<?php
/**
 * @package   Arlo_For_Wordpress
 * @author    Arlo <info@arlo.co>
 * @license   GPL-2.0+
 * @link      https://arlo.co
 * @copyright 2018 Arlo
 */

class Arlo_For_Wordpress_Categories_Widget extends WP_Widget {

	/**
	 * Instance of this class.
	 *
	 * @since    1.0.0
	 *
	 * @var      object
	 */
	protected static $instance = null;

    /**
     * @TODO - Rename "widget-name" to the name your your widget
     *
     * Unique identifier for your widget.
     *
     *
     * The variable name is used as the text domain when internationalizing strings
     * of text. Its value should match the Text Domain file header in the main
     * widget file.
     *
     * @since    1.0.0
     *
     * @var      string
     */
    protected $widget_slug = 'arlo-for-wordpress-categories-widget';

	/*--------------------------------------------------*/
	/* Constructor
	/*--------------------------------------------------*/

	/**
	 * Specifies the classname and description, instantiates the widget,
	 * loads localization files, and includes necessary stylesheets and JavaScript.
	 */
	public function __construct() {

		// load plugin text domain
		add_action( 'init', array( $this, 'widget_textdomain' ) );

		// Hooks fired when the Widget is activated and deactivated
		register_activation_hook( __FILE__, array( $this, 'activate' ) );
		register_deactivation_hook( __FILE__, array( $this, 'deactivate' ) );

		// TODO: update description
		parent::__construct(
			$this->get_widget_slug(),
			__( 'Arlo Categories', 'arlo-for-wordpress-categories-widget' ),
			array(
				'classname'  => $this->get_widget_slug().'-class',
				'description' => __( 'Display Categories.', 'arlo-for-wordpress-categories-widget' )
			)
		);

		/* 
		 * Currently we have no widget styles or scripts,
		 * so no point enqueuing empty files
		 */

		// Register admin styles and scripts
		//add_action( 'admin_print_styles', array( $this, 'register_admin_styles' ) );
		//add_action( 'admin_enqueue_scripts', array( $this, 'register_admin_scripts' ) );

		// Register site styles and scripts
		//add_action( 'wp_enqueue_scripts', array( $this, 'register_widget_styles' ) );
		//add_action( 'wp_enqueue_scripts', array( $this, 'register_widget_scripts' ) );

		// Refreshing the widget's cached output with each new post
		add_action( 'save_post',    array( $this, 'flush_widget_cache' ) );
		add_action( 'deleted_post', array( $this, 'flush_widget_cache' ) );
		add_action( 'switch_theme', array( $this, 'flush_widget_cache' ) );

	} // end constructor

	/**
	 * Return an instance of this class.
	 *
	 * @since     1.0.0
	 *
	 * @return    object    A single instance of this class.
	 */
	public static function get_instance() {

		// If the single instance hasn't been set, set it now.
		if ( null == self::$instance ) {
			self::$instance = new self;
		}

		return self::$instance;
	}


    /**
     * Return the widget slug.
     *
     * @since    1.0.0
     *
     * @return    Plugin slug variable.
     */
    public function get_widget_slug() {
        return $this->widget_slug;
    }

	/*--------------------------------------------------*/
	/* Widget API Functions
	/*--------------------------------------------------*/

	/**
	 * Outputs the content of the widget.
	 *
	 * @param array args  The array of form elements
	 * @param array instance The current instance of the widget
	 */
	public function widget( $args, $instance ) {
		if (get_option('arlo_plugin_disabled', '0') == '1') return;
		
		// Check if there is a cached output
		$cache = wp_cache_get( $this->get_widget_slug(), 'widget' );

		if ( !is_array( $cache ) )
			$cache = array();

		if ( ! isset ( $args['widget_id'] ) )
			$args['widget_id'] = $this->id;

		if ( isset ( $cache[ $args['widget_id'] ] ) )
			return print $cache[ $args['widget_id'] ];
		
		// go on with your widget logic, put everything into a string and …


		extract( $args, EXTR_SKIP );

		$widget_string = $before_widget;

		// TODO: Here is where you manipulate your widget's values based on their input fields
		ob_start();
		include( plugin_dir_path( __FILE__ ) . 'views/widget.php' );
		$widget_string .= ob_get_clean();
		$widget_string .= $after_widget;


		$cache[ $args['widget_id'] ] = $widget_string;

		wp_cache_set( $this->get_widget_slug(), $cache, 'widget' );

		print $widget_string;

	} // end widget
	
	
	public function flush_widget_cache() 
	{
    	wp_cache_delete( $this->get_widget_slug(), 'widget' );
	}
	/**
	 * Processes the widget's options to be saved.
	 *
	 * @param array new_instance The new instance of values to be generated via the update.
	 * @param array old_instance The previous instance of values before the update.
	 */
	public function update( $new_instance, $old_instance ) {

		$instance = $old_instance;

		$instance['title'] = strip_tags( wp_unslash($new_instance['title']) );
		$instance['depth'] = intval($new_instance['depth']);
		$instance['parent'] = $new_instance['parent'];


		return $instance;

	} // end widget

	/**
	 * Generates the administration form for the widget.
	 *
	 * @param array instance The array of keys and values for the widget.
	 */
	public function form( $instance ) {

		// TODO: Define default values for your variables
		$instance = wp_parse_args(
			(array) $instance,
			array('title'=>'','depth'=> 5,'parent' => false)
		);

		// TODO: Store the values of the widget in their own variable
		$title = esc_attr( $instance['title'] );
		$depth = esc_attr( $instance['depth']);
		$parent = esc_attr( $instance['parent']);

		// Display the admin form
		include( plugin_dir_path(__FILE__) . 'views/admin.php' );

	} // end form

	/*--------------------------------------------------*/
	/* Public Functions
	/*--------------------------------------------------*/

	/**
	 * Loads the Widget's text domain for localization and translation.
	 */
	public function widget_textdomain() {

		// TODO be sure to change 'widget-name' to the name of *your* plugin
		load_plugin_textdomain( $this->get_widget_slug(), false, plugin_dir_path( __FILE__ ) . 'lang/' );

	} // end widget_textdomain

	/**
	 * Fired when the plugin is activated.
	 *
	 * @param  boolean $network_wide True if WPMU superadmin uses "Network Activate" action, false if WPMU is disabled or plugin is activated on an individual blog.
	 */
	public function activate( $network_wide ) {
		// TODO define activation functionality here
	} // end activate

	/**
	 * Fired when the plugin is deactivated.
	 *
	 * @param boolean $network_wide True if WPMU superadmin uses "Network Activate" action, false if WPMU is disabled or plugin is activated on an individual blog
	 */
	public function deactivate( $network_wide ) {
		// TODO define deactivation functionality here
	} // end deactivate

	/**
	 * Registers and enqueues admin-specific styles.
	 */
	public function register_admin_styles() {

		wp_enqueue_style( $this->get_widget_slug().'-admin-styles', plugins_url( 'css/admin.css', __FILE__ ) );

	} // end register_admin_styles

	/**
	 * Registers and enqueues admin-specific JavaScript.
	 */
	public function register_admin_scripts() {

		wp_enqueue_script( $this->get_widget_slug().'-admin-script', plugins_url( 'js/admin.js', __FILE__ ), array('jquery') );

	} // end register_admin_scripts

	/**
	 * Registers and enqueues widget-specific styles.
	 */
	public function register_widget_styles() {

		wp_enqueue_style( $this->get_widget_slug().'-widget-styles', plugins_url( 'css/widget.css', __FILE__ ) );

	} // end register_widget_styles

	/**
	 * Registers and enqueues widget-specific scripts.
	 */
	public function register_widget_scripts() {

		wp_enqueue_script( $this->get_widget_slug().'-script', plugins_url( 'js/widget.js', __FILE__ ), array('jquery') );

	} // end register_widget_scripts

} // end class

// TODO: Remember to change 'Widget_Name' to match the class name definition
add_action( 'widgets_init', 'register_widget_categories_widget' );
function register_widget_categories_widget() {
	register_widget("Arlo_For_Wordpress_Categories_Widget");
}