+use List::Util qw(sum);
+
+# use warnings;
+use strict;
+
+# new implementation of balance sheet
+# readme!
+#
+# stuff missing from the original implementation:
+# - bold stuff
+# - subdescription
+# - proper testing for heading charts
+# - transmission from $form to TMPL realm is not as clear as i'd like
+
+sub get_balance_starting_date {
+
+ # determine date from which the balance is calculated. The method is
+ # configured in the client configuration.
+
+ my $asofdate = shift;
+ return unless $asofdate;
+
+ $asofdate = $::locale->parse_date_to_object(\%::myconfig, $asofdate);
+
+ my $form = $main::form;
+ my $dbh = $::form->get_standard_dbh;
+
+ my $startdate_method = $::instance_conf->get_balance_startdate_method;
+
+ # We could use the following objects to determine the starting date for
+ # calculating the balance from asofdate (the reference date for the balance):
+ # * start_of_year - 1.1., no deviating fiscal year supported
+ # * closed_to - all transactions since the books were last closed
+ # * last_ob - all transactions since last opening balance transaction (usually 1.1.)
+ # * mindate - all transactions in database
+
+ my $start_of_year = $asofdate->clone();
+ $start_of_year->set_day(1);
+ $start_of_year->set_month(1);
+
+ # closedto assumes that we only close the books at the end of a fiscal year,
+ # never during the fiscal year. If this assumption is valid closedto should
+ # also work for deviating fiscal years. But as the trial balance (SuSa)
+ # doesn't yet deal with deviating fiscal years, and is useful to also close
+ # the books after a month has been exported via DATEV, so this method of
+ # determining the starting date isn't recommended and has been removed as
+ # default.
+ my ($closedto) = selectfirst_array_query($form, $dbh, 'SELECT closedto FROM defaults');
+ if ($closedto) {
+ $closedto = $::locale->parse_date_to_object(\%::myconfig, $closedto);
+ $closedto->subtract(years => 1) while ($asofdate - $closedto)->is_negative;
+ $closedto->add(days => 1);
+ };
+
+ my ($query, $startdate, $last_ob, $mindate);
+ $query = qq|select max(transdate) from acc_trans where ob_transaction is true and transdate <= ?|;
+ ($last_ob) = selectrow_query($::form, $dbh, $query, $::locale->format_date(\%::myconfig, $asofdate));
+ $last_ob = $::locale->parse_date_to_object(\%::myconfig, $last_ob) if $last_ob;
+
+ $query = qq|select min(transdate) from acc_trans|;
+ ($mindate) = selectrow_query($::form, $dbh, $query);
+ $mindate = $::locale->parse_date_to_object(\%::myconfig, $mindate);
+
+ # the default method is to use all transactions ($mindate)
+
+ if ( $startdate_method eq 'closed_to' and $closedto ) {
+ # if no closedto is configured use default
+ return $::locale->format_date(\%::myconfig, $closedto);
+
+ } elsif ( $startdate_method eq 'start_of_year' ) {
+
+ return $::locale->format_date(\%::myconfig, $start_of_year);
+
+ } elsif ( $startdate_method eq 'all_transactions' ) {
+
+ return $::locale->format_date(\%::myconfig, $mindate);
+
+ } elsif ( $startdate_method eq 'last_ob_or_all_transactions' and $last_ob ) {
+ # use default if there are no ob transactions
+
+ return $::locale->format_date(\%::myconfig, $last_ob);
+
+ } elsif ( $startdate_method eq 'last_ob_or_start_of_year' ) {
+
+ if ( $last_ob ) {
+ return $::locale->format_date(\%::myconfig, $last_ob);
+ } else {
+ return $::locale->format_date(\%::myconfig, $start_of_year);
+ };
+
+ } else {
+ # default action, also used for closedto and last_ob_or_all_transactions if
+ # there are no valid dates
+
+ return $::locale->format_date(\%::myconfig, $mindate);
+ };
+
+};