<?php
// $Id: uc_aac.module,v 1.10.2.21 2010/08/09 17:59:35 cyu Exp $

/**
 * @file
 * Ajax Attribute Calculations
 *
 * Updates product information using AJAX whenever a product attribute is
 * altered. Also updates the attribute adjustments dynamically if they are
 * configured to display.
 */


/******************************************************************************
 * Drupal Hooks
 *****************************************************************************/

/**
 * Implementation of hook_menu().
 */
function uc_aac_menu() {
  $items['uc_aac'] = array(
    'title' => t('Product Adjustments'),
    'description' => t('Calculate the price of your product.'),
    'page callback' => '_uc_aac_calculate',
    'access arguments' => array('access content'),
    'weight' => 5,
    'type' => MENU_CALLBACK,
  );

  return $items;
}

/**
 * Implementation of hook_form_alter().
 */
function uc_aac_form_alter(&$form, $form_state, $form_id) {
  if (strstr($form_id, 'uc_product_add_to_cart_form')) {
    static $uc_aac_js = FALSE;

    // Add a class to the cart form. This will allow us to easily identify it for binding ajax stuff.
    $form['#attributes']['class'] .= ' uc-aac-cart';

    if (!$uc_aac_js) {
      $uc_aac_js = TRUE;

      drupal_add_js('misc/jquery.form.js');
      drupal_add_js(drupal_get_path('module', 'uc_aac') .'/uc_aac.js');
      // Call uc_aac_calculate once for each form on page load
      drupal_add_js("$('.attributes').find('[name^=attributes]:first').each(function(i) { ucAacCalculate(this); });", 'inline', 'footer');
      // Best that I can do until http://drupal.org/node/481560 goes in.
      drupal_add_js(array('uc_aac_path' => url('uc_aac')), 'setting');
    }

    // If the product has attributes.
    if (isset($form['#parameters'][2]->attributes)) {
      $nid = $form['nid']['#value'];
      $product =& $form['#parameters'][2];

      // Add the products nid to the form, to avoid parsing formid's for an NID that may not exist.
      $form['aac_nid'] = array(
        '#type' => 'hidden',
        '#value' => $nid,
      );

      // Use qty from post or use default qty
      if (isset($_POST['qty'])) {
        $form['qty']['#default_value'] = check_plain($_POST['qty']);
      }
      else {
        $form['qty']['#default_value'] = $product->default_qty;
      }

      $context = array(
        'revision' => 'formatted',
        'type' => 'product',
        'class' => array(
          'product',
        ),
        'subject' => array(
          'node' => $product,
        ),
      );

      foreach (element_children($form['attributes']) as $aid) {
        // Reset options for each $aid
        $options = array();
        $selected_oid = array();

        if (isset($_POST['attributes'][$aid])) {
          if (is_array($_POST['attributes'][$aid])) {
            foreach ($_POST['attributes'][$aid] as $key => $value) {
              $selected_oid[] = check_plain($value);
            }
          }
          else {
            $selected_oid = check_plain($_POST['attributes'][$aid]);
          }
        }
        else {
          $selected_oid = $product->attributes[$aid]->default_option;
        }

        // TODO: Find out why the default checkbox option is not always an array.
        if ($form['attributes'][$aid]['#type'] == 'checkboxes' && !is_array($selected_oid)) {
          $selected_oid = array();
        }
        // TODO: Find out why the default text option is not always an empty string.
        if ($form['attributes'][$aid]['#type'] == 'textfield') {
          $selected_oid = ($selected_oid === '0' ? '' : $selected_oid);
        }
        $form['attributes'][$aid]['#default_value'] = $selected_oid;

        // If reprice is enabled and price adjustments are to be displayed
        if (variable_get('uc_aac_reprice', 1) == 1 && (variable_get('uc_attribute_option_price_format', 'adjustment') == 'adjustment'
            || (count(uc_attribute_priced_attributes($nid)) > 1) && variable_get('uc_attribute_option_price_format', 'adjustment') != 'none')) {
          foreach ($product->attributes[$aid]->options as $option) {
            if ($form['attributes'][$aid]['#type'] == 'checkboxes') {
              // Negate selected options
              if (in_array($option->oid, $selected_oid)) {
                $price = -$option->price;
              }
              else {
                $price = $option->price;
              }
            }
            else {
              $price = $option->price - $product->attributes[$aid]->options[$selected_oid]->price;
            }

            // Rebuild option text
            $oid_text = '';
            if ($price != 0) {
              $oid_text = ', ';
              if ($price > 0) {
                $oid_text .= '+'. uc_price($price, $context);
              }
              else {
                $oid_text .= '('. uc_price($price, $context) .')';
              }
            }
            $options[$option->oid] = $option->name . $oid_text;
          }
        }

        // If options have been reconfigured
        if (!empty($options)) {
          $form['attributes'][$aid]['#options'] = $options;
        }
      }
    }
  }
  elseif ($form_id == 'uc_attribute_admin_settings') {
    $form['uc_attribute_option_price_format']['uc_aac_reprice'] = array(
      '#type' => 'checkbox',
      '#title' => t('Ajax Attribute Calculations dynamically adjusts product information as a product\'s attribute options are changed.'),
      '#default_value' => variable_get('uc_aac_reprice', 1),
      '#weight' => 0,
      '#description' => t('When checked, a customer\'s selected attributes will display no price adjustment and all other attribute prices will be relative to the current price.'),
    );
  }
}


/******************************************************************************
 * Module Functions
 *****************************************************************************/

/**
 * Calculate product adjustments based on attribute option selections.
 */
function _uc_aac_calculate() {
  //@todo use filter_input_array() instead of is_array and check_plain and require PHP 5.2
  // If the nid is not set, we can't do anything.
  if (!is_numeric($_POST['aac_nid'])) {
    return;
  }
  $nid = $_POST['aac_nid'];
  $form_id = $_POST['form_id'];
  // $_POST['attributes'] can be empty if only checkbox attributes are on the product and none are checked.
  $attributes = isset($_POST['attributes']) ? $_POST['attributes'] : array();

  $output['nid'] = $nid;

  // Load the node and store the submitted data for later.
  $product = node_load($nid);

  // Create a fake cart item with the submitted node, quantity and attributes.
  $item = new stdClass();
  $item->nid = $nid;
  $item->qty = check_plain($_POST['qty']);
  $item->model = $product->model;
  $item->cost = $product->cost;
  $item->price = $product->sell_price;
  $item->weight = $product->weight;
  $item->data = unserialize($product->data);
  $item->data['nid'] = $nid;
  foreach ($attributes as $key => $value) {
    $key = check_plain($key);
    if (is_array($value)) {
      foreach ($value as $array_key => $array_value) {
        $item->data['attributes'][$key][check_plain($array_key)] = check_plain($array_value);
      }
    }
    else {
      $item->data['attributes'][$key] = check_plain($value);
    }
  }

  // Let other modules adjust our cart item as needed.
  $item->data = module_invoke_all('add_to_cart_data', $item->data);

  // Invoke hook_cart_item() with $op = 'load' in enabled modules.
  foreach (module_list() as $module) {
    $func = $module .'_cart_item';
    if (function_exists($func)) {
      // $item must be passed by reference.
      $func('load', $item);
    }
  }

  $context = array(
    'revision' => 'themed',
    'type' => 'product',
    'class' => array(
      'product',
    ),
    'subject' => array(
      'node' => $product,
    ),
  );

  // Render the updated display price
  $context['class'][1] = 'display';
  $context['field'] = 'sell_price';
  $output['replacements']['display'] = theme('uc_product_price', $item->price, $context);

  // Render the updated model
  $output['replacements']['model'] = theme('uc_product_model', $item->model, 0, 0);

  // Render the updated cost
  $context['class'][1] = 'cost';
  $context['field'] = 'cost';
  $output['replacements']['cost'] = theme('uc_product_price', $item->cost, $context);

  // Render the updated sell price
  $context['class'][1] = 'sell';
  $context['field'] = 'sell_price';
  $output['replacements']['sell'] = theme('uc_product_price', $item->price, $context, array('label' => 1));

  // Render the updated weight
  $output['replacements']['weight'] = theme('uc_product_weight', $item->weight, $product->weight_units, 0, 0);

  // Unset the form id to ensure Drupal doesn't attempt to process it.
  unset($_POST['form_id']);
  // Render the updated form
  // If the original form used the nid, then add it.
  if (strstr($form_id, 'uc_product_add_to_cart_form_')) {
    $output['form'] = drupal_get_form('uc_product_add_to_cart_form_'. $nid, $product);
  }
  // Otherwise use the non-standard form.
  else {
    $output['form'] = drupal_get_form('uc_product_add_to_cart_form', $product);
  }

  // TODO: Fix bug where multiple add_to_cart forms on a single page have
  // elements with identical css id's after regenerating the forms
  // http://drupal.org/node/384992
  drupal_json($output);
  exit;
}