#!/usr/bin/perl
use strict;
use warnings;

use Data::Dumper;

sub analyze_run_data {
	my $test_name = shift;
	my $data = shift;

	my $i;
	my $deviation;
	my $cnt;
	my $averages = {};
	my $k;
	my $avg;

	$cnt = scalar @{$data};

	for ($i = 0; $i < $cnt; ++$i) {
		if ($data->[$i]->{'swaps'} != 0) {
			# Did we run out of memory?
			warn(sprintf(
				"%s: run_try=%d: swaps is non-zero: %d\n",
				$test_name, $i + 1, $data->[$i]->{'swaps'}
			));
		}
		if ($data->[$i]->{'sys_t'} + $data->[$i]->{'user_t'} > $data->[$i]->{'real_t'}) {
			warn(sprintf(
				"%s: run_try=%d: CPU time (%.1f) is bigger than wall-clock time (%.1f); multi-threaded?\n",
				$test_name, $i + 1,
				$data->[$i]->{'sys_t'} + $data->[$i]->{'user_t'},
				$data->[$i]->{'real_t'}
			));
		}
	}

	foreach $k (qw/ real_t sys_t user_t cpu_t /) {
		$averages->{$k} = 0;
	}

	for ($i = 0; $i < $cnt; ++$i) {
		$data->[$i]->{'cpu_t'} = $data->[$i]->{'sys_t'} + $data->[$i]->{'user_t'};

		$data->[$i]->{'per_10_lines'} = {};
		foreach $k (qw/ real_t sys_t user_t cpu_t /) {
			$data->[$i]->{'per_10_lines'}->{$k} = $data->[$i]->{$k} / $data->[$i]->{'nlines'} * 10;

			# XXX: Average values for 10 lines of output.
			# XXX: So that we can compare with the previous test method.
			$averages->{$k} += $data->[$i]->{'per_10_lines'}->{$k};
		}
	}

	foreach $k (qw/ real_t sys_t user_t cpu_t /) {
		$averages->{$k} = $averages->{$k} / $cnt;
	}

	#print Dumper($data)."\n";
	#print Dumper($averages)."\n";

	for ($i = 0; $i < $cnt; ++$i) {
		foreach $k (qw/ real_t cpu_t /) {
			$avg = $averages->{$k};
			$deviation = (($avg - $data->[$i]->{'per_10_lines'}->{$k}) / $avg) * 100;
			if (abs($deviation) > 5) { # percents
				warn(sprintf(
					"%s: run_try=%d: Measurement deviations are too high for '%s': %.1f\n",
					$test_name, $i + 1, $k, $deviation
				));
			}
		}
	}

	return $averages;
}

sub _print_results_as_html_header {
	print <<'EOF'
<table border="1" style="border-collapse:collapse;" cellpadding="4">
<thead>
<tr>
<th rowspan="2" align="center">Language</th>
<th colspan="3" align="center">CPU time</th>
<th colspan="2" align="center">Slower than</th>
<th rowspan="2" align="center">Language<br>version</th>
<th rowspan="2" align="center">Source<br>code</th>
</tr>
<tr>
<th align="center">User</th>
<th align="center">System</th>
<th align="center">Total</th>
<th align="center">C++</th>
<th align="center">previous</th>
</tr>
</thead>
<tbody>
EOF
}

sub _print_results_as_html_footer {
	print <<'EOF'
</tbody>
</table>
EOF
}

sub _print_results_as_html_template {
	return <<'EOF'
<tr>
<td>%s</td>
<td align="right">%.3f</td>
<td align="right">%.3f</td>
<td align="right">%.3f</td>
<td align="center">%s</td>
<td align="center">%s</td>
<td align="right">%s</td>
<td align="center"><a href="https://github.com/famzah/langs-performance/blob/master/%s">link</a></td>
</tr>
EOF
}

sub _print_results_as_html_enrich_test_name {
	my $test_name = shift;

	if ($test_name eq 'C++ (optimized with -O2)') {
		return 'C++ <em>(<a href="http://gcc.gnu.org/onlinedocs/gcc-4.4.4/gcc/Optimize-Options.html#Optimize-Options">optimized with -O2</a>)</em>';
	}
	if ($test_name =~ /^Java (\d)$/) {
		return 'Java '.$1.' (<a href="https://github.com/famzah/langs-performance/tree/master/java-optimizations">see notes</a>)';
	}
	if ($test_name =~ /^Java (\d) \(non-std lib\)$/) {
		return '<font color="#D1D0CE">Java '.$1.' <em>(<a href="/2010/07/01/cpp-vs-python-vs-perl-vs-php-performance-benchmark/#comment-4084">non-std lib</a>)</em></font>';
	}
	if ($test_name =~ /^Python (\d\.\d) \+ PyPy$/) {
		return '<font color="#D1D0CE">Python '.$1.' + PyPy</font>';
	}
	if ($test_name eq 'JavaScript (nodejs)') {
		return 'Javascript (<a href="http://nodejs.org/">nodejs</a>)';
	}
	if ($test_name eq 'C++ (not optimized)') {
		return '<font color="#D1D0CE">C++ <em>(not optimized)</em></font>';
	}
	if ($test_name =~ /^C# .NET Core(.*)$/) {
		return '<a href="https://dotnet.github.io/">C# .NET Core</a>'.$1;
	}

	return $test_name;
}

sub _print_results_as_html {
	my $test_name = shift;
	my $averages = shift;
	my @slower = @{ $_[0] }; shift;
	my $test_data = shift;

	printf(
		_print_results_as_html_template(),
		_print_results_as_html_enrich_test_name($test_name),
		$averages->{'user_t'},
		$averages->{'sys_t'},
		$averages->{'cpu_t'},
		$slower[0],
		$slower[1],
		$test_data->{'meta'}->{'version'},
		$test_data->{'meta'}->{'src_file'}
	);
}

sub _print_results_as_text {
	my $test_name = shift;
	my $averages = shift;
	my @slower = @{ $_[0] }; shift;
	my $test_data = shift;

	printf(
		"%-30s: user_t=%6.3f sys_t=%6.3f cpu_t=%6.3f to_CPP=%5s to_prev=%5s version=%s\n",
		$test_name,
		$averages->{'user_t'},
		$averages->{'sys_t'},
		$averages->{'cpu_t'},
		$slower[0],
		$slower[1],
		$test_data->{'meta'}->{'version'}
	);
}

sub print_results {
	my $output = shift;
	my @sorted_all = @{ $_[0] }; shift;
	my $test_data;
	my $test_name;
	my $averages;
	my @slower = ();
	my $idx = -1;
	my ($sl_idx, $src_idx);
	my $ratio;
	my @args;

	foreach (@sorted_all) {
		$test_name = $_->{'test_name'};
		$test_data = $_->{'test_data'};
		$averages = $_->{'averages'};
		++$idx;

		#print Dumper($test_data->{'run_data'})."\n";
		#print Dumper($averages)."\n";

		if ($idx == 0) {
			$slower[0] = '-';
			$slower[1] = '-';
		} else {
			foreach $sl_idx (0,1) {
				if ($sl_idx == 0) {
					$src_idx = 0;
				} else {
					$src_idx = $idx - 1;
				}

				$ratio = $averages->{'cpu_t'} / $sorted_all[$src_idx]->{'averages'}->{'cpu_t'};

				$slower[$sl_idx] = sprintf('%d%%', ($ratio - 1.00) * 100);
			}
		}

		@args = ($test_name, $averages, \@slower, $test_data);
		if ($output eq 'text') {
			_print_results_as_text(@args);
		} elsif ($output eq 'html') {
			_print_results_as_html(@args);
		} else {
			die("Unknown output: $output");
		}
	}
}

sub usage {
	die("Usage: $0 [text|html]\nRead results at STDIN and format them as specified.\n");
}

sub parse_ARGV {
	my $output_mode = shift @ARGV;

	if (!defined($output_mode)) {
		usage();
	}
	if ($output_mode !~ /^(text|html)$/) {
		usage();
	}

	return $output_mode;
}

sub main {
	my $line;
	my $data = {};
	my $averages;
	my $k;
	my $test_data;
	my $test_name;
	my @sorted_all = ();
	my $output_mode;

	$output_mode = parse_ARGV();

	while ($line = <STDIN>) {
		chomp($line);

		if ($line =~ /^(\s*#|SKIPPING)/) {
			next;
		}

		if ($line !~ /^real_TIME:(\d+\.\d+)sec user_CPU:(\d+\.\d+)sec sys_CPU:(\d+\.\d+)sec max_RSS:(\d+)kb swaps:(\d+) ctx_sw:(\d+)\+(\d+) nlines:(\d+) run_try:(\d+)  header:'([^']+)' version:'([^']+)' src_file:(\S+)$/) {
			die("Unable to parse line: $line\n");
		}

		my $row = {}; # new reference every time
		my $run_try;
		my $test_name;
		$row->{'real_t'} = $1;
		$row->{'user_t'} = $2;
		$row->{'sys_t'} = $3;
		$row->{'max_RSS'} = $4;
		$row->{'swaps'} = $5;
		$row->{'ctx_sw_unvol'} = $6;
		$row->{'ctx_sw_vol'} = $7;
		$row->{'nlines'} = $8;
		$run_try = $9 - 1; # XXX: fix index
		#
		$test_name = $10;
		$row->{'version'} = $11;
		$row->{'src_file'} = $12;

		# trim white-space
		$row->{'version'} =~ s/^\s*//;
		$row->{'version'} =~ s/\s*$//;

		if (!exists($data->{$test_name})) {
			$data->{$test_name} = {
				'meta' => {},
				'run_data' => [],
			};
			foreach $k (qw/ version src_file /) {
				$data->{$test_name}->{'meta'}->{$k} = $row->{$k};
			}
		}

		foreach $k (qw/ version src_file /) {
			if ($data->{$test_name}->{'meta'}->{$k} ne $row->{$k}) {
				die("Sanity check failed for meta: $line");
			}
		}

		if (exists($data->{$test_name}->{'run_data'}->[$run_try])) {
			die("Duplicate run#: $line");
		}
		delete($row->{'version'});
		delete($row->{'src_file'});
		$data->{$test_name}->{'run_data'}->[$run_try] = $row;
		foreach $k (qw/ version src_file /) {
			delete($data->{$test_name}->{'run_data'}->[$run_try]->{$k});
		}
	}

	while (($test_name, $test_data) = each %{$data}) {
		$averages = analyze_run_data($test_name, $test_data->{'run_data'});
		push(@sorted_all,
		{
			'test_name' => $test_name,
			'test_data' => $test_data,
			'averages' => $averages,
		});
	}

	@sorted_all = sort {
		$a->{'averages'}->{'cpu_t'} <=> $b->{'averages'}->{'cpu_t'};
	} @sorted_all;

	if ($output_mode eq 'html') {
		_print_results_as_html_header();
	}
	print_results($output_mode, \@sorted_all);
	if ($output_mode eq 'html') {
		_print_results_as_html_footer();
	}
}

main();