Added fixed assets module

[fa-stable.git] / fixed_assets / includes / depreciation.inc

diff --git a/fixed_assets/includes/depreciation.inc b/fixed_assets/includes/depreciation.inc
new file mode 100644 (file)
index 0000000..dda99f9
--- /dev/null
+++ b/fixed_assets/includes/depreciation.inc
@@ -0,0 +1,117 @@
+<?php
+/**********************************************************************
+  Copyright (C) FrontAccounting, LLC.
+  Released under the terms of the GNU General Public License, GPL, 
+  as published by the Free Software Foundation, either version 3 
+  of the License, or (at your option) any later version.
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
+  See the License here <http://www.gnu.org/licenses/gpl-3.0.html>.
+ ***********************************************************************/
+
+function next_depreciation_date($depreciation_date) {
+
+  $start = strtotime($depreciation_date);
+
+  $y = date('Y', $start);
+  $m = date('n', $start) + 1;
+
+  if ($m > 12) {
+    $m = 1;
+    $y++;
+  }
+
+  return strtotime("$y-$m-1");
+}
+
+function depreciation_months($depreciation_start) {
+
+  // assume that depreciation start is the same fiscal year
+  //$start = strtotime($depreciation_start);
+  //$end = strtotime($year['end']);
+
+  $start = next_depreciation_date($depreciation_start);
+
+  return 12 - date('n', $start) + 1;
+
+  //$d1 = date('j', $start); // day of the month
+  //$d2 = date('t', $start); // number of days in month
+
+  //if ($d2 > $d1)
+    //$months++;
+}
+
+function months_between_dates($start, $end) {
+  $start = strtotime($start);
+  $end = strtotime($end);
+
+  $y1 = date('Y', $start);
+  $m1 = date('n', $start);
+
+  $y2 = date('Y', $end);
+  $m2 = date('n', $end);
+
+  return 12 * ($y2 - $y1) + $m2 - $m1;
+}
+
+function compute_gl_rows_for_depreciation($item, $no_months, $period) {
+  $rows = array();
+
+  $year = get_current_fiscalyear();
+  $y = date('Y', strtotime($year['end']));
+
+  switch ($item['depreciation_method']) {
+    case 'D':
+      $value = $item['material_cost'] * $item['depreciation_rate'] / 100 / 12;
+      break;
+
+    case 'S':
+      // depreciation_rate is the period here.
+      $done_months = months_between_dates($item['depreciation_start'], $item['depreciation_date']);
+      $remaining_months = $item['depreciation_rate'] * 12 - $done_months;
+      $value = $item['material_cost'] / $remaining_months;
+      break;
+
+    case 'O':
+      $value = $item['material_cost'];
+      break;
+  }
+
+  $next = next_depreciation_date($item['depreciation_date']);
+  $m = date('n', $next);
+
+  $total = 0;
+  $cnt = 0;
+  for ($i=$m; $i < $m + $no_months; $i++) {
+    $date = sql2date(date("$y-$i-t", strtotime("$y-$i-1")));
+
+    $total += $value;
+
+    if (FA_YEARLY == $period) {
+      // yearly
+      if ($i == $m + $no_months - 1)
+        $rows[] = array('date' => $date, 'value' => $total);
+      /*else
+        $rows[] = array('date' => $date, 'value' => 0);
+        */
+    }
+    else {
+      // monthly
+      $rows[] = array('date' => $date, 'value' => $value);
+    }
+
+    $cnt++;
+
+    if ($item['depreciation_method'] == 'S') {
+      if ($cnt >= $remaining_months)
+        $value = 0;
+    }
+    elseif ($item['depreciation_method'] == 'O') {
+      // depreciate only in the first month
+      $value = 0;
+    }
+  }
+
+  return $rows;
+}