#!/usr/bin/perl

# This program writes a line containing the current time in seconds to a data
# file for suspend and resume events so that the time asleep and a history of
# time asleep can be parsed

use strict;

# If you like, change this..  However it makes sense to keep it in /root because
# most likely have to be root to suspend anyway.
my $file = "/root/.sleeptime";

# No need to edit below here..
my $now = time(); # epoch seconds
my $linefailed = 0;
my $lastlinefailed;

my $arg=@ARGV[0];

if ($arg eq "-h" || $arg eq "--help")
{
	printhelp();
	exit;
}

# Record a "sleep" record
if ($arg eq "sleep")
{ 
	open(OUT,">>".$file) || die "Could not open $file for writing\n";
	print OUT "S:" . $now . "\n";
}

# Record a "resume" record
if ($arg eq "resume")
{
	open(OUT,">>".$file) || die "Could not open $file for writing\n";
	print OUT "R:" . $now . "\n";
}

# Print the latest sleep time result
if ($arg eq "sleeptime" || $arg eq "")
{
	open(IN, "$file") || die "Could not open $file for reading\n";
	my ($line,$prevline,$oldline,$lastline);
	foreach $line (<IN>)
	{
		chomp($line);
		$oldline = $lastline;
		$lastline = $line;
	}
	sleeptime($oldline,$lastline);
}

# Print the entire sleep history.  In this routine, we do some additional work to 
# check to see if there was some bad data, ie: Multiple suspend or resume lines
# in a row.  As could happen if the laptop doesn't resume properly, etc.
# We kludge the test a little to make sure we don't hit sleeptime() twice.
if ($arg eq "sleephistory")
{
	open(IN, "$file") || die "Could not open $file for reading\n";
	my ($line,$prevline,$oldline,$lastline);
	my $test = 1;
	foreach $line (<IN>)
	{
		chomp($line);
		$oldline = $lastline;
		$lastline = $line;
# We go here if the last data pair failed
		if ($linefailed)
		{
			$test = 1;
			$linefailed = 0;
			sleeptime($oldline,$lastline);
		}
# Only hit sleeptime every other $line we read
		unless ($test % 2)
		{
			sleeptime($oldline,$lastline);
		}
		$test++;
	}
}

# This function validates the two lines of data and sends the time difference
# to the printtime() function if there is no bad data.
sub sleeptime()
{
	my ($oldline,$lastline) = (@_);
	my ($var,$oldlinetime) = split(':',$oldline);
	unless ($var eq "S")
	{
#		print "Previous line not sleep!  Corrupted data?\n";
		$linefailed = 1;
		$lastlinefailed = $lastline;
	}
	my ($var,$lastlinetime) = split(':',$lastline);
	unless ($var eq "R")
	{
#		print "last line not resume!  Corrupted data?\n";
		$linefailed = 1;
		$lastlinefailed = $lastline;
	}
	my $sleeptime = $lastlinetime - $oldlinetime;
	unless ($linefailed) { printtime($sleeptime); }
}

# Print the amount of time that we were asleep in D:H:M:S and a string..
sub printtime()
{
	my $sleeptime = shift;
	my @parts = gmtime($sleeptime);
	my ($days,$hours,$minutes,$seconds) = @parts[7,2,1,0];
	if ($days > 0)
	{
		printf ("\(%02d:%02d:%02d:%02d\) ",$days,$hours,$minutes,$seconds);
		print ("Asleep $days days $hours hours $minutes minutes $seconds seconds\n");
		$hours = $minutes = $seconds = 0;
	}
	if ($hours > 0)
	{
		printf ("\(%02d:%02d:%02d:%02d\) ",$days,$hours,$minutes,$seconds);
		printf ("Asleep $hours hours $minutes minutes $seconds seconds\n");
		$minutes = $seconds = 0;
	}
	if ($minutes > 0)
	{
		printf ("\(%02d:%02d:%02d:%02d\) ",$days,$hours,$minutes,$seconds);
		printf ("Asleep $minutes minutes $seconds seconds\n");
		$seconds = 0;
	}
	if ($seconds > 0)
	{
		printf ("\(%02d:%02d:%02d:%02d\) ",$days,$hours,$minutes,$seconds);
		printf ("Asleep $seconds seconds\n");
	}
}

sub printhelp()
{
	print "Usage:  [sleep] [resume] [sleeptime] [sleephistory]\n\n";
	print "       sleep - Records a Sleep record\n";
	print "      resume - Records a Resume record\n";
	print "   sleeptime - Prints the last time asleep (default)\n";
	print "sleephistory - Prints the entire history\n\n";
	print "If multiple Sleep or Resume entries are found in a row when";
	print "parsing the data file the program attempts to print the data";
	print "which makes sense.  It skips the duplicate data until it finds";
	print "a valid S/R pair.\n\n";
	print "If no arguments are given, sleeptime is assumed.\n";
}