<?php
/**
 * Activation, deactivation and multisite site lifecycle.
 *
 * @package Consentfold
 */

declare(strict_types=1);

namespace Consentfold\Install;

use RuntimeException;
use Consentfold\Scanner\Cron as ScanCron;
use WP_Site;

/**
 * Installs the plugin on a site (tables, schema version, cron) and removes the scheduled events again.
 * On multisite, network activation installs on every existing site, new sites are installed when they
 * are created while the plugin is network-active, and a deleted site's tables are dropped with it.
 */
final class Activator {

	public const PRUNE_HOOK = 'consentfold_prune_logs';

	/**
	 * Schema upgrader.
	 *
	 * @var Upgrader
	 */
	private Upgrader $upgrader;

	/**
	 * Scan continuation.
	 *
	 * @var ScanCron
	 */
	private ScanCron $scan_cron;

	/**
	 * Plugin basename (`consentfold/consentfold.php`).
	 *
	 * @var string
	 */
	private string $basename = '';

	/**
	 * Constructor.
	 *
	 * @param Upgrader $upgrader  Schema upgrader.
	 * @param ScanCron $scan_cron Scan continuation.
	 */
	public function __construct( Upgrader $upgrader, ScanCron $scan_cron ) {
		$this->upgrader  = $upgrader;
		$this->scan_cron = $scan_cron;
	}

	/**
	 * Hook the lifecycle callbacks.
	 *
	 * @param string $plugin_file Absolute path of the main plugin file.
	 */
	public function register( string $plugin_file ): void {
		$this->basename = plugin_basename( $plugin_file );

		$this->register_file( $plugin_file );
		// Deactivating the sibling package unschedules the events this package needs, and its own activation may not have run.
		add_action( 'init', array( $this, 'ensure_scheduled' ) );
		// After core has created the new site's own tables and options (priority 100).
		add_action( 'wp_initialize_site', array( $this, 'activate_new_site' ), 900 );
		add_filter( 'wpmu_drop_tables', array( $this, 'add_tables_to_drop' ), 10, 2 );
	}

	/**
	 * Hook the lifecycle of one package's main file: the sibling package's file too, because only one of them boots.
	 *
	 * Its uninstall hook is registered here, ahead of the SDK's, which only exists once an administrator deactivated
	 * the plugin in wp-admin. {@see Uninstaller::handle_uninstall()} hands the SDK its part of the job back.
	 *
	 * @param string $plugin_file Absolute path of a main plugin file.
	 */
	public function register_file( string $plugin_file ): void {
		register_activation_hook(
			$plugin_file,
			function ( bool $network_wide = false ) use ( $plugin_file ): void {
				$this->activate( $network_wide );
				register_uninstall_hook( $plugin_file, array( Uninstaller::class, 'handle_uninstall' ) );
			}
		);
		register_deactivation_hook( $plugin_file, array( $this, 'deactivate' ) );
		// After the SDK's own deactivation hook has put its uninstall hook in the same slot.
		add_action(
			'deactivated_plugin',
			static function ( string $plugin ) use ( $plugin_file ): void {
				if ( plugin_basename( $plugin_file ) === $plugin ) {
					register_uninstall_hook( $plugin_file, array( Uninstaller::class, 'handle_uninstall' ) );
				}
			},
			99
		);
	}

	/**
	 * Bring the prune event back when it is missing: deactivating one package of the plugin while the other stays active
	 * removes it. An earlier version's recurring scan event goes. Never throws on a request.
	 */
	public function ensure_scheduled(): void {
		try {
			$this->schedule_prune();
			$this->scan_cron->remove_recurring();
		} catch ( RuntimeException $e ) {
			wp_trigger_error( __METHOD__, $e->getMessage() );
		}
	}

	/**
	 * Install on the current site, or on every site when network-activated.
	 *
	 * @param bool $network_wide Whether the plugin is being network-activated.
	 */
	public function activate( bool $network_wide = false ): void {
		$this->for_each_site( $network_wide, array( $this, 'activate_site' ) );
	}

	/**
	 * Unschedule the plugin's events on the current site, or on every site when network-deactivated.
	 * Data stays: only uninstalling may remove it.
	 *
	 * @param bool $network_wide Whether the plugin is being network-deactivated.
	 */
	public function deactivate( bool $network_wide = false ): void {
		$this->for_each_site( $network_wide, array( $this, 'deactivate_site' ) );
	}

	/**
	 * Install on a freshly created site when the plugin is network-active.
	 *
	 * @param WP_Site $new_site The new site.
	 */
	public function activate_new_site( WP_Site $new_site ): void {
		if ( ! function_exists( 'is_plugin_active_for_network' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}

		if ( ! is_plugin_active_for_network( $this->basename ) ) {
			return;
		}

		switch_to_blog( (int) $new_site->blog_id ); // phpcs:ignore WordPressVIPMinimum.Functions.RestrictedFunctions.switch_to_blog_switch_to_blog -- Installing a site's own tables.
		try {
			$this->activate_site();
		} finally {
			restore_current_blog();
		}
	}

	/**
	 * Have core drop our tables together with a deleted site's.
	 *
	 * @param array<string, string> $tables  Tables core is about to drop.
	 * @param int                   $site_id Site being deleted.
	 * @return array<string, string>
	 */
	public function add_tables_to_drop( array $tables, int $site_id ): array {
		global $wpdb;

		$prefix = $wpdb->get_blog_prefix( $site_id );

		foreach ( array_merge( Schema::tables( $prefix ), Schema::extension_tables( $prefix ) ) as $table ) {
			$tables[ $table ] = $table;
		}

		return $tables;
	}

	/**
	 * Install on the current site.
	 *
	 * @throws RuntimeException When the tables or the prune event cannot be created.
	 */
	private function activate_site(): void {
		$this->upgrader->run();
		$this->schedule_prune();
		$this->scan_cron->remove_recurring();
	}

	/**
	 * Schedule the daily prune on the current site unless it is.
	 *
	 * @throws RuntimeException When the event cannot be created.
	 */
	private function schedule_prune(): void {
		if ( false !== wp_next_scheduled( self::PRUNE_HOOK ) ) {
			return;
		}

		$scheduled = wp_schedule_event( time(), 'daily', self::PRUNE_HOOK, array(), true );

		if ( is_wp_error( $scheduled ) ) {
			throw new RuntimeException( esc_html( $scheduled->get_error_message() ) );
		}
	}

	/**
	 * Unschedule on the current site.
	 */
	private function deactivate_site(): void {
		wp_unschedule_hook( self::PRUNE_HOOK );
		$this->scan_cron->unschedule();
		self::unschedule_extension_events();
	}

	/**
	 * Unschedule the cron events add-on code scheduled on the current site: every hook named
	 * `consentfold_ext_*`. They are found by name, so no add-on code has to be loaded.
	 */
	public static function unschedule_extension_events(): void {
		$crons = _get_cron_array();

		foreach ( is_array( $crons ) ? $crons : array() as $events ) {
			foreach ( array_keys( $events ) as $hook ) {
				if ( str_starts_with( (string) $hook, 'consentfold_ext_' ) ) {
					wp_unschedule_hook( (string) $hook );
				}
			}
		}
	}

	/**
	 * Run a callback on the current site, or on each site of the network.
	 *
	 * @param bool     $network_wide Whether to visit every site (multisite only).
	 * @param callable $callback     Called with the site switched in.
	 */
	private function for_each_site( bool $network_wide, callable $callback ): void {
		if ( ! $network_wide || ! is_multisite() ) {
			$callback();
			return;
		}

		foreach ( get_sites(
			array(
				'fields' => 'ids',
				'number' => 0,
			)
		) as $site_id ) {
			switch_to_blog( (int) $site_id ); // phpcs:ignore WordPressVIPMinimum.Functions.RestrictedFunctions.switch_to_blog_switch_to_blog -- Network-wide install touches every site.
			try {
				$callback();
			} finally {
				restore_current_blog();
			}
		}
	}
}