<?php
/**
 * @file
 * Prevents from adding products to cart with insufficient stock level.
 */

/**
 * Implements hook_form_alter().
 */
function uc_stock_validate_form_alter(&$form, &$form_state, $form_id) {
  if (strstr($form_id, 'uc_product_add_to_cart_form')) {
    // Avoid overwriting of any other element validation functions.
    if (!isset($form['qty']['#element_validate'])) {
      $form['qty']['#element_validate'] = array();
    }
    
    // Add our validation function directly to the quantity form element.
    $form['qty']['#element_validate'][] = 'uc_stock_validate_quantity';
  }
}

/**
 * Implements hook_form_uc_cart_view_form_alter().
 */
function uc_stock_validate_form_uc_cart_view_form_alter(&$form, &$form_state, $form_id) {
  foreach (element_children($form['items']) as $item) {
    if (isset($form['items'][$item]['qty'])) {
      // Avoid overwriting of any other element validation functions.
      if (!isset($form['items'][$item]['qty']['#element_validate'])) {
        $form['items'][$item]['qty']['#element_validate'] = array();
      }
    
      // Add our validation function directly to the quantity form element.
      $form['items'][$item]['qty']['#element_validate'][] = 'uc_stock_validate_quantity';
    }
  }
}

/**
 * Validate a qty form element.
 */
function uc_stock_validate_quantity($element, &$form_state, $form)  {
  // Don't validate if user tries to remove the product.
  if (strstr($form_state['clicked_button']['#name'], 'remove')) {
    return;
  }

	$attributes = "";

  // Find the right SKU for this product combination before checking stock
  if ($form['#form_id'] == 'uc_cart_view_form') {
    // Cart overview/edit form
    $cart_product_index = $element['#parents'][1];
    $product = $form_state['values']['items'][$cart_product_index];
    $nid = $product['nid'];
    $data = unserialize($product['data']);
    $attributes = $data['attributes'];
  
  }
  else {
    $nid = $form_state['values']['nid'];
		if(!empty($form_state['values']['attributes'])){
			$attributes = $form_state['values']['attributes'];
		}
  }
  
	// Product with attributes
	if(!empty($attributes)){
	  ksort($attributes); // Need to sort attributes by key to match those in {uc_product_stock}
	  // Fetch the SKU from {uc_product_adjustments}
	  $sku = db_query("SELECT model FROM {uc_product_adjustments} WHERE nid = :nid AND combination = :combination", array(':nid' => $nid, ':combination' => serialize($attributes)))->fetchField();
	}
	// Product without attributes
	else {
	  // Fetch the SKU from {uc_products}
	  $sku = db_query("SELECT model FROM {uc_products} WHERE nid = :nid", array(':nid' => $nid))->fetchField();
	}

	// Update qty from cart
  if ($form_state['clicked_button']['#name'] == 'update-cart') {
		$qty = $element['#value'];
  }
	// Add to cart from product 
	else {
		// Fetch the qty in cart from {uc_cart_products}
		$qty_cart = db_query("SELECT qty FROM {uc_cart_products} WHERE nid = :nid", array(':nid' => $nid))->fetchField();

		// Add qty of cart to the qty 
		$qty = $qty_cart + $element['#value'];
	}

  // Verify stock level
  $stock_level = _uc_stock_validate_level($sku, $qty, $form['#form_id']);

  if ($stock_level !== TRUE) {
    form_error($element, $stock_level);
  }
}

/**
 * Validate stock level of a specific product. 
 */
function _uc_stock_validate_level($sku = NULL, $qty = 1, $form_id = NULL) {
  // Get stock level of the product's SKU.
  $stock_level = uc_stock_level($sku);
 
  // If no stock level is set, we can skip further validation.
  if ($stock_level === FALSE) {
    return TRUE;
  }
  
  if ($stock_level <= 0) {
    //return t('This product is currently not available in stock with your selected options.');        
    preg_match_all('!\d+!', $form_id, $matches);                                     
    $prod_id = $matches[0][0];                                                       
    $date_of_expiry = time() +7200;                                                  
    setcookie("pds[" . $prod_id . "]", "ano", $date_of_expiry, "/", ".nasastopa.sk"); 
    return TRUE;                                                                      
  }
  
  // Check if selected quantity exceeds available product quantity.
  else if ($stock_level < $qty) {
    
    if ($stock_level == 1) {
			$str = t('Insufficient stock level. Only one product left.');
    }
    else {
      $str = t('Insufficient stock level. Only !number products left.', array('!number' => $stock_level));
    }
    
    $correct_qty = "";
		// If the user add to cart from the product, text "correct selected qty" is not necesary  
    if(strpos($form_id, 'uc_product_add_to_cart_form') === false){
 			$correct_qty = t('Please correct the selected quantity.');
       
    $cart_product_index = $element['#parents'][1];                                        //AKO ZISKAT  $NID?
    $product = $form_state['values']['items'][$cart_product_index];                       //AKO ZISKAT  $NID?
    $nid = $product['nid'];                                                               //AKO ZISKAT  $NID?
    $date_of_expiry = time() +7200;                                                  
    setcookie("pds[" . $nid . "]", "ano", $date_of_expiry, "/", ".nasastopa.sk"); 
          
    }
    
    //return $str.' '.$correct_qty;                                                  
                                                                                      
    preg_match_all('!\d+!', $form_id, $matches);                                     
    $prod_id = $matches[0][0];                                                       
    $date_of_expiry = time() +7200;                                                  
    setcookie("pds[" . $prod_id . "]", "ano", $date_of_expiry, "/", ".nasastopa.sk"); 
    return TRUE;                                                                      
  }
  
    preg_match_all('!\d+!', $form_id, $matches);                                     
    $prod_id = $matches[0][0];                                                       
    $date_of_expiry = time() -7200;                                                  
    setcookie("pds[" . $prod_id . "]", "ano", $date_of_expiry, "/", ".nasastopa.sk");                                                          
   return TRUE;
}