#!/usr/bin/perl -w

use strict;

use YAML qw/LoadFile/;
use XML::Simple;
use Template;
use DateTime;
use Math::BigFloat;
#use Data::Dump qw/dd/;

my $config_file = '/usr/share/mga-treasurer/config';
my $config = LoadFile($ENV{MGATRES_CONF} ? $ENV{MGATRES_CONF} : $config_file);
my $etc_config_file = '/etc/mga-treasurer.conf';
my $etc_config = LoadFile($etc_config_file);

foreach my $k (keys %{$etc_config}) {
    $config->{$k} = $etc_config->{$k};
}


sub donation_category {
    my $r = shift;
    my @c = grep {$_->{Na} eq 'Donation'} @{$r->{Category}};
    return @c ? $c[0]->{Nb} : undef;
}

sub party_name {
    my ($r, $Nb) = @_;
    $Nb == 0 ? '' : (grep { $_->{Nb} == $Nb } @{$r->{Party}})[0]->{Na};
}

sub cat_name {
    my ($r, $Nb) = @_;
    $Nb == 0 ? '' : (grep { $_->{Nb} == $Nb } @{$r->{Category}})[0]->{Na};
}

sub subcat_name {
    my ($r, $Nb, $Nbc) = @_;
    (grep { $_->{Nb} == $Nb && $_->{Nbc} == $Nbc }
        @{$r->{Sub_category}})[0]->{Na};
}

sub account_name {
    my ($r, $Ac) = @_;
    (grep { $_->{Number} == $Ac } @{$r->{Account}})[0]->{Name};
}

sub epoch_date {
    my ($m, $d, $y) = split /\//, shift;
    DateTime->new(day => $d, month => $m, year => $y)->epoch;
}

sub transactions_list {
    my ($r, $cat) = @_;
    my @res;
    my @transactions = $cat ? grep { $_->{Ca} == $cat } @{$r->{Transaction}}
                                : @{$r->{Transaction}};
    foreach my $tra (@transactions) {
        my %d = (
            nb      => $tra->{Nb},
            amount  => (new Math::BigFloat $tra->{Am}),
            date    => epoch_date($tra->{Dt}),
            pa      => $tra->{Pa},
            who     => party_name($r, $tra->{Pa}),
            ac      => $tra->{Ac},
            account => account_name($r, $tra->{Ac}),
            $tra->{Trt} != 0 ? (trt => $tra->{Trt}) : (),
            $tra->{Sca} != 0 ? (sc_name => subcat_name($r, $tra->{Sca}, $tra->{Ca})) : (),
            $tra->{Ca} != 0 ? (c_name => cat_name($r, $tra->{Ca}), ca => $tra->{Ca}) : (),
            $tra->{No} ne '(null)' ? (notes  => $tra->{No}) : (),
        );
        push @res, \%d;
    }
    return \@res;
}

sub donations_infos {
    my $r = shift;
    my %res = (
        donations => transactions_list($r, donation_category($r)),
        by_month  => {},
        by_year   => {},
        by_pa     => {},
        total_30  => 0,
    );
    foreach my $don (@{$res{donations}}) {
        my $dt = DateTime->from_epoch(epoch => $don->{date});
        my $month = $dt->year . '-' . sprintf("%02d", $dt->month);
        my $year = $dt->year;
        push @{$res{by_month}->{$month}->{donations}}, $don;
        $res{by_month}->{$month}->{year} = $year;
        $res{by_month}->{$month}->{month} = $dt->month;
        push @{$res{by_year}->{$year}->{donations}}, $don;
        push @{$res{by_year}->{$year}->{months}}, $month;
        push @{$res{by_pa}->{$don->{pa}}->{donations}}, $don;
        if (time - $don->{date} < '2592000') { # last 30 days
            $res{total_30} += $don->{amount};
        }
    }
    foreach my $d ((values %{$res{by_month}}), (values %{$res{by_year}}),
                   (values %{$res{by_pa}})) {
        foreach my $don (@{$d->{donations}}) {
            $d->{total} += $don->{amount};
            $d->{type}->{$don->{sc_name}} += $don->{amount};
        }
    }
    return \%res;
}

sub transactions_infos {
    my $r = shift;
    my %res = (
        transactions => transactions_list($r),
        by_month     => {},
        by_year      => {},
        by_pa        => {},
        by_ac        => {},
        by_ca        => {},
        balance      => new Math::BigFloat 0,
    );
    foreach my $tra (@{$res{transactions}}) {
        my $dt = DateTime->from_epoch(epoch => $tra->{date});
        my $month = $dt->year . '-' . sprintf("%02d", $dt->month);
        my $year = $dt->year;
        push @{$res{by_month}->{$month}->{transactions}}, $tra;
        $res{by_month}->{$month}->{year} = $year;
        $res{by_month}->{$month}->{month} = $dt->month;
        $res{by_ac}->{$tra->{ac}}->{account} = $tra->{account};
        push @{$res{by_year}->{$year}->{transactions}}, $tra;
        push @{$res{by_year}->{$year}->{months}}, $month;
        push @{$res{by_pa}->{$tra->{pa}}->{transactions}}, $tra;
        push @{$res{by_ac}->{$tra->{ac}}->{transactions}}, $tra;
        if ($tra->{ca}) {
            push @{$res{by_ca}->{$tra->{ca}}->{transactions}}, $tra;
            $res{by_ca}->{$tra->{ca}}->{c_name} = $tra->{c_name};
        }
        $res{balance} += $tra->{amount};
    }
    foreach my $by ('by_ac', 'by_year', 'by_month', 'by_ca') {
        foreach my $t (values %{$res{$by}}) {
            $t->{balance} = new Math::BigFloat 0;
            $t->{revenues} = new Math::BigFloat 0;
            $t->{expenses} = new Math::BigFloat 0;
            foreach my $tra (@{$t->{transactions}}) {
                $t->{balance} += $tra->{amount};
                next if $tra->{trt} && $by ne 'by_ac';
                if ($tra->{amount} > 0) {
                    $t->{revenues} += $tra->{amount};
                } else {
                    $t->{expenses} -= $tra->{amount};
                }
            }
        }
    }
    foreach my $by ('by_year', 'by_month') {
        my ($prev, $start_balance);
        foreach my $b (sort keys %{$res{$by}}) {
            my $y = $res{$by}->{$b};
            foreach my $tra (@{$y->{transactions}}) {
                next unless $tra->{ca};
                $y->{ca_balance}->{$tra->{ca}} += $tra->{amount};
            }
            $y->{start_balance} = $start_balance ? $start_balance : new Math::BigFloat 0;
            $y->{end_balance} = $y->{balance} + new Math::BigFloat $y->{start_balance};
            $start_balance = $y->{end_balance};
            $y->{prev} = $prev if $prev;
            $prev = $b;
        }
    }
    return \%res;
}

sub process_template {
    my ($template, $src, $vars, $dest) = @_;
    foreach my $extension (@{$config->{output_format}}) {
        next unless -f "$config->{tmpl_dir}/$src.$extension";
        $template->process("$src.$extension", $vars, "$dest.$extension");
    }
}

sub output_pages {
    my ($r, $donations, $transactions) = @_;
    my $template = Template->new(
        INCLUDE_PATH => $config->{tmpl_dir},
        OUTPUT_PATH  => $config->{out_dir},
    );

    my $last_update = (stat $config->{grisbi_file})[9];
    foreach my $month (keys %{ { %{$donations->{by_month}},
                                 %{$transactions->{by_month}} } }) {
        my $vars = {
            config       => $config,
            month        => $month,
            donations    => $donations,
            transactions => $transactions,
        };
        process_template($template, 'donations_by_month', $vars,
            "donations_m_$month") if $donations->{by_month}->{$month};
        process_template($template, 'transactions_by_month', $vars,
            "m_$month") if $transactions->{by_month}->{$month};
    }

    foreach my $year (keys %{ { %{$donations->{by_year}},
                                %{$transactions->{by_year}} } }) {
        my $vars = {
            config       => $config,
            year         => $year,
            donations    => $donations,
            transactions => $transactions,
        };
        process_template($template, 'donations_by_year', $vars,
            "donations_y_$year") if $donations->{by_year}->{$year};
        process_template($template, 'transactions_by_year', $vars,
            "y_$year") if $transactions->{by_year}->{$year};
    }

    foreach my $pa (keys %{ { %{$donations->{by_pa}},
                              %{$transactions->{by_pa}} } }) {
        my $vars = {
            config       => $config,
            pa           => $pa,
            who          => party_name($r, $pa),
            donations    => $donations,
            transactions => $transactions,
        };
        process_template($template, 'donations_by_pa', $vars,
            "donations_p_$pa") if $donations->{by_pa}->{$pa};
        process_template($template, 'transactions_by_pa', $vars,
            "p_$pa") if $transactions->{by_pa}->{$pa};
    }

    foreach my $ac (keys %{$transactions->{by_ac}}) {
        my $vars = {
            config       => $config,
            ac           => $ac,
            account      => $transactions->{by_ac}->{$ac}->{account},
            donations    => $donations,
            transactions => $transactions,
        };
        process_template($template, 'transactions_by_ac', $vars, "a_$ac");
    }

    my $vars = {
        config       => $config,
        donations    => $donations,
        transactions => $transactions,
        last_update  => $last_update,
    };
    process_template($template, 'donations', $vars, 'donations');
    process_template($template, 'transactions', $vars, 'transactions');
    process_template($template, 'index', $vars, 'index');
}

my $r = XMLin($config->{grisbi_file});
my $donations = donations_infos($r);
my $transactions = transactions_infos($r);

output_pages($r, $donations, $transactions);