#!/usr/bin/perl
use diagnostics;
use warnings;
use strict;
use CGI;

## Column headings
my @members = qw/ Algeria Indonesia Iran Iraq Kuwait Libya Nigeria Qatar Saudi_Arabia UAE Venezuela total_OPEC /;
@members = map { tr/_/ /; $_ } @members;

## Load data
my (%quotas, @dates, @notes, %notes);
while (<DATA>) {
    ( my $period, $_ ) = split ':';
    @{$quotas{$period}}{@members} = split ' ';
    push @dates, $period;
}

## Load notes
open (NOTES, 'notes.dat') or die "Couldn't open notes.dat: $!";
my @dates_copy = @dates;
while (<NOTES>) {
    $/ = "\n\n";
    my $date = shift @dates_copy;
    push @notes, ($date, $_);
    %notes = @notes;
}

## Introductory paragraph
my $query = CGI->new();
print $query->header("text/html"),
      $query->start_html( -title   => "QuotaBase: a database of OPEC oil production quotas",
                      -bgcolor => "#cbcbcb" ),
  $query->h1("Welcome to QuotaBase!"),
  $query->table(
                $query->Tr(
                           $query->td({-width => "600"},
                                      $query->p(<<EOP)
QuotaBase is an interactive database of OPEC oil production quotas. By default, the <b>current quotas</b> are displayed. To view <b>historical quota information</b>, select the period you want from the drop-down list and click the 'Show quotas' button.
A table of all the quotas for that period will be displayed.
EOP
                                     )
                          )
               ),
  $query->start_form(),
  "Choose a period: ",
  "&nbsp;",
  $query->popup_menu( -name=>'period',
                      -values=>[@dates],
                      -default=>$dates[0]),
  "&nbsp;&nbsp;",
  $query->submit(-name=>'submit', -value=>'Show quotas'),
  "&nbsp;&nbsp;",
  $query->defaults('Reset current quotas'),
  $query->endform;

## Outer table
print $query->start_table({ -border => 0,
                            -width  => 520 }),
      $query->start_Tr,
      $query->start_td;

## Data table
my $period = $query->param('period') || $dates[0];
print $query->table({-border=>1},
                    $query->Tr(
                               $query->td({-colspan=>2,-align=>"center"},"<b>$period</b>")
                              ),
                    map {
                      $query->Tr(
                                 $query->td({-width=>130,-align=>"left" }, $_),
                                 $query->td({-width=>130,-align=>"right"}, $quotas{$period}{$_})
                                )
                    } sort keys %{$quotas{$period}}                        );

print $query->end_td,
      $query->start_td({-width=>260,-valign=>"top"});

## Notes table
print $query->table({-border=>1,-width=>260},
                    $query->Tr(
                                $query->td({-align=>"center"},"<b>Notes</b>")
                              ),
                    $query->Tr(
                                $query->td("<font size=2>$notes{$period}</font>"),
                              ),
                  );

## End outer table
print $query->end_td,
      $query->end_Tr,
      $query->end_table;

print $query->end_html;
__DATA__
Jan 02 - Dec 02:        693 1125 3186    0 1741 1162 1787 562 7053 1894 2497 21700
Sep 01 - Dec 01:        741 1203 3406    0 1861 1242 1911 601 7541 2025 2670 23201
Apr 01 - Aug 01:        773 1255 3552    0 1941 1296 1993 627 7865 2113 2786 24201
Feb 01 - Mar 01:        805 1307 3698    0 2021 1350 2075 653 8189 2201 2902 25201