use strict;
use warnings;
	
	# Declare globals
	my (@dates, @hlahdd, @rain, @snow);							
	
	# Create date list
	use Date::Simple::D8 (':all');					 
		my $start = Date::Simple::D8->new('19400101');	 
		my $end = Date::Simple::D8->new('20090718');	 
	
		while ( $start < $end ) {						
			push @dates, "$start";						
			chomp(@dates);								
			$start = $start->next;						
		}														

	# Open file for writing
	open(FH, '>', "c:/perl/scripts/496/hla.txt") or die "open: $!\n";

	# Initiate browsing agent
	use WWW::Mechanize;
	my $url = "http://bub2.meteo.psu.edu/wxstn/wxstn.htm";
	my $mech = WWW::Mechanize->new(keep_alive => 1);
		
	$mech->get($url);
		
		# Start the loop 
		while (@dates) {
			
			# Submit the first form
			$mech->submit_form(
				form_number => 1,
				fields      => { dtg => $dates[0], }
			);
			
			# Download the resulting page, text only, and scrape for data
			my $page = $mech->content(format=>'text');		
			my @data = ($page =~ /:\s\s\s\s(\d\d)/g);
			my @rain = ($page =~ /Rain or Liquid Equivalent\s+:\s+(\S*)/);
			# Replace 'TRACE' 
			if ($rain[0] eq 'TRACE') {
				$rain[0] = '0.00';
				}
			my @snow = ($page =~ /Snow and\/or Ice Pellets\s+:\s+(\S*)/);
			# Replace 'TRACE'
			if ($snow[0] eq 'TRACE') {
				$snow[0] = '0.00';
				}
			my @depth = ($page =~ /Snow Depth\s+:\s+(\S*)/);
			# Replace '(N/A)/TRACE/0'
			if ($depth[0] eq '(N/A)' or $depth[0] eq 'TRACE' or$depth[0] eq '0') {
				$depth[0] = "99";
				}
			my @hdd = ($page =~ /Degree-Days\s+:\s+(\S*)/);
			
			# Format the output for Fortran analysis
			use Fortran::Format;
			my $fdepth = Fortran::Format->new("I2.1,6X")->write($depth[0]);
				chomp $fdepth;
			my $frain = Fortran::Format->new("F4.2,6X")->write($rain[0]);
				chomp $frain;
			my $fsnow = Fortran::Format->new("F4.2,6X")->write($snow[0]);
				chomp $fsnow;
			my $f = Fortran::Format->new("I2.1,6X")->write($hdd[0]);
				chomp $f;
			
			# Assign data to the array
			@hlahdd = ("$dates[0] $data[0] $data[1] $data[2] $fdepth $f $frain $fsnow\n");
			
			# Print the array to screen and to file
			print "@hlahdd";
			print FH "@hlahdd"; 
			
			# Slow down boi... then go back a page
			sleep .1;	
			$mech->back();
			
			shift(@dates);
			
		}	# Exit the loop

# Close the written file
close(FH);