<?php

/**
 * Check PHP and WP compatibility
 *
 * @since 8.0.0
 */
class MonsterInsights_Ecommerce_Compatibility_Check {
	/**
	 * Holds singleton instance
	 *
	 * @since 8.0.0
	 * @var MonsterInsights_Ecommerce_Compatibility_Check
	 */
	private static $instance;

	/**
	 * Return Singleton instance
	 *
	 * @since 8.0.0
	 * @return MonsterInsights_Ecommerce_Compatibility_Check
	 */
	public static function get_instance() {
		if ( empty( self::$instance ) ) {
			self::$instance = new self();
		}

		return self::$instance;
	}

	/**
	 * @since 8.0.0
	 * @var array {
	 *     PHP Version requirement and recommendation
	 *
	 *     @type string $required Halt and deactivate plugin if PHP is under this version
	 *     @type string $warning Display undismissable warning if PHP is under this version
	 *     @type string $recommended Display undismissable warning if PHP is under this version
	 * }
	 */
	private $compatible_php_version = array(
		'required'    => '5.5',
		'warning'     => '7.0',
		'recommended' => '7.2',
	);

	/**
	 * @since 8.0.0
	 * @var array {
	 *     WP Version requirement and recommendation
	 *
	 *     @type string $required Halt and deactivate plugin if WP is under this version
	 *     @type string $warning Display undismissable warning if WP is under this version
	 *     @type string $recommended Display undismissable warning if WP is under this version
	 * }
	 */
	private $compatible_wp_version = array(
		'required'    => '4.8',
		'warning'     => '4.9',
		'recommended' => false,
	);

	/**
	 * Private constructor
	 *
	 * @since 8.0.0
	 */
	private function __construct() {
		add_filter( 'monsterinsights_compatible_php_version', array( $this, 'filter_compatible_php_version' ), 10, 1 );
		add_filter( 'monsterinsights_compatible_wp_version', array( $this, 'filter_compatible_wp_version' ), 10, 1 );
	}

	/**
	 * Return the strictest php compatibility versions
	 *
	 * @param array $version {
	 *     PHP Version requirement and recommendation
	 *
	 *     @type string $required    Halt and deactivate plugin if PHP is under this version
	 *     @type string $warning     Display undismissable warning if PHP is under this version
	 *     @type string $recommended Display undismissable warning if PHP is under this version
	 * }
	 *
	 * @since 8.0.0
	 * @return array {
	 *     PHP Version requirement and recommendation
	 *
	 *     @type string $required    Halt and deactivate plugin if PHP is under this version
	 *     @type string $warning     Display undismissable warning if PHP is under this version
	 *     @type string $recommended Display undismissable warning if PHP is under this version
	 * }
	 */
	public function filter_compatible_php_version( $version ) {
		if ( ! $version || version_compare( $version['required'], $this->compatible_php_version['required'], '<' ) ) {
			return $this->compatible_php_version;
		}

		return $version;
	}

	/**
	 * Return the strictest WP compatibility versions
	 *
	 * @param array $version     {
	 *     WP Version requirement and recommendation
	 *
	 *     @type string $required Halt and deactivate plugin if WP is under this version
	 *     @type string $warning Display undismissable warning if WP is under this version
	 *     @type string $recommended Display undismissable warning if WP is under this version
	 * }
	 *
	 * @since 8.0.0
	 * @return array {
	 *     WP Version requirement and recommendation
	 *
	 *     @type string $required Halt and deactivate plugin if WP is under this version
	 *     @type string $warning Display undismissable warning if WP is under this version
	 *     @type string $recommended Display undismissable warning if WP is under this version
	 * }
	 */
	public function filter_compatible_wp_version( $version ) {
		if ( ! $version || version_compare( $version['required'], $this->compatible_wp_version['required'], '<' ) ) {
			return $this->compatible_wp_version;
		}

		return $version;
	}

	/**
	 * Return required, warning and recommended PHP versions
	 *
	 * @since 8.0.0
	 * @return array {
	 *     PHP Version requirement and recommendation
	 *
	 *     @type string $required    Halt and deactivate plugin if PHP is under this version
	 *     @type string $warning     Display undismissable warning if PHP is under this version
	 *     @type string $recommended Display undismissable warning if PHP is under this version
	 * }
	 */
	public function get_compatible_php_version() {
		return apply_filters( 'monsterinsights_compatible_php_version', $this->compatible_php_version );
	}

	/**
	 * Check to see if PHP version meets the minimum required version
	 *
	 * @since 8.0.0
	 * @return bool
	 */
	public function is_php_compatible() {
		$compatible_php_version = $this->get_compatible_php_version();

		return empty( $compatible_php_version['required'] ) || version_compare( phpversion(), $compatible_php_version['required'], '>=' );
	}

	/**
	 * Return required, warning and recommended WP versions
	 *
	 * @since 8.0.0
	 * @return array {
	 *     WP Version requirement and recommendation
	 *
	 *     @type string $required Halt and deactivate plugin if WP is under this version
	 *     @type string $warning Display undismissable warning if WP is under this version
	 *     @type string $recommended Display undismissable warning if WP is under this version
	 * }
	 */
	public function get_compatible_wp_version() {
		return apply_filters( 'monsterinsights_compatible_wp_version', $this->compatible_wp_version );
	}

	/**
	 * Check to see if WP version meets the minimum required version
	 *
	 * @since 8.0.0
	 * @return bool
	 */
	public function is_wp_compatible() {
		global $wp_version;
		$compatible_wp_version = $this->get_compatible_wp_version();

		return empty( $compatible_wp_version['required'] ) || version_compare( $wp_version, $compatible_wp_version['required'], '>=' );
	}

	/**
	 * Check to see if the main plugin or any other add-ons have displayed the required version notice
	 *
	 * @since 8.0.0
	 * @return bool
	 */
	private function is_notice_already_active() {
		return defined( 'MONSTERINSIGHTS_VERSION_NOTICE_ACTIVE' ) && MONSTERINSIGHTS_VERSION_NOTICE_ACTIVE;
	}

	/**
	 * Set global constant so that main plugin or other add-ons are aware that the version notice
	 * has been set for display already
	 *
	 * @since 8.0.0
	 * @return void
	 */
	private function set_notice_active() {
		if ( ! defined( 'MONSTERINSIGHTS_VERSION_NOTICE_ACTIVE' ) ) {
			define( 'MONSTERINSIGHTS_VERSION_NOTICE_ACTIVE', true );
		}
	}

	/**
	 * Display version notice in admin area if:
	 * 1. Minimum PHP and WP versions are not met
	 * 2. The notice has been displayed elsewhere (in case there are multiple add-ons)
	 *
	 * @since 8.0.0
	 * @return void
	 */
	public function maybe_display_notice() {
		if ( defined( 'MONSTERINSIGHTS_FORCE_ACTIVATION' ) && MONSTERINSIGHTS_FORCE_ACTIVATION ) {
			return;
		}

		if ( $this->is_notice_already_active() ) {
			return;
		}

		if ( ! $this->is_php_compatible() ) {
			add_action( 'admin_notices', array( $this, 'display_php_notice' ) );
		}

		if ( ! $this->is_wp_compatible() ) {
			add_action( 'admin_notices', array( $this, 'display_wp_notice' ) );
		}
	}

	/**
	 * Output a nag notice if the user has an out of date PHP version installed
	 *
	 * @since 8.0.0
	 * @return void
	 */
	public function display_php_notice() {
		$url = admin_url( 'plugins.php' );
		// Check for MS dashboard
		if ( is_network_admin() ) {
			$url = network_admin_url( 'plugins.php' );
		}

		$compatible_php_version = $this->get_compatible_php_version();
		if ( empty( $compatible_php_version['required'] ) ) {
			return;
		}

		$this->set_notice_active();
		?>
		<div class="error">
			<p>
				<?php echo sprintf(
					esc_html__( 'Sorry, but your version of PHP does not meet MonsterInsights eCommerce Addon\'s required version of %1$s%2$s%3$s to run properly. The plugin has not been activated. %4$sClick here to return to the Dashboard%5$s.', 'monsterinsights-ecommerce' ),
					'<strong>',
					$compatible_php_version['required'],
					'</strong>',
					'<a href="' . $url . '">',
					'</a>' );
				?>
			</p>
		</div>
		<?php
	}

	/**
	 * Output a nag notice if the user has an out of date WP version installed
	 *
	 * @since 8.0.0
	 * @return void
	 */
	public function display_wp_notice() {
		$url = admin_url( 'plugins.php' );

		// Check for MS dashboard
		if( is_network_admin() ) {
			$url = network_admin_url( 'plugins.php' );
		}

		$compatible_wp_version = $this->get_compatible_wp_version();
		if ( empty( $compatible_wp_version['required'] ) ) {
			return;
		}

		$this->set_notice_active();
		?>
		<div class="error">
			<p>
				<?php
				// Translators: Make version number bold and add a link to return to the plugins page.
				echo sprintf(
					esc_html__( 'Sorry, but your version of WordPress does not meet MonsterInsights eCommerce Addon\'s required version of %1$s%2$s%3$s to run properly. The plugin has not been activated. %4$sClick here to return to the Dashboard%5$s.', 'monsterinsights-ecommerce' ),
					'<strong>',
					$compatible_wp_version['required'],
					'</strong>',
					'<a href="' . $url . '">',
					'</a>'
				);
				?>
			</p>
		</div>
		<?php
	}
}