#!/usr/bin/perl -w

open TRACEFILE, $ARGV[0];

@packet_numbers = ();
$num_dropped = 0;
$max_queue_length = 0;
$num_in_queue = 0;
@queue_length_hist = ();

$current_queue_time = 0;

while (<TRACEFILE>) {
    @fields = split;
    if ($fields[0] eq "r") { #received packet
	# if it's a packet receipt indication, save it:
	$packet_numbers[$#packet_numbers + 1] = $fields[11];
    } elsif ($fields[0] eq "d") { #dropped packet
	$num_dropped++;
    } elsif ($fields[0] eq "+") {
	$queue_length_hist[$num_in_queue] += $fields[1] - $current_queue_time;

	$current_queue_time = $fields[1];
	$num_in_queue++;
	if ($num_in_queue > $max_queue_length) {
	    $max_queue_length = $num_in_queue;
	}
    } elsif ($fields[0] eq "-") {
	$queue_length_hist[$num_in_queue] += $fields[1] - $current_queue_time;

	$current_queue_time = $fields[1];
	$num_in_queue--;
	if ($num_in_queue < 0) {
	    exit 1;
	}
    }
}

@aux_packet_numbers = sort {$a <=> $b} @packet_numbers;

# get arrival times:
for ($k = 0; $k < $#packet_numbers + 1; $k++) {
    $arrival_time[$packet_numbers[$k]] = $k;
}

for ($i = 0; $i < ($#packet_numbers + 2) * 2; $i++) {
    $reorder_distances[$i] = 0;
}

$biggest_distance = 0;
@big_packet = (-1, -1);

for ($i = 0; $i < $#packet_numbers + 1; $i++) {
    for ($j = $i; $j < $#packet_numbers + 1; $j++) {
	# get j's arrival time:
	$distance = abs( ($i - $j) - ($arrival_time[$aux_packet_numbers[$i]] - $arrival_time[$aux_packet_numbers[$j]]) );
	$reorder_distances[$distance]++;

	if ($distance > $biggest_distance) {
	    $biggest_distance = $distance;
	    @big_packet = ($aux_packet_numbers[$i], $aux_packet_numbers[$j]);
	}
    }
}

$queue_sum = 0.0;
for ($i=0; $i < $#queue_length_hist + 1; $i++) {
    $queue_sum += $queue_length_hist[$i];
}
$test_sum = 0.0;


if ($#ARGV < 3) {
    printf("\n");
    printf("Number of packets: %d\n", $#packet_numbers + 1 + $num_dropped);
    printf("Number of packets dropped: %d\n", $num_dropped);
    printf("Packets furthest out of order: %d and %d (out of order by %d)\n", $big_packet[0], $big_packet[1], $biggest_distance);
    printf("Longest queue length during simulation: %d\n", $max_queue_length);

    for ($i=0; $i < $#queue_length_hist + 1; $i++) {
	printf("Percent of time at length %d: %f\n", $i, $queue_length_hist[$i] / $queue_sum);
	$test_sum += $queue_length_hist[$i] / $queue_sum;
    }
    printf("Sum of queue length times: %f (check: %f)\n", $queue_sum, $test_sum);
    printf("\n");
} else {
    open STAT, ">$ARGV[3]";
    printf(STAT "\n");
    printf(STAT "Number of packets: %d\n", $#packet_numbers + 1 + $num_dropped);
    printf(STAT "Number of packets dropped: %d\n", $num_dropped);
    printf(STAT "Packets furthest out of order: %d and %d (out of order by %d)\n", $big_packet[0], $big_packet[1], $biggest_distance);
    printf(STAT "Longest queue length during simulation: %d\n", $max_queue_length);
    for ($i=0; $i < $#queue_length_hist + 1; $i++) {
	printf(STAT "Percent of time at length %d: %f\n", $i, $queue_length_hist[$i] / $queue_sum);
	$test_sum += $queue_length_hist[$i] / $queue_sum;
    }
    printf(STAT "Sum of queue length times: %f (check: %f)\n", $queue_sum, $test_sum);
    printf(STAT "\n");
}

if ($#ARGV >= 1) {
    if ($ARGV[1] eq "y") {
	if ($#ARGV < 2) {
	    for ($i=0; $i < $#reorder_distances + 1; $i++) {
		printf "$i:$reorder_distances[$i]\n";
	    }
	} else {
	    open REORDER, ">$ARGV[2]";
	    for ($i=0; $i < $#reorder_distances + 1; $i++) {
		printf REORDER "$i:$reorder_distances[$i]\n";
	    }
	    close REORDER;
	}
    }
}

#for ($i=0; $i < $#packet_numbers + 1; $i++) {
#    print "$packet_numbers[$i]\n";
#}