,
				'supports_webp'            => true,
				'cdn_based'                => false,
				'cloud_service'            => true,
			);
		}

		// Optimole.
		if ( defined( 'OPTIMOLE_VERSION' ) || class_exists( 'Optml_Main' ) ) {
			$optimization_plugins[] = array(
				'name'                     => 'Optimole',
				'slug'                     => 'optimole',
				'handles_compression'      => false,
				'handles_format_conversion' => false,
				'supports_avif'            => true,
				'supports_webp'            => true,
				'cdn_based'                => true,
				'cloud_service'            => true,
			);
		}

		// TinyPNG / Compress JPEG & PNG images.
		if ( defined( 'TINYPNG_VERSION' ) || class_exists( 'Tiny_Settings' ) || class_exists( 'Tiny_Plugin' ) ) {
			$optimization_plugins[] = array(
				'name'                     => 'TinyPNG',
				'slug'                     => 'tinypng',
				'handles_compression'      => true,
				'handles_format_conversion' => false,
				'supports_avif'            => false,
				'supports_webp'            => true,
				'cdn_based'                => false,
				'cloud_service'            => true,
			);
		}

		// Jetpack (Photon / Site Accelerator).
		if ( class_exists( 'Jetpack' ) && method_exists( 'Jetpack', 'is_module_active' ) ) {
			if ( \Jetpack::is_module_active( 'photon' ) || \Jetpack::is_module_active( 'photon-cdn' ) ) {
				$optimization_plugins[] = array(
					'name'                     => 'Jetpack (Site Accelerator)',
					'slug'                     => 'jetpack',
					'handles_compression'      => false,
					'handles_format_conversion' => false,
					'supports_avif'            => false,
					'supports_webp'            => true,
					'cdn_based'                => true,
					'cloud_service'            => true,
				);
			}
		}

		// Cache the results.
		self::$detected_plugins = $optimization_plugins;

		return $optimization_plugins;
	}

	/**
	 * Check if any optimization plugin is active.
	 *
	 * @return bool True if at least one optimization plugin is detected.
	 * @since 1.3.0
	 */
	public static function has_optimization_plugin() {
		return ! empty( self::get_active_optimization_plugins() );
	}

	/**
	 * Check if an active plugin can handle format conversion.
	 *
	 * @param string $format Target format (webp, avif).
	 * @return bool True if an external plugin can handle this format.
	 * @since 1.3.0
	 */
	public static function external_plugin_handles_format( $format ) {
		$plugins = self::get_active_optimization_plugins();

		foreach ( $plugins as $plugin ) {
			if ( $format === 'webp' && ! empty( $plugin['supports_webp'] ) && $plugin['handles_format_conversion'] ) {
				return true;
			}
			if ( $format === 'avif' && ! empty( $plugin['supports_avif'] ) && $plugin['handles_format_conversion'] ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Get recommended cooperation mode based on detected plugins and server capabilities.
	 *
	 * @return string Recommended mode ('gatewell_primary', 'external_primary', 'both', or 'auto').
	 * @since 1.3.0
	 */
	public static function get_recommended_mode() {
		$plugins = self::get_active_optimization_plugins();

		if ( empty( $plugins ) ) {
			return 'gatewell_primary'; // No competition, Gatewell is in charge.
		}

		foreach ( $plugins as $plugin ) {
			// CDN-based plugins don't conflict - Gatewell can be primary.
			if ( ! empty( $plugin['cdn_based'] ) ) {
				continue;
			}

			// If external plugin supports AVIF and server doesn't, recommend external.
			if ( $plugin['supports_avif'] && ! Format_Capabilities::supports_avif() && $plugin['handles_format_conversion'] ) {
				return 'external_primary';
			}

			// If external plugin supports WebP and server doesn't, recommend external.
			if ( $plugin['supports_webp'] && ! Format_Capabilities::supports_webp() && $plugin['handles_format_conversion'] ) {
				return 'external_primary';
			}

			// If external plugin has cloud service and server has limited capabilities.
			if ( ! empty( $plugin['cloud_service'] ) && $plugin['handles_compression'] ) {
				// Server has both compression plugins - let user decide.
				return 'auto';
			}
		}

		// Default: Gatewell primary.
		return 'gatewell_primary';
	}

	/**
	 * Get recommendations and warnings based on active plugins.
	 *
	 * @return array Array of recommendation/warning messages.
	 * @since 1.3.0
	 */
	public static function get_recommendations() {
		$plugins = self::get_active_optimization_plugins();
		$recommendations = array();

		if ( empty( $plugins ) ) {
			return $recommendations;
		}

		$recommended_mode = self::get_recommended_mode();

		foreach ( $plugins as $plugin ) {
			// CDN-based plugins play nicely.
			if ( ! empty( $plugin['cdn_based'] ) ) {
				$recommendations[] = array(
					'type'    => 'info',
					'message' => sprintf(
						/* translators: %s: plugin name */
						__( '%s detected: This CDN-based plugin works alongside Gatewell without conflicts. Both can remain active.', 'gatewell' ),
						'<strong>' . $plugin['name'] . '</strong>'
					),
					'action'  => 'none',
				);
				continue;
			}

			// External plugin has better format support.
			if ( $recommended_mode === 'external_primary' ) {
				if ( $plugin['supports_avif'] && ! Format_Capabilities::supports_avif() ) {
					$recommendations[] = array(
						'type'    => 'warning',
						'message' => sprintf(
							/* translators: %s: plugin name */
							__( '%s can create AVIF images (your server cannot). We recommend setting cooperation mode to "External Plugin Primary" to use this capability.', 'gatewell' ),
							'<strong>' . $plugin['name'] . '</strong>'
						),
						'action'  => 'set_external_primary',
					);
					continue;
				}
			}

			// Compression conflict warning.
			if ( $plugin['handles_compression'] && ! $plugin['cdn_based'] ) {
				$recommendations[] = array(
					'type'    => 'warning',
					'message' => sprintf(
						/* translators: %s: plugin name */
						__( '%s detected: This plugin compresses images. To avoid double processing, choose a cooperation mode below.', 'gatewell' ),
						'<strong>' . $plugin['name'] . '</strong>'
					),
					'action'  => 'choose_mode',
				);
			}
		}

		return $recommendations;
	}

	/**
	 * Get a user-friendly explanation of what each cooperation mode does.
	 *
	 * @return array Array of mode explanations.
	 * @since 1.3.0
	 */
	public static function get_mode_explanations() {
		$plugins = self::get_active_optimization_plugins();
		$plugin_name = ! empty( $plugins[0]['name'] ) ? $plugins[0]['name'] : __( 'external plugin', 'gatewell' );

		return array(
			'auto'               => array(
				'label'       => __( 'Auto (Recommended)', 'gatewell' ),
				'description' => __( 'Automatically choose the best mode based on your server capabilities and installed plugins. Gatewell will coordinate intelligently.', 'gatewell' ),
			),
			'gatewell_primary'  => array(
				'label'       => __( 'Gatewell Primary', 'gatewell' ),
				'description' => sprintf(
					/* translators: %s: plugin name */
					__( 'Gatewell handles compression and format conversion. %s will skip processing or only optimize thumbnails.', 'gatewell' ),
					$plugin_name
				),
			),
			'external_primary'   => array(
				'label'       => __( 'External Plugin Primary', 'gatewell' ),
				'description' => sprintf(
					/* translators: %s: plugin name */
					__( 'Gatewell collects metadata (alt text, captions) only. %s handles all compression and format conversion.', 'gatewell' ),
					$plugin_name
				),
			),
			'both'               => array(
				'label'       => __( 'Both (Advanced)', 'gatewell' ),
				'description' => sprintf(
					/* translators: %s: plugin name */
					__( 'Both Gatewell and %s process images. May result in better compression but risks quality loss from double processing. Use with caution.', 'gatewell' ),
					$plugin_name
				),
			),
		);
	}

	/**
	 * Get the effective cooperation mode (resolves 'auto' to actual mode).
	 *
	 * @return string Effective mode ('gatewell_primary', 'external_primary', or 'both').
	 * @since 1.3.0
	 */
	public static function get_effective_mode() {
		$mode = get_option( 'gatewell_plugin_cooperation', 'auto' );

		if ( $mode === 'auto' ) {
			// Auto mode: use recommendation logic.
			$recommended = self::get_recommended_mode();
			return $recommended === 'auto' ? 'gatewell_primary' : $recommended;
		}

		return $mode;
	}

	/**
	 * Check if Gatewell should process compression.
	 *
	 * @return bool True if Gatewell should compress images.
	 * @since 1.3.0
	 */
	public static function should_gatewell_compress() {
		$mode = self::get_effective_mode();

		// External primary: skip compression.
		if ( $mode === 'external_primary' ) {
			return false;
		}

		// Gatewell primary or Both: compress.
		return true;
	}

	/**
	 * Check if Gatewell should process format conversion.
	 *
	 * @return bool True if Gatewell should convert formats.
	 * @since 1.3.0
	 */
	public static function should_gatewell_convert() {
		$mode = self::get_effective_mode();

		// External primary: skip conversion.
		if ( $mode === 'external_primary' ) {
			return false;
		}

		// Gatewell primary or Both: convert.
		return true;
	}
}