#!/usr/bin/perl -w
use strict;
use XML::Simple;
use Data::Dumper;
use Getopt::Std;

# Figure out which ADSL connection is best.
# Paul Fenwick <pjf@cpan.org>
# November 2001
# 
# This program is in the public domain.
#
# Usage: analyse.pl [-b] [-v] [-s min_speed] [-f providerfile.xml]
#                   [monthly_mb_usage] [top_n_plans]
# 
# -b - Business plans only
# -v - Verbose, show all calculated costs.
# -s - Set minimum downlink speed.
#
# Abbreviations used:
#
# 	EMC	- Estimated monthly cost
# 	EYC	- Estimated yearly cost
# 	EFYC	- Estimated first yearly cost

my %opt = (v => 0, f => "./providers.xml", b => 0, s=>0);
getopts('bvfs:',\%opt);

# Bandwidth usage.
my $usage = shift || 500;

# Top N providers to show.
my $top   = shift || 5;

my $xs = XML::Simple->new();

my $providers = $xs->XMLin($opt{f}, forcearray=>[qw/feature plan/]);
my %compare = ();
$providers = $providers->{provider};

foreach my $provider_name (sort keys %$providers) {
	my $provider = $providers->{$provider_name};
	print "\n$provider_name\n" if $opt{v};
	PLAN: foreach my $plan_name (keys %{$provider->{plan}}) {
		next if ($plan_name eq "null");
		my $plan = $provider->{plan}{$plan_name};

		# Skip any plan that doesn't meet out minimum speed.
		# A speed of 0 in the XML is considered to be uncapped,
		# and hence "fast enough".

		my $downlink = $plan->{speed}{downlink} ||
			       $provider->{speed}{downlink} || 0;
		next if ($downlink and $downlink < $opt{s});

		# Skip any plan that mentions residential in the
		# name if we've been asked for business plans only.

		if ($opt{b}) {
			foreach (@{$plan->{feature}}) {
				next PLAN if /residential/i;
			}
		}

		# Figure out some basic costs.

		my $setup = $plan->{setup}{fee} || $provider->{setup}{fee};
		my $excess = $usage - $plan->{monthly}{download};
		($excess < 0) and ($excess = 0);
		my $monthly = $plan->{monthly}{fee} + 
		              ($excess/100) * ($plan->{bandwidth}{fee}||
			                       $provider->{bandwidth}{fee}||0);

		# Calculate various costs, record features, and insert into
		# our comparison hash for later sorting.

		my $ckey = "$provider_name/$plan_name";

		$compare{$ckey}{EFYC} = $monthly*12+$setup;
		$compare{$ckey}{EYC}  = $monthly*12;
		$compare{$ckey}{features} = [@{$provider->{feature}||[]},
		                             @{$plan->{feature}||[]}];

		# If we're in verbose mode, print out the calculated
		# costs.
		next unless $opt{v};
		print "\t$plan_name\n";
		print "\t\tSetup: $setup\n";
		print "\t\tEMC: $monthly\n";
		print "\t\tEYC: ",$compare{$ckey}{EYC},"\n";
		print "\t\tEFYC: ",$compare{$ckey}{EFYC},"\n";
	}
}

# Print the final summary of the top N providers with features, sorted
# by estimated yearly cost.

print "EFYC\tEYC\tProvider/Plan\n","-"x75,"\n";
$top = keys %compare if ($top > keys %compare);
foreach my $plan ((sort {$compare{$a}{EYC} <=> $compare{$b}{EYC}} (keys %compare))[0..$top-1]) {
	print join("\t",$compare{$plan}{EFYC},$compare{$plan}{EYC},$plan),"\n";
	print map { "\t\t$_\n"; } @{$compare{$plan}{features}};
}
__END__