#!/usr/bin/perl -w

use strict;
use Getopt::Long;

my $help;
my $headers = 1;
my $sourcecolumn = 1;
my $sourcetype = 'partial';
my $first_headers;
my $use_tab = 1;
my $use_comma = 0;

GetOptions(
    'headers!' => \$headers,
    'source!' => \$sourcecolumn,
    'source-type=s' => \$sourcetype,
    'use-tab' => \$use_tab,
    'use-comma' => \$use_comma,
    'help|?' => \$help
);
if ($use_comma) {
    $use_tab = 0;
}
if ($help || @ARGV == 0 || ($sourcetype ne 'partial' && $sourcetype ne 'full')) {
    print "$0 <--headers|--noheaders> <--source|--nosource> <--source-type=full|--source-type=partial> <--use-tab|--use-comma> [file1] [file2] <fileN...>\n";
    exit 0;
}

sub munged_source {
    my $fn = shift;
    my $s = $fn;
    if ($sourcetype eq 'partial') {
        my @f = split(/\//, $fn);
        $s = $f[0];
    }
    return "$s" . ($use_tab ? "\t" : ',');
}

sub cat_file {
    my $fn = shift;
    open FILE, "$fn";
    if ($headers) {
        if ($fn ne $ARGV[0]) {
            my $check = <FILE>; # check and throw away headers for subsequent files
            if ($check ne $first_headers) {
                print STDERR "Mismatched headers between $ARGV[0] and $fn\n";
                print STDERR "$first_headers\n$check\n";
                exit 1;
            }
        } else {
            print "x_source" . ($use_tab ? "\t" : ',') if $sourcecolumn; # potential column header
            $first_headers = <FILE>;
            print $first_headers;
        }
    }
    while (my $line = <FILE>) {
        print munged_source($fn) if $sourcecolumn;
        print $line;
    }
    close FILE;
}

my @files = @ARGV;
foreach my $file (@files) {
    cat_file($file);
}