taxes/tax_rules.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 /*
  13         FA tax rules basic reimplementation. Final version would involve changes in database scheme,
  14         and/or tax system class selection according to site requirements.
  15
  16         TODO:
  17         . changes in Sales module
  18         . change all tax related methods in supp_trans to use split_item_price instead of other functions like get_taxes_for_item
  19 */
  20 define('TAX_NONE', 0); // none option
  21 define('TQ_NONE', 0); // none option
  22
  23 // implemented taxation options
  24 // basic:
  25 define('TAX_PAYABLE', 1);
  26 define('TAX_DEDUCTIBLE', 2);
  27 define('TAX_CHARGED', 4);
  28 // category depenedent:
  29 define('TAX_DUEDATE', 8);
  30 define('TAX_PARTIAL', 16);
  31
  32 // quirks dependent on vat_categories
  33 define('TQ_NONDEDUCT', 1);      // never deductible
  34 define('TQ_PARTIAL', 2);        // partially deductible (using global factor)
  35 define('TQ_DUEDATE', 4);        // taxable on due date instead of transaction date
  36 define('TQ_REVERSE', 8);        // tax is reverse charged
  37 define('TQ_IMPDEDUCTIBLE', 16); // import tax is deductible
  38
  39 class tax_system
  40 {
  41         //-------------------------- entity taxation rules ----------------------------
  42         // general rules: who and when pays taxes
  43         //
  44         // FIXME: credit notes
  45         //
  46         var     $description;
  47         var $ts_basic_rules;
  48         var $ts_category_quirks;
  49
  50         function __construct()
  51         {
  52                 $this->ts_basic_rules = array(
  53                         TA_DOMESTIC => array(
  54                                 ST_SALESQUOTE => TAX_CHARGED,
  55                                 ST_SALESORDER => TAX_CHARGED,
  56                                 ST_CUSTDELIVERY => TAX_CHARGED,
  57                                 ST_SALESINVOICE => TAX_PAYABLE | TAX_CHARGED,
  58                                 ST_CUSTCREDIT => TAX_PAYABLE | TAX_CHARGED,
  59                                 ST_PURCHORDER => TAX_CHARGED,
  60                                 ST_SUPPRECEIVE => TAX_CHARGED,
  61                                 ST_SUPPINVOICE => TAX_DEDUCTIBLE | TAX_CHARGED,
  62                                 ST_SUPPCREDIT => TAX_DEDUCTIBLE | TAX_CHARGED,
  63                         ),
  64                         TA_EXPORT => array(
  65                                 ST_SALESQUOTE => TAX_NONE,
  66                                 ST_SALESORDER => TAX_NONE,
  67                                 ST_CUSTDELIVERY => TAX_NONE,
  68                                 ST_SALESINVOICE => TAX_NONE,
  69                                 ST_CUSTCREDIT => TAX_NONE,
  70                                 ST_PURCHORDER => TAX_NONE,
  71                                 ST_SUPPRECEIVE => TAX_NONE,
  72                                 ST_SUPPINVOICE => TAX_NONE,
  73                                 ST_SUPPCREDIT => TAX_NONE,
  74                         ),
  75                         TA_EU => array(
  76                                 ST_SALESQUOTE => TAX_NONE,
  77                                 ST_SALESORDER => TAX_NONE,
  78                                 ST_CUSTDELIVERY => TAX_NONE,
  79                                 ST_SALESINVOICE => TAX_NONE,
  80                                 ST_CUSTCREDIT => TAX_NONE,
  81                                 ST_PURCHORDER => TAX_NONE,
  82                                 ST_SUPPRECEIVE => TAX_NONE,
  83                                 ST_SUPPINVOICE => TAX_DEDUCTIBLE | TAX_PAYABLE,
  84                                 ST_SUPPCREDIT => TAX_DEDUCTIBLE | TAX_PAYABLE,
  85                         ),
  86                 );
  87
  88                 //-------------------------- special goods dependent rules  ----------------------------
  89                 //
  90                 $this->ts_category_quirks = array(
  91                         VC_OTHER => TQ_NONE,
  92                         VC_MEDIA => TQ_DUEDATE,                 // is no longer used ?
  93                         VC_ASSETS => TQ_NONE,                   // just separate category in tax reg
  94                         VC_NONDEDUCT => TQ_NONDEDUCT,
  95                         VC_SERVICES => TQ_IMPDEDUCTIBLE,
  96                         VC_PARTIAL => TQ_PARTIAL,
  97                         VC_REVERSE => TQ_REVERSE,
  98                 );
  99         }
 100         /*
 101                 Returns tax options applicable for the arguments set
 102
 103                 $allow_reverse - decides whether reverse charging option is honoured for sales invoice
 104                 (this depends on 'continue transaction' value as defined by law, so have to be set by case).
 105         */
 106         function options($trans_type, $tax_area, $vat_category, $allow_reverse=true)
 107         {
 108                 if (!isset($vat_category)) // exempt goods has really no category
 109                         return TAX_NONE;
 110
 111                 $options = $this->ts_basic_rules[$tax_area][$trans_type];
 112
 113                 // per vat category quirks
 114                 $quirks = $this->ts_category_quirks[$vat_category];
 115
 116                 if ($quirks & TQ_DUEDATE)
 117                         $options |= TAX_DUEDATE;
 118
 119                 if ($quirks & TQ_NONDEDUCT)
 120                         $options &= ~TAX_DEDUCTIBLE;
 121
 122                 if ($quirks & TQ_PARTIAL)
 123                         if ($options & TAX_DEDUCTIBLE)
 124                                 $options |= TAX_PARTIAL;
 125
 126                 if ($quirks & TQ_IMPDEDUCTIBLE)
 127                         if ($tax_area == TA_EXPORT && in_array($trans_type, array(ST_SUPPINVOICE, ST_SUPPCREDIT)))
 128                         {
 129                                 $options |= TAX_DEDUCTIBLE | TAX_PAYABLE;
 130                         }
 131
 132                 if (($quirks & TQ_REVERSE) && (!in_array($trans_type,array(ST_SALESINVOICE, ST_CUSTCREDIT)) || $allow_reverse))
 133                         if ($tax_area == TA_DOMESTIC)
 134                         {
 135                                 $options ^= TAX_PAYABLE;
 136                                 $options &= ~TAX_CHARGED;
 137                         }
 138
 139                 return $options;
 140         }
 141 };
 142
 143 function dbg_tax($options)
 144 {
 145         $dbg_rules = array(
 146                 TAX_PAYABLE => 'payable',
 147                 TAX_DEDUCTIBLE => 'deductible',
 148                 TAX_CHARGED => 'charged',
 149                 TAX_DUEDATE => 'due_date',
 150                 TAX_PARTIAL => 'partial'
 151         );
 152
 153         $opts = array();
 154         foreach($dbg_rules as $key => $name)
 155                 if ($options & $key)
 156                         $opts[] = $name;
 157
 158         _vd(implode($opts, ','));
 159 }