<?php

namespace DeliciousBrains\WPMDB\Common\Migration;

use DeliciousBrains\WPMDB\Common\Error\HandleRemotePostError;
use DeliciousBrains\WPMDB\Common\Http\Helper;
use DeliciousBrains\WPMDB\Common\Http\Http;
use DeliciousBrains\WPMDB\Common\Http\RemotePost;
use DeliciousBrains\WPMDB\Common\MigrationPersistence\Persistence;
use DeliciousBrains\WPMDB\Common\Util\Util;
use WP_Error;

class Flush {
	/**
	 * @var Helper
	 */
	protected $http_helper;

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

	/**
	 * @var RemotePost
	 */
	protected $remote_post;

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

	public function __construct(
		Helper $helper,
		Util $util,
		RemotePost $remote_post,
		Http $http
	) {
		$this->http_helper = $helper;
		$this->util        = $util;
		$this->remote_post = $remote_post;
		$this->http        = $http;
	}

	public function register() {
		add_action( 'wp_ajax_wpmdb_flush', array( $this, 'ajax_flush' ) );
		add_action( 'wpmdb_after_finalize_migration', [ $this, 'flush_after_finalize' ], 10, 2 );

		add_action( 'wpmdb_async_post_flush', [ $this, 'async_flush' ] );
	}

	/**
	 * Handles the request to flush caches and cleanup migration when pushing or not migrating user tables.
	 *
	 * @return void
	 */
	public function ajax_flush() {
		$this->http->check_ajax_referer( 'flush' );

		$state_data = Persistence::getStateData();

		$this->http->end_ajax($this->flush($state_data));
	}

	/**
	 * Flush destination site's caches after finalize.
	 *
	 * @param array|WP_Error      $state_data
	 * @param array|bool|WP_Error $result
	 *
	 * @return void
	 */
	public function flush_after_finalize( $state_data, $result ) {
		if ( is_wp_error( $state_data ) || is_wp_error( $result ) ) {
			return;
		}

		// Intentionally ignoring errors in flushing at present.
		// In the future we may catch and re-throw errors,
		// if they can result in either manual or automatic re-try.
		$this->flush();
	}

	/**
	 * Flush caches and cleanup migration when pushing or pulling with user tables being migrated.
	 *
	 * @param bool|array $state_data
	 *
	 * @return mixed|bool|WP_Error
	 *
	 * @handles wpmdb_migration_complete
	 */
	public function flush( $state_data = false ) {
		$state_data = ! $state_data ? Persistence::getStateData() : $state_data;

		if ( 'push' === $state_data['intent'] ) {
			$data                 = array();
			$data['action']       = 'wpmdb_remote_flush';
			$data['migration_id'] = MigrationHelper::get_current_migration_id();
			$data['sig']          = $this->http_helper->create_signature( $data, $state_data['key'] );
			$ajax_url             = $this->util->ajax_url();
			$response             = $this->remote_post->post( $ajax_url, $data, __FUNCTION__ );

			return HandleRemotePostError::handle( 'wpmdb-remote-flush-failed', $response );
		} else {
			return $this->flush_local();
		}
	}

	/**
	 * Flushes the cache and rewrite rules.
	 *
	 * Also schedules the async cache flush action. This is needed on some platforms
	 * to ensure post-migration tasks such as flushing rewrite rules happen
	 * correctly.
	 *
	 * @return bool
	 */
	public function flush_local() {
		do_action( 'wpmdb_flush' );
		// flush rewrite rules to prevent 404s and other oddities
		wp_cache_flush();
		global $wp_rewrite;
		$endpoints = $wp_rewrite->endpoints;
		$wp_rewrite->init();
		$wp_rewrite->endpoints = $endpoints;
		flush_rewrite_rules(); // default true = hard refresh, recreates the .htaccess file

		// We schedule an async job to run a short time after migration to do any
		// additional cache flushing or code-building actions.
		wp_schedule_single_event( time() + 2, 'wpmdb_async_post_flush' );

		return true;
	}

	/**
	 * Runs cache flush actions that need to happen asynchronously. This is needed on some
	 * platforms to ensure sites are running properly after a migration.
	 *
	 * @return void
	 *
	 * @handles wpmdb_async_post_flush
	 */
	public function async_flush() {
		// Run hooked flush actions.
		do_action( 'wpmdb_flush' );

		// Flush rewrite rules to prevent 404s and other oddities.
		wp_cache_flush();
		flush_rewrite_rules(); // default true = hard refresh, recreates the .htaccess file
	}
}