<?php

namespace AM\TransientsManager;

/**
 * Transients Manager class
 */
class TransientsManager {

    /** @var ?self */
    private static $instance = null;

    /**
     * ID of the plugin page
     *
     * @since 2.0
     * @var   string
     */
    public $page_id = 'transients-manager';

    /**
     * ID of the Admin Screen
     *
     * @since 2.0.5
     * @var   string
     */
    public $screen_id = '';

    /**
     * Capability the current-user needs to manage transients
     *
     * @since 2.0
     * @var   string
     */
    public $capability = 'manage_options';

    /**
     * Timestamp for right now
     *
     * @since 2.0
     * @var   int
     */
    public $time_now = 0;

    /**
     * The next timestamp to delete expired transients (via WP Cron)
     *
     * @since 2.0
     * @var   int
     */
    public $next_cron_delete = 0;

    /**
     * Transient ID
     *
     * @since 2.0.4
     * @var   int
     */
    public $transient_id = 0;

    /**
     * Transient object
     *
     * @since 2.0.4
     * @var   object
     */
    public $transient = false;

    /**
     * Action name
     *
     * @since 2.0.4
     * @var   string
     */
    public $action = '';

    /**
     *
     * @return self
     */
    public static function getInstance()
    {
        if (is_null(self::$instance)) {
            self::$instance = new self();
        }

        return self::$instance;
    }


    /**
     * Get things started
     *
     * @since 1.0
     */
    public function __construct() {
        // nothing to do
    }

    /**
     * Get the plugin install time
     *
     * @return int
     */
    public function getInstallTime()
    {
        $installTime = get_option('am_tm_install_time', false);
        if (!$installTime) {
            $installTime = time();
            update_option('am_tm_install_time', $installTime);
        }
        return $installTime;
    }


    /**
     * Add all of the hooks
     *
     * @since 2.0
     */
    public function init() {
        add_action( 'after_setup_theme', array( $this, 'text_domain' ) );
        add_action( 'admin_init',        array( $this, 'set_vars' ) );
        add_action( 'admin_init',        array( $this, 'process_actions' ) );
        add_action( 'admin_menu',        array( $this, 'tools_link' ) );
        add_action( 'admin_notices',     array( $this, 'notices' ) );
        add_action( 'admin_bar_menu',    array( $this, 'suspend_transients_button' ), 99 );
        add_filter( 'pre_update_option', array( $this, 'maybe_block_update_transient' ), -1, 2 );
        add_filter( 'pre_get_option',    array( $this, 'maybe_block_update_transient' ), -1, 2 );
        add_action( 'added_option',      array( $this, 'maybe_block_set_transient' ), -1, 1 );

        // Styles
        add_action( "admin_print_styles-tools_page_{$this->page_id}", array( $this, 'print_styles' ) );

        /**
         * Allow third-party plugins a chance to modify the hooks above
         *
         * @since 2.0
         * @param object $this
         */
        do_action( 'transients_manager_hooks', $this );
    }

    /**
     * Set many of the class variables
     *
     * @since 2.0
     */
    public function set_vars() {

        // Times
        $this->time_now         = time();
        $this->next_cron_delete = wp_next_scheduled( 'delete_expired_transients' );

        // Sanitize the transient ID
        $this->transient_id = ! empty( $_GET['trans_id'] )
            ? absint( $_GET['trans_id'] )
            : 0;

        // Get the transient
        $this->transient = ! empty( $this->transient_id )
            ? $this->get_transient_by_id( $this->transient_id )
            : false;

        // Sanitize the action
        $this->action = ! empty( $_REQUEST['action'] )
            ? sanitize_key( $_REQUEST['action'] )
            : '';
    }

    /**
     * Load text domain
     *
     * @since 1.0
     */
    public function text_domain() {
        load_plugin_textdomain( 'transients-manager' );
    }

    /**
     * Register menu link under Tools
     *
     * @since 1.0
     */
    public function tools_link() {

        // Set the screen ID
        $this->screen_id = add_management_page(
            esc_html__( 'Transients Manager', 'transients-manager' ),
            esc_html__( 'Transients', 'transients-manager' ),
            $this->capability,
            $this->page_id,
            array( $this, 'admin' )
        );
    }

    /**
     * Editing or showing?
     *
     * @since  2.0
     * @return string
     */
    protected function page_type() {

        // Edit or Show?
        return ! empty( $this->action ) && ( 'edit_transient' === $this->action ) && ! empty( $this->transient )
            ? 'edit'
            : 'show';
    }

    /**
     * Render the admin UI
     *
     * @since 1.0
     */
    public function admin() {

        // Editing a single Transient
        ( 'edit' === $this->page_type() )
            ? $this->page_edit_transient( $this->transient )
            : $this->page_show_transients();
    }

    /**
     * Admin notices
     *
     * @since 2.0
     */
    public function notices() {

        // Get the current screen
        $screen = get_current_screen();

        // Bail if not the correct screen
        if ( $screen->id !== $this->screen_id ) {
            return;
        }

        // Persistent Transients
        if ( wp_using_ext_object_cache() ) :

?>
<div class="notice notice-info">
    <p><?php esc_html_e( 'You are using a persistent object cache. This screen may show incomplete information.', 'transients-manager' ); ?></p>
</div>
<?php

        endif;

        // Updated Transient
        if ( ! empty( $_GET['updated'] ) ) :

?>
<div class="notice notice-success is-dismissible">
    <p><strong><?php esc_html_e( 'Transient updated.', 'transients-manager' ); ?></strong></p>
</div>
<?php

        endif;

        // Deleted Transients
        if ( ! empty( $_GET['deleted'] ) ) :

?>
<div class="notice notice-success is-dismissible">
    <p><strong><?php esc_html_e( 'Transient deleted.', 'transients-manager' ); ?></strong></p>
</div>
<?php

        endif;
    }

    /**
     * Output the page HTML for the Transients mock-list-table
     *
     * @since 2.0
     */
    protected function page_show_transients() {

        // Vars
        $search   = ! empty( $_GET['s'] ) ? sanitize_text_field( $_GET['s'] ) : '';
        $per_page = ! empty( $_GET['per_page'] ) ? absint( $_GET['per_page'] ) : 30;
        $page     = isset( $_GET['paged'] ) ? absint( $_GET['paged'] ) : 1;
        $offset   = $per_page * ( $page - 1 );
        $count    = $this->get_total_transients( $search );
        $pages    = ceil( $count / $per_page );
        $one_page = ( 1 === $pages ) ? 'one-page' : '';

        // Pagination
        $pagination = paginate_links( array(
            'base'      => 'tools.php?%_%',
            'format'    => '&paged=%#%',
            'prev_text' => '&laquo;',
            'next_text' => '&raquo;',
            'total'     => $pages,
            'current'   => $page
        ) );

        // Transients
        $transients = $this->get_transients( array(
            'search' => $search,
            'offset' => $offset,
            'number' => $per_page
        ) );

?>

<div class="wrap">
    <h1 class="wp-heading-inline"><?php esc_html_e( 'Transients', 'transients-manager' ); ?></h1>
    <hr class="wp-header-end">

    <form method="get">
        <p class="search-box">
            <label class="screen-reader-text" for="transient-search-input"><?php esc_html_e( 'Search', 'transients-manager' ); ?></label>
            <input type="search" id="transient-search-input" name="s" value="<?php echo esc_attr( $search ); ?>" />
            <input type="submit" id="search-submit" class="button" value="<?php esc_attr_e( 'Search Transients', 'transients-manager' ); ?>" />
            <input type="hidden" name="page" value="<?php echo esc_html( $this->page_id ); ?>" />
        </p>
    </form>

    <form method="post" id="transients-delete">
        <input type="hidden" name="transient" value="all" />
        <?php wp_nonce_field( 'transients_manager' ); ?>

        <div class="tablenav top">
            <div class="alignleft actions bulkactions">
                <label for="bulk-action-selector-top" class="screen-reader-text"><?php esc_html_e( 'Select Bulk action', 'transients-manager' ); ?></label>
                <select name="action" id="bulk-action-selector-top">
                    <option value="-1"><?php esc_html_e( 'Bulk actions', 'transients-manager' ); ?></option>

                    <optgroup label="<?php esc_attr_e( 'Selection', 'transients-manager' ); ?>">
                        <option value="delete_selected_transients"><?php esc_html_e( 'Delete Selected', 'transients-manager' ); ?></option>
                    </optgroup>

                    <optgroup label="<?php esc_attr_e( 'Expiration', 'transients-manager' ); ?>">
                        <option value="delete_expired_transients"><?php esc_html_e( 'Delete Expired', 'transients-manager' ); ?></option>
                        <option value="delete_transients_with_expiration"><?php esc_html_e( 'Delete With Expiration', 'transients-manager' ); ?></option>
                        <option value="delete_transients_without_expiration"><?php esc_html_e( 'Delete Without Expiration', 'transients-manager' ); ?></option>
                    </optgroup>

                    <optgroup label="<?php esc_attr_e( 'Reset', 'transients-manager' ); ?>">
                        <option value="delete_all_transients"><?php esc_html_e( 'Delete All', 'transients-manager' ); ?></option>
                    </optgroup>
                </select>
                <input type="submit" class="button secondary" value="<?php esc_attr_e( 'Apply', 'transients-manager' ); ?>" />
            </div>

            <div class="alignleft actions">
                <input type="button" class="button secondary" value="<?php esc_attr_e( 'Delete All', 'transients-manager' ); ?>" onclick="const select = document.getElementById('bulk-action-selector-top'); select.value='delete_all_transients'; select.dispatchEvent(new Event('change')); document.getElementById('transients-delete').submit();" />
            </div>

            <div class="tablenav-pages <?php echo esc_attr( $one_page ); ?>">
                <span class="displaying-num"><?php printf( _n( '%s Transient', '%s Transients', $count, 'transients-manager' ), number_format_i18n( $count ) ); ?></span>
                <span class="pagination-links"><?php echo $pagination; // HTML OK  ?></span>
            </div>
        </div>

        <table class="wp-list-table widefat fixed transients striped">
            <thead>
                <tr>
                    <td id="cb" class="manage-column column-cb check-column">
                        <label for="cb-select-all-<?php echo (int) $page; ?>" class="screen-reader-text"><?php esc_html_e( 'Select All', 'transients-manager' ); ?></label>
                        <input type="checkbox" id="cb-select-all-<?php echo (int) $page; ?>">
                    </td>
                    <th class="column-primary"><?php esc_html_e( 'Name', 'transients-manager' ); ?></th>
                    <th class="column-value"><?php esc_html_e( 'Value', 'transients-manager' ); ?></th>
                    <th class="column-expiration"><?php esc_html_e( 'Expiration', 'transients-manager' ); ?></th>
                </tr>
            </thead>
            <tbody>
                <?php if ( ! empty( $transients ) ) :

                    foreach ( $transients as $transient ) :

                        // Get Transient name
                        $name       = $this->get_transient_name( $transient );
                        $value      = $this->get_transient_value( $transient );
                        $expiration = $this->get_transient_expiration( $transient );

                        // Delete
                        $delete_url = wp_nonce_url(
                            remove_query_arg(
                                array( 'deleted', 'updated' ),
                                add_query_arg(
                                    array(
                                        'action'    => 'delete_transient',
                                        'transient' => $name,
                                        'name'      => $transient->option_name
                                    )
                                )
                            ),
                            'transients_manager'
                        );

                        // Edit
                        $edit_url = remove_query_arg(
                            array( 'updated', 'deleted' ),
                            add_query_arg(
                                array(
                                    'action'   => 'edit_transient',
                                    'trans_id' => $transient->option_id
                                )
                            )
                        ); ?>

                        <tr>
                            <th id="cb" class="manage-column column-cb check-column">
                                <label for="cb-select-<?php echo (int) $page; ?>" class="screen-reader-text"><?php printf( esc_attr__( 'Select %s', 'transients-manager' ), esc_html( $name ) ); ?></label>
                                <input type="checkbox" id="cb-select-<?php echo (int) $transient->option_id; ?>" name="transients[]" value="<?php echo (int) $transient->option_id; ?>">
                            </th>

                            <td class="column-primary" data-colname="<?php esc_attr_e( 'Name', 'transients-manager' ); ?>">
                                <pre class="truncate">
                                    <code class="transient-name" title="<?php printf( esc_attr__( 'Option ID: %d', 'transients-manager' ), (int) $transient->option_id ); ?>"><?php echo esc_html( $name ); ?></code>
                                </pre>

                                <div class="row-actions">
                                    <span class="edit"><a href="<?php echo esc_url( $edit_url ); ?>" class="edit"><?php esc_html_e( 'Edit', 'transients-manager' ); ?></a></span>
                                    |
                                    <span class="delete"><a href="<?php echo esc_url( $delete_url ); ?>" class="delete"><?php esc_html_e( 'Delete', 'transients-manager' ); ?></a></span>
                                </div>

                                <button type="button" class="toggle-row">
                                    <span class="screen-reader-text"><?php esc_html_e( 'Show more details', 'transients-manager' ); ?></span>
                                </button>
                            </td>

                            <td data-colname="<?php esc_attr_e( 'Value', 'transients-manager' ); ?>">
                                <span class="transient-value truncate"><?php
                                    echo $value; // HTML OK
                                ?></span>
                            </td>

                            <td data-colname="<?php esc_attr_e( 'Expiration', 'transients-manager' ); ?>">
                                <span class="transient-expiration"><?php
                                    echo $expiration; // HTML OK
                                ?></span>
                            </td>
                        </tr>

                    <?php endforeach;

                else : ?>

                    <tr><td colspan="4"><?php esc_html_e( 'No transients found.', 'transients-manager' ); ?></td>

                <?php endif; ?>
            </tbody>
            <tfoot>
                <tr>
                    <td class="manage-column column-cb check-column">
                        <label for="cb-select-all-<?php echo (int) $page; ?>" class="screen-reader-text"><?php esc_html_e( 'Select All', 'transients-manager' ); ?></label>
                        <input type="checkbox" id="cb-select-all-<?php echo (int) $page; ?>">
                    </td>
                    <th class="column-primary"><?php esc_html_e( 'Name', 'transients-manager' ); ?></th>
                    <th><?php esc_html_e( 'Value', 'transients-manager' ); ?></th>
                    <th><?php esc_html_e( 'Expiration', 'transients-manager' ); ?></th>
                </tr>
            </tfoot>
        </table>

        <div class="tablenav bottom">
            <div class="alignleft actions bulkactions">
                <label for="bulk-action-selector-top" class="screen-reader-text"><?php esc_html_e( 'Select Bulk action', 'transients-manager' ); ?></label>
                <select name="action" id="bulk-action-selector-bottom">
                    <option value="-1"><?php esc_html_e( 'Bulk actions', 'transients-manager' ); ?></option>

                    <optgroup label="<?php esc_attr_e( 'Selection', 'transients-manager' ); ?>">
                        <option value="delete_selected_transients"><?php esc_html_e( 'Delete Selected', 'transients-manager' ); ?></option>
                    </optgroup>

                    <optgroup label="<?php esc_attr_e( 'Expiration', 'transients-manager' ); ?>">
                        <option value="delete_expired_transients"><?php esc_html_e( 'Delete Expired', 'transients-manager' ); ?></option>
                        <option value="delete_transients_with_expiration"><?php esc_html_e( 'Delete With Expiration', 'transients-manager' ); ?></option>
                        <option value="delete_transients_without_expiration"><?php esc_html_e( 'Delete Without Expiration', 'transients-manager' ); ?></option>
                    </optgroup>

                    <optgroup label="<?php esc_attr_e( 'Reset', 'transients-manager' ); ?>">
                        <option value="delete_all_transients"><?php esc_html_e( 'Delete All', 'transients-manager' ); ?></option>
                    </optgroup>
                </select>
                <input type="submit" class="button secondary" value="<?php esc_attr_e( 'Apply', 'transients-manager' ); ?>" />
            </div>

            <div class="tablenav-pages <?php echo esc_attr( $one_page ); ?>">
                <span class="displaying-num"><?php printf( _n( '%s Transient', '%s Transients', $count, 'transients-manager' ), number_format_i18n( $count ) ); ?></span>
                <span class="pagination-links"><?php echo $pagination; // HTML OK ?></span>
            </div>
        </div>
    </form>

    <?php $this->site_time(); ?>
</div>

<?php
    }

    /**
     * Output the page HTML for editing a Transient
     *
     * @since 2.0
     * @param object $transient
     */
    protected function page_edit_transient( $transient = false) {

        // Get values
        $name       = $this->get_transient_name( $transient );
        $expiration = $this->get_transient_expiration_time( $transient );
?>

<div class="wrap">
    <h1 class="wp-heading-inline"><?php esc_html_e( 'Edit Transient', 'transients-manager' ); ?></h1>
    <hr class="wp-header-end">

    <form method="post">
        <input type="hidden" name="transient" value="<?php echo esc_attr( $name ); ?>" />
        <input type="hidden" name="action" value="update_transient" />
        <?php wp_nonce_field( 'transients_manager' ); ?>

        <table class="form-table">
            <tbody>
                <tr>
                    <th><?php esc_html_e( 'Option ID', 'transients-manager' ); ?></th>
                    <td><input type="text" disabled class="large-text code" name="name" value="<?php echo esc_attr( $transient->option_id ); ?>" /></td>
                </tr>
                <tr>
                    <th><?php esc_html_e( 'Name', 'transients-manager' ); ?></th>
                    <td><input type="text" class="large-text code" name="name" value="<?php echo esc_attr( $transient->option_name ); ?>" /></td>
                </tr>
                <tr>
                    <th><?php esc_html_e( 'Expiration', 'transients-manager' ); ?></th>
                    <td><input type="text" class="large-text" name="expires" value="<?php echo esc_attr( $expiration ); ?>" />
                </tr>
                <tr>
                    <th><?php esc_html_e( 'Value', 'transients-manager' ); ?></th>
                    <td>
                        <textarea class="large-text code" name="value" id="transient-editor" style="height: 302px; padding-left: 35px;"><?php
                            echo esc_textarea( $transient->option_value );
                        ?></textarea>
                    </td>
                </tr>
            </tbody>
        </table>

        <p class="submit">
            <?php submit_button( '', 'primary', '', false ); ?>
        </p>
    </form>
</div>

<?php
    }

    /**
     * Output the time for the site
     *
     * (Props to WP Crontrol for this approach)
     *
     * @since 2.0
     */
    public function site_time() {

        // Get options
        $timezone_string = get_option( 'timezone_string', '' );
        $gmt_offset      = get_option( 'gmt_offset', 0 );
        $timezone_name   = 'UTC';

        // UTC
        if ( ( 'UTC' !== $timezone_string ) || ! empty( $gmt_offset ) ) {

            $formatted_offset = ( 0 <= $gmt_offset )
                ? '+' . (string) $gmt_offset
                : (string) $gmt_offset;

            $formatted_offset = str_replace(
                array( '.25', '.5',  '.75' ),
                array( ':15', ':30', ':45' ),
                $formatted_offset
            );
        }

        // Format the timezone name
        $timezone_name = ! empty( $formatted_offset )
            ? 'UTC' . $formatted_offset
            : str_replace( '_', ' ', $timezone_string );

        // Site time
        $site_time     = date_i18n( 'Y-m-d H:i:s', $this->time_now );
        $site_time_utc = gmdate( 'Y-m-d\TH:i:s+00:00', $this->time_now );
        $st_html       = esc_html( sprintf(
            /* translators: 1: Date and time, 2: Timezone */
            __( 'Site time: %1$s (%2$s)', 'transients-manager' ),
            $site_time,
            $timezone_name
        ) );

        // Cron time
        $cron_time     = wp_date( 'Y-m-d H:i:s', $this->next_cron_delete );
        $cron_time_utc = gmdate( 'Y-m-d\TH:i:s+00:00', $this->next_cron_delete );
        $ct_time_since = $this->time_since( $this->next_cron_delete - $this->time_now );
        $nc_time       = esc_html( sprintf(
            /* translators: 1: Date and time, 2: Timezone, 3: Time since */
            __( 'Expired transients scheduled for deletion on: %1$s (%2$s) – %3$s from now', 'transients-manager' ),
            $cron_time,
            $timezone_name,
            $ct_time_since
        ) );
?>

<p class="transients-manager-helpful-times">
    <?php

    echo sprintf( '<time datetime="%1$s" title="%1$s">%2$s</time>',
        $site_time_utc,
        $st_html
    );

    ?><br><br><?php

    echo sprintf( '<time datetime="%1$s" title="%1$s">%2$s</time>',
        $cron_time_utc,
        $nc_time
    );

?></p>

<?php
    }

    /**
     * Add toolbar node for suspending transients
     *
     * @since 1.6
     * @param object $wp_admin_bar
     */
    public function suspend_transients_button( $wp_admin_bar ) {

        // Bail if user is not capable
        if ( ! current_user_can( $this->capability ) ) {
            return;
        }

        // Suspended
        if ( get_option( 'pw_tm_suspend' ) ) {
            $action = 'unsuspend_transients';
            $label  = '<span style="color: #b32d2e;">' . esc_html__( 'Unsuspend Transients', 'transients-manager' ) . '</span>';

        // Not suspended
        } else {
            $action = 'suspend_transients';
            $label  = esc_html__( 'Suspend Transients', 'transients-manager' );
        }

        // Suspend
        $wp_admin_bar->add_node( array(
            'id'     => 'tm-suspend',
            'title'  => $label,
            'parent' => 'top-secondary',
            'href'   => wp_nonce_url(
                add_query_arg(
                    array(
                        'action' => $action
                    )
                ),
                'transients_manager'
            )
        ) );

        // View
        $wp_admin_bar->add_node( array(
            'id'     => 'tm-view',
            'title'  => esc_html__( 'View Transients', 'transients-manager' ),
            'parent' => 'tm-suspend',
            'href'   => add_query_arg(
                array(
                    'page' => $this->page_id
                ),
                admin_url( 'tools.php' )
            )
        ) );
    }

    /**
     * Get transients from the database
     *
     * These queries are uncached, to prevent race conditions with persistent
     * object cache setups and the way Transients use them.
     *
     * @since  1.0
     * @param  array $args
     * @return array
     */
    private function get_transients( $args = array() ) {
        global $wpdb;

        // Parse arguments
        $r = $this->parse_args( $args );

        // Escape some LIKE parts
        $esc_name = '%' . $wpdb->esc_like( '_transient_'         ) . '%';
        $esc_time = '%' . $wpdb->esc_like( '_transient_timeout_' ) . '%';

        // SELECT
        $sql = array( 'SELECT' );

        // COUNT
        if ( ! empty( $r['count'] ) ) {
            $sql[] = 'count(option_id)';
        } else {
            $sql[] = '*';
        }

        // FROM
        $sql[] = "FROM {$wpdb->options} WHERE option_name LIKE %s AND option_name NOT LIKE %s";

        // Search
        if ( ! empty( $r['search'] ) ) {
            $search = '%' . $wpdb->esc_like( $r['search'] ) . '%';
            $sql[]  = $wpdb->prepare( "AND option_name LIKE %s", $search );
        }

        // Limits
        if ( empty( $r['count'] ) ) {
            $offset = absint( $r['offset'] );
            $number = absint( $r['number'] );
            $sql[]  = $wpdb->prepare( "ORDER BY option_id DESC LIMIT %d, %d", $offset, $number );
        }

        // Combine the SQL parts
        $query = implode( ' ', $sql );

        // Prepare
        $prepared = $wpdb->prepare( $query, $esc_name, $esc_time );

        // Query
        $transients = empty( $r['count'] )
            ? $wpdb->get_results( $prepared ) // Rows
            : $wpdb->get_var( $prepared );    // Count

        // Return transients
        return $transients;
    }

    /**
     * Parse the query arguments
     *
     * @since  2.0
     * @param  array $args
     * @return array
     */
    private function parse_args( $args = array() ) {

        // Parse
        $r = wp_parse_args( $args, array(
            'offset' => 0,
            'number' => 30,
            'search' => '',
            'count'  => false
        ) );

        // Return
        return $r;
    }

    /**
     * Retrieve the total number transients in the database
     *
     * If a search is performed, it returns the number of found results
     *
     * @since  1.0
     * @param  string $search
     * @return int
     */
    private function get_total_transients( $search = '' ) {

        // Query
        $count = $this->get_transients( array(
            'count'  => true,
            'search' => $search
        ) );

        // Return int
        return absint( $count );
    }

    /**
     * Retrieve a transient by its ID
     *
     * @since  1.0
     * @param  int $id
     * @return object
     */
    private function get_transient_by_id( $id = 0 ) {
        global $wpdb;

        $id = absint( $id );

        // Bail if empty ID
        if ( empty( $id ) ) {
            return false;
        }

        // Prepare
        $prepared = $wpdb->prepare( "SELECT * FROM {$wpdb->options} WHERE option_id = %d", $id );

        // Query
        return $wpdb->get_row( $prepared );
    }

    /**
     * Is a transient name site-wide?
     *
     * @since  2.0
     * @param  string $transient_name
     * @return boolean
     */
    private function is_site_wide( $transient_name = '' ) {
        return ( false !== strpos( $transient_name, '_site_transient' ) );
    }

    /**
     * Retrieve the transient name from the transient object
     *
     * @since  1.0
     * @return string
     */
    private function get_transient_name( $transient = false ) {

        // Bail if no Transient
        if ( empty( $transient ) ) {
            return '';
        }

        // Position
        $pos = $this->is_site_wide( $transient->option_name )
            ? 16
            : 11;

        return substr( $transient->option_name, $pos, strlen( $transient->option_name ) );
    }

    /**
     * Retrieve the human-friendly transient value from the transient object
     *
     * @since  1.0
     * @param  object $transient
     * @return string/int
     */
    private function get_transient_value( $transient ) {

        // Get the value type
        $type = $this->get_transient_value_type( $transient );

        // Trim value to 100 chars
        $value = substr( $transient->option_value, 0, 100 );

        // Escape & wrap in <code> tag
        $value = '<code>' . esc_html( $value ) . '</code>';

        // Return
        return $value . '<br><span class="transient-type badge">' . esc_html( $type ) . '</span>';
    }

    /**
     * Try to guess the type of value the Transient is
     *
     * @since  2.0
     * @param  object $transient
     * @return string
     */
    private function get_transient_value_type( $transient ) {

        // Default type
        $type = esc_html__( 'unknown', 'transients-manager' );

        // Try to unserialize
        $value = maybe_unserialize( $transient->option_value );

        // Array
        if ( is_array( $value ) ) {
            $type = esc_html__( 'array', 'transients-manager' );

        // Object
        } elseif ( is_object( $value ) ) {
            $type = esc_html__( 'object', 'transients-manager' );

        // Serialized array
        } elseif ( is_serialized( $value ) ) {
            $type = esc_html__( 'serialized', 'transients-manager' );

        // HTML
        } elseif ( strip_tags( $value ) !== $value ) {
            $type = esc_html__( 'html', 'transients-manager' );

        // Scalar
        } elseif ( is_scalar( $value ) ) {

            if ( is_numeric( $value ) ) {

                // Likely a timestamp
                if ( 10 === strlen( $value ) ) {
                    $type = esc_html__( 'timestamp?', 'transients-manager' );

                // Likely a boolean
                } elseif ( in_array( $value, array( '0', '1' ), true ) ) {
                    $type = esc_html__( 'boolean?', 'transients-manager' );

                // Any number
                } else {
                    $type = esc_html__( 'numeric', 'transients-manager' );
                }

            // JSON
            } elseif ( is_string( $value ) && is_object( json_decode( $value ) ) ) {
                $type = esc_html__( 'json', 'transients-manager' );

            // Scalar
            } else {
                $type = esc_html__( 'scalar', 'transients-manager' );
            }

        // Empty
        } elseif ( empty( $value ) ) {
            $type = esc_html__( 'empty', 'transients-manager' );
        }

        // Return type
        return $type;
    }

    /**
     * Retrieve the expiration timestamp
     *
     * @since  1.0
     * @param  object $transient
     * @return int
     */
    private function get_transient_expiration_time( $transient ) {

        // Get the same to use in the option key
        $name = $this->get_transient_name( $transient );

        // Get the value of the timeout
        $time = $this->is_site_wide( $transient->option_name )
            ? get_option( "_site_transient_timeout_{$name}" )
            : get_option( "_transient_timeout_{$name}" );

        // Return the value
        return $time;
    }

    /**
     * Retrieve the human-friendly expiration time
     *
     * @since  1.0
     * @param  object $transient
     * @return string
     */
    private function get_transient_expiration( $transient ) {

        $expiration = $this->get_transient_expiration_time( $transient );

        // Bail if no expiration
        if ( empty( $expiration ) ) {
            return '&mdash;<br><span class="badge">' . esc_html__( 'Persistent', 'transients-manager' ) . '</span>';
        }

        // UTC & local dates
        $date_utc   = gmdate( 'Y-m-d\TH:i:s+00:00', $expiration );
        $date_local = get_date_from_gmt( date( 'Y-m-d H:i:s', $expiration ), 'Y-m-d H:i:s' );

        // Create <time> tag
        $time = sprintf(
            '<time datetime="%1$s" title="%1$s">%2$s</time>',
            esc_attr( $date_utc ),
            esc_html( $date_local )
        );

        // Expired
        if ( $this->time_now > $expiration ) {
            return $time . '<br><span class="transient-expired badge">' . esc_html__( 'Expired', 'transients-manager' ) . '</span>';
        }

        // Return time since
        return $time . '<br><span class="badge green">' . $this->time_since( $expiration - $this->time_now ) . '</span>';
    }

    /**
     * Process delete and update actions
     *
     * @since 1.0
     */
    public function process_actions() {

        if ( empty( $this->action ) ) {
            return;
        }

        // Bail if malformed Transient request
        if ( empty( $_REQUEST['transient'] ) && ! in_array( $this->action, array( 'suspend_transients', 'unsuspend_transients' ), true ) ) {
            return;
        }

        // Bail if user is not capable
        if ( ! current_user_can( $this->capability ) ) {
            return;
        }

        // Bail if nonce fails
        if ( empty( $_REQUEST['_wpnonce'] ) || ! wp_verify_nonce( $_REQUEST['_wpnonce'], 'transients_manager' ) ) {
            return;
        }

        if ( ! in_array( $this->action, array( 'suspend_transients', 'unsuspend_transients' ), true ) ) {

            // Encode search string
            $search = ! empty( $_REQUEST['s'] )
                ? urlencode( $_REQUEST['s'] )
                : '';

            // Sanitize transient
            $transient = sanitize_key( $_REQUEST['transient'] );

            // Site wide
            $site_wide = ! empty( $_REQUEST['name'] ) && $this->is_site_wide( $_REQUEST['name'] );
        }

        switch ( $this->action ) {

            case 'suspend_transients' :
                update_option( 'pw_tm_suspend', 1 );
                wp_safe_redirect( remove_query_arg( array( 'updated', 'deleted', 'action', '_wpnonce' ) ) );
                exit;

            case 'unsuspend_transients' :
                delete_option( 'pw_tm_suspend', 1 );
                wp_safe_redirect( remove_query_arg( array( 'updated', 'deleted', 'action', '_wpnonce' ) ) );
                exit;

            case 'delete_transient' :
                $this->delete_transient( $transient, $site_wide );
                wp_safe_redirect(
                    remove_query_arg(
                        array( 'updated' ),
                        add_query_arg(
                            array(
                                'page'    => $this->page_id,
                                's'       => $search,
                                'deleted' => true
                            ),
                            admin_url( 'tools.php' )
                        )
                    )
                );
                exit;

            case 'update_transient' :
                $this->update_transient( $transient, $site_wide );
                wp_safe_redirect(
                    remove_query_arg(
                        array( 'deleted' ),
                        add_query_arg(
                            array(
                                'page'    => $this->page_id,
                                's'       => $search,
                                'updated' => true
                            ),
                            admin_url( 'tools.php' )
                        )
                    )
                );
                exit;

            case 'delete_selected_transients' :
                $this->delete_selected_transients();
                wp_safe_redirect(
                    remove_query_arg(
                        array( 'updated' ),
                        add_query_arg(
                            array(
                                'page'    => $this->page_id,
                                'deleted' => true
                            ),
                            admin_url( 'tools.php' )
                        )
                    )
                );
                exit;

            case 'delete_expired_transients' :
                $this->delete_expired_transients();
                wp_safe_redirect(
                    remove_query_arg(
                        array( 'updated' ),
                        add_query_arg(
                            array(
                                'page'    => $this->page_id,
                                'deleted' => true
                            ),
                            admin_url( 'tools.php' )
                        )
                    )
                );
                exit;

            case 'delete_transients_with_expiration' :
                $this->delete_transients_with_expirations();
                wp_safe_redirect(
                    remove_query_arg(
                        array( 'updated' ),
                        add_query_arg(
                            array(
                                'page'    => $this->page_id,
                                'deleted' => true
                            ),
                            admin_url( 'tools.php' )
                        )
                    )
                );
                exit;

            case 'delete_transients_without_expiration' :
                $this->delete_transients_without_expirations();
                wp_safe_redirect(
                    remove_query_arg(
                        array( 'updated' ),
                        add_query_arg(
                            array(
                                'page'    => $this->page_id,
                                'deleted' => true
                            ),
                            admin_url( 'tools.php' )
                        )
                    )
                );
                exit;

            case 'delete_all_transients' :
                $this->delete_all_transients();
                wp_safe_redirect(
                    remove_query_arg(
                        array( 'updated' ),
                        add_query_arg(
                            array(
                                'page'    => $this->page_id,
                                'deleted' => true
                            ),
                            admin_url( 'tools.php' )
                        )
                    )
                );
                exit;
        }
    }

    /**
     * Delete a transient by name
     *
     * @since  1.0
     * @param  object $transient
     * @param  boolean $site_wide
     * @return boolean
     */
    private function delete_transient( $transient = '', $site_wide = false ) {

        // Bail if no Transient
        if ( empty( $transient ) ) {
            return false;
        }

        // Transient type
        $retval = ( false !== $site_wide )
            ? delete_site_transient( $transient )
            : delete_transient( $transient );

        // Return
        return $retval;
    }

    /**
     * Bulk delete function
     *
     * @since  1.5
     * @param  array $transients
     * @return boolean
     */
    private function bulk_delete_transients( $transients = array() ) {

        // Bail if empty or error
        if ( empty( $transients ) || is_wp_error( $transients ) ) {
            return false;
        }

        // Loop through Transients, and delete them
        foreach ( $transients as $transient ) {

            // Site wide
            $site_wide = $this->is_site_wide( $transient );

            // Get prefix based on site-wide
            $prefix = ! empty( $site_wide )
                ? '_site_transient_timeout_'
                : '_transient_timeout_';

            // Strip prefix from name
            $name = str_replace( $prefix, '', $transient );

            // Delete
            $this->delete_transient( $name, $site_wide );
        }

        // No errors
        return true;
    }

    /**
     * Delete Selected transients.
     *
     * @since  1.8
     * @return false|int
     */
    public function delete_selected_transients() {
        global $wpdb;

        // Bail if no Transients
        if ( empty( $_REQUEST['transients'] ) || ! is_array( $_REQUEST['transients'] ) ) {
            return 0;
        }

        // Filter
        $transients_ids_filtered = wp_parse_id_list( $_REQUEST['transients'] );

        // Bail if no IDs
        if ( empty( $transients_ids_filtered ) ) {
            return 0;
        }

        // Query
        $placeholders = array_fill( 0, count( $transients_ids_filtered ), '%d' );
        $format       = implode( ', ', $placeholders );
        $count        = $wpdb->query( $wpdb->prepare( "DELETE FROM {$wpdb->options} WHERE option_id IN ({$format})", $transients_ids_filtered ) );

        // Return count of deleted
        return $count;
    }

    /**
     * Delete all expired transients
     *
     * @since  1.1
     * @return boolean
     */
    public function delete_expired_transients() {
        global $wpdb;

        // Query
        $esc_time = '%' . $wpdb->esc_like( '_transient_timeout_' ) . '%';
        $prepared = $wpdb->prepare( "SELECT option_name FROM {$wpdb->options} where option_name LIKE %s AND option_value+0 < %d", $esc_time, $this->time_now );
        $expired  = $wpdb->get_col( $prepared );

        // Bulk delete
        return $this->bulk_delete_transients( $expired );
    }

    /**
     * Delete all transients with expiration
     *
     * @since  1.2
     * @return boolean
     */
    public function delete_transients_with_expirations() {
        global $wpdb;

        // Query
        $esc_time    = '%' . $wpdb->esc_like( '_transient_timeout_' ) . '%';
        $prepared    = $wpdb->prepare( "SELECT option_name FROM {$wpdb->options} where option_name LIKE %s", $esc_time );
        $will_expire = $wpdb->get_col( $prepared );

        // Bulk delete
        return $this->bulk_delete_transients( $will_expire );
    }

    /**
     * Delete all transients without expiration
     *
     * @since  2.0
     * @return boolean
     */
    public function delete_transients_without_expirations() {
        global $wpdb;

        // Escape likes
        $esc_time = '%' . $wpdb->esc_like( '_transient_timeout_' ) . '%';
        $esc_name = '%' . $wpdb->esc_like( '_transient_'         ) . '%';

        // Queries
        $timeouts = $wpdb->get_col( $wpdb->prepare( "SELECT option_name FROM {$wpdb->options} where option_name LIKE %s", $esc_time ) );
        $names    = $wpdb->get_col( $wpdb->prepare( "SELECT option_name FROM {$wpdb->options} where option_name LIKE %s", $esc_name ) );

        // Diff to remove timeouts from names
        $items = array_diff( $names, $timeouts );

        // Remove "%_transient_timeout_" from left of timeouts
        foreach ( $timeouts as $index => $timeout ) {
            $pos = strrpos( $timeout, '_transient_timeout_' ) + strlen( '_transient_timeout_' );
            $timeouts[ $index ] = substr( $timeout, $pos );
        }

        // Remove "%_transient_" from left of items
        foreach ( $items as $index => $item ) {
            $pos = strrpos( $item, '_transient_' ) + strlen( '_transient_' );
            $items[ $index ] = substr( $item, $pos );
        }

        // Remove timeouts from items
        $bulk = array_diff( $items, $timeouts );

        // Bulk delete
        return $this->bulk_delete_transients( $bulk );
    }

    /**
     * Delete all transients
     *
     * @since  1.0
     * @return false|int
     */
    public function delete_all_transients() {
        global $wpdb;

        // Escape like
        $esc_name = '%' . $wpdb->esc_like( '_transient_' ) . '%';

        // Query
        $count = $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM {$wpdb->options} WHERE option_name LIKE %s",
                $esc_name
            )
        );

        // Return count
        return $count;
    }

    /**
     * Update an existing transient
     *
     * @since  1.0
     * @param  object  $transient
     * @param  boolean $site_wide
     * @return boolean
     */
    private function update_transient( $transient = '', $site_wide = false ) {

        // Bail if no Transient
        if ( empty( $transient ) ) {
            return false;
        }

        // Values
        $value      = stripslashes( $_POST['value'] );
        $expiration = absint( stripslashes( $_POST['expires'] ) );

        // Subtract now
        $expiration = ( $expiration - $this->time_now );

        // Transient type
        $retval = ( false !== $site_wide )
            ? set_site_transient( $transient, $value, $expiration )
            : set_transient( $transient, $value, $expiration );

        // Return
        return $retval;
    }

    /**
     * Prevent transient from being updated if transients are suspended
     *
     * @since  1.6
     * @param  mixed  $value
     * @param  string $option
     * @return mixed
     */
    public function maybe_block_update_transient( $value = '', $option = '' ) {

        // Bail if not Suspended
        if ( ! get_option( 'pw_tm_suspend' ) ) {
            return $value;
        }

        // Bail if not a Transient
        if ( false === strpos( $option, '_transient' ) ) {
            return $value;
        }

        // Return false
        return false;
    }

    /**
     * Prevent transient from being updated if transients are suspended
     *
     * @since 1.6
     */
    public function maybe_block_set_transient( $option = '' ) {

        // Bail if not Suspended
        if ( ! get_option( 'pw_tm_suspend' ) ) {
            return;
        }

        // Bail if not a Transient
        if ( false === strpos( $option, '_transient' ) ) {
            return;
        }

        // Delete the Transient
        delete_option( $option );
    }

    /**
     * Converts a period of time in seconds into a human-readable format
     * representing the interval.
     *
     * @since  2.0
     * @param  int $since A period of time in seconds.
     * @return string An interval represented as a string.
     */
    public function time_since( $since = 0 ) {

        // Array of time period chunks.
        $chunks = array(
            /* translators: 1: The number of years in an interval of time. */
            array( 60 * 60 * 24 * 365, _n_noop( '%s year', '%s years', 'transients-manager' ) ),
            /* translators: 1: The number of months in an interval of time. */
            array( 60 * 60 * 24 * 30, _n_noop( '%s month', '%s months', 'transients-manager' ) ),
            /* translators: 1: The number of weeks in an interval of time. */
            array( 60 * 60 * 24 * 7, _n_noop( '%s week', '%s weeks', 'transients-manager' ) ),
            /* translators: 1: The number of days in an interval of time. */
            array( 60 * 60 * 24, _n_noop( '%s day', '%s days', 'transients-manager' ) ),
            /* translators: 1: The number of hours in an interval of time. */
            array( 60 * 60, _n_noop( '%s hour', '%s hours', 'transients-manager' ) ),
            /* translators: 1: The number of minutes in an interval of time. */
            array( 60, _n_noop( '%s minute', '%s minutes', 'transients-manager' ) ),
            /* translators: 1: The number of seconds in an interval of time. */
            array( 1, _n_noop( '%s second', '%s seconds', 'transients-manager' ) ),
        );

        if ( $since <= 0 ) {
            return esc_html__( 'now', 'transients-manager' );
        }

        /**
         * We only want to output two chunks of time here, eg:
         * x years, xx months
         * x days, xx hours
         * so there's only two bits of calculation below:
         */
        $j = count( $chunks );

        // Step one: the first chunk.
        for ( $i = 0; $i < $j; $i++ ) {
            $seconds = $chunks[ $i ][ 0 ];
            $name    = $chunks[ $i ][ 1 ];

            // Finding the biggest chunk (if the chunk fits, break).
            $count = floor( $since / $seconds );

            if ( ! empty( $count ) ) {
                break;
            }
        }

        // Set output var.
        $output = sprintf( translate_nooped_plural( $name, $count, 'transients-manager' ), $count );

        // Step two: the second chunk.
        if ( $i + 1 < $j ) {
            $seconds2 = $chunks[ $i + 1 ][ 0 ];
            $name2    = $chunks[ $i + 1 ][ 1 ];
            $count2   = floor( ( $since - ( $seconds * $count ) ) / $seconds2 );

            // Add to output var.
            if ( ! empty( $count2 ) ) {
                $output .= ' ' . sprintf( translate_nooped_plural( $name2, $count2, 'transients-manager' ), $count2 );
            }
        }

        return $output;
    }

    /**
     * Add <style> tag to "admin_print_styles-{$this->page_id}" hook
     *
     * @since 2.0
     */
    public function print_styles() {

        // Get the page type
        $type = $this->page_type();

        // Editing...
        if ( 'edit' === $type ) {

            // Try to enqueue the code editor
            $settings = wp_enqueue_code_editor(
                array(
                    'type'       => 'text/plain',
                    'codemirror' => array(
                        'indentUnit' => 4,
                        'tabSize'    => 4,
                    ),
                )
            );

            // Bail if user disabled CodeMirror.
            if ( false === $settings ) {
                return;
            }

            // Target the textarea
            wp_add_inline_script(
                'code-editor',
                sprintf(
                    'jQuery( function() { wp.codeEditor.initialize( "transient-editor", %s ); } );',
                    wp_json_encode( $settings )
                )
            );

            // Custom styling
            wp_add_inline_style(
                'code-editor',
                '.CodeMirror-wrap {
                    width: 99%;
                    border: 1px solid #8c8f94;
                    border-radius: 3px;
                    overflow: hidden;
                }
                .CodeMirror-gutters {
                    background: transparent;
                }'
            );

        // Showing list-table...
        } else {

            // Escape once
            $esc = esc_attr( $this->page_id );

?>

<style type="text/css" id="transients-manager">
    body.tools_page_<?php echo $esc; // Escaped ?> table.transients .column-value {
        width: 38%;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients .column-expiration {
        width: 170px;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients .truncate {
        overflow: hidden;
        white-space: nowrap;
        text-overflow: ellipsis;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients .column-primary pre {
        margin: 0;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients span.transient-value {
        display: block;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients code {
        background: transparent;
        margin: 0;
        padding: 0;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients span.transient-value,
    body.tools_page_<?php echo $esc; // Escaped ?> table.transients span.transient-expiration {
        cursor: default;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients span.badge,
    body.tools_page_<?php echo $esc; // Escaped ?> table.transients div.row-actions {
        margin-top: 5px;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients span.badge {
        padding: 2px 7px;
        border-radius: 4px;
        display: inline-flex;
        align-items: center;
        background: rgba(0, 0, 0, 0.07);
        color: #50575e;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients span.badge.green {
        color: #017d5c;
        background: #e5f5f0;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> table.transients span.transient-expired {
        color: #b32d2e;
        background: #ffd6d6;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> .tablenav .info {
        display: inline-block;
        margin: 2px 0;
        padding: 2px 7px;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> .tablenav-pages span.displaying-num {
        display: inline-block;
        margin: 5px 0;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> span.pagination-links .page-numbers {
        border-color: #7e8993;
        color: #32373c;
        display: inline-block;
        vertical-align: baseline;
        min-width: 30px;
        min-height: 30px;
        text-decoration: none;
        text-align: center;
        font-size: 13px;
        line-height: 2.15384615;
        margin: 0;
        padding: 0 10px;
        cursor: pointer;
        border-width: 1px;
        border-style: solid;
        border-radius: 3px;
        -webkit-appearance: none;
        white-space: nowrap;
        box-sizing: border-box;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> span.pagination-links .page-numbers.next,
    body.tools_page_<?php echo $esc; // Escaped ?> span.pagination-links .page-numbers.prev {
        font-size: 16px;
        line-height: 1.625;
        padding: 0 4px;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> span.pagination-links a.page-numbers:hover {
        background-color: #f0f0f1;
        border-color: #717c87;
        color: #262a2e;
    }

    body.tools_page_<?php echo $esc; // Escaped ?> span.pagination-links span.page-numbers {
        color: #a7aaad;
        border-color: #dcdcde;
        background: #f6f7f7;
        box-shadow: none;
        cursor: default;
        transform: none;
    }
</style>

<?php
        }
    }
}