<?php

/**
 * Handles log entries by writing to database.
 *
 * @class          WPF_Log_Handler
 */

class WPF_Log_Handler {

    /**
     * Log Levels
     *
     * Description of levels:.
     *     'error': Error conditions.
     *     'warning': Warning conditions.
     *     'notice': Normal but significant condition.
     *     'info': Informational messages.
     *
     * @see @link {https://tools.ietf.org/html/rfc5424}
     */
    const ERROR   = 'error';
    const WARNING = 'warning';
    const NOTICE  = 'notice';
    const INFO    = 'info';

    /**
     * Level strings mapped to integer severity.
     *
     * @var array
     */
    protected static $level_to_severity = array(
        self::ERROR   => 500,
        self::WARNING => 400,
        self::NOTICE  => 300,
        self::INFO    => 200,
    );

    /**
     * Severity integers mapped to level strings.
     *
     * This is the inverse of $level_severity.
     *
     * @var array
     */
    protected static $severity_to_level = array(
        500 => self::ERROR,
        400 => self::WARNING,
        300 => self::NOTICE,
        200 => self::INFO,
    );

    /**
     * Constructor for the logger.
     */
    public function __construct() {

        add_action( 'init', array( $this, 'init' ) );

    }

    /**
     * Prepares logging functionalty if enabled
     *
     * @access public
     * @return void
     */

    public function init() {

        if ( wp_fusion()->settings->get( 'enable_logging' ) != true ) {
            return;
        }

        add_filter( 'wpf_configure_sections', array( $this, 'configure_sections' ), 10, 2 );

        add_action( 'admin_menu', array( $this, 'register_logger_subpage' ) );
        add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_scripts' ) );

        // Screen options
        add_action( 'load-tools_page_wpf-settings-logs', array( $this, 'add_screen_options' ) );
        add_filter( 'set-screen-option', array( $this, 'set_screen_option' ), 10, 3 );

        // Error handling
        add_action( 'shutdown', array( $this, 'shutdown' ) );

        $this->create_update_table();

    }

    /**
     * Adds standalone log management page
     *
     * @access public
     * @return void
     */

    public function register_logger_subpage() {

        $page = add_submenu_page(
            'tools.php',
            'WP Fusion Activity Logs',
            'WP Fusion Logs',
            'manage_options',
            'wpf-settings-logs',
            array( $this, 'show_logs_section' )
        );

    }

    /**
     * Enqueues logger styles
     *
     * @access public
     * @return void
     */

    public function enqueue_scripts() {

        $screen = get_current_screen();

        if ( 'tools_page_wpf-settings-logs' !== $screen->id ) {
            return;
        }

        wp_enqueue_style( 'wpf-options', WPF_DIR_URL . 'assets/css/wpf-options.css', array(), WP_FUSION_VERSION );
        wp_enqueue_style( 'wpf-admin', WPF_DIR_URL . 'assets/css/wpf-admin.css', array(), WP_FUSION_VERSION );

    }

    /**
     * Adds per-page screen option
     *
     * @access public
     * @return void
     */

    public function add_screen_options() {

        $args = array(
            'label'   => __( 'Entries per page', 'wp-fusion' ),
            'default' => 20,
            'option'  => 'wpf_status_log_items_per_page',
        );

        add_screen_option( 'per_page', $args );

    }

    /**
     * Save screen options
     *
     * @access public
     * @return int Value
     */

    public function set_screen_option( $status, $option, $value ) {

        if ( 'wpf_status_log_items_per_page' == $option ) {
            return $value;
        }

        return $status;

    }

    /**
     * Adds logging tab to main settings for access
     *
     * @access public
     * @return array Page
     */

    public function configure_sections( $page, $options ) {

        $page['sections'] = wp_fusion()->settings->insert_setting_after(
            'advanced', $page['sections'], array(
                'logs' => array(
                    'title' => __( 'Logs', 'wp-fusion' ),
                    'slug'  => 'wpf-settings-logs',
                ),
            )
        );

        return $page;

    }

    /**
     * Creates logging table if logging enabled
     *
     * @access public
     * @return void
     */

    public function create_update_table() {

        global $wpdb;
        $table_name = $wpdb->prefix . 'wpf_logging';

        if ( $wpdb->get_var( "show tables like '$table_name'" ) != $table_name ) {

            require_once ABSPATH . 'wp-admin/includes/upgrade.php';

            $collate = '';

            if ( $wpdb->has_cap( 'collation' ) ) {
                $collate = $wpdb->get_charset_collate();
            }

            $sql = 'CREATE TABLE ' . $table_name . " (
                log_id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
                timestamp datetime NOT NULL,
                level smallint(4) NOT NULL,
                user bigint(8) NOT NULL,
                source varchar(200) NOT NULL,
                message longtext NOT NULL,
                context longtext NULL,
                PRIMARY KEY (log_id),
                KEY level (level)
            ) $collate;";

            dbDelta( $sql );

        }

    }

    /**
     * Logging tab content
     *
     * @access public
     * @return void
     */

    public function show_logs_section() {

        include_once WPF_DIR_PATH . 'includes/admin/logging/class-log-table-list.php';

        // Flush
        if ( ! empty( $_REQUEST['flush-logs'] ) ) {
            self::flush();
        }

        // Bulk actions
        if ( isset( $_REQUEST['action'] ) && isset( $_REQUEST['log'] ) ) {
            self::log_table_bulk_actions();
        }

        $log_table_list = new WPF_Log_Table_List();
        $log_table_list->prepare_items();

        // Stop _wp_http_referer getting appended to the logs URL, so it doesn't get too long
        add_filter(
            'removable_query_args', function( $query_args ) {

                $query_args[] = '_wp_http_referer';
                return $query_args;

            }
        );

        ?>

        <div class="wrap">
            <h1><?php _e( 'WP Fusion Activity Log', 'wp-fusion' ); ?></h1>

            <form method="get" id="mainform">

                <input type="hidden" name="page" value="wpf-settings-logs">

                <?php $log_table_list->display(); ?>

                <?php submit_button( __( 'Flush all logs', 'wp-fusion' ), 'delete', 'flush-logs' ); ?>
                <?php wp_nonce_field( 'wp-fusion-status-logs' ); ?>

            </form>
        </div>

        <?php

    }


    /**
     * Validate a level string.
     *
     * @param string $level
     * @return bool True if $level is a valid level.
     */
    public static function is_valid_level( $level ) {
        return array_key_exists( strtolower( $level ), self::$level_to_severity );
    }

    /**
     * Translate level string to integer.
     *
     * @param string $level emergency|alert|critical|error|warning|notice|info|debug
     * @return int 100 (debug) - 800 (emergency) or 0 if not recognized
     */
    public static function get_level_severity( $level ) {
        if ( self::is_valid_level( $level ) ) {
            $severity = self::$level_to_severity[ strtolower( $level ) ];
        } else {
            $severity = 0;
        }
        return $severity;
    }

    /**
     * Translate severity integer to level string.
     *
     * @param int $severity
     * @return bool|string False if not recognized. Otherwise string representation of level.
     */
    public static function get_severity_level( $severity ) {
        if ( array_key_exists( $severity, self::$severity_to_level ) ) {
            return self::$severity_to_level[ $severity ];
        } else {
            return false;
        }
    }

    /**
     * Handle a log entry.
     *
     * @param int    $timestamp Log timestamp.
     * @param string $level emergency|alert|critical|error|warning|notice|info|debug
     * @param string $message Log message.
     * @param array  $context {
     *      Additional information for log handlers.
     *
     *     @type string $source Optional. Source will be available in log table.
     *                  If no source is provided, attempt to provide sensible default.
     * }
     *
     * @see WPF_Log_Handler::get_log_source() for default source.
     *
     * @return bool False if value was not handled and true if value was handled.
     */
    public function handle( $level, $user, $message, $context = array() ) {

        $timestamp = current_time( 'timestamp' );

        do_action( 'wpf_handle_log', $timestamp, $level, $user, $message, $context );

        if ( wp_fusion()->settings->get( 'enable_logging' ) != true ) {
            return;
        }

        if ( wp_fusion()->settings->get( 'logging_errors_only' ) == true && $level != 'error' ) {
            return;
        }

        if ( isset( $context['source'] ) && $context['source'] ) {
            $source = $context['source'];
        } else {
            $source = $this->get_log_source();
        }

        // Filter out irrelevant meta fields
        if ( isset( $context['meta_array'] ) && $context['meta_array'] ) {

            $contact_fields = wp_fusion()->settings->get( 'contact_fields' );

            foreach ( $context['meta_array'] as $key => $data ) {

                if ( ! isset( $contact_fields[ $key ] ) || $contact_fields[ $key ]['active'] == false ) {
                    unset( $context['meta_array'][ $key ] );
                }
            }
        }

        if ( empty( $user ) ) {
            $user = 0;
        }

        // Don't log meta data pushes where no enabled fields are being synced
        if ( isset( $context['meta_array'] ) && empty( $context['meta_array'] ) ) {
            return;
        }

        do_action( 'wpf_log_handled', $timestamp, $level, $user, $message, $source, $context );

        return $this->add( $timestamp, $level, $user, $message, $source, $context );
    }

    /**
     * Add a log entry to chosen file.
     *
     * @param string $level emergency|alert|critical|error|warning|notice|info|debug
     * @param string $message Log message.
     * @param string $source Log source. Useful for filtering and sorting.
     * @param array  $context {
     *      Context will be serialized and stored in database.
     *  }
     *
     * @return bool True if write was successful.
     */
    protected static function add( $timestamp, $level, $user, $message, $source, $context ) {
        global $wpdb;

        $insert = array(
            'timestamp' => date( 'Y-m-d H:i:s', $timestamp ),
            'level'     => self::get_level_severity( $level ),
            'user'      => $user,
            'message'   => $message,
            'source'    => $source,
        );

        $format = array(
            '%s',
            '%d',
            '%d',
            '%s',
            '%s',
            '%s', // possible serialized context
        );

        if ( ! empty( $context ) ) {
            $insert['context'] = serialize( $context );
        }

        $result = $wpdb->insert( "{$wpdb->prefix}wpf_logging", $insert, $format );

        if ( $result === false ) {
            return false;
        }

        $rowcount = $wpdb->get_var( "SELECT COUNT(*) FROM {$wpdb->prefix}wpf_logging" );

        $max_log_size = apply_filters( 'wpf_log_max_entries', 10000 );

        if ( $rowcount > $max_log_size ) {
            $wpdb->query( "DELETE FROM {$wpdb->prefix}wpf_logging ORDER BY log_id ASC LIMIT 1" );
        }

        return $result;

    }

    /**
     * Clear all logs from the DB.
     *
     * @return bool True if flush was successful.
     */
    public static function flush() {
        global $wpdb;

        return $wpdb->query( "TRUNCATE TABLE {$wpdb->prefix}wpf_logging" );
    }

    /**
     * Bulk DB log table actions.
     *
     * @since 3.0.0
     */
    private function log_table_bulk_actions() {

        if ( empty( $_REQUEST['_wpnonce'] ) || ! wp_verify_nonce( $_REQUEST['_wpnonce'], 'wp-fusion-status-logs' ) ) {
            wp_die( __( 'Action failed. Please refresh the page and retry.', 'wp-fusion' ) );
        }

        $log_ids = array_map( 'absint', (array) $_REQUEST['log'] );

        if ( 'delete' === $_REQUEST['action'] || 'delete' === $_REQUEST['action2'] ) {
            self::delete( $log_ids );
        }
    }

    /**
     * Delete selected logs from DB.
     *
     * @param int|string|array Log ID or array of Log IDs to be deleted.
     *
     * @return bool
     */
    public static function delete( $log_ids ) {
        global $wpdb;

        if ( ! is_array( $log_ids ) ) {
            $log_ids = array( $log_ids );
        }

        $format = array_fill( 0, count( $log_ids ), '%d' );

        $query_in = '(' . implode( ',', $format ) . ')';

        $query = $wpdb->prepare(
            "DELETE FROM {$wpdb->prefix}wpf_logging WHERE log_id IN {$query_in}",
            $log_ids
        );

        return $wpdb->query( $query );
    }


    /**
     * Get appropriate source based on file name.
     *
     * Try to provide an appropriate source in case none is provided.
     *
     * @return string Text to use as log source. "" (empty string) if none is found.
     */

    protected static function get_log_source() {

        static $ignore_files = array( 'class-log-handler' );

        /**
         * PHP < 5.3.6 correct behavior
         *
         * @see http://php.net/manual/en/function.debug-backtrace.php#refsect1-function.debug-backtrace-parameters
         */

        if ( defined( 'DEBUG_BACKTRACE_IGNORE_ARGS' ) ) {
            $debug_backtrace_arg = DEBUG_BACKTRACE_IGNORE_ARGS;
        } else {
            $debug_backtrace_arg = false;
        }

        $full_trace = debug_backtrace( $debug_backtrace_arg );

        $slugs = array( 'user-profile', 'api', 'access-control', 'class-auto-login', 'class-ajax' );

        foreach ( wp_fusion()->get_integrations() as $slug => $integration ) {
            $slugs[] = $slug;
        }

        $found_integrations = array();

        foreach ( $full_trace as $i => $trace ) {

            if ( isset( $trace['file'] ) ) {

                foreach ( $slugs as $slug ) {

                    if ( empty( $slug ) ) {
                        continue;
                    }

                    if ( strpos( $trace['file'], $slug ) !== false ) {

                        $found_integrations[] = $slug;
                    }
                }
            }
        }

        // Figure out most likely integration
        if ( ! empty( $found_integrations ) ) {

            $source = serialize( array_reverse( array_unique( $found_integrations ) ) );

        } else {
            $source = 'unknown';
        }

        return $source;
    }


    /**
     * Check for PHP errors on shutdown and log them
     *
     * @access public
     * @return void
     */
    public function shutdown() {

        $error = error_get_last();

        if ( is_null( $error ) ) {
            return;
        }

        if ( false !== strpos( $error['file'], 'wp-fusion' ) || false !== strpos( $error['message'], 'wp-fusion' ) ) {

            if ( E_ERROR == $error['type'] || E_WARNING == $error['type'] ) {

                // Get the source

                $source = 'unknown';

                $slugs = array( 'user-profile', 'api', 'access-control', 'class-auto-login', 'class-ajax', 'class-user' );

                foreach ( wp_fusion()->get_integrations() as $slug => $integration ) {
                    $slugs[] = $slug;
                }

                foreach ( $slugs as $slug ) {

                    if ( empty( $slug ) ) {
                        continue;
                    }

                    if ( strpos( $error['file'], $slug ) !== false ) {

                        $source = $slug;
                        break;

                    }
                }

                if ( E_ERROR == $error['type'] ) {
                    $level = 'error';
                } elseif ( E_WARNING == $error['type'] ) {
                    $level = 'warning';
                }

                $this->handle( $level, wpf_get_current_user_id(), '<strong>PHP error:</strong> ' . nl2br( $error['message'] ) . '<br /><br />' . $error['file'] . ':' . $error['line'], array( 'source' => $source ) );

            }

        }

    }

}