#!/usr/bin/perl

# <short description of program>

    use strict;
    use warnings;
    use CGI::Carp qw(fatalsToBrowser);
    BEGIN {$ENV{HOME} ||= (getpwuid($<))[7]}       # in case $HOME isn't set
    BEGIN {require "$ENV{HOME}/.cgiEnvVars.pm"}

    use CGI;
    use Data::Dumper;

my $data = parse(<<'EOF');

    $153    1366x768    16"     http://www.newegg.com/Product/Product.aspx?Item=N82E16824009132
    $159    1024x768    15"     http://www.ewiz.com/detail.php?p=ACER-1516B&c=pw
    $159    1024x768    15"     http://www.newegg.com/Product/Product.aspx?Item=N82E16824009093
    $163    1440x900    17"     http://www.newegg.com/Product/Product.aspx?Item=N82E16824254018
    $168    1280x1024   17"     http://www.newegg.com/Product/Product.aspx?Item=N82E16824009117
    $169    1440x900    17"     http://www.ewiz.com/detail.php?p=ACE-X17WB&c=pw
    $2000   1920x1080   37"     http://www.pcmag.com/article2/0,1759,1885043,00.asp

EOF

print "Content-Type: text/html; charset=utf-8\n\n";

#cgidmp($data); exit;


print <<'EOF';
<style>
    table {border-collapse:collapse}
    td, th {border:1px solid #aaa; padding:0.3em}
    pre {background-color:#afa}
    th.sorted {background-color:#888; color:#fff}
</style>
<h3>Building a <a href="http://kvmsansv.com/multi-megapixel_displays.html">monitor wall</a> from heterogeneous LCDs</h3>

<p><a href="http://youtube.com/watch?v=Id3GHAruhAk">Synergy</a>: making vast amounts of screen real-estate actually usable, today.  (it may be the best solution until we get <a href="http://paperlined.org/academics/computer_science/multimegapixel_window_managers.html">better window managers</a>)
<p>

<table>
<tr><th>shipped cost <th>resolution <th>diagonal <th>megapixels <th class=sorted>$/mp <th><a href="http://en.wikipedia.org/wiki/Pixels_per_inch">PPI</a> <th>seller
EOF

my $orig_data = $data;
$data = [ sort {$a->{cost_per_mp} <=> $b->{cost_per_mp}} @$data ];
foreach my $display (@$data) {
    printf q{<tr><td><a href='%s'>$%d</a> <td>%dx%d <td>%d" <td>%5.2f <td>$%5.2f <td>%5.2f <td>%s},
        $display->{url},
        $display->{price},
        $display->{resolution}[0],  $display->{resolution}[1],
        $display->{diagonal_inches},
        $display->{megapixels},
        $display->{cost_per_mp},
        $display->{ppi},
        $display->{seller},
        ;
    print "\n";
}

my $underlying_database = CGI::escapeHTML(join("\n", map {$_->{original_line}} @$orig_data));

print <<"EOF";
</table>

<br><br>Places to find decent prices:
<ul>
<li><a href="http://castle.pricewatch.com/s/search.asp?s=lcd&group1=2&sci=34&c=Monitors">pricewatch</a>
<li><a href="http://computers.pricegrabber.com/flat-panel-lcd-monitors/p/37/st=sort/sortby=priceA">pricegrabber</a>
</ul>

<br><br>
Underlying <!-- <a href="http://en.wikipedia.org/wiki/Domain-specific_programming_language">custom</a> --> text "database":<pre>$underlying_database</pre>


EOF




sub parse {
    my @ret;
    foreach my $line (split /[\n\r]+/, shift) {
        next unless ($line =~ /\S/si);
        my @f = split ' ', $line;

        my %display = (
            price => $f[0],
            resolution => [ split 'x', $f[1] ],
            diagonal_inches => $f[2],
            url => $f[3],
            original_line => $line,
        );

        $display{price} =~ s/^\$//si;
        $display{diagonal_inches} =~ s/"$//si;

        # analysis/synthesys
        ($display{seller}) = ($display{url} =~ m#^http://(?:[^\./]*\.)*([^\./]+\.[^\./]+)/#si);
        $display{megapixels} = ($display{resolution}[0] * $display{resolution}[1]) / 1000000;
        $display{cost_per_mp} = $display{price} / $display{megapixels};

        #$display{diagonal_resolution} = sqrt($display{resolution}[0]**2 + $display{resolution}[1]**2);
        #$display{ppi} = $display{diagonal_resolution} / $display{diagonal_inches};
                # von http://en.wikipedia.org/wiki/Pixels_per_inch
        $display{ppi} = ($display{resolution}[0] / $display{diagonal_inches}) * sqrt(1 + $display{resolution}[0] / $display{resolution}[1]);

        push(@ret, \%display);
    }

    return \@ret;
}



sub cgidmp {print "<pre>", CGI::escapeHTML(join("", Dumper(@_))), "</pre>"}