<?php

namespace DeliciousBrains\WPMDB\Common\Compatibility;

use DeliciousBrains\WPMDB\Common\Filesystem\Filesystem;
use DeliciousBrains\WPMDB\Common\Http\Helper;
use DeliciousBrains\WPMDB\Common\Http\Http;
use DeliciousBrains\WPMDB\Common\Http\WPMDBRestAPIServer;
use DeliciousBrains\WPMDB\Common\MigrationState\MigrationStateManager;
use DeliciousBrains\WPMDB\Common\Properties\Properties;
use DeliciousBrains\WPMDB\Common\Settings\Settings;
use DeliciousBrains\WPMDB\Common\UI\Notice;
use DeliciousBrains\WPMDB\Common\UI\TemplateBase;
use DeliciousBrains\WPMDB\Common\Util\Util;

/**
 * Class CompatibilityManager
 *
 * Class to handle the copying and removing of the Compatibility Mode MU plugin for WP Migrate DB Pro
 *
 */
class CompatibilityManager {
	/**
	 * @var string
	 */
	public $mu_plugin_source;

	/**
	 * @var string
	 */
	public $mu_plugin_dest;

	/**
	 * @var Filesystem
	 */
	public $filesystem;

	/**
	 * @var
	 */
	public $settings;

	/**
	 * @var string
	 */
	public $compatibility_plugin_version;

	/**
	 * @var string
	 */
	public $mu_plugin_dir;

	/**
	 * @var Properties
	 */
	public $props;

	/**
	 * @var Properties
	 */
	public static $static_props;

	/**
	 * @var Notice
	 */
	public $notices;

	/**
	 * @var TemplateBase
	 */
	public $template;

	/**
	 * @var Http
	 */
	public $http;

	/**
	 * @var MigrationStateManager
	 */
	public $migration_state;

	/**
	 * @var WPMDBRestAPIServer
	 */
	private $rest_API_server;

	/**
	 * @var Helper
	 */
	private $http_helper;

	/**
	 * @var Util
	 */
	private $util;

	public function __construct(
		Filesystem $filesystem,
		Settings $settings,
		Notice $notice,
		Http $http,
		Helper $http_helper,
		TemplateBase $template,
		MigrationStateManager $migration_state,
		Util $util,
		Properties $properties,
		WPMDBRestAPIServer $rest_API_server
	) {
		$this->filesystem      = $filesystem;
		$this->settings        = $settings->get_settings();
		$this->props           = $properties;
		self::$static_props    = $this->props;
		$this->template        = $template;
		$this->notices         = $notice;
		$this->http            = $http;
		$this->migration_state = $migration_state;
		$this->util            = $util;

		//Version of the compatibility plugin, to force an update of the MU plugin, increment this value
		$this->compatibility_plugin_version = '1.4';

		$this->mu_plugin_dir    = $this->props->mu_plugin_dir;
		$this->mu_plugin_source = $this->props->mu_plugin_source;
		$this->mu_plugin_dest   = $this->props->mu_plugin_dest;
		$this->http_helper      = $http_helper;
	}

	public function register() {
		if ( $this->is_muplugin_externally_managed() ) {
			return;
		}

		// Checks the compatibility mode MU plugin version and updates if it's out of date.
		add_action( 'admin_init', array( $this, 'muplugin_version_check' ), 1 );

		// Fired in the register_deactivation_hook() call in both the pro and non-pro plugins.
		add_action( 'wp_migrate_db_remove_compatibility_plugin', array( $this, 'remove_muplugin_on_deactivation' ) );
	}

	public function addNotices() {
		if ( $this->is_muplugin_externally_managed() ) {
			return;
		}

		add_filter( 'wpmdb_notification_strings', array( $this, 'template_muplugin_update_fail' ) );
	}

	/**
	 * Triggered with the `admin_init` hook on the WP Migrate DB Pro dashboard page
	 *
	 * The 'compatibility_plugin_version' option key signifies that the latest compatibility plugin has been installed. If it's not present, copy the plugin, enabling it by default.
	 *
	 * Otherwise check the 'compatibility_plugin_version' option to see if the MU plugin needs updating.
	 *
	 * @return bool|string
	 */
	public function muplugin_version_check() {
		if ( isset( $_GET['page'] ) && in_array( $_GET['page'],
				array( 'wp-migrate-db-pro', 'wp-migrate-db', 'wpe-site-migration' ) ) ) {
			if ( true === $this->is_muplugin_update_required() ) {
				return $this->copy_muplugin();
			}
		}

		return false;
	}

	/**
	 * Checks if the compatibility mu-plugin requires an update based on the 'compatibility_plugin_version' setting in
	 * the database
	 *
	 * @param bool $wpmdb_settings
	 *
	 * @return bool
	 */
	public function is_muplugin_update_required( $wpmdb_settings = false ) {
		$update_required = false;

		if ( false === $wpmdb_settings ) {
			$wpmdb_settings = $this->settings;
		}

		if ( ! isset( $wpmdb_settings['compatibility_plugin_version'] ) ) {
			$update_required = true;
		} elseif (
			version_compare(
				$this->compatibility_plugin_version,
				$wpmdb_settings['compatibility_plugin_version'],
				'>'
			) &&
			$this->util->is_muplugin_installed()
		) {
			$update_required = true;
		}

		return $update_required;
	}

	/**
	 * Preemptively shows a warning on WPMDB pages if the mu-plugins folder isn't writable
	 */
	function template_muplugin_update_fail( $notifications ) {
		if ( $this->is_muplugin_update_required() && false === $this->util->is_muplugin_writable() ) {
			$notice_id    = 'muplugin_failed_update_' . $this->compatibility_plugin_version;
			$notice_links = $this->notices->check_notice( $notice_id, 'SHOW_ONCE' );

			if ( is_array( $notice_links ) ) {
				$notifications[ $notice_id ] = [
					'message' => $this->template->template_to_string(
						'muplugin-failed-update-warning',
						'common',
						$notice_links
					),
					'link'    => $notice_links,
					'id'      => $notice_id,
				];
			}
		}

		return $notifications;
	}

	/**
	 *
	 * Copies the compatibility plugin as well as updates the version number in the database
	 *
	 * @return bool|string
	 */
	public function copy_muplugin() {
		$wpmdb_settings = $this->settings;

		if (
			! $this->filesystem->mkdir( $this->mu_plugin_dir ) ||
			! $this->filesystem->copy( $this->mu_plugin_source, $this->mu_plugin_dest )
		) {
			return sprintf(
				__(
					'The compatibility plugin could not be activated because your mu-plugin directory is currently not writable.  Please update the permissions of the mu-plugins folder:  %s',
					'wp-migrate-db'
				),
				$this->mu_plugin_dir
			);
		}

		//Rename muplugin in header
		if ( ! $this->props->is_pro ) {
			$mu_contents = file_get_contents( $this->mu_plugin_dest );
			$mu_contents = str_replace(
				'Plugin Name: WP Migrate Compatibility',
				'Plugin Name: WP Migrate DB Compatibility',
				$mu_contents
			);
			file_put_contents( $this->mu_plugin_dest, $mu_contents );
		}

		if ( $this->is_muplugin_update_required() ) {
			// Update version number in the database
			$wpmdb_settings['compatibility_plugin_version'] = $this->compatibility_plugin_version;

			// Remove blacklist_plugins key as it's no longer used.
			if ( isset( $wpmdb_settings['blacklist_plugins'] ) ) {
				unset( $wpmdb_settings['blacklist_plugins'] );
			}

			update_site_option( WPMDB_SETTINGS_OPTION, $wpmdb_settings );
		}

		return true;
	}

	/**
	 *
	 * Removes the compatibility plugin
	 *
	 * @return bool|string
	 */
	public function remove_muplugin() {
		if ( $this->filesystem->file_exists( $this->mu_plugin_dest ) && ! $this->filesystem->unlink( $this->mu_plugin_dest ) ) {
			return sprintf(
				__(
					'The compatibility plugin could not be deactivated because your mu-plugin directory is currently not writable.  Please update the permissions of the mu-plugins folder: %s',
					'wp-migrate-db'
				),
				$this->mu_plugin_dir
			);
		}

		return true;
	}

	/**
	 *
	 * Fired on the `wp_migrate_db_remove_compatibility_plugin` action. Removes the compatibility plugin on deactivation
	 *
	 * @return bool|string
	 */
	public function remove_muplugin_on_deactivation() {
		$plugin_removed = $this->remove_muplugin();

		if ( true === $plugin_removed ) {
			$wpmdb_settings = $this->settings;
			unset( $wpmdb_settings['compatibility_plugin_version'] );

			update_site_option( WPMDB_SETTINGS_OPTION, $wpmdb_settings );

			return true;
		}

		return $plugin_removed;
	}

	/**
	 * Check if the mu-plugin is managed externally by the hosting platform.
	 *
	 * Some platforms pre-install the compatibility mu-plugin
	 * and manage it, for example on a read-only filesystem, so WPMDB should 
	 * not attempt to install, update, or remove it.
	 *
	 * @return bool
	 */
	public function is_muplugin_externally_managed() {
		return apply_filters( 'wpmdb_is_muplugin_externally_managed', false );
	}
}