taxes/tax_calc.inc

   1 <?php
   2
   3 include_once($path_to_root . "/taxes/db/tax_groups_db.inc");
   4 include_once($path_to_root . "/taxes/db/tax_types_db.inc");
   5 include_once($path_to_root . "/taxes/db/item_tax_types_db.inc");
   6
   7 //---------------------------------------------------------------------------------
   8
   9 // returns the tax cost for a given item
  10 /*
  11 function get_tax_value_for_item($stock_id, $price, $tax_group)
  12 {
  13         // if price is zero, then can't be taxed
  14         if ($price == 0)
  15                 return 0;
  16
  17         $ret_tax_array = get_tax_group_items_as_array($tax_group);
  18
  19         $tax_array = get_taxes_for_item($stock_id, $ret_tax_array);
  20         if ($tax_array == null)
  21                 return 0;
  22
  23         $tax_multiplier = 0;
  24
  25         // loop for all items
  26         foreach ($tax_array as $taxitem) {
  27                 $tax_multiplier += $taxitem["rate"];
  28         }
  29
  30         return $price * ($tax_multiplier / 100);
  31 }
  32 */
  33 //---------------------------------------------------------------------------------
  34
  35 // returns the price of a given item minus any included taxes
  36 // for item $stock_id with line price $price,
  37 // with applicable tax rates $tax_group_array or group id $tax_group
  38 //
  39
  40 function get_tax_free_price_for_item($stock_id, $price, $tax_group, $tax_included, $tax_group_array=null)
  41 {
  42         // if price is zero, then can't be taxed !
  43         if ($price == 0)
  44                 return 0;
  45
  46         if ($tax_included==0) return $price;
  47
  48         // if array already read, then make a copy and use that
  49         if ($tax_group_array)
  50                 $ret_tax_array = $tax_group_array;
  51         else
  52                 $ret_tax_array = get_tax_group_items_as_array($tax_group);
  53
  54         //print_r($ret_tax_array);
  55
  56         $tax_array = get_taxes_for_item($stock_id, $ret_tax_array);
  57         // if no exemptions or taxgroup is empty, then no included/excluded taxes
  58         if ($tax_array == null)
  59                 return $price;
  60
  61         $tax_multiplier = 0;
  62
  63         // loop for all items
  64
  65         foreach ($tax_array as $taxitem)
  66         {
  67                         $tax_multiplier += $taxitem["rate"];
  68         }
  69
  70         return round($price / (1 + ($tax_multiplier / 100)),  user_price_dec());
  71 }
  72 //
  73 //      Full price (incl. VAT) for item $stock_id with line price $price,
  74 //      with tax rates $tax_group_array or applicable group $tax_group
  75 //
  76 function get_full_price_for_item($stock_id, $price, $tax_group, $tax_included, $tax_group_array=null)
  77 {
  78         // if price is zero, then can't be taxed !
  79         if ($price == 0)
  80                 return 0;
  81
  82         if ($tax_included==1) return $price;
  83
  84         // if array already read, then make a copy and use that
  85         if ($tax_group_array)
  86                 $ret_tax_array = $tax_group_array;
  87         else
  88                 $ret_tax_array = get_tax_group_items_as_array($tax_group);
  89
  90         //print_r($ret_tax_array);
  91
  92         $tax_array = get_taxes_for_item($stock_id, $ret_tax_array);
  93         // if no exemptions or taxgroup is empty, then no included/excluded taxes
  94         if ($tax_array == null)
  95                 return $price;
  96
  97         $tax_multiplier = 0;
  98
  99         // loop for all items
 100
 101         foreach ($tax_array as $taxitem)
 102         {
 103                         $tax_multiplier += $taxitem["rate"];
 104         }
 105
 106         return round($price * (1 + ($tax_multiplier / 100)),  user_price_dec());
 107 }
 108
 109 //---------------------------------------------------------------------------------
 110 // return an array of (tax_type_id, tax_type_name, sales_gl_code, purchasing_gl_code, rate)
 111
 112 function get_taxes_for_item($stock_id, $tax_group_items_array)
 113 {
 114         $item_tax_type = get_item_tax_type_for_item($stock_id);
 115
 116         // if the item is exempt from all taxes then return 0
 117         if ($item_tax_type["exempt"])
 118                 return null;
 119
 120         // get the exemptions for this item tax type
 121         $item_tax_type_exemptions_db = get_item_tax_type_exemptions($item_tax_type["id"]);
 122
 123         // read them all into an array to minimize db querying
 124         $item_tax_type_exemptions = array();
 125         while ($item_tax_type_exemp = db_fetch($item_tax_type_exemptions_db))
 126         {
 127                 $item_tax_type_exemptions[] = $item_tax_type_exemp["tax_type_id"];
 128         }
 129
 130         $ret_tax_array = array();
 131
 132         // if any of the taxes of the tax group are in the exemptions, then skip
 133         foreach ($tax_group_items_array as $tax_group_item)
 134         {
 135
 136                 $skip = false;
 137
 138                 // if it's in the exemptions, skip
 139                 foreach ($item_tax_type_exemptions as $exemption)
 140                 {
 141                         if (($tax_group_item['tax_type_id'] == $exemption))
 142                         {
 143                         $skip = true;
 144                         break;
 145                         }
 146                 }
 147
 148                 if (!$skip)
 149                 {
 150                         $index = $tax_group_item['tax_type_id'];
 151                         $ret_tax_array[$index] = $tax_group_item;
 152                 }
 153         }
 154
 155         return $ret_tax_array;
 156 }
 157 //-----------------------------------------------------------------------------------
 158 // return an array of (tax_type_id, tax_type_name, sales_gl_code, purchasing_gl_code, rate, included_in_price, Value)
 159
 160 function get_tax_for_items($items, $prices, $shipping_cost, $tax_group, $tax_included=null, $tax_items_array=null)
 161 {
 162         // first create and set an array with all the tax types of the tax group
 163         if($tax_items_array!=null)
 164           $ret_tax_array = $tax_items_array;
 165         else
 166           $ret_tax_array = get_tax_group_items_as_array($tax_group);
 167
 168         // loop for all items
 169         for ($i = 0; $i < count($items); $i++)
 170         {
 171                 $item_taxes = get_taxes_for_item($items[$i], $ret_tax_array);
 172
 173                 if ($item_taxes != null)
 174                 {
 175                         foreach ($item_taxes as $item_tax)
 176                         {
 177                                 $index = $item_tax['tax_type_id'];
 178                                 if($tax_included==1) // 2008-11-26 Joe Hunt Taxes are stored without roundings
 179                                   //$ret_tax_array[$index]['Value'] += round($prices[$i] * $item_tax['rate']
 180                                   //    / ($item_tax['rate'] + 100),  user_price_dec());
 181                                   $ret_tax_array[$index]['Value'] += ($prices[$i] * $item_tax['rate'] / ($item_tax['rate'] + 100));
 182                                 else
 183                                   //$ret_tax_array[$index]['Value'] +=
 184                                   //    round($prices[$i] * $item_tax['rate'] / 100,  user_price_dec());
 185                                   $ret_tax_array[$index]['Value'] += ($prices[$i] * $item_tax['rate'] / 100);
 186                         }
 187                 }
 188         }
 189
 190         // add the shipping taxes, only if non-zero, and only if tax group taxes shipping
 191         if ($shipping_cost != 0)
 192         {
 193                 $item_taxes = get_shipping_tax_as_array();
 194                 if ($item_taxes != null)
 195                 {
 196                         foreach ($item_taxes as $item_tax)
 197                         {
 198                                 $index = $item_tax['tax_type_id'];
 199                                 if(isset($ret_tax_array[$index])) {
 200                                   if($tax_included==1) // 2008-11-26 Joe Hunt Taxes are stored without roundings
 201                                         //$ret_tax_array[$index]['Value'] += round($shipping_cost * $item_tax['rate']
 202                                         //  / ($item_tax['rate'] + 100),  user_price_dec());
 203                                         $ret_tax_array[$index]['Value'] += ($shipping_cost * $item_tax['rate'] / ($item_tax['rate'] + 100));
 204                                   else
 205                                         //$ret_tax_array[$index]['Value'] +=
 206                                         //  round($shipping_cost * $item_tax['rate'] / 100,  user_price_dec());
 207                                         $ret_tax_array[$index]['Value'] += ($shipping_cost * $item_tax['rate'] / 100);
 208                                 }
 209                         }
 210                 }
 211         }
 212
 213         //print_r($ret_tax_array);
 214
 215         return $ret_tax_array;
 216 }
 217
 218
 219 ?>