<?php
/**
 * Plugin Name: Advanced Ordernumbers
 * Plugin URI: http://open-tools.net/WooCommerce/Advanced-Ordernumbers.php
 * Description: Lets the user freely configure the order numbers in WooCommerce.
 * Version: 0.1.0
 * Author: Open Tools, Reinhold Kainhofer
 * Author URI: http://open-tools.net
 * Text Domain: woocommerce-advanced-ordernumbers
 * Domain Path: 
 * License: GPL2+
 WC requires at least: 2.2
WC tested up to: 2.3
*/

/**
 * The structure of this plugin originally followed the tutorial, although much of the plugin has been rewritten since then:
 * http://www.yaconiello.com/blog/how-to-write-wordpress-plugin/
 * A lot of coding ideas were also taken directly from the way things are implemented in WooCommerce itself.
 */
 
if ( ! defined( 'ABSPATH' ) ) { 
	exit; // Exit if accessed directly
}
/**
 * Check if WooCommerce is active
 **/
if ( in_array( 'woocommerce/woocommerce.php', apply_filters( 'active_plugins', get_option( 'active_plugins' ) ) ) ) {
    // Put your plugin code here
    // Load the language files

	if (!class_exists("OpenToolsOrdernumbers")) {
		class OpenToolsOrdernumbers {
			public $ordernumber_meta = "_order_number";
			public $ordernumber_new_placeholder = "[New Order]";
			public $ordernumber_counter_prefix = 'ordernumber-counter-';
			
			
			/**
			 * STATIC HELPER FUNCTIONS, WooCommerce-specific
			 */
			public static function __($string) {
				return __($string, 'opentools-advanced-ordernumbers');
			}
			public static function rel_url($file) {
				return plugins_url($file, __FILE__);
			}
			public static function img_url($img) {
				return self::rel_url('assets/images/'.$img );
			}
			public static function css_url($css) {
				return self::rel_url('assets/css/'.$css );
			}
			public static function js_url($js) {
				return self::rel_url('assets/js/'.$js );
			}
			
			
			/**
			 * Construct the plugin object
			 */
			public function __construct()
			{
				$plugin = plugin_basename(__FILE__); 
				load_plugin_textdomain('opentools-ordernumbers', false, basename( dirname( __FILE__ ) ) . '/languages' );


				// Init settings
				$this->settings = array(
					array(
						'name' 		=> self::__( 'Advanced Order Numbers'),
						'desc'		=> self::__( 'Configure the format and the counters of the order numbers in WooCommerce.'),
						'type' 		=> 'title',
						'id' 		=> 'ordernumber_options'
					),

					array(
						'name' 		=> self::__( 'Customize Order Numbers'),
						'desc' 		=> self::__( 'Check to use custom order numbers rather than the default wordpress post ID.'),
						'id' 		=> 'customize_ordernumber',
						'type' 		=> 'checkbox',
						'default'	=> 'no'
					),
					array(
						'title'		=> self::__( 'Order number format'),
						'desc' 		=> self::__( 'The format for the order numbers (variables can be entered as [...], the counter is indicated by the #). To use a different counter name than displayed, put the custom counter name after a |, e.g. "[year]-[month]/#|[year]" to use the month in the order number, but reset the counter only yearly. Advanced settings for the counter can be added as [#####:start/step], e.g. [#:100] to start new counters at 100, or [#/5] to increment the counter by 5. The number of # in the format determine how many digits are shown at least, e.g. [########] will always show at least 8 digits for the counter, e.g. 00000014.'),
						'desc_tip'	=> true,
						'id' 		=> 'ordernumber_format',
						'default'	=> '#',
						'type' 		=> 'text',
						'css'		=> 'width: 100%',
					),
					array(
						'title'		=> self::__( 'Use global counter'),
						'desc' 		=> self::__( 'A global counter is independent of the number format and will never reset. A non-global counter runs within the number format and will start from the inital value whenever any of the variables used in the format changes (to be precise: a new counter will be used, so it is possible to have multiple counters running in parallel).'),
						'desc_tip'	=> true,
						'id' 		=> 'ordernumber_global',
						'type' 		=> 'checkbox',
						'default'	=> 'no',
					),
// 					array(
// 						'title' 	=> self::__( 'Counter Digits'),
// 						'desc' 		=> self::__( 'Minimum number of digits for the number'),
// 						'desc_tip'	=> true,
// 						'id' 		=> 'ordernumber_padding',
// 						'type' 		=> 'number',
// 						'default'	=> '0'
// 					),
// 					array(
// 						'title' 	=> self::__( 'Counter Start'),
// 						'desc' 		=> self::__( 'Start value for each new counter'),
// 						'desc_tip'	=> true,
// 						'id' 		=> 'ordernumber_start',
// 						'type' 		=> 'number',
// 						'default'	=> '1'
// 					),
// 					array(
// 						'title'		=> self::__( 'Counter step'),
// 						'desc' 		=> self::__( 'By how much the counter will be increased after each order. Typically 1.'),
// 						'desc_tip'	=> true,
// 						'id' 		=> 'ordernumber_step',
// 						'type' 		=> 'number',
// 						'default'	=> '1'
// 					),
					array( 'type' => 'sectionend', 'id' => 'ordernumber_options' ),
					
					// TODO: customize order password, and other numbers!

					array(
						'name' 		=> self::__( 'Custom Variables'),
						'desc'		=> self::__( 'Define your own (conditional) variables for use in the number formats'),
						'type' 		=> 'title',
						'id' 		=> 'ordernumber_variables'
					),
					array(
						'id' 		=> 'ordernumber_variables',
						'type' 		=> 'ordernumber_variables',
					),
					array( 'type' => 'sectionend', 'id' => 'ordernumber_variables' ),

					array(
						'name' 		=> self::__( 'Current Counters'),
						'type' 		=> 'title',
						'id' 		=> 'ordernumber_counters'
					),
					array(
						'name' 		=> self::__( 'All Ordernumber Counters'),
						'desc'		=> self::__( 'View and modify the current counter values. The counter value is the value used for the previous number. All changes are immediately applied!'),
						'desc_tip'	=> true,
						'id' 		=> 'ordernumber_counters',
						'type' 		=> 'ordernumber_counters',
					),
					array( 'type' => 'sectionend', 'id' => 'ordernumber_counters' ),

				);
				// Default options

				add_option ('customize_ordernumber', '0');
				add_option ('ordernumber_format',    "#");
				add_option ('ordernumber_global',    'no');
// 				add_option ('ordernumber_padding',   '1');
// 				add_option ('ordernumber_start',     '1');
// 				add_option ('ordernumber_step',      '1');
				
 				add_option ('ordernumber_variables',  array());

				// register filters and actions
				
				// CONFIGURATION SCREENS
				add_filter( 'woocommerce_get_sections_checkout',                array($this, 'add_admin_section'));
				// The checkout settings page assumes all subpages are payment gateways, so we have to override this and manually pass our settings:
				add_action( 'woocommerce_settings_checkout',                    array( $this, 'settings_output' ) );
				add_action( 'woocommerce_settings_save_checkout',               array( $this, 'settings_save' ) );
				add_action( 'woocommerce_admin_field_ordernumber_counters',     array( $this, 'admin_field_counters' ) );
				add_action( 'woocommerce_admin_field_ordernumber_variables',    array( $this, 'admin_field_variables' ) );
				add_action( 'pre_update_option_ordernumber_variables',          array( $this, 'update_option_variables'));

				add_action( 'admin_print_styles-woocommerce_page_wc-settings',  array($this, 'print_admin_styles'));
				add_action( 'admin_print_scripts-woocommerce_page_wc-settings', array($this, 'print_admin_scripts'));
				
				// AJAX counter modifications
				add_action( 'wp_ajax_set_counter',    array($this, 'counter_set_callback') );
				add_action( 'wp_ajax_add_counter',    array($this, 'counter_add_callback') );
				add_action( 'wp_ajax_delete_counter', array($this, 'counter_delete_callback') );

				// Add the ordernumber post meta to the search in the backend
				add_filter( 'woocommerce_shop_order_search_fields', array($this, 'order_search_fields'));
				// Sort the order list in the backend by order number rather than ID, make sure this is called LAST so we modify the defaults passed as arguments
				add_filter( 'manage_edit-shop_order_sortable_columns', array( $this, 'modify_order_column_sortkey' ), 9999 );

				// When a new order is created, we immediately assign the order number:
				add_action( 'wp_insert_post', array(&$this, 'check_create_ordernumber'), 10, 3);
// 				add_action( 'save_post', array(&$this, 'check_create_ordernumber'), 10, 3);
				// The filter to actually return the order number for the given order
				add_filter ('woocommerce_order_number', array(&$this, 'get_ordernumber'), 10, 2/*<= Also get the order object! */);
			}
    
			// Activate the plugin
			public static function activate() {}
    
			// Deactivate the plugin
			public static function deactivate() {}

			/**
			 * Insert our own section in the checkout setting page. Rearrange the sections array to make sure our settings
			 * come second place, directly after the default page with the '' key and before all the payment gateways
			 */
			function add_admin_section($sections) {
				$newsections = array();
				foreach ($sections as $sec => $name ) {
					$newsections[$sec] = $name;
					if ($sec == '') {
						$newsections['ordernumber'] = self::__('Order Numbers');
					}
				}
				return $newsections;
			}
			
			public function settings_output() {
				global $current_section;
				if ($current_section == 'ordernumber') {
					$settings = $this->settings;
					WC_Admin_Settings::output_fields( $settings );
				}
			}

			public function settings_save() {
				global $current_section;
				if ($current_section == 'ordernumber') {
					$settings = $this->settings;
					WC_Admin_Settings::save_fields( $settings );
				}
			}
			
			/** 
			 * Print the CSS for the counter values and counter variables tables to the page header in the WC backend admin setting page
			 */
			public function print_admin_styles () {
				wp_register_style ( 'ordernumber-counter-style',  self::css_url('ordernumber-counter.css') );
				wp_enqueue_style('ordernumber-counter-style');

				wp_register_style ( 'ordernumber-variables-style',  self::css_url('ordernumber-variables.css') );
				wp_enqueue_style('ordernumber-variables-style');
			}
			/** 
			 * Print the JS for the counter values and counter variables tables to the page header in the WC backend admin setting page
			 */
			public function print_admin_scripts() {
			
				wp_register_script( 'ordernumber-counter-script', self::js_url( 'ordernumber-counter.js',  __FILE__), array('jquery') );
				wp_enqueue_script( 'ordernumber-counter-script');
				
				// Handle the translations:
				$localizations = array( 'ajax_url' => admin_url( 'admin-ajax.php' ) );
				
				$localizations['ORDERNUMBER_JS_JSONERROR'] = self::__("Error reading response from server:");
				$localizations['ORDERNUMBER_JS_NOT_AUTHORIZED'] = self::__("You are not authorized to modify order number counters.");
				$localizations['ORDERNUMBER_JS_NEWCOUNTER'] = self::__("Please enter the format/name of the new counter:");
				$localizations['ORDERNUMBER_JS_ADD_FAILED'] = self::__("Failed adding counter {0}");
				$localizations['ORDERNUMBER_JS_INVALID_COUNTERVALUE'] = self::__("You entered an invalid value for the counter.\n\n");
				
				$localizations['ORDERNUMBER_JS_EDITCOUNTER'] = self::__("{0}Please enter the new value for the counter '{1}' (current value: {2}):");
				$localizations['ORDERNUMBER_JS_MODIFY_FAILED'] = self::__("Failed modifying counter {0}");
				$localizations['ORDERNUMBER_JS_DELETECOUNTER'] = self::__("Really delete counter '{0}' with value '{1}'?");
				$localizations['ORDERNUMBER_JS_DELETE_FAILED'] = self::__("Failed deleting counter {0}");

				// in JavaScript, object properties are accessed as ajax_object.ajax_url, ajax_object.we_value
				wp_localize_script( 'ordernumber-counter-script', 'ajax_ordernumber', $localizations );


				wp_register_script( 'ordernumber-variables-script', self::js_url( 'ordernumber-variables.js'), array('jquery') );
				wp_enqueue_script( 'ordernumber-variables-script');
			}

			/**
			 * Render the Custom Variables configuration table
			 */
			public function admin_field_variables($settings) {
				$variables = get_option( $settings['id'], array() );
				if (!is_array($variables)) {
					$variables = array();
				} ?>
		<tr valign="top">
		    <td class="forminp forminp-<?php echo sanitize_title( $settings['type'] ) ?>" colspan="2">
				<?php
					print $this->customvar_admin_table($settings['id'], $variables);
				?>
			</td>
		</tr> 
		<?php
			}
			
			protected function customvar_admin_table($id, $variables) { ?>
			
				<table id="ordernumber_variables_template" style="display:none">
					<?php echo $this->create_replacements_row_html($id, array(), 'disabled'); ?>
				</table>

				<table id="ordernumber_variables" class="ordernumber_variables widefat wc_input_table sortable" cellspacing="0">
					<?php
						$columns = array(
							'variables_ifvar'    => self::__( 'If variable ...'),
							'variables_ifop'     => '',
							'variables_ifval'    => self::__( 'Value'),
							'variables_then'     => self::__( ''),
							'variables_thenvar'  => self::__( 'Set variable ...'),
							'variables_thenval'  => self::__( 'to value ...'),
							'sort'     => '&nbsp;',
							'variables_settings' => '',
						);
					?>
					<thead>
						<tr>
							<?php
								foreach ( $columns as $key => $column ) {
									echo '<th class="' . esc_attr( $key ) . '">' . esc_html( $column ) . '</th>';
								}
							?>
						</tr>
						<tr id = "ordernumber-replacements-empty-row" class="oton-empty-row-notice <?php echo (empty($variables))?'':'rowhidden'; ?>">
							<td class="oton-empty-row-notice" colspan="8">
								<em> <?php echo self::__('No custom variables have been defined.'); ?></em>
								<input type="hidden" name="<?php echo $id; ?>" value="" <?php echo (empty($variables))?'':'disabled'; ?>>
							</td>
						</tr>
					</thead>
					<colgroup>
						<?php 
							foreach ($columns as $key => $column) {
								echo '<col class="' . esc_attr($key) . '" />';
							}
						?>
					</colgroup>

					<tbody>
						<?php
						foreach ($variables as $var) {
							echo $this->create_replacements_row_html($id, $var);
						} ?>
					</tbody>
					<tfoot>
						<tr class='addreplacement_row'>
							<td colspan=8 class='variable_add'>
								<div class='ordernumber-variables-addbtn ordernumber-btn' onClick="ordernumberVariablesAddRow('ordernumber_variables_template', 'ordernumber_variables')">
									<div class='ordernumber-ajax-loading'><img src='<?php echo self::img_url( 'icon-16-new.png' ); ?>' class='ordernumber-counter-addbtn' /></div>
									<?php _e('Add new custom variable'); ?>
								</div>
							</td>
						</tr>
					</tfoot>
				</table>
				<?php
			}

			protected function create_replacements_row_html($name, $values = array(), $disabled = '') {
				$operator = (isset($values['conditionop'])?$values['conditionop']:'');
				$operators = array(
					'equals'       => '=', 
					'contains'     => self::__('contains'), 
					'smaller'      => '<',
					'smallerequal' => '<=',
					'larger'       => '>',
					'largerequal'  => '>=', 
					'startswith'   => self::__('starts with'),
					'endswith'     => self::__('ends with'),
				);
				$html  = '
				<tr>
					<td class="oton-replacement-variable"><input name="' . $name . '[conditionvar][]" value="' . (isset($values['conditionvar'])?$values['conditionvar']:'') . '" ' . $disabled . '/></td>
					<td class="oton-replacement-op"      ><select name="' . $name . '[conditionop][]" ' . $disabled . '>';
				foreach ($operators as $op => $opname) {
					$html .= '		<option value="' . esc_attr($op) . '" ' . (($op === $operator)?'selected':'') . '>' . esc_html($opname) . '</option>';
				}
				$html .= '</td>
					<td class="oton-replacement-value"   ><input name="' . $name . '[conditionval][]" value="' . (isset($values['conditionval'])?$values['conditionval']:'') . '" ' . $disabled . '/></td>
					<td>=></td>
					<td class="oton-replacement-variable"><input name="' . $name . '[newvar][]"       value="' . (isset($values['newvar'])?$values['newvar']:'') .       '" ' . $disabled . '/></td>
					<td class="oton-replacement-newvalue"><input name="' . $name . '[newval][]"       value="' . (isset($values['newval'])?$values['newval']:'') .       '" ' . $disabled . '/></td>
					<td class="sort">&nbsp;</td>
					<td><img src="' . self::img_url( 'icon-16-delete.png' ) . '" class="ordernumber-replacement-deletebtn ordernumber-btn"></td>
				</tr>';
				return $html;
			}
			
			/** 
			 * Store the variable replacements array into the options. Need to transpose the array before we can store it into the options...
			 * This filter is called directly before the option is saved.
			 */
			public function update_option_variables ($value) {
				if (!is_array($value)) 
					return array();
				$keys = array_keys($value);
				$vallist = array();
				
				foreach (array_keys($value[$keys[0]]) as $i) {
					$entry = array();
					foreach ($keys as $k) {
						$entry[$k] = $value[$k][$i];
					}
					$vallist[] = $entry;
				}
				return $vallist;
			}

			
			/**
			 * Render the Counter Values modification table
			 */
			public function admin_field_counters ($settings) {
				// Description handling
				$field_description = WC_Admin_Settings::get_field_description( $settings );
				extract( $field_description );

				// First, get all counter names:
				$counters = array();
				$pfxlen = strlen($this->ordernumber_counter_prefix );
				foreach (wp_load_alloptions() as $name => $value) {
					if (substr($name, 0, $pfxlen) == $this->ordernumber_counter_prefix) {
						$parts = explode('-', substr($name, $pfxlen), 2);
						if (sizeof($parts)==1) {
							array_unshift($parts, 'ordernumber');
						}
						$counters[] = array(
							'type' => $parts[0],
							'name' => $parts[1],
							'value' => $value,
						);
					}
				} 
				?>

				
		<tr valign="top">
			<th scope="row" class="titledesc">
				<label for="<?php echo esc_attr( $settings['id'] ); ?>"><?php echo esc_html( $settings['title'] ); ?></label>
				<?php echo $tooltip_html; ?>
			</th>
		    <td class="forminp forminp-<?php echo sanitize_title( $settings['type'] ) ?>">
				<img src='<?php echo self::img_url( 'loading.gif' ); ?>' class='wc-ordernumber-loading' style="display: none; position: absolute; top: 2px; left: 0px; z-index: 9999;"/>
				<table class="wc_ordernumber_counters widefat" cellspacing="0">
					<?php
						$columns = apply_filters( 'woocommerce_ordernumber_counters_columns', array(
							'type'     => self::__( ''),
							'name'     => self::__( 'Counter name'),
							'value'    => self::__( 'Counter value'),
							'settings' => ''
						) );
					?>
					<thead>
						<tr>
							<?php
								foreach ( $columns as $key => $column ) {
									echo '<th class="counter_' . esc_attr( $key ) . '">' . esc_html( $column ) . '</th>';
								}
							?>
						</tr>
					</thead>
					<colgroup>
						<?php 
							foreach ($columns as $key => $column) {
								echo '<col class="counter_' . esc_attr($key) . '" />';
							}
						?>
					</colgroup>

					<tbody>
						<?php
						foreach ($counters as $counter) {
							echo $this->create_admin_counter_row($counter['type'], $counter['name'], $counter['value']);
						} 
						?>
					</tbody>
					<tfoot>
						<tr class='addcounter_row'>
							<td class="counter_type"></td>
							<td colspan=3 class='counter_add'>
								<div class='ordernumber-counter-addbtn ordernumber-btn' onClick="ajaxAddCounter(this, 'ordernumber')">
									<div class='ordernumber-ajax-loading'><img src='<?php echo self::img_url( 'icon-16-new.png' ); ?>' class='ordernumber-counter-addbtn' /></div>
									<?php _e('Add new counter'); ?>
								</div>
							</td>
						</tr>
					</tfoot>
				</table>
			</td>
		</tr> 
		<?php
			}
			
			public function create_admin_counter_row ($type, $format, $value=0) {
				$html =	"
					<tr class='counter_row counter_type_" . $type . "'>
						<td class='counter_type'>" . self::__($type, 'wooocommerce-advanced-ordernumbers' ) . "</td>
						<td class='counter_format'>" . (empty($format)?("<i>".self::__("[Global]")."</i>"):esc_html($format)) . "</td>
						<td class='counter_value'>" . esc_html($value) . "</td>
						<td class='counter_buttons'>
							<div class='ordernumber-ajax-loading'>
							<img src='" . self::img_url( 'icon-16-edit.png' ) . "' 
										class='ordernumber-counter-editbtn ordernumber-btn' 
										onClick='ajaxEditCounter(this, " . json_encode($type) . ", " . json_encode($format) . ", " . json_encode($value) . ")' />
							</div>
							<div class='ordernumber-ajax-loading'>
								<img src='" . self::img_url( 'icon-16-delete.png' ) . "' 
										class='ordernumber-counter-deletebtn ordernumber-btn' 
										onClick='ajaxDeleteCounter(this, " . json_encode($type) . ", " . json_encode($format) . ", " . json_encode($value) . ")' />
							</div>
						</td>
					</tr>";
				return $html;
			}
			
			
			/** 
			 * Hook to add the order numer post meta field to the searchable field 
			 * (so the admin can search for the order number in the backend)
			 */
			public function order_search_fields($fields) {
				$fields[] = $this->ordernumber_meta;
				return $fields;
			}
			
			/**
			 * Sort the order list's "Order" column by our post meta rather than by ID
			 */
			public function modify_order_column_sortkey($columns) {
				$custom = array(
					'order_title' => $this->ordernumber_meta,
				);
				// Use the passed columns as "default", so effectively, only the order_title will be changed:
				return wp_parse_args ($custom, $columns);
			}
			
			/**
			 * Add the "create new order number" action to the edit order page in the Backend
			 */
			public function add_order_action_new_number($actions) {
				$actions['assign_new_ordernumber'] = self::__('Assign a new order number');
			}
			/**
			 * Handle the "Assign a new order number" action from the edit order page in the backend
			 */
			public function order_action_assign_new_ordernumber( $order ) {
				$number = $this->create_ordernumber($order->id, $order, 'ordernumber');
			}
			
			
			/** 
			 * Handle new posts created in the frontend. This action will be called for all posts, 
			 * not only for orders, so we need to check explicitly. Also, this function will be called
			 * for order updates, so we need to check the update argument, too.
			 */
			public function check_create_ordernumber($post_id, $post, $update) {
				// Is the post really an order?
				// Order numbers are only assigned to orders on creation, not when updating!
				if ($post->post_type != 'shop_order') {
					return;
				} else {
					// Handle new admin-created orders, where the address is entered later on!
					// Assign an order number:
					$number = $this->assign_new_ordernumber($post_id, $post, $update);
				}
				
			}

			/**
			 * Counter handling (simple loading/storing counters), storing them as options
			 */
			function _getCounter($type, $format, $start=0) {
				$count = get_option ($this->ordernumber_counter_prefix.$type.'-'.$format, $start);
				return $count;
			}
			// Insert new counter value into the db or update existing one
			function _setCounter($type, $format, $value) {
				return update_option($this->ordernumber_counter_prefix.$type.'-'.$format, $value);
			}
			function _deleteCounter($type, $format) {
				return delete_option($this->ordernumber_counter_prefix.$type.'-'.$format);
			}
			
			public function counter_delete_callback() {
				$json = array('action' => 'delete_counter', 'success' => 0);
				$json['success'] = $this->_deleteCounter($_POST['nrtype'], $_POST['counter']);
				wp_send_json($json);
			}

			public function counter_add_callback () {
				$type = $_POST['nrtype'];
				$format = $_POST['counter'];
				$value = isset($_POST['value'])?$_POST['value']:"0";
				$json = array('action' => 'add_counter', 'success' => 0);
				if ($this->_getCounter($type, $format, -1) != -1) {
					// Counter already exists => error message
					$json['error'] = sprintf(self::__('Counter "%s" already exists, cannot create again.'), $format);
				} else {
					$json['success'] = $this->_setCounter($type, $format, $value);
					$json['newrow']  = $this->create_admin_counter_row($type, $format, $value);
				}
				wp_send_json($json);
			}
			
			public function counter_set_callback () {
				$json = array('action' => 'set_counter', 'success' => 0);
				$json['success'] = $this->_setCounter($_POST['nrtype'], $_POST['counter'], $_POST['value']);
				wp_send_json($json);
			}
			
			
			/** ***********************************************************
			 * 
			 *  REPLACEMENT FUNCTIONS
			 *
			 **************************************************************/
			
			/* Return a random "string" of the given length taken from the given alphabet */
			static function randomString($alphabet, $len) {
				$alen = strlen($alphabet);
				$r = "";
				for ($n=0; $n<$len; $n++) {
					$r .= $alphabet[mt_rand(0, $alen-1)];
				}
				return $r;
			}

			function replaceRandom ($match) {
				/* the regexp matches (random)(Type)(Len) as match, Type and Len is optional */
				$len = ($match[3]?$match[3]:1);
				// Fallback: If no Type is given, use Digit
				$alphabet = "0123456789";
				// Select the correct alphabet depending on Type
				switch (strtolower($match[2])) {
					case "digit": $alphabet = "0123456789"; break;
					case "hex": $alphabet = "0123456789abcdef"; break;
					case "letter": $alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; break;
					case "uletter": $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; break;
					case "lletter": $alphabet = "abcdefghijklmnopqrstuvwxyz"; break;
					case "alphanum": $alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; break;
				}
				return self::randomString ($alphabet, $len);
			}
	
			protected function setupDateTimeReplacements (&$reps, $order, $nrtype) {
				$utime = microtime(true);
				$reps["[year]"] = date ("Y", $utime);
				$reps["[year2]"] = date ("y", $utime);
				$reps["[month]"] = date("m", $utime);
				$reps["[day]"] = date("d", $utime);
				$reps["[hour]"] = date("H", $utime);
				$reps["[hour12]"] = date("h", $utime);
				$reps["[ampm]"] = date("a", $utime);
				$reps["[minute]"] = date("i", $utime);
				$reps["[second]"] = date("s", $utime);
				$milliseconds = (int)(1000*($utime - (int)$utime));
				$millisecondsstring = sprintf('%03d', $milliseconds);
				$reps["[decisecond]"] = $millisecondsstring[0];
				$reps["[centisecond]"] = substr($millisecondsstring, 0, 2);
				$reps["[millisecond]"] = $millisecondsstring;
			}

			protected function setupAddressReplacements(&$reps, $prefix, $address, $nrtype) {
				$reps["[email]"]     = $address->billing_email;
				$reps["[firstname]"] = $address->billing_first_name;
				$reps["[lastname]"]  = $address->billing_last_name;

				$reps["[company]"]   = $address->billing_company;
				$reps["[zip]"]       = $address->billing_postcode;
				$reps["[postcode]"]  = $address->billing_postcode;
				$reps["[city]"]      = $address->billing_city;
        
				$country = $address->billing_country;
				$state = $address->billing_state;
				$allcountries = WC()->countries->get_countries();
				$states = WC()->countries->get_states($country);
				$reps["[country]"]     = $country;
				$reps["[countryname]"] = ( isset( $allcountries[ $country ] ) ) ? $allcountries[ $country ] : $country;

				$reps["[state]"]       = $state;
				$reps["[statename]"]   = ( $country && $state && isset( $states[ $country ][ $state ] ) ) ? $states[ $country ][ $state ] : $state;
			}
			
			protected function setupStoreReplacements (&$reps, $order, $nrtype) {
			}
    
			protected function setupOrderReplacements (&$reps, $order, $nrtype) {
				$reps["[orderid]"] = $order->id;
				$reps["[ipaddress]"]   = $order->customer_ip_address;
				
				if ($nrtype != 'ordernumber') {
					$reps["[ordernumber]"] = $order->get_order_number();
				}
				$reps["[orderstatus]"] = $order->get_status();
				$reps["[currency]"]    = $order->get_order_currency();
				$reps["[userid]"]      = $order->get_user_id();

				$this->setupAddressReplacements($reps, "", $order, $nrtype);
	
				$reps["[articles]"]    = $order->get_item_count();
// 				$reps["[downloadpermitted]"] = $order->is_download_permitted();
// 				$reps["[hasdownloads]"] = $order->has_downloadable_item();
// 				$reps["[coupons]"] = $order->get_used_coupons();
				$reps["[ordertotal]"]      = $order->get_total();
				$reps["[amount]"]      = $order->get_total();
				$reps["[ordersubtotal]"]      = $order->get_subtotal();
				$reps["[totaltax]"]      = $order->get_total_tax();
				$reps["[totalshipping]"]      = $order->get_total_shipping();
			}
   
			protected function setupShippingReplacements(&$reps, $order, $nrtype) {
// 				$reps["[shippingmethod]"] = $order->getShippingMethod();
			}
			
			/*protected function setupInvoiceReplacements (&$reps, $invoice, $order, $nrtype) {
				$reps["[invoiceid]"] = $invoice->getId();
			}*/

			protected function setupReplacements($nrtype, $order) {
				$reps = array();
				$this->setupDateTimeReplacements($reps, $order, $nrtype);
				$this->setupStoreReplacements($reps, $order, $nrtype);
				$this->setupOrderReplacements($reps, $order, $nrtype);
				$this->setupShippingReplacements($reps, $order, $nrtype);
				$reps = apply_filters( 'opentools_ordernumber_replacements', $reps, $order, $nrtype);
				return $reps;
			}

			
			protected function setupCustomVariables ($nrtype, $order, $reps, $customvars) {
				foreach ($customvars as $c) {
					$conditionvar = strtolower($c['conditionvar']);
					$op = $c['conditionop'];

					$found = false;
					$match = false;
					$compareval = null;

					if (isset($reps[$conditionvar])) {
						$found = true;
						$compareval = $reps[$conditionvar];
					} elseif (isset($reps['['.$conditionvar.']'])) {
						$found = true;
						$compareval = $reps['['.$conditionvar.']'];
					}/* elseif ($order && $compareval = $order->getData($conditionvar)) {
						// TODO: Handle order property
						$found = true;
					}*/ else {
						// TODO: Handly other possible properties!
						// TODO: Print out warning that variable could not be found.
					}
					if ($found) {
						$condval = $c['conditionval'];
						switch ($op) {
							case 'equals': 
									$match = ($compareval == $condval); break;
							case 'contains':
									if (is_array($compareval)) {
										$match = in_array($condval, $compareval);
									} else {
										$match = strpos ($compareval, $condval);
									}
									break;
							case 'smaller':
									$match = ($compareval<$condval); break;
							case 'smallerequal':
									$match = ($compareval<=$condval); break;
							case 'larger':
									$match = ($compareval>$condval); break;
							case 'largerequal':
									$match = ($compareval>=$condval); break;
							case 'startswith':
									$match = (substr("$compareval", 0, strlen("$condval")) === "$condval"); break;
							case 'endswith':
									$match = (substr("$compareval", -strlen("$condval")) === "$condval"); break;
						}
					} elseif (empty($conditionvar)) {
						$match = true;
					}
					if ($match) {
						$varname = '['.strtolower($c['newvar']).']';
						$reps[$varname] = $c['newval'];
					}
				}
				return $reps;
			}

			// Allow the user to override the format like any other custom variable:
			protected function setupNumberFormatString($fmt, $type, $order, $reps) {
				if (isset($reps['['.$type.'_format]'])) {
					return $reps['['.$type.'_format]'];
				} else {
					return $fmt;
				}
			}
			
			protected function doReplacements ($fmt, $reps) {
				// First, replace all random...[n] fields. This needs to be done with a regexp and a callback:
				$fmt = preg_replace_callback ('/\[(random)(.*?)([0-9]*?)\]/', array($this, 'replaceRandom'), $fmt);
				return str_ireplace (array_keys($reps), array_values($reps), $fmt);
			}
			
			protected function extractCounterSettings ($fmt, $type, $ctrsettings) {
				// First, extract all counter settings, i.e. all strings of the form [#####:startval/increment] or [####/increment:startval]
				$regexp = '%\[(#+)(/([0-9]+))?(:([0-9]+))?(/([0-9]+))?\]%';
// 				$counters = array();
				
				if (preg_match($regexp, $fmt, $counters)) {
					// $counters is an array of the form:
					// Array (
					// 		[0] => [#####:100/3]
					// 		[1] => #####
					// 		[2] => 
					// 		[3] => 
					// 		[4] => :100
					// 		[5] => 100
					// 		[6] => /3
					// 		[7] => 3
					// )
					$ctrsettings["${type}_padding"] = strlen($counters[1]);
					if (!empty($counters[2])) {
						// $counters[2] contains the whole "/n" part, while $counters[3] contains just the step itself
						$ctrsettings["${type}_step"] = $counters[3]; 
					}
					if (!empty($counters[4])) {
						// $counters[4] contains the whole ":n" part, while $counters[5] contains just the start value itself
						$ctrsettings["${type}_start"] = $counters[5]; 
					}
					
					if (!empty($counters[6])) {
						// $counters[6] contains the whole ":n" part, while $counters[7] contains just the start value itself
						$ctrsettings["${type}_step"] = $counters[7]; 
					}
					
// print("<pre>Counters regexp matches: ".print_r($counters,1)."</pre>");
// 					$ctrsettings["${type}_padding"] = 
					$fmt = preg_replace($regexp, "#", $fmt);
				} else {
// print("<pre>No counters match the regexp '$regexp' in the format '$fmt'</pre>");
				}
				// Replace all extended counter definitions by a single #
				
				// Split at a | to get the number format and a possibly different counter increment format
				// If a separate counter format is given after the |, use it, otherwise reuse the number format itself as counter format
				
				
				$parts = explode ("|", $fmt);
				$ctrsettings["${type}_format"] = $parts[0];
				
				$ctrsettings["${type}_counter"] = ($ctrsettings["${type}_global"]=='yes')?"":$parts[(count($parts)>1)?1:0];
				
// print("<pre>Counter settings are: ".print_r($ctrsettings,1)."</pre>");
				return $ctrsettings;
			}

			/* replace the variables in the given format. $type indicates the type of number, currently only 'ordernumber', because WooCommerce does not support invoices or customer numbers. We might allow the shop owner to customize the order password, though. */
			function createNumber ($fmt, $type, $order, $customvars, $ctrsettings) {
				$reps   = $this->setupReplacements ($type, $order);
				$reps   = $this->setupCustomVariables ($type, $order, $reps, $customvars);
				$format = $this->setupNumberFormatString($fmt, $type, $order, $reps);
				$format = $this->doReplacements($format, $reps);
				$ctrsettings = $this->extractCounterSettings ($format, $type, $ctrsettings);
        
				$countername = $ctrsettings["${type}_counter"];
				// Look up the current counter
				$count = $this->_getCounter($type, $countername, $ctrsettings["${type}_start"] - $ctrsettings["${type}_step"]) + $ctrsettings["${type}_step"];
				$this->_setCounter($type, $countername, $count);
				// return the format with the counter inserted
				$number = str_replace ("#", sprintf('%0' . $ctrsettings["${type}_padding"] . 's', $count), $ctrsettings["${type}_format"]);
				return $number;
			}
			
			function create_ordernumber($orderid, $order, $type='ordernumber') {
				if (get_option('customize_'.$type, 'false')) {
					$fmt     = get_option ($type.'_format',  "#");
					$ctrsettings = array(
						"${type}_format"  => '',
						"${type}_counter" => '',
						"${type}_global"  => get_option ($type.'_global',  'no'),
						"${type}_padding" => 1,
						"${type}_step"    => 1,
						"${type}_start"   => 1,
// 						"${type}_padding" => get_option ($type.'_padding', 1),
// 						"${type}_step"    => get_option ($type.'_step',    1),
// 						"${type}_start"   => get_option ($type.'_start',   1),
					);
					$customvars = get_option ('ordernumber_variables',   array());

					$number = $this->createNumber ($fmt, $type, $order, $customvars, $ctrsettings);
					update_post_meta( $orderid, $this->ordernumber_meta, $number );
					return $number;
				} else {
					return $orderid;
				}
			}
			
			/** 
			 * The hook to assign a customized order number (unless the order already has one assigned)
			 */
			function assign_new_ordernumber($orderid, $order, $update=true) {
				if ((!$update) /*&& ($order->post_status == 'auto-draft')*/) {
					// New order => assign placeholder, which will later be overwritten the real order number
					update_post_meta( $orderid, $this->ordernumber_meta, $this->ordernumber_new_placeholder );
				}
				// If we do not have an order (yet), we cannot proceed. But we probably have created the 
				// ordernumber placeholder for that post, so this function has done its job and we can return
				if (!$order instanceof WC_Order) {
					return;
				}
				$number = get_post_meta( $orderid, $this->ordernumber_meta, 'true');
				if ($number == $this->ordernumber_new_placeholder && $order->post_status != 'auto-draft') {
					$number = $this->create_ordernumber($orderid, $order, 'ordernumber');
					// Assign a new number
				}
				return $number;
			}

			/** 
			 * The hook to customize order numbers (requests the order number from the database; creates a new ordernumber if no entry exists in the database)
			 */
			function get_ordernumber($orderid, $order) {
				$stored_number = get_post_meta( $orderid, $this->ordernumber_meta, 'true');
				if ($stored_number == $this->ordernumber_new_placeholder) {
					// Check whether the order was now really created => create order number now
					return $this->assign_new_ordernumber($orderid, $order);
				} elseif (!empty($stored_number)) {
					// Order number already exists => simply return it
					return $stored_number;
				} else {
					// No order number was created for this order, so simply use the orderid as default.
					return $orderid;
				}
			}

		}
	}

	if (class_exists("OpenToolsOrdernumbers")) {
		// Installation and uninstallation hooks
		register_activation_hook(__FILE__, array('OpenToolsOrdernumbers', 'activate'));
		register_deactivation_hook(__FILE__, array('OpenToolsOrdernumbers', 'deactivate'));

		// instantiate the plugin class
		$ordernumber_plugin = new OpenToolsOrdernumbers();
	}
 
}