<?php
/**
 * Detects other active SEO plugins.
 *
 * @package OrbitstemSEO
 */

namespace Orbitstem\SEO\Conflicts;

defined( 'ABSPATH' ) || exit;

/**
 * Identifies SEO plugins whose head output would duplicate Orbitstem's.
 * Detection only: Orbitstem never deactivates or changes another plugin.
 */
class PluginDetector {

	/**
	 * Known SEO plugins: a load-time constant and the plugin basename.
	 *
	 * @return array<string,array{name:string,constant:string,basename:string}>
	 */
	public static function signatures() {
		return array(
			'yoast'      => array(
				'name'     => 'Yoast SEO',
				'constant' => 'WPSEO_VERSION',
				'basename' => 'wordpress-seo/wp-seo.php',
			),
			'rank-math'  => array(
				'name'     => 'Rank Math SEO',
				'constant' => 'RANK_MATH_VERSION',
				'basename' => 'seo-by-rank-math/rank-math.php',
			),
			'aioseo'     => array(
				'name'     => 'All in One SEO',
				'constant' => 'AIOSEO_VERSION',
				'basename' => 'all-in-one-seo-pack/all_in_one_seo_pack.php',
			),
			'seopress'   => array(
				'name'     => 'SEOPress',
				'constant' => 'SEOPRESS_VERSION',
				'basename' => 'wp-seopress/seopress.php',
			),
			'tsf'        => array(
				'name'     => 'The SEO Framework',
				'constant' => 'THE_SEO_FRAMEWORK_VERSION',
				'basename' => 'autodescription/autodescription.php',
			),
			'slim-seo'   => array(
				'name'     => 'Slim SEO',
				'constant' => 'SLIM_SEO_VER',
				'basename' => 'slim-seo/slim-seo.php',
			),
			'smartcrawl' => array(
				'name'     => 'SmartCrawl',
				'constant' => 'SMARTCRAWL_VERSION',
				'basename' => 'smartcrawl-seo/wpmu-dev-seo.php',
			),
			'squirrly'   => array(
				'name'     => 'Squirrly SEO',
				'constant' => 'SQ_VERSION',
				'basename' => 'squirrly-seo/squirrly.php',
			),
		);
	}

	/**
	 * Active SEO plugins found, keyed by id, with the evidence for each.
	 *
	 * @return array<string,array{name:string,evidence:string}>
	 */
	public function detect() {
		$active = (array) get_option( 'active_plugins', array() );
		if ( is_multisite() ) {
			$active = array_merge( $active, array_keys( (array) get_site_option( 'active_sitewide_plugins', array() ) ) );
		}

		$found = array();
		// Safe mode is decided on plugins_loaded; translations may only load from init on.
		$translate = did_action( 'init' ) > 0;
		foreach ( self::signatures() as $id => $sig ) {
			if ( defined( $sig['constant'] ) ) {
				$found[ $id ] = array(
					'name'     => $sig['name'],
					/* translators: %s: PHP constant name */
					'evidence' => sprintf( $translate ? __( 'Constant %s is defined.', 'orbitstem-seo' ) : 'Constant %s is defined.', $sig['constant'] ),
				);
			} elseif ( in_array( $sig['basename'], $active, true ) ) {
				$found[ $id ] = array(
					'name'     => $sig['name'],
					/* translators: %s: plugin file path */
					'evidence' => sprintf( $translate ? __( 'Plugin %s is active.', 'orbitstem-seo' ) : 'Plugin %s is active.', $sig['basename'] ),
				);
			}
		}

		/**
		 * Filters the detected SEO plugins.
		 *
		 * @param array $found Detected plugins keyed by id.
		 */
		return apply_filters( 'orbitstem_seo_detected_seo_plugins', $found );
	}

	/**
	 * Whether any other SEO plugin is active.
	 *
	 * @return bool
	 */
	public function has_conflicts() {
		return array() !== $this->detect();
	}
}