#!/usr/bin/perl -w

# make_exhibit.plx

# this script reads a pair of data files, extracts information
# relating to a group of tradeshow exhibitors, and writes
# out a browseable Web-based directory of those exhibitors

use strict;

# configuration section:

my $exhibit_file = './exhibit.txt';

# script-wide variable:

my %listing; # key:   company name ($co_name). 
             # value: HTML-ized listing for this company.

# read and parse the main exhibitor file

my @listing_lines = (); # holds current listing's lines for passing
                        # to the &parse_exhibitor subroutine

open EXHIBIT, $exhibit_file
    or die "Can't open $exhibit_file for reading: $!\n";

while (<EXHIBIT>) {
    if (/^\s*$/) {
        # this line is blank (or has nothing but space chars)
        if (@listing_lines) {
            &parse_exhibitor(@listing_lines);
            @listing_lines = ();
        }
    } else {
        # this line actually has data
        push @listing_lines, $_;
    }
}

# process last batch of lines, if the file didn't have a trailing
# blank line to trigger it already.

if (@listing_lines) {
    &parse_exhibitor(@listing_lines);
}

close EXHIBIT or die "Can't close $exhibit_file after reading: $!\n";

# output parsed data for debugging

print "LISTINGS:\n\n";

foreach my $co_name (sort keys %listing) {
    print $listing{$co_name}, "\n";
}

# script proper ends. subroutine follows.

sub parse_exhibitor {

    # extract the relevant information about a particular
    # exhibitor and store it in the appropriate hash.
    # 
    # invoked with an array of lines read from $exhibit_file.
    # has no return value, but instead modifies the following 
    # script-wide variable:
    #
    # %listing

    my @lines = @_;

    my($co_name, $booth, $address, $address2, $phone, $fax, $email,
        $url, $description);

    my $line_count = 0;
    
    foreach my $line (@lines) {

        chomp $line;
        ++$line_count;
        
        if ($line_count == 1) {
            $co_name = $line;            
        } elsif ($line_count == 2) {
            $booth = $line;
        } elsif ($line_count == 3) {
            $address = $line;
        } elsif ($line_count == 4) {
            $address2 = $line;
        } elsif ($line_count == 5) {
            $phone = $line;
        } elsif ($line_count == 6){
            $fax = $line;
        } elsif ($line =~ /^\S+@\S+$/) {
            $email = $line;
        } elsif ($line =~ /^http:\S+$/) {
            $url = $line;
        } else {
            $description .= "$line\n"; # append so that multi-line
                                       # descriptions work right
        }
    }
    
    # done cycling through @lines.
    # create the %listing entry.

    $listing{$co_name} = <<"EOF";
co_name:  $co_name
booth:    $booth
address:  $address
address2: $address2
phone:    $phone
fax:      $fax
email:    $email
url:      $url

description:
$description
EOF
}