<?php

namespace No3x\WPML;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) exit;

/**
 * Log rotation for database.
 * @author No3x
 * @since 1.4
 */
class WPML_LogRotation {

    const WPML_LOGROTATION_SCHEDULE_HOOK = 'wpml_log_rotation';
    const WPML_LOGROTATION_SCHEDULE_ACTION = 'LogRotationSchedule';
    private $plugin_meta;

    function __construct( $plugin_meta ) {
        $this->plugin_meta = $plugin_meta;
    }

    /**
     * Add actions and filters for this module.
     * @since 1.6.0
     */
    public function addActionsAndFilters() {
        add_action( 'plugins_loaded', array( $this, 'init') );
        add_action( self::WPML_LOGROTATION_SCHEDULE_HOOK , array( __CLASS__, self::WPML_LOGROTATION_SCHEDULE_ACTION) );
        register_deactivation_hook( plugin_dir_path( __FILE__ ) . $this->plugin_meta['main_file'], array( $this, 'unschedule' ) );
    }

    /**
     * Init this module.
     * @since 1.6.0
     */
    public function init() {
        global $wpml_settings;

        // if plugin is installed the first time settings are not initialized properly so quit early.
        if( !isset($wpml_settings) || !array_key_exists('log-rotation-limit-amout', $wpml_settings) ) {
            return;
        }

        if ( $wpml_settings['log-rotation-limit-amout'] == true || $wpml_settings['log-rotation-delete-time'] == true ) {
            $this->schedule();
        } else {
            $this->unschedule();
        }
    }

    /**
     * Schedules an event.
     * @since 1.4
     */
    function schedule() {
        if ( ! wp_next_scheduled( self::WPML_LOGROTATION_SCHEDULE_HOOK ) ) {
            wp_schedule_event( time(), 'hourly', self::WPML_LOGROTATION_SCHEDULE_HOOK );
        }
    }

    /**
     * Unschedules an event.
     * @since 1.4
     */
    function unschedule() {
        wp_clear_scheduled_hook( self::WPML_LOGROTATION_SCHEDULE_HOOK );
    }

    /**
     * The LogRotation supports the limitation of stored mails by amount.
     * @since 1.6.0
     */
    static function limitNumberOfMailsByAmount() {
        global $wpml_settings, $wpdb;

        if(!isset($wpml_settings)) {
            return;
        }

        $tableName = WPML_Plugin::getTablename( 'mails' );

        if ( $wpml_settings['log-rotation-limit-amout'] == true) {
            $keep = $wpml_settings['log-rotation-limit-amout-keep'];
            if ( $keep > 0 ) {
                $wpdb->query(
                    "DELETE p
						FROM
						$tableName AS p
						JOIN
						( SELECT mail_id
						FROM $tableName
						ORDER BY mail_id DESC
						LIMIT 1 OFFSET $keep
				) AS lim
						ON p.mail_id <= lim.mail_id;"
                );
            }
        }
    }

    /**
     * The LogRotation supports the limitation of stored mails by date.
     * @since 1.6.0
     */
    static function limitNumberOfMailsByTime() {
        global $wpml_settings, $wpdb;

        if(!isset($wpml_settings)) {
            return;
        }

        $tableName = WPML_Plugin::getTablename( 'mails' );

        if ( $wpml_settings['log-rotation-delete-time'] == true) {
            $days = $wpml_settings['log-rotation-delete-time-days'];
            if ( $days > 0 ) {
                $wpdb->query( "DELETE FROM `$tableName` WHERE DATEDIFF( NOW(), `timestamp` ) >= $days" );
            }
        }
    }

    /**
     * Executes log rotation periodically.
     * @since 1.4
     */
    static function LogRotationSchedule() {
        self::limitNumberOfMailsByAmount();
        self::limitNumberOfMailsByTime();
    }
}
