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, $ret_tax_array);
  39
  40         // if no exemptions or taxgroup is empty, then no included/excluded taxes
  41         if ($tax_array == null)
  42                 return $price;
  43
  44         // to avoid rounding errors we have to just subtract taxes from tax_included price.
  45         $tax_multiplier = 0;
  46         foreach ($tax_array as $taxitem)
  47         {
  48                 $tax_multiplier += $taxitem["rate"];
  49         }
  50
  51         $tax = 0;
  52         foreach ($tax_array as $taxitem)
  53         {
  54                 $tax += round($price*$taxitem['rate']/(100+$tax_multiplier), user_price_dec());
  55         }
  56         return $price-$tax;
  57 }
  58 //
  59 //      Full price (incl. VAT) for item $stock_id with line price $price,
  60 //      with tax rates $tax_group_array or applicable group $tax_group
  61 //
  62 function get_full_price_for_item($stock_id, $price, $tax_group, $tax_included, $tax_group_array=null)
  63 {
  64         // if price is zero, then can't be taxed !
  65         if ($price == 0)
  66                 return 0;
  67
  68         if ($tax_included==1) return $price;
  69
  70         // if array already read, then make a copy and use that
  71         if ($tax_group_array)
  72                 $ret_tax_array = $tax_group_array;
  73         else
  74                 $ret_tax_array = get_tax_group_items_as_array($tax_group);
  75
  76         //print_r($ret_tax_array);
  77
  78         $tax_array = get_taxes_for_item($stock_id, $ret_tax_array);
  79         // if no exemptions or taxgroup is empty, then no included/excluded taxes
  80         if ($tax_array == null)
  81                 return $price;
  82
  83         $tax_multiplier = 0;
  84
  85         // loop for all items
  86
  87         foreach ($tax_array as $taxitem)
  88         {
  89                         $tax_multiplier += $taxitem["rate"];
  90         }
  91
  92         return round($price * (1 + ($tax_multiplier / 100)),  user_price_dec());
  93 }
  94
  95 //---------------------------------------------------------------------------------
  96 // return an array of (tax_type_id, tax_type_name, sales_gl_code, purchasing_gl_code, rate)
  97
  98 function get_taxes_for_item($stock_id, $tax_group_items_array)
  99 {
 100         $item_tax_type = get_item_tax_type_for_item($stock_id);
 101
 102         // if the item is exempt from all taxes then return 0
 103         if ($item_tax_type["exempt"])
 104                 return null;
 105
 106         // get the exemptions for this item tax type
 107         $item_tax_type_exemptions_db = get_item_tax_type_exemptions($item_tax_type["id"]);
 108
 109         // read them all into an array to minimize db querying
 110         $item_tax_type_exemptions = array();
 111         while ($item_tax_type_exemp = db_fetch($item_tax_type_exemptions_db))
 112         {
 113                 $item_tax_type_exemptions[] = $item_tax_type_exemp["tax_type_id"];
 114         }
 115
 116         $ret_tax_array = array();
 117
 118         // if any of the taxes of the tax group are in the exemptions, then skip
 119         foreach ($tax_group_items_array as $tax_group_item)
 120         {
 121
 122                 $skip = false;
 123
 124                 // if it's in the exemptions, skip
 125                 foreach ($item_tax_type_exemptions as $exemption)
 126                 {
 127                         if (($tax_group_item['tax_type_id'] == $exemption))
 128                         {
 129                         $skip = true;
 130                         break;
 131                         }
 132                 }
 133
 134                 if (!$skip)
 135                 {
 136                         $index = $tax_group_item['tax_type_id'];
 137                         $ret_tax_array[$index] = $tax_group_item;
 138                 }
 139         }
 140
 141         return $ret_tax_array;
 142 }
 143 //-----------------------------------------------------------------------------------
 144 // return an array of (tax_type_id, tax_type_name, sales_gl_code, purchasing_gl_code, rate, included_in_price, Value)
 145
 146 function get_tax_for_items($items, $prices, $shipping_cost, $tax_group, $tax_included=null, $tax_items_array=null, $tax_algorithm = null)
 147 {
 148         if (!$tax_algorithm)
 149                 $tax_algorithm = get_company_pref('tax_algorithm');
 150         // first create and set an array with all the tax types of the tax group
 151         if($tax_items_array!=null)
 152           $ret_tax_array = $tax_items_array;
 153         else
 154           $ret_tax_array = get_tax_group_items_as_array($tax_group);
 155
 156         $dec = user_price_dec();
 157
 158         $fully_exempt = true;
 159         foreach($ret_tax_array as $k=>$t)
 160         {
 161                 if ($t['rate'] !== null)
 162                         $fully_exempt = false;
 163                 $ret_tax_array[$k]['Net'] = 0;
 164         }
 165
 166         $ret_tax_array['exempt'] = array('Value'=>0, 'Net'=>0, 'rate' => null, 'tax_type_id' => '');
 167         $dec = user_price_dec();
 168         // loop for all items
 169         for ($i = 0; $i < count($items); $i++)
 170         {
 171                 $item_taxes = get_taxes_for_item($items[$i], $ret_tax_array);
 172                 if ($item_taxes == null || $fully_exempt)
 173                 {
 174                           $ret_tax_array['exempt']['Value'] += round2(0, $dec);
 175                           $ret_tax_array['exempt']['Net'] += $prices[$i];
 176                 }
 177                 else
 178                 {
 179                         $tax_multiplier = 0;
 180                         foreach ($item_taxes as $taxitem)
 181                         {
 182                                 $tax_multiplier += $taxitem['rate'];
 183                         }
 184                         foreach ($item_taxes as $item_tax)
 185                         {
 186                                 if ($item_tax['rate'] !== null) {
 187                                         $index = $item_tax['tax_type_id'];
 188                                         if ($tax_included == 1) {
 189                                           $ret_tax_array[$index]['Value'] += round2($prices[$i]*$item_tax['rate']/(100+$tax_multiplier), $dec);
 190                                           $ret_tax_array[$index]['Net'] += round2($prices[$i]*100/(100+$tax_multiplier), $dec);
 191                                         } else {
 192                                           $ret_tax_array[$index]['Value'] += round2($prices[$i] * $item_tax['rate'] / 100, $dec);
 193                                           $ret_tax_array[$index]['Net'] += $prices[$i];
 194                                         }
 195                                 }
 196                         }
 197                 }
 198         }
 199         // add the shipping taxes, only if non-zero, and only if tax group taxes shipping
 200         if ($shipping_cost != 0)
 201         {
 202                 $item_taxes = get_shipping_tax_as_array($tax_group);
 203                 if ($item_taxes != null)
 204                 {
 205                         if ($tax_included == 1)
 206                         {
 207                                 $tax_rate = 0;
 208                                 foreach ($item_taxes as $item_tax)
 209                                 {
 210                                         $index = $item_tax['tax_type_id'];
 211                                         if(isset($ret_tax_array[$index])) {
 212                                                 $tax_rate += $item_tax['rate'];
 213                                         }
 214                                 }
 215                                 $shipping_net = round2($shipping_cost*100/(100+$tax_rate), $dec);
 216                         }
 217                         foreach ($item_taxes as $item_tax)
 218                         {
 219                                 $index = $item_tax['tax_type_id'];
 220                                 if ($item_tax['rate'] !== null && $ret_tax_array[$index]['rate'] !== null) {
 221                                           if($tax_included==1) {
 222                                             $ret_tax_array[$index]['Value'] += round2($shipping_cost*$item_tax['rate']/(100+$tax_rate), $dec);
 223                                             $ret_tax_array[$index]['Net'] += $shipping_net;
 224                                           } else {
 225                                                 $ret_tax_array[$index]['Value'] += round2($shipping_cost * $item_tax['rate'] / 100, $dec);
 226                                             $ret_tax_array[$index]['Net'] += $shipping_cost;
 227                                           }
 228                                 }
 229                         }
 230                 }
 231         }
 232
 233         if ($tax_algorithm == TCA_TOTALS ) {
 234                 // update taxes with
 235                 foreach($ret_tax_array as $index => $item_tax) {
 236                         $ret_tax_array[$index]['Value'] = round2($item_tax['Net'] * $item_tax['rate'] / 100, $dec);
 237                 }
 238         }
 239
 240         return $ret_tax_array;
 241 }
 242
 243 ?>