<?php

namespace WpMailCatcher;

class ScreenOptions
{
    static private $instance;
    private $options = [];
    private $helpTabs = [];
    private $currentScreen = null;
    static public $optionIdsToWatch = [
        'logs_per_page' => 'toplevel_page_wp_mail_catcher_per_page',
        'logs_hidden_table_columns' => 'managetoplevel_page_wp-mail-catchercolumnshidden'
    ];

    private function __construct()
    {
        add_filter('set-screen-option', [$this, 'saveOption'], 10, 3);

        foreach (self::$optionIdsToWatch as $key => $value) {
            add_filter('set_screen_option_' . $value, [$this, 'saveOption'], 10, 3);
        }
    }

    static public function getInstance()
    {
        if (self::$instance == null) {
            self::$instance = new self();
        }

        return self::$instance;
    }

    public function saveOption($keep, $option, $value)
    {
        return in_array($option, self::$optionIdsToWatch) ? $value : $keep;
    }

    public function newOption($pageHook, $type, $args)
    {
        add_action('load-' . $pageHook, [$this, 'addToScreen']);

        $this->options[] = [
            'type' => $type,
            $args
        ];
    }

    public function newHelpTab($pageHook, $title, $content)
    {
        $this->helpTabs[] = [
            'id' => $pageHook . count($this->helpTabs),
            'title' => $title,
            'content' => $content
        ];
    }

    /**
     * Forces WP to handle dynamic column visibility tick boxes
     * inside of "Screen Options" tab. Because they're singletons
     * initialising them now won't cause any extra overhead
     */
    private function initTables()
    {
        MailAdminTable::getInstance();
    }

    public function addToScreen()
    {
        $this->currentScreen = get_current_screen();
        $this->initTables();

        foreach ($this->helpTabs as $helpTab) {
            $this->currentScreen->add_help_tab($helpTab);
        }

        foreach ($this->options as $option) {
            add_screen_option($option['type'], $option);
        }
    }
}