#!/usr/bin/perl
use Data::Dumper;

$Data::Dumper::Indent = 0;
$Data::Dumper::Useqq = 1;

$Data::Dumper::Purity = 1;
	
die "Usage: updatemegadata <data file> <site name> <new map reference>\n"
unless @ARGV == 3;

my $megalithFile = $ARGV[0];
my $siteName = $ARGV[1];
my $siteMapRef = $ARGV[2];
my $tempFile = "tmp.$$";

open MEGADATA, "<$megalithFile" or die "Can't open $megalithFile: $!\n";

open TMPMEGADATA, ">$tempFile" or die "Can't open temporary file $tempFile: $!\n";

while ( <MEGADATA> ) {

	next unless m/\Q$siteName/;

	my $fields;
	eval $_;
	die if $@;

	my ( $name, $location, $mapref, $type, $description ) = @$fields;

	next unless $siteName eq $name;

	$fields = [ $name, $location, $siteMapRef, $type, $description ];

	$_ = Data::Dumper->new( [ $fields ], [ 'fields' ] )->Dump();
	$_ .= "\n";

} continue {
	print TMPMEGADATA $_ or die "Error writing $tempFile: $!\n";
}
close MEGADATA;

close TMPMEGADATA or die "Error closing $tempFile: $!\n";

unlink $megalithFile or die "Can't delete old $megalithFile: $!\n";

rename $tempFile, $megalithFile or die "Can't rename '$tempFile' to '$megalithFile': $!\n";
exit 0;