#!/usr/bin/perl
use strict;
use warnings;
use File::Spec;
use File::Path qw(remove_tree);
use Cwd qw(getcwd abs_path);

my ($files, $depth) = @ARGV;
if (!defined $files || !defined $depth) {
	die "Usage: perl bench.pl <files> <depth>\n";
}

my $base_dir = getcwd();
my $urn_bin  = abs_path(File::Spec->catfile("..", "urn")); 
my $seed_bin = abs_path("seed.pl");
my $bm_repo  = "bm_repo";

my %results;
my @actions = qw(Status Add Commit);

# Helper to count inodes (files/folders) in the metadata directory
sub count_inodes {
	my $dir = shift;
	return 0 unless -d $dir;
	my $count = `find $dir | wc -l`;
	$count =~ s/\s+//g;
	return $count;
}

# Helper to get folder size in KB
sub get_size {
	my $dir = shift;
	return 0 unless -d $dir;
	my $size = `du -sk $dir`;
	$size =~ /^(\d+)/;
	return $1 || 0;
}

sub run_benchmark {
	my ($tool_name) = @_;
	print "Benchmarking $tool_name...\n";

	# 1. Seed the directory
	system("perl $seed_bin $files $depth > /dev/null 2>&1") == 0 or die "Seeding failed";
	chdir($bm_repo) or die "Could not enter $bm_repo: $!";

	my $meta_dir = ($tool_name eq "URN") ? ".urn" : ".git";
	my $init_cmd = ($tool_name eq "URN") ? "perl $urn_bin init" : "git init";
	system("$init_cmd > /dev/null 2>&1");

	my %cmds = (
		"Status" => ($tool_name eq "URN") ? "perl $urn_bin status" : "git status",
		"Add"    => ($tool_name eq "URN") ? "perl $urn_bin add ."   : "git add .",
		"Commit" => ($tool_name eq "URN") ? "perl $urn_bin commit -m 'bench'" : "git commit -m 'bench'",
	);

	foreach my $action (@actions) {
		my $cmd = $cmds{$action};
		# Capture time metrics via STDERR
		my $raw = `(/usr/bin/time -l $cmd > /dev/null) 2>&1`;
		
		# Parse OpenBSD 'time -l' output
		my ($real) = $raw =~ /(\d+\.\d+)\s+real/;
		my ($rss)  = $raw =~ /(\d+)\s+maximum resident set size/;
		my ($maj)  = $raw =~ /(\d+)\s+page faults caused by physical I\/O/;
		my ($min)  = $raw =~ /(\d+)\s+page reclaims by virtual memory/;

		$results{$action}{$tool_name} = {
			real   => $real // "0.00",
			rss    => $rss  ? sprintf("%.1fM", $rss / 1024 / 1024) : "0M",
			fault  => sprintf("%d/%d", $maj // 0, $min // 0), 
			inodes => count_inodes($meta_dir),
			disk   => get_size($meta_dir) . "K",
		};
	}

	chdir($base_dir) or die $!;
	remove_tree($bm_repo) if -d $bm_repo;
}

# Run sequence
run_benchmark("URN");
run_benchmark("GIT");

# --- Final Report Formatting ---
my $out_file = "BM_ULTIMATE_${files}_${depth}.txt";
open(my $res, '>', $out_file) or die $!;

my $fmt = "%-8s | %-32s | %-32s\n";
my $sep = ("-" x 78);

print $res "BENCHMARK: $files files @ $depth depth\n$sep\n";
printf $res $fmt, "ACTION", "URN (Time/RSS/Faults/Inodes/Size)", "GIT (Time/RSS/Faults/Inodes/Size)";
print $res "$sep\n";

foreach my $action (@actions) {
	my $u = $results{$action}{"URN"};
	my $g = $results{$action}{"GIT"};

	printf $res "%-8s | %5ss %5s %7s %4s %5s | %5ss %5s %7s %4s %5s\n",
		$action,
		$u->{real}, $u->{rss}, $u->{fault}, $u->{inodes}, $u->{disk},
		$g->{real}, $g->{rss}, $g->{fault}, $g->{inodes}, $g->{disk};
}
print $res "$sep\n";
close($res);

# Use PAGER for output
print "\nComparison complete! Results saved to $out_file\n";
my $pager = $ENV{PAGER} || 'less';
system("$pager $out_file");