taxes/tax_calc.inc

   1 <?php
   2 /**********************************************************************
   3     Copyright (C) FrontAccounting, LLC.
   4         Released under the terms of the GNU General Public License, GPL,
   5         as published by the Free Software Foundation, either version 3
   6         of the License, or (at your option) any later version.
   7     This program is distributed in the hope that it will be useful,
   8     but WITHOUT ANY WARRANTY; without even the implied warranty of
   9     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  10     See the License here <http://www.gnu.org/licenses/gpl-3.0.html>.
  11 ***********************************************************************/
  12 include_once($path_to_root . "/taxes/db/tax_groups_db.inc");
  13 include_once($path_to_root . "/taxes/db/tax_types_db.inc");
  14 include_once($path_to_root . "/taxes/db/item_tax_types_db.inc");
  15
  16 //---------------------------------------------------------------------------------
  17
  18 // returns the price of a given item minus any included taxes
  19 // for item $stock_id with line price $price,
  20 // with applicable tax rates $tax_group_array or group id $tax_group
  21
  22 function get_tax_free_price_for_item($stock_id, $price, $tax_group, $tax_included, $tax_group_array=null)
  23 {
  24         // if price is zero, then can't be taxed !
  25         if ($price == 0)
  26                 return 0;
  27
  28         if ($tax_included==0) return $price;
  29
  30         // if array already read, then make a copy and use that
  31         if ($tax_group_array)
  32                 $ret_tax_array = $tax_group_array;
  33         else
  34                 $ret_tax_array = get_tax_group_items_as_array($tax_group);
  35
  36         //print_r($ret_tax_array);
  37
  38         $tax_array = get_taxes_for_item($stock_id, $ret_tax_array);
  39         // if no exemptions or taxgroup is empty, then no included/excluded taxes
  40         if ($tax_array == null)
  41                 return $price;
  42
  43         // to avoid rounding errors we have to just subtract taxes from tax_included price.
  44         $tax_multiplier = 0;
  45         foreach ($tax_array as $taxitem)
  46         {
  47                 $tax_multiplier += $taxitem["rate"];
  48         }
  49
  50         $tax = 0;
  51         foreach ($tax_array as $taxitem)
  52         {
  53                 $tax += round($price*$taxitem['rate']/(100+$tax_multiplier), user_price_dec());
  54         }
  55         return $price-$tax;
  56 }
  57 //
  58 //      Full price (incl. VAT) for item $stock_id with line price $price,
  59 //      with tax rates $tax_group_array or applicable group $tax_group
  60 //
  61 function get_full_price_for_item($stock_id, $price, $tax_group, $tax_included, $tax_group_array=null)
  62 {
  63         // if price is zero, then can't be taxed !
  64         if ($price == 0)
  65                 return 0;
  66
  67         if ($tax_included==1) return $price;
  68
  69         // if array already read, then make a copy and use that
  70         if ($tax_group_array)
  71                 $ret_tax_array = $tax_group_array;
  72         else
  73                 $ret_tax_array = get_tax_group_items_as_array($tax_group);
  74
  75         //print_r($ret_tax_array);
  76
  77         $tax_array = get_taxes_for_item($stock_id, $ret_tax_array);
  78         // if no exemptions or taxgroup is empty, then no included/excluded taxes
  79         if ($tax_array == null)
  80                 return $price;
  81
  82         $tax_multiplier = 0;
  83
  84         // loop for all items
  85
  86         foreach ($tax_array as $taxitem)
  87         {
  88                         $tax_multiplier += $taxitem["rate"];
  89         }
  90
  91         return round($price * (1 + ($tax_multiplier / 100)),  user_price_dec());
  92 }
  93
  94 //---------------------------------------------------------------------------------
  95 // return an array of (tax_type_id, tax_type_name, sales_gl_code, purchasing_gl_code, rate)
  96
  97 function get_taxes_for_item($stock_id, $tax_group_items_array)
  98 {
  99         $item_tax_type = get_item_tax_type_for_item($stock_id);
 100
 101         // if the item is exempt from all taxes then return 0
 102         if ($item_tax_type["exempt"])
 103                 return null;
 104
 105         // get the exemptions for this item tax type
 106         $item_tax_type_exemptions_db = get_item_tax_type_exemptions($item_tax_type["id"]);
 107
 108         // read them all into an array to minimize db querying
 109         $item_tax_type_exemptions = array();
 110         while ($item_tax_type_exemp = db_fetch($item_tax_type_exemptions_db))
 111         {
 112                 $item_tax_type_exemptions[] = $item_tax_type_exemp["tax_type_id"];
 113         }
 114
 115         $ret_tax_array = array();
 116
 117         // if any of the taxes of the tax group are in the exemptions, then skip
 118         foreach ($tax_group_items_array as $tax_group_item)
 119         {
 120
 121                 $skip = false;
 122
 123                 // if it's in the exemptions, skip
 124                 foreach ($item_tax_type_exemptions as $exemption)
 125                 {
 126                         if (($tax_group_item['tax_type_id'] == $exemption))
 127                         {
 128                         $skip = true;
 129                         break;
 130                         }
 131                 }
 132
 133                 if (!$skip)
 134                 {
 135                         $index = $tax_group_item['tax_type_id'];
 136                         $ret_tax_array[$index] = $tax_group_item;
 137                 }
 138         }
 139
 140         return $ret_tax_array;
 141 }
 142 //-----------------------------------------------------------------------------------
 143 // return an array of (tax_type_id, tax_type_name, sales_gl_code, purchasing_gl_code, rate, included_in_price, Value)
 144
 145 function get_tax_for_items($items, $prices, $shipping_cost, $tax_group, $tax_included=null, $tax_items_array=null)
 146 {
 147         // first create and set an array with all the tax types of the tax group
 148         if($tax_items_array!=null)
 149           $ret_tax_array = $tax_items_array;
 150         else
 151           $ret_tax_array = get_tax_group_items_as_array($tax_group);
 152
 153         foreach($ret_tax_array as $k=>$t)
 154                 $ret_tax_array[$k]['Net'] = 0;
 155
 156         $dec = user_price_dec();
 157         // loop for all items
 158         for ($i = 0; $i < count($items); $i++)
 159         {
 160                 $item_taxes = get_taxes_for_item($items[$i], $ret_tax_array);
 161                 if ($item_taxes != null)
 162                 {
 163                         $tax_multiplier = 0;
 164                         foreach ($item_taxes as $taxitem)
 165                         {
 166                                 $tax_multiplier += $taxitem['rate'];
 167                         }
 168                         foreach ($item_taxes as $item_tax)
 169                         {
 170                                 if ($item_tax['rate'] !== null) {
 171                                         $index = $item_tax['tax_type_id'];
 172                                         if ($tax_included == 1) {
 173                                           $ret_tax_array[$index]['Value'] += round2($prices[$i]*$item_tax['rate']/(100+$tax_multiplier), $dec);
 174                                           $ret_tax_array[$index]['Net'] += round2($prices[$i]*100/(100+$tax_multiplier), $dec);
 175                                         } else {
 176                                           $ret_tax_array[$index]['Value'] += ($prices[$i] * $item_tax['rate'] / 100);
 177                                           $ret_tax_array[$index]['Net'] += $prices[$i];
 178                                         }
 179                                 }
 180                         }
 181                 }
 182         }
 183
 184         // add the shipping taxes, only if non-zero, and only if tax group taxes shipping
 185         if ($shipping_cost != 0)
 186         {
 187                 $item_taxes = get_shipping_tax_as_array();
 188                 if ($item_taxes != null)
 189                 {
 190                         if ($tax_included == 1)
 191                         {
 192                                 $tax_rate = 0;
 193                                 foreach ($item_taxes as $item_tax)
 194                                 {
 195                                         $index = $item_tax['tax_type_id'];
 196                                         if(isset($ret_tax_array[$index])) {
 197                                                 $tax_rate += $item_tax['rate'];
 198                                         }
 199                                 }
 200                                 $shipping_net = round2($shipping_cost*100/(100+$tax_rate), $dec);
 201                         }
 202                         foreach ($item_taxes as $item_tax)
 203                         {
 204                                 $index = $item_tax['tax_type_id'];
 205                                 if ($item_tax['rate'] !== null && $ret_tax_array[$index]['rate'] !== null) {
 206                                           if($tax_included==1) {
 207                                             $ret_tax_array[$index]['Value'] += round2($shipping_cost*$item_tax['rate']/(100+$tax_rate), $dec);
 208                                             $ret_tax_array[$index]['Net'] += $shipping_net;
 209                                           } else {
 210                                                 $ret_tax_array[$index]['Value'] += ($shipping_cost * $item_tax['rate'] / 100);
 211                                             $ret_tax_array[$index]['Net'] += $shipping_cost;
 212                                           }
 213                                 }
 214                         }
 215                 }
 216         }
 217         //print_r($ret_tax_array);
 218
 219         return $ret_tax_array;
 220 }
 221
 222 ?>