<?php
/**
 * Audit log: every step of every request, with who did it and when.
 *
 * For EU withdrawals this is the evidence trail: when the statement was
 * submitted, what it said, and when the acknowledgement was sent. Entries are
 * only ever added, never edited.
 *
 * @package ReturnKit
 */

namespace ReturnKit\Store;

defined( 'ABSPATH' ) || exit;

// phpcs:disable WordPress.DB.DirectDatabaseQuery

/**
 * Log storage.
 */
class Log {

	/**
	 * Table name.
	 *
	 * @return string
	 */
	public static function table() {
		global $wpdb;
		return $wpdb->prefix . 'rtkt_log';
	}

	/**
	 * CREATE TABLE statement.
	 *
	 * @param string $collate Charset/collation clause.
	 * @return string
	 */
	public static function schema( $collate ) {
		$table = self::table();
		return "CREATE TABLE {$table} (
			id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
			request_id bigint(20) unsigned NOT NULL DEFAULT 0,
			created_at datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
			actor varchar(20) NOT NULL DEFAULT 'system',
			user_id bigint(20) unsigned NOT NULL DEFAULT 0,
			event varchar(40) NOT NULL DEFAULT '',
			message text NULL,
			data longtext NULL,
			PRIMARY KEY  (id),
			KEY request_id (request_id),
			KEY created_at (created_at)
		) {$collate};";
	}

	/**
	 * Add an entry.
	 *
	 * @param int    $request_id Request ID.
	 * @param string $event      Event key (created, approved, refunded, email_sent …).
	 * @param string $message    Human text (already translated; stored as written).
	 * @param string $actor      customer | admin | system.
	 * @param array  $data       Extra structured data.
	 * @return int Entry ID.
	 */
	public static function add( $request_id, $event, $message = '', $actor = 'system', array $data = array() ) {
		global $wpdb;
		$wpdb->insert(
			self::table(),
			array(
				'request_id' => absint( $request_id ),
				'created_at' => current_time( 'mysql', true ),
				'actor'      => sanitize_key( $actor ),
				'user_id'    => get_current_user_id(),
				'event'      => sanitize_key( $event ),
				'message'    => wp_strip_all_tags( (string) $message ),
				'data'       => $data ? wp_json_encode( $data ) : null,
			)
		);
		return (int) $wpdb->insert_id;
	}

	/**
	 * Entries of a request, oldest first.
	 *
	 * @param int $request_id Request ID.
	 * @return array[]
	 */
	public static function for_request( $request_id ) {
		global $wpdb;
		$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT * FROM %i WHERE request_id = %d ORDER BY id ASC', self::table(), absint( $request_id ) ), ARRAY_A );
		return array_map( array( __CLASS__, 'decode' ), $rows ? $rows : array() );
	}

	/**
	 * Latest entries across all requests.
	 *
	 * @param int $limit Rows.
	 * @return array[]
	 */
	public static function recent( $limit = 10 ) {
		global $wpdb;
		$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT * FROM %i ORDER BY id DESC LIMIT %d', self::table(), max( 1, (int) $limit ) ), ARRAY_A );
		return array_map( array( __CLASS__, 'decode' ), $rows ? $rows : array() );
	}

	/**
	 * Whether a request has an entry for an event.
	 *
	 * @param int    $request_id Request ID.
	 * @param string $event      Event key.
	 * @return bool
	 */
	public static function has( $request_id, $event ) {
		global $wpdb;
		return (bool) $wpdb->get_var( $wpdb->prepare( 'SELECT id FROM %i WHERE request_id = %d AND event = %s LIMIT 1', self::table(), absint( $request_id ), sanitize_key( $event ) ) );
	}

	/**
	 * Decode the data column.
	 *
	 * @param array $row Row.
	 * @return array
	 */
	private static function decode( $row ) {
		$data        = isset( $row['data'] ) ? json_decode( (string) $row['data'], true ) : null;
		$row['data'] = is_array( $data ) ? $data : array();
		return $row;
	}
}