<?php

/**
 * include those two lines at the top of the main plugin file
 *
 * include_once( plugin_dir_path(__FILE__) . '/php/utils/plugin_tools.php');
 * PLGNTLS_class::set_root_dir( plugin_dir_path(__FILE__), plugin_dir_url(__FILE__) );
 *
 * PLGNTLS means PLUGIN TOOLS
 */

class PLGNTLS_class
{
	private static $_root_path;
	private static $_root_url;

	private static $_ajax_already_there;
	private $_first_script;
	private $_prefix;
	private $_js_dependencies;
	private $_css_dependencies;

	/**
	 */
	public function __construct() {
		if (! isset( self::$_ajax_already_there ))
			self::$_ajax_already_there = false;
		$this->_prefix = "PLGNTLS";
		$this->_first_script = null;
		$this->_js_dependencies = array();
		$this->_css_dependencies = array();
	}

	/**
	 * can be used before class is instanciated :
	 * PLGNTLS_class::set_root_dir( plugin_dir_path(__FILE__), plugin_dir_url(__FILE__) );
	 */
	public static function set_root_dir($path, $url) {
		if (isset( self::$_root_path ))
			return ;
		if (isset( self::$_root_url ))
			return ;
		self::$_root_path = $path;
		self::$_root_url = $url;
	}
	public static function get_path() {
		return(self::$_root_path);
	}
	public static function get_url() {
		return(self::$_root_url);
	}


	public function add_to_front($scripts_arr = null, $vars = null) {
		if (!is_null($scripts_arr))
		{
			// add ajax file at beginning of files list
			array_unshift($scripts_arr, "utils/plugin_ajax.js");
			$nonce = array("ajax_nonce" => wp_create_nonce('wp-pageviews-nonce'));
			$url = array("ajax_url" => admin_url('admin-ajax.php'));
			$vars = array_merge($vars, $nonce);
			$vars = array_merge($vars, $url);
		}

		$scripts = array();
		foreach($scripts_arr as $key => $script_name) {
			$scripts[] = $this->init_script($key, $script_name);
		}
		if (!is_null($scripts_arr))
			$this->add_scripts_to_front($scripts);
		if (!is_null($vars))
			$this->add_vars_to_front($vars);
		return $this->create_html($scripts, $vars);
	}


/**
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * PRIVATES FUNCTIONS
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 */


	/**
	 * @param two arguments :
	 * 1. html files to include in front
	 * 	- can be a string of 1 filename
	 * 	- or an array of strings of filenames
	 * 	( https://stackoverflow.com/q/4747876/9497573 )
	 * 	- it's probably better to only add 1 file, and let it include other files
	 * 2. list of variables to make available to this files
	 * 	- in the form of key => val
	 * 	- recommanded to do it with compact()
	 * ex: create_html( "file.html", compact("var1","var2",) );
	 * ex: create_html( array("file1.html", "file2.html"), array("var1"=>"value") );
	 * @return a string of html code
	 *
	 * using ob_start() and ob_get_clean()
	 * allows to have php expansion inside the html loaded
	 * in opposition to the methode file_get_contents()
	 *
	 * https://stackoverflow.com/a/4402045/9497573
	 */
	private function create_html($files = null, $vars = null) {
		if (is_null($files))
			return null;
		$plgn_dir = $this->get_path();
		if (!is_null($vars))
			extract($vars);

		ob_start();
		foreach($files as $file) {
			if ($file->ext === 'html')
				include($file->path);
		}
		$html = ob_get_clean();

		return $html;
	}

	/**
	 * pass variables to js front as global variables
	 * @param array : list of key => value
	 * 	 with the key being name of the variable, like this :
	 * 		'my_var' => 'value',
	 * 	 simpler way to do it is to use compact when calling the function :
	 * 		add_var_to_front(compact("var1", "var2", "var3"));
	 * @param string (optionnal) : name of first embended script that need these variables
	 * 	 (it will be available to this script and all followings)
	 * 	 this name is the filename + "_" + extension :
	 * 	 init.js -> init_js
	 */
	private function add_vars_to_front($vars_arr)
	{
		if (is_null($this->_first_script))
			return ;
		if (is_null($vars_arr))
			return ;
		$handle = $this->_first_script;
		$object_name = $this->_prefix . "_data";

		$vars_json = json_encode($vars_arr);
		$front = "let $object_name = $vars_json;";
		wp_add_inline_script($handle, $front, 'before');
	}

	/**
	 * @param array : list of files :
	 * 	- with their path from root of their type of file (ex: from js/ to .js files)
	 * 	- and with their extension
	 * @param boolean
	 * 	- to add ajax script and variables
	 * 	- default to true
	 */
	private function add_scripts_to_front($scripts_arr) {
		//wp_enqueue_script(<give_it_a_name>, /url/to/script, [depends on], version, defer? );
		//wp_enqueue_style( <give_it_a_name>, /url/to/script, [depends on], version, media );

		$previous_css_basename = '';
		$previous_js_basename = '';
		foreach ($scripts_arr as $script) {
			if (in_array($script->ext, array("js", "url"))) {
				if (is_null($this->_first_script))
					$this->_first_script = $script->handle;
				$depends_on = $this->check_dependencies($script, $previous_js_basename);
				if ($depends_on !== null)
					wp_enqueue_script( $script->handle, $script->url, $depends_on, $script->version, true);
				$previous_js_basename = $script->handle;
			}
			else if ($script->ext === "css") {
				$depends_on = $this->check_dependencies($script, $previous_css_basename);
				if ($depends_on !== null)
					wp_enqueue_style( $script->handle, $script->url, $depends_on, $script->version, '');
				$previous_css_basename = $script->handle;
			}
		}
	}
	private function check_dependencies(&$script, $previous_basename)
	{
		if (in_array($script->ext, array("js", "url")))
		{
			global $wp_scripts;
			$already_enqueued = array_search($script->handle, $wp_scripts->queue);
			if ($already_enqueued !== false)
				return null;
		}
		else if ($script->ext === "css")
		{
			global $wp_styles;
			$already_enqueued = array_search($script->handle, $wp_styles->queue);
			if ($already_enqueued !== false)
				return null;
		}

		$depends_on = array();
		if (isset($script->depends) && $script->depends !== '')
			$depends_on[] = $script->depends;
		if (isset($previous_basename) && $previous_basename !== '')
			$depends_on[] = $previous_basename;

		return $depends_on;
	}

	/**
	 * @param string : name of the file, with its path from its extension directory
	 * 	- from js/ root for .js files
	 * 	- from css/ root for .css files
	 * @return object / null :
	 * 	- null if file is not js or css
	 * 	- or an object with all the necessary infos :
	 * 	  - ext      : name.js -> "js"
	 * 	  - basename : name.js -> "name"
	 * 	  - handle   : name.js -> "name_js"
	 * 	  - url     : url to file in wordpress
	 * 	  - path    : path to file in server
	 * 	  - version : used to avoid browser caching
	 * 	  - depends : string if depends on a handle, or ''
	 */
	private function init_script($key, $script_name) {
		$script = (object)[];

		if(filter_var($script_name, FILTER_VALIDATE_URL))
			$script->ext = "url";
		else
			$script->ext = pathinfo($script_name, PATHINFO_EXTENSION);
		if (! in_array($script->ext, array("js", "css", "html", "url")))
			return null;

		if ($script->ext === "url")
			$script->basename = parse_url($script_name, PHP_URL_HOST);
		else
			$script->basename = pathinfo($script_name, PATHINFO_BASENAME);
		$script->handle = "PLGNTLS_" . str_replace(".", "_", $script->basename);
		console_log("script->handle:");
		console_log($script->handle);

		if ($script->ext === "url") {
			$script->url = $script_name;
			$script->path = null;
			$script->version = null;
		}
		else {
			$script->url = $this->get_url().$script_name;
			$script->path = $this->get_path().$script_name;
			$script->version = date("ymd-Gis", filemtime($script->path));
		}

		$script->depends = '';
		if (is_string($key))
			$script->depends = $key;

		return $script;
	}


}


?>