<?php
/**
 * A helper class that checks and returns the statuses of objects. 
 * 
 * @author Dan Suleski
 * @package ski
 * @since ski 1.0
 */

namespace ski;



/**
 * A utility class that queries WP.
 */
class question
{
	/* PUBLIC */

    /**
     * Given a table name, this function looks at the current
     * WP database to determine if that table exists.
     * @global object $wpdb Provided by WP
     * @param string $table_name The full name of the table (including prefix 'wp_', for instance)
     * @return boolean 'true' if the table does exist
     */
    public static function does_table_exist( $table_name )
    {
        global $wpdb;
        return ( $wpdb->get_var( 'show tables like "'.$table_name.'"' ) === $table_name );
    }

	/**
	 * Determines if the user is currently looking at a specific screen -
     * typically used in the Administrative area.
     * 
     * Here are some IDs of popular screens:
     *      nav-menus       => Appearance > Menus
     *      widgets         => Appearance > Widgets
     * 
     * Note: This does not work with the Customizer.  Use "is_customizer" instead.
     * 
     * 
     * @param string $screen_id The ID of the screen to test
	 * @return boolean true if on the screen with the desired ID; otherwise, false
	 */
	public static function is_admin_screen( $screen_id )
	{
        $screen = get_current_screen();
        if ( $screen != null )
        {
            return ( $screen->id == $screen_id );
        }
        return false;
	}

	/**
	 * Determines if the user is currently looking at the Theme Customizer
     * typically found under Appearance >> Customize.
     * 
     * Note: the API for "get_current_screen" appears to be undefined when
     * in the Customizer, so the test for a customizer is different than 
     * calling "is_admin_screen".
     * 
	 * @return boolean
	 */
	public static function is_customizer()
	{
        return ( array_key_exists( 'HTTP_REFERER', $_SERVER ) && string::contains( $_SERVER['HTTP_REFERER'], 'wp-admin/customize.php' ) );
	}

    /**
	 * Determines if the a given plugin has been installed and activated.
     * @param type $plugin Something like 'my-plugin/my-plugin.php'
	 * @return boolean
     */
	public static function is_plugin_active( $plugin )
	{
        $active_plugins = get_option( 'active_plugins' );
        return in_array( $plugin, $active_plugins );
	}

    /**
     * This is a copy of thr 3.9.1 version of WP's locate_template -
     * the primary difference here makes the use of:
     *      get_xxx_directory_uri
     * 
     * Instead of:
     *      get_xxx_directory (or the XXXPATH constant)
     * 
     * For the return value.  This was put into place because file_exists does not work
     * with the 'http://' (uri example), but does work with 'c:\' (local example).  It is
     * a subtle difference, but one that works in cases where the return value will not
     * necessarily be used in a 'require' call.
     *
     * @param string|array $template_names Template file(s) to search for, in order.
     * @return string The template filename if one is located.
     */
    public static function locate_template_uri( $template_names )
    {
        $located = '';
        foreach ( (array) $template_names as $template_name )
        {
            if ( !$template_name ) continue;
            
            if ( file_exists( get_stylesheet_directory().'/'.$template_name ) )
            {
                $located = get_stylesheet_directory_uri().'/'.$template_name;
                break;
            }
            
            if ( file_exists( get_template_directory().'/'.$template_name ) )
            {
                $located = get_template_directory_uri().'/'.$template_name;
                break;
            }
        }
        return $located;
    }

    
	/* PRIVATE */

	/**
	 * Only use this class as a utility..
	 */
	private function __construct()
	{
		//	Intentionally blank..
	}
}


?>