<?php
/**
 * Kinsta Cache Purge classes.
 *
 * @package KinstaMUPlugins
 * @subpackage Cache
 * @since 1.0.0
 */

namespace Kinsta;

use Kinsta\KMP\Helpers\Whitelabel;
use function Kinsta\KMP\debug_log;
use function Kinsta\KMP\is_autopurge_enabled;
use function Kinsta\KMP\whitelabel;

if ( ! defined( 'ABSPATH' ) ) { // If this file is called directly.
	die( 'No script kiddies please!' );
}

/**
 * Cache_Purge class.
 *
 * Functions to purge the cache upon specific actions such as when a post is updated, a comment is added, etc.
 *
 * @since 1.0.0
 */
class Cache_Purge {

	/**
	 * ID of the Page assigned to display the Blog Posts Index.
	 *
	 * @var int
	 */
	public $posts_page_id;

	/**
	 * URL of the Page assigned to display the Blog Posts Index.
	 *
	 * @var string
	 */
	public $posts_page_url;

	/**
	 * KMP Object.
	 *
	 * @var object
	 */
	public $kmp;

	/**
	 * Cache Object.
	 *
	 * @var object
	 */
	public $kinsta_cache;

	/**
	 * Number of pages at home or archive page to purge.
	 *
	 * @var int
	 */
	public $immediate_depth;

	/**
	 * Defines if a single purge action happened.
	 *
	 * @var boolean
	 */
	public $purge_single_happened;

	/**
	 * Defines if the all purge action happened.
	 *
	 * @var boolean
	 */
	public $purge_all_happened = false;

	/**
	 * Holds the controller class for whitelabel feature.
	 *
	 * @var Whitelabel
	 */
	private Whitelabel $whitelabel;

	/**
	 * Constructor.
	 *
	 * Detect actions that causes content to changes root.
	 *
	 * @param object|false $kmp KMP object.
	 */
	public function __construct( $kmp = false ) {
		if ( false === $kmp ) {
			return;
		}

		// Set our class variables.
		global $wp_rewrite;
		global $wp_version;

		$this->kmp = $kmp;
		$this->kinsta_cache = $kmp->kinsta_cache;
		$this->posts_page_id = get_option( 'page_for_posts' );
		$this->posts_page_url = ( ! empty( $this->posts_page_id ) && ! empty( $wp_rewrite ) && null !== $wp_rewrite ) ? get_permalink( $this->posts_page_id ) : false;
		$this->immediate_depth = 3;
		$this->purge_single_happened = false;
		$this->whitelabel = whitelabel();

		// Ajax actions for cache clearing.
		add_action( 'wp_ajax_kinsta_clear_all_cache', array( $this, 'action_kinsta_clear_all_cache' ) );
		add_action( 'wp_ajax_kinsta_clear_site_cache', array( $this, 'action_kinsta_clear_site_cache' ) );
		add_action( 'wp_ajax_kinsta_clear_object_cache', array( $this, 'action_kinsta_clear_object_cache' ) );
		add_action( 'wp_ajax_kinsta_clear_cdn_cache', array( $this, 'action_kinsta_clear_cdn_cache' ) );

		// Cache clear for Admin Toolbar.
		add_action( 'admin_init', array( $this, 'clear_cache_admin_bar' ) );
		add_action( 'admin_init', array( $this, 'set_autopurge_option' ) );

		// Comment actions.
		add_action( 'edit_comment', array( $this, 'comment_edit_actions' ), 10, 2 );
		add_action( 'transition_comment_status', array( $this, 'comment_transition_actions' ), 10, 3 );
		add_action( 'wp_insert_comment', array( $this, 'comment_insert_actions' ), 10, 2 );

		// Post type related actions.
		add_action( 'pre_post_update', array( $this, 'post_unpublished' ), 10, 2 );
		add_action( 'wp_insert_post', array( $this, 'post_updated' ), 10, 3 );
		add_action( 'wp_trash_post', array( $this, 'post_trashed' ) );

		// Purge all cache on the following hooks.
		$hooks = array(
			'wp_update_nav_menu', // Menu update.
			'edited_term', // Term edit but not add.
			'delete_term', // Term deletion.
		);
		foreach ( $hooks as $hook ) {
			add_action( $hook, array( $this, 'purge_complete_caches' ) );
		}
	}

	/**
	 * Fires when a post switches from publish status to another post status such as draft.
	 *
	 * @param int   $post_ID The Post ID.
	 * @param array $updated Array of unslashed post data.
	 *
	 * @return void
	 *
	 * @see https://developer.wordpress.org/reference/hooks/pre_post_update/
	 */
	public function post_unpublished( $post_ID, $updated = array() ) {
		if ( $this->purge_single_happened ) {
			return;
		}

		$post_status = get_post_status( $post_ID );
		if ( 'publish' !== $post_status ) {
			return;
		}

		if ( isset( $updated['post_status'] ) && 'publish' !== $updated['post_status'] ) {
			$this->purge_single_happened = true;
			$this->initiate_purge( $post_ID );
		}
	}

	/**
	 * Figures out which published post is updated and initiates a cache purge with that post.
	 *
	 * @param int      $post_id The post ID.
	 * @param \WP_Post $post Post object following the update.
	 * @param bool     $update Whether this is an existing post being updated.
	 *
	 * @return void
	 */
	public function post_updated( $post_id, $post, $update ) {
		if ( $this->purge_single_happened || wp_is_post_autosave( $post_id ) || wp_is_post_revision( $post_id ) ) {
			return;
		}

		if ( true === $update && 'publish' === get_post_status( $post_id ) ) {
			$this->purge_single_happened = true;
			$this->initiate_purge( $post_id );
		}
	}

	/**
	 * Clear cache when the post is going to Trash.
	 *
	 * @param int $post_ID Post ID.
	 *
	 * @return void
	 */
	public function post_trashed( $post_ID ) {
		if ( $this->purge_single_happened ) {
			return;
		}

		$this->purge_single_happened = true;
		$this->initiate_purge( $post_ID );
	}

	/**
	 * Figures out if comment status changes and initiates a cache purge with the post.
	 *
	 * @param  int|string  $new_status The new comment status.
	 * @param  int|string  $old_status The old comment status.
	 * @param \WP_Comment $comment The comment data.
	 *
	 * @return void
	 */
	public function comment_transition_actions( $new_status, $old_status, $comment ) {
		if ( 'approved' === $new_status || 'approved' === $old_status ) {
			$this->initiate_purge( absint( $comment->comment_post_ID ) );
		}
	}

	/**
	 * Figures out if a comment is added and initiates a cache purge with the post.
	 *
	 * @param int         $comment_id The comment's ID.
	 * @param \WP_Comment $comment    The comment data.
	 *
	 * @return void
	 */
	public function comment_insert_actions( $comment_id, $comment ) {
		if ( 1 === (int) $comment->comment_approved ) {
			$this->initiate_purge( absint( $comment->comment_post_ID ) );
		}
	}

	/**
	 * Figures out if a comment is edited/updated and initiates a cache purge with the post.
	 *
	 * @param int   $comment_id The comment's ID.
	 * @param array $data The comment data.
	 *
	 * @return void
	 */
	public function comment_edit_actions( $comment_id, $data ) {
		$comment = get_comment( $comment_id );
		if ( ! $comment instanceof \WP_Comment ) {
			return;
		}

		if ( 1 === (int) $comment->comment_approved ) {
			$this->initiate_purge( absint( $comment->comment_post_ID ) );
		}
	}

	/**
	 * Flush the object cache.
	 *
	 * @return bool False on failure, true on success
	 */
	public function purge_complete_object_cache() {
		$response = wp_cache_flush();

		return $response;
	}

	/**
	 * Send the cache purge request.
	 *
	 * @return array<string,mixed>|\WP_Error
	 **/
	public function purge_complete_site_cache() {
		$response = wp_remote_get(
			'https://localhost/kinsta-clear-cache-all',
			array(
				'sslverify' => false,
				'timeout' => 5,
			)
		);

		return $response;
	}

	/**
	 * Send the CDN cache purge request.
	 *
	 * @return array<string,mixed>|\WP_Error
	 **/
	public function purge_complete_cdn_cache() {
		$response = wp_remote_get(
			'https://localhost/kinsta-clear-cache-cdn',
			array(
				'sslverify' => false,
				'timeout' => 5,
			)
		);

		return $response;
	}

	/**
	 * Purge object, cdn and site cache
	 *
	 * @param bool $force (Optional) Whether to force the cache even if the global autopurge is disabled.
	 * @return void
	 */
	public function purge_complete_caches( $force = false ) {
		/**
		 * Do not clear the cache if the global autopurge is disabled, unless `$force` is `true`.
		 *
		 * @see https://kinsta.atlassian.net/browse/KMP-285
		 */
		if ( ! is_autopurge_enabled() && ! $force ) {
			return;
		}

		if ( $this->purge_all_happened ) {
			return;
		}
		$this->purge_complete_object_cache();
		$this->purge_complete_site_cache();
		$this->purge_complete_cdn_cache();
		$this->purge_all_happened = true;

		// Hook that fires after all caches are cleared.
		do_action( 'kinsta_purge_complete_caches_happened' );
	}

	/**
	 * Initiate selective purge.
	 *
	 * @param int $post_id the post id.
	 *
	 * @return array<string,mixed>|false|null The result of the purge request.
	 **/
	public function initiate_purge( $post_id ) {
		if ( ! is_autopurge_enabled() ) {
			return null;
		}

		$autopurge = get_option( 'kinsta_kmp_cache_autopurge' );

		/**
		 * If the post controller is disabled, do not proceed with the purge.
		 *
		 * @see kinsta-mu-plugins/app/Cache/Autopurge/WPPostController.php
		 * @todo Move this method to the `WPPostController`.
		 */
		if ( ( $autopurge['wp_post_controller'] ?? null ) === false ) {
			return false;
		}

		$post = get_post( $post_id );
		if ( ! $post instanceof \WP_Post ) {
			return null;
		}

		if ( false === is_post_type_viewable( $post->post_type ) ) {
			return null;
		}
		$archives = $this->get_post_archives_list( $post );

		$purge_list = array(
			'throttled' => $archives,
			'immediate' => array(
				'single' => array(),
				'group' => array(),
			),
		);

		// Immediately remove first page of archives.
		foreach ( $archives['group'] as $key => $url ) {
			$purge_list['immediate']['single'][ $key ] = $url;
		}

		$purge_list['immediate']['group']['singular_post'] = get_permalink( $post_id );

		if ( ! empty( $this->posts_page_url ) ) {
			$purge_list['immediate']['single']['home_page'] = home_url( '/' );
			$purge_list['immediate']['single']['blog_page'] = $this->posts_page_url;
		} else {
			$purge_list['immediate']['single']['home_blog_page'] = home_url( '/' );
		}

		if ( ! empty( $purge_list['throttled']['single']['post_type'] ) ) {
			$purge_list['immediate']['single']['post_type'] = $purge_list['throttled']['single']['post_type'];
			unset( $purge_list['throttled']['single']['post_type'] );
		}

		// Add custom URLS.
		$custom_paths = get_option( 'kinsta-cache-additional-paths' );
		if ( ! empty( $custom_paths ) ) {
			foreach ( $custom_paths as $i => $item ) {
				if ( 'single' === $item['type'] ) {
					$purge_list['immediate']['single'][ 'custom|' . $i ] = home_url( '/' ) . $item['path'];
				}
				if ( 'group' === $item['type'] ) {
					$purge_list['immediate']['group'][ 'custom|' . $i ] = home_url( '/' ) . $item['path'];
				}
			}
		}

		// Add related sitemaps.
		$purge_list['throttled']['group']['sitemap'] = home_url( '/' ) . 'sitemap';
		// Add feed purging.
		$purge_list['immediate']['group']['feed'] = home_url( '/' ) . 'feed/';

		// Add AMP immediate single requests.
		foreach ( $purge_list['immediate']['single'] as $key => $value ) {
			if ( substr( $key, 0, 6 ) !== 'custom' ) {
				$purge_list['immediate']['single'][ $key . '|amp' ] = $value . 'amp/';
			}
		}

		// Convert To Request Format.
		$purge_request['throttled'] = $this->convert_purge_list_to_request( $purge_list['throttled'] );
		$purge_request['immediate'] = $this->convert_purge_list_to_request( $purge_list['immediate'] );

		/**
		 * Filters the immediate/throttled cache purge requests.
		 *
		 * @param array $purge_request['type'] The purge request type either immediate or throttled.
		 */
		$purge_request['immediate'] = apply_filters( 'KinstaCache/purgeImmediate', $purge_request['immediate'] ); // phpcs:ignore
		$purge_request['throttled'] = apply_filters( 'KinstaCache/purgeThrottled', $purge_request['throttled'] ); // phpcs:ignore

		$result['requests'] = $purge_request;

		$result['response'] = array(
			'immediate' => $this->send_cache_purge_request( $this->kinsta_cache->config['immediate_path'], $purge_request['immediate'] ),
			'throttled' => $this->send_cache_purge_request( $this->kinsta_cache->config['throttled_path'], $purge_request['throttled'] ),
		);

		// Hook that fires after specific event purges cache.
		do_action( 'kinsta_initiate_purge_happened' );
		debug_log(
			'Cache purge initiated.',
			array(
				'post_id' => $post_id,
				'purge_request' => $purge_request,
				'response' => $result['response'],
			)
		);

		return $result;
	}

	/**
	 * Send POST request to cache endpoint. Returns array of curl information
	 *
	 * @param string $endpoint_url Endpoint to send purge list to.
	 * @param array  $post_body URLs to send.
	 *
	 * @return array
	 */
	public function send_cache_purge_request( $endpoint_url, $post_body ) {
		$cache_purge_timeout = ( defined( 'KINSTAMU_CACHE_PURGE_TIMEOUT' ) ) ? (int) KINSTAMU_CACHE_PURGE_TIMEOUT : 5;
		$response_data = array(
			'response_code' => 0,
			'error_code' => 0,
			'response_body' => '',
			'error_message' => '',
		);

		$post_request = curl_init( $endpoint_url );
		curl_setopt( $post_request, CURLOPT_POST, true );
		curl_setopt( $post_request, CURLOPT_POSTFIELDS, http_build_query( $post_body ) );
		curl_setopt( $post_request, CURLOPT_RETURNTRANSFER, true );
		curl_setopt( $post_request, CURLOPT_SSL_VERIFYPEER, false );
		curl_setopt( $post_request, CURLOPT_SSL_VERIFYHOST, false );
		curl_setopt( $post_request, CURLOPT_CONNECTTIMEOUT, $cache_purge_timeout );
		curl_setopt( $post_request, CURLOPT_TIMEOUT, $cache_purge_timeout );
		$response_data['response_body'] = curl_exec( $post_request );
		$response_data['error_code'] = curl_errno( $post_request );
		$response_data['error_message'] = curl_error( $post_request );
		$response_data['response_code'] = curl_getinfo( $post_request, CURLINFO_HTTP_CODE );

		/**
		 * The curl_close function is deprecated in PHP 8.5.
		 *
		 * See https://php.watch/versions/8.5/curl_close-curl_share_close-deprecated
		 */
		if ( PHP_VERSION_ID < 80500 ) {
			curl_close( $post_request );
		}

		return $response_data;
	}

	/**
	 * Convert to cache purge URL.
	 *
	 * @param  array $purge_list List of URLs.
	 *
	 * @return array
	 */
	public function convert_purge_list_to_request( $purge_list ) {
		$purge = array();

		if ( ! empty( $purge_list['group'] ) ) {
			foreach ( $purge_list['group'] as $key => $value ) {
				$purge[ 'group|' . $key ] = str_replace( array( 'http://', 'https://' ), '', $value );
			}
		}

		if ( ! empty( $purge_list['single'] ) ) {
			foreach ( $purge_list['single'] as $key => $value ) {
				$purge[ 'single|' . $key ] = str_replace( array( 'http://', 'https://' ), '', $value );
			}
		}

		return $purge;
	}

	/**
	 * Get the post archive/taxonomy.
	 *
	 * @param  \WP_Post $post WP_Post object.
	 *
	 * @return array<string,array<string,string>>
	 */
	public function get_post_archives_list( $post ) {
		$taxonomies = get_taxonomies();
		unset( $taxonomies['nav_menu'] );
		unset( $taxonomies['link_category'] );
		$taxonomies = array_values( $taxonomies );
		$terms = wp_get_object_terms( $post->ID, $taxonomies );

		$purge = array(
			'group' => array(),
			'single' => array(),
		);

		// Author archive.
		$purge['group']['author'] = get_author_posts_url( (int) $post->post_author );
		// Term archives.
		if ( ! empty( $terms ) ) {
			foreach ( $terms as $term ) {
				$purge['group'][ 'term|' . $term->taxonomy . '|' . $term->slug ] = get_term_link( $term );
			}
		}

		$year = get_the_date( 'Y', $post );
		$month = get_the_date( 'm', $post );
		$day = get_the_date( 'd', $post );
		$purge['group']['year'] = get_year_link( $year );
		$purge['group']['month'] = get_month_link( $year, $month );
		$purge['group']['day'] = get_day_link( $year, $month, $day );

		$post_type_archive = get_post_type_archive_link( $post->post_type );
		if ( ! ( home_url() === $post_type_archive || $post_type_archive === $this->posts_page_url ) ) {
			$purge['group']['post_type'] = $post_type_archive;
		}

		return array_filter( $purge );
	}

	/**
	 * AJAX Action to clear all cache.
	 *
	 * @return void
	 */
	public function action_kinsta_clear_all_cache() {
		check_ajax_referer( 'kinsta-clear-all-cache' );

		$this->purge_complete_caches( true );

		die();
	}

	/**
	 * AJAX action to clear page cache.
	 *
	 * @return void
	 */
	public function action_kinsta_clear_site_cache() {
		check_ajax_referer( 'kinsta-clear-site-cache' );

		$this->purge_complete_site_cache();

		die();
	}

	/**
	 * AJAX action to clear Object Cache.
	 *
	 * @return void
	 */
	public function action_kinsta_clear_object_cache() {
		check_ajax_referer( 'kinsta-clear-object-cache' );

		$this->purge_complete_object_cache();

		die();
	}

	/**
	 * AJAX action to clear Object Cache.
	 *
	 * @return void
	 */
	public function action_kinsta_clear_cdn_cache() {
		check_ajax_referer( 'kinsta-clear-cdn-cache' );

		$this->purge_complete_cdn_cache();

		die();
	}

	/**
	 * * Function to handle Admin Bar cache clear requests.
	 * *
	 * * @return void
	 */
	public function clear_cache_admin_bar() {
		$menu_slug = $this->whitelabel->getMenuKey( 'tools' );

		if ( empty( $_GET['page'] ) || empty( $_GET['clear-cache'] ) || ( ! empty( $_GET['page'] ) && $menu_slug !== $_GET['page'] ) ) {
			return;
		}
		check_admin_referer( 'kinsta-clear-cache-admin-bar' );

		$clear_cache_type = sanitize_text_field( wp_unslash( $_GET['clear-cache'] ) );
		$query_key = $this->whitelabel->getMenuKey( 'cache-cleared' );
		$query_vars = array( $query_key => 'true' );

		/**
		 * When clearing the cache, we set a query variable to indicate which type of cache was cleared.
		 * This allows us to display a relevant success message on the admin page.
		 *
		 * @see Kinsta\KMP_Admin::cleared_cache_notice
		 * @see Kinsta\KMP_Admin::$clear_values
		 */
		if ( $this->whitelabel->getMenuKey( 'clear-all-cache' ) === $clear_cache_type ) {
			$this->purge_complete_caches( true );
			$query_vars[ $query_key ] = 'all-cache';
		} elseif ( $this->whitelabel->getMenuKey( 'clear-object-cache' ) === $clear_cache_type ) {
			$this->purge_complete_object_cache();
			$query_vars[ $query_key ] = 'object-cache';
		} elseif ( $this->whitelabel->getMenuKey( 'clear-site-cache' ) === $clear_cache_type ) {
			$this->purge_complete_site_cache();
			$query_vars[ $query_key ] = 'site-cache';
		} elseif ( $this->whitelabel->getMenuKey( 'clear-cdn-cache' ) === $clear_cache_type ) {
			$this->purge_complete_cdn_cache();
			$query_vars[ $query_key ] = 'cdn-cache';
		} else {
			return;
		}

		$referrer = wp_get_referer();

		if ( empty( $referrer ) ) {
			// If the referrer is empty, we set the target page to the Kinsta Tools page.
			$query_vars['page'] = $this->whitelabel->getMenuKey( 'tools' );
			$redirect_url = add_query_arg( $query_vars, admin_url( 'admin.php' ) );
		} else {
			$redirect_url = add_query_arg( $query_vars, $referrer );
		}

		wp_safe_redirect( $redirect_url );
		exit;
	}

	/**
	 * * Function to handle Admin page cache clear requests.
	 * *
	 * * @return void
	 */
	public function clear_cache_admin_page() {
		$menu_slug = $this->whitelabel->getMenuKey( 'tools' );

		if ( empty( $_GET['page'] ) || empty( $_GET['clear-cache'] ) || ( ! empty( $_GET['page'] ) && $menu_slug !== $_GET['page'] ) ) {
			return;
		}
		check_admin_referer( 'kinsta-clear-cache-admin-bar' );

		$clear_cache_type = sanitize_text_field( wp_unslash( $_GET['clear-cache'] ) );
		$query_key        = $this->whitelabel->getMenuKey( 'cache-cleared' );
		$query_vars       = array( $query_key => 'true' );

		// Prefer whitelabeled keys, but accept legacy values for backward compatibility.
		if ( $this->whitelabel->getMenuKey( 'clear-all-cache' ) === $clear_cache_type || 'kinsta-clear-all-cache' === $clear_cache_type ) {
			$this->purge_complete_caches( true ); // Force purge even if autopurge is disabled.
			$query_vars[ $query_key ] = 'all-cache';
		} elseif ( $this->whitelabel->getMenuKey( 'clear-object-cache' ) === $clear_cache_type || 'kinsta-clear-object-cache' === $clear_cache_type ) {
			$this->purge_complete_object_cache();
			$query_vars[ $query_key ] = 'object-cache';
		} elseif ( $this->whitelabel->getMenuKey( 'clear-site-cache' ) === $clear_cache_type || 'kinsta-clear-site-cache' === $clear_cache_type ) {
			$this->purge_complete_site_cache();
			$query_vars[ $query_key ] = 'site-cache';
		} elseif ( $this->whitelabel->getMenuKey( 'clear-cdn-cache' ) === $clear_cache_type || 'kinsta-clear-cdn-cache' === $clear_cache_type ) {
			$this->purge_complete_cdn_cache();
			$query_vars[ $query_key ] = 'cdn-cache';
		} else {
			return;
		}

		$referrer = wp_get_referer();
		if ( empty( $referrer ) ) {
			$query_vars['page'] = $menu_slug;
			$redirect_url       = add_query_arg( $query_vars, admin_url( 'admin.php' ) );
		} else {
			$redirect_url = add_query_arg( $query_vars, $referrer );
		}

		wp_safe_redirect( $redirect_url );
		exit;
	}

	/**
	 * * Function to handle Admin Bar cache clear requests.
	 * *
	 * * @return void
	 */
	public function set_autopurge_option() {
		$menu_slug = $this->whitelabel->getMenuKey( 'tools' );

		if ( empty( $_GET['page'] ) || empty( $_GET['cache-autopurge'] ) || ( ! empty( $_GET['page'] ) && $menu_slug !== $_GET['page'] ) ) {
			return;
		}
		check_admin_referer( 'kinsta-autopurge-toggle', 'kinsta_nonce' );

		if ( 'disable' === $_GET['cache-autopurge'] ) {
			update_option( 'kinsta-autopurge-status', 'disabled' );
		} elseif ( 'enable' === $_GET['cache-autopurge'] ) {
			update_option( 'kinsta-autopurge-status', 'enabled' );
		} else {
			return;
		}

		$query_key   = $this->whitelabel->getMenuKey( 'autopurge-updated' );
		$query_value = ( 'enable' === $_GET['cache-autopurge'] ) ? 'enabled' : 'disabled';
		$referrer    = wp_get_referer();

		if ( empty( $referrer ) ) {
			$query_vars = array(
				'page' => $menu_slug,
				$query_key => $query_value,
			);
			$redirect_url = add_query_arg( $query_vars, admin_url( 'admin.php' ) );
		} else {
			$redirect_url = add_query_arg( $query_key, $query_value, $referrer );
		}

		wp_safe_redirect( $redirect_url );
		exit;
	}
}