correctly apply monthly tax exemptions to irregular billing cycles, #25135

diff --git a/FS/FS/cust_main_county.pm b/FS/FS/cust_main_county.pm
index a61d67e..10a007c 100644 (file)
--- a/FS/FS/cust_main_county.pm
+++ b/FS/FS/cust_main_county.pm
@@ -244,7 +244,7 @@ are inserted.
 In addition to calculating the tax for the line items, this will calculate
 any appropriate tax exemptions and attach them to the line items.
 
 In addition to calculating the tax for the line items, this will calculate
 any appropriate tax exemptions and attach them to the line items.
 

-Options may include 'custnum' and 'invoice_date' in case the cust_bill_pkg
+Options may include 'custnum' and 'invoice_time' in case the cust_bill_pkg

 objects belong to an invoice that hasn't been inserted yet.
 
 Options may include 'exemptions', an arrayref of L<FS::cust_tax_exempt_pkg>
 objects belong to an invoice that hasn't been inserted yet.
 
 Options may include 'exemptions', an arrayref of L<FS::cust_tax_exempt_pkg>


@@ -276,7 +276,7 @@ sub taxline {
 
   my $cust_bill = $taxables->[0]->cust_bill;
   my $custnum   = $cust_bill ? $cust_bill->custnum : $opt{'custnum'};
 
   my $cust_bill = $taxables->[0]->cust_bill;
   my $custnum   = $cust_bill ? $cust_bill->custnum : $opt{'custnum'};

-  my $invoice_date = $cust_bill ? $cust_bill->_date : $opt{'invoice_date'};
+  my $invoice_time = $cust_bill ? $cust_bill->_date : $opt{'invoice_time'};

   my $cust_main = FS::cust_main->by_key($custnum) if $custnum > 0;
   if (!$cust_main) {
     # better way to handle this?  should we just assume that it's taxable?
   my $cust_main = FS::cust_main->by_key($custnum) if $custnum > 0;
   if (!$cust_main) {
     # better way to handle this?  should we just assume that it's taxable?


@@ -364,22 +364,36 @@ sub taxline {
   
     if ( $self->exempt_amount && $self->exempt_amount > 0 
       and $taxable_charged > 0 ) {
   
     if ( $self->exempt_amount && $self->exempt_amount > 0 
       and $taxable_charged > 0 ) {

-      #my ($mon,$year) = (localtime($cust_bill_pkg->sdate) )[4,5];
-      my ($mon,$year) =
-        (localtime( $cust_bill_pkg->sdate || $invoice_date ) )[4,5];
-      $mon++;
-      $year += 1900;
-      my $freq = $cust_bill_pkg->freq;
-      unless ($freq) {
-        $freq = $part_pkg->freq || 1;  # less trustworthy fallback
-      }
-      if ( $freq !~ /(\d+)$/ ) {
-        $dbh->rollback if $oldAutoCommit;
-        return "daily/weekly package definitions not (yet?)".
-               " compatible with monthly tax exemptions";
+      # If the billing period extends across multiple calendar months, 
+      # there may be several months of exemption available.
+      my $sdate = $cust_bill_pkg->sdate || $invoice_time;
+      my $start_month = (localtime($sdate))[4] + 1;
+      my $start_year  = (localtime($sdate))[5] + 1900;
+      my $edate = $cust_bill_pkg->edate || $invoice_time;
+      my $end_month   = (localtime($edate))[4] + 1;
+      my $end_year    = (localtime($edate))[5] + 1900;
+
+      # If the partial last month + partial first month <= one month,
+      # don't use the exemption in the last month
+      # (unless the last month is also the first month, e.g. one-time
+      # charges)
+      if ( (localtime($sdate))[3] >= (localtime($edate))[3]
+           and ($start_month != $end_month or $start_year != $end_year)
+      ) { 
+        $end_month--;
+        if ( $end_month == 0 ) {
+          $end_year--;
+          $end_month = 12;
+        }

       }
       }

-      my $taxable_per_month =
-        sprintf("%.2f", $taxable_charged / $freq );
+
+      # number of months of exemption available
+      my $freq = ($end_month - $start_month) +
+                 ($end_year  - $start_year) * 12 +
+                 1;
+
+      # divide equally among all of them
+      my $permonth = sprintf('%.2f', $taxable_charged / $freq);

 
       #call the whole thing off if this customer has any old
       #exemption records...
 
       #call the whole thing off if this customer has any old
       #exemption records...


@@ -392,9 +406,15 @@ sub taxline {
           'run bin/fs-migrate-cust_tax_exempt?';
       }
 
           'run bin/fs-migrate-cust_tax_exempt?';
       }
 

-      foreach my $which_month ( 1 .. $freq ) {
-  
-        #maintain the new exemption table now
+      my ($mon, $year) = ($start_month, $start_year);
+      while ($taxable_charged > 0.005 and 
+             ($year < $end_year or
+               ($year == $end_year and $mon <= $end_month)
+             )
+      ) {
+ 
+        # find the sum of the exemption used by this customer, for this tax,
+        # in this month

         my $sql = "
           SELECT SUM(amount)
             FROM cust_tax_exempt_pkg
         my $sql = "
           SELECT SUM(amount)
             FROM cust_tax_exempt_pkg


@@ -408,7 +428,7 @@ sub taxline {
         ";
         my $sth = dbh->prepare($sql) or do {
           $dbh->rollback if $oldAutoCommit;
         ";
         my $sth = dbh->prepare($sql) or do {
           $dbh->rollback if $oldAutoCommit;

-          return "fatal: can't lookup exising exemption: ". dbh->errstr;
+          return "fatal: can't lookup existing exemption: ". dbh->errstr;

         };
         $sth->execute(
           $custnum,
         };
         $sth->execute(
           $custnum,


@@ -417,10 +437,11 @@ sub taxline {
           $mon,
         ) or do {
           $dbh->rollback if $oldAutoCommit;
           $mon,
         ) or do {
           $dbh->rollback if $oldAutoCommit;

-          return "fatal: can't lookup exising exemption: ". dbh->errstr;
+          return "fatal: can't lookup existing exemption: ". dbh->errstr;

         };
         my $existing_exemption = $sth->fetchrow_arrayref->[0] || 0;
 
         };
         my $existing_exemption = $sth->fetchrow_arrayref->[0] || 0;
 

+        # add any exemption we're already using for another line item

         foreach ( grep { $_->taxnum == $self->taxnum &&
                          $_->exempt_monthly eq 'Y'   &&
                          $_->month  == $mon          &&
         foreach ( grep { $_->taxnum == $self->taxnum &&
                          $_->exempt_monthly eq 'Y'   &&
                          $_->month  == $mon          &&


@@ -430,13 +451,15 @@ sub taxline {
         {
           $existing_exemption += $_->amount;
         }
         {
           $existing_exemption += $_->amount;
         }

-        
+

         my $remaining_exemption =
           $self->exempt_amount - $existing_exemption;
         if ( $remaining_exemption > 0 ) {
         my $remaining_exemption =
           $self->exempt_amount - $existing_exemption;
         if ( $remaining_exemption > 0 ) {

-          my $addl = $remaining_exemption > $taxable_per_month
-            ? $taxable_per_month
+          my $addl = $remaining_exemption > $permonth
+            ? $permonth

             : $remaining_exemption;
             : $remaining_exemption;

+          $addl = $taxable_charged if $addl > $taxable_charged;
+

           push @new_exemptions, FS::cust_tax_exempt_pkg->new({
               amount          => sprintf('%.2f', $addl),
               exempt_monthly  => 'Y',
           push @new_exemptions, FS::cust_tax_exempt_pkg->new({
               amount          => sprintf('%.2f', $addl),
               exempt_monthly  => 'Y',


@@ -445,7 +468,6 @@ sub taxline {
             });
           $taxable_charged -= $addl;
         }
             });
           $taxable_charged -= $addl;
         }

-        last if $taxable_charged < 0.005;

         # if they're using multiple months of exemption for a multi-month
         # package, then record the exemptions in separate months
         $mon++;
         # if they're using multiple months of exemption for a multi-month
         # package, then record the exemptions in separate months
         $mon++;


@@ -454,7 +476,7 @@ sub taxline {
           $year++;
         }
 
           $year++;
         }
 

-      } #foreach $which_month
+      }

     } # if exempt_amount
 
     $_->taxnum($self->taxnum) foreach @new_exemptions;
     } # if exempt_amount
 
     $_->taxnum($self->taxnum) foreach @new_exemptions;