#!/usr/bin/perl

#Copyright (c) 2016 Wind River Systems, Inc.
#
#SPDX-License-Identifier: Apache-2.0
#

# parse_iostat
#
# Purpose:
#
# Modification history:
# - 2015-Dec-259 - Jim Gauld, prototype created.

use 5.10.0;
use warnings;
use strict;
use Time::Local 'timelocal_nocheck'; # inverse time functions
use File::Basename;
use File::Spec ();
use Data::Dumper;

my $SCRIPT = basename($0);

# Timestamp variables
my ($wday, $month, $day, $hh, $mm, $ss, $yy, $ns) = ();
my @T0 = localtime();
my $yy00 = 1900 + $T0[5];
my $cc00 = 100*int($yy00/100);

# Argument list parameters
our ($arg_device, @arg_files) = ();

# Determine location of gunzip binary
our $GUNZIP = which('gunzip');
if (!(defined $GUNZIP)) {
   die "*error* cannot find 'gunzip' binary. Cannot continue.\n";
}
our $BUNZIP2 = which('bunzip2');
if (!(defined $BUNZIP2)) {
   die "*error* cannot find 'bunzip2' binary. Cannot continue.\n";
}

# Parse input arguments and print tool usage if necessary
&get_parse_iostat_args(\$arg_device, \@arg_files);

# Compile regular expressions
my $re_dev = qr/\Q$::arg_device\E/;

foreach my $file (@ARGV) {
	print "processing file: $file\n";
	if ($file =~ /\.gz$/) {
		open(FILE, "$::GUNZIP -c $file |") || die "Cannot open file: $file ($!)\n";
	} elsif ($file =~ /\.bz2$/) {
		open(FILE, "$::BUNZIP2 -c $file |") || die "Cannot open file: $file ($!)\n";
	} else {
		open(FILE, $file) || die "Cannot open file: $file ($!)\n";
	}

	#my ($timestamp, $timestamp0, $time_fmt) = ("", "", "");

	my ($field, $idx, $len);
	my $found = 0;
	my @dev_x;
	my @dev_T;
	my $dev_N;
	my %dev_H;
	my ($time_fmt) = ("");

	# Wipe out data and statistics per file.
	my (%data, %stats, %series) = ();
	my $first = 1;

	READ_LOOP: while($_ = <FILE>) {
		s/[\0\e\f\r\a]//g; chomp; # strip control characters if any

		# timestamp
		# 12/23/15 18:56:50
		if (/^(\d{2})\/(\d{2})\/(\d{2})\s+(\d{2}):(\d{2}):(\d{2})/) { # ignore timezone
			$month = $1; $day = $2; $yy = $3 + $cc00; $hh = $4; $mm = $5; $ss = $6; $ns = 0;
			#print "TIME: $_";
			$found = 0;
			next;
		}

		if (/^avg-cpu:/) {
			$_ = <FILE>; $_ = <FILE>;
			#print "AVG: $_";
			next
		}

		if (/^Device:/) {
			#print "DEV: $_\n";
			@dev_T = split(/\s+/, $_); shift @dev_T if (/^\s+/);
			$dev_N = scalar(@dev_T);

			# determine lower and upper indices for numerical fields
			for ($idx=0; $idx < $dev_N; $idx++) {
				$field = $dev_T[$idx];
				$dev_H{ $field } = $idx;
			}

			# Read in each device
			DEV_LOOP: while($_ = <FILE>) {
				s/[\0\e\f\r\a]//g; chomp; # strip control characters if any
				last DEV_LOOP if (/^$/);

				if (/\b$re_dev\b/) {
					@dev_x = split(/\s+/, $_); shift @dev_x if (/^\s+/);
					$len = scalar(@dev_x);
					$found = 1;
				}
			}
		}

		# Print line of data if we have it
		if ($found == 1) {
			# Print header (per file)
			if ($first == 1) {
				printf "%4s-%2s-%2s %2s:%2s:%2s ",  'yyyy', 'mm', 'dd', 'hh', 'mm', 'ss';
				printf "%-8s ", $dev_T[0];
				for ($idx=1; $idx < $dev_N; $idx++) {
					printf "%9s ", $dev_T[$idx];
				}
				printf "\n";
				$first = 0;
			}

			printf "%04d-%02d-%02d %02d:%02d:%02d ",  $yy, $month, $day, $hh, $mm, $ss;
			printf "%-8s ", $dev_x[0];
			for ($idx=1; $idx < $dev_N; $idx++) {
				printf "%9.2f ", $dev_x[$idx];
			}
			printf "\n";
		}
	}

	# Print blank line between files
	print "\n";
}
exit 0;

#######################################################################################################################
# Lightweight which(), derived from CPAN File::Which
sub which {
   my ($exec) = @_;
   return undef unless $exec;
   my $all = wantarray;
   my @results = ();
   my @path = File::Spec->path;
   foreach my $file ( map { File::Spec->catfile($_, $exec) } @path ) {
      next if -d $file;
      if (-x _) { return $file unless $all; push @results, $file; }
    }
    $all ? return @results : return undef;
}

# Process "parse_memory" command line arguments and set defaults
sub get_parse_iostat_args {
	# Returned parameters
	(local *::arg_device, local *::arg_files) = @_;

	# Local variables
	my ($fail, $arg_help) = ();
	my @tmp = ();

	# Use the Argument processing module
	use Getopt::Long;

	# Print usage if no arguments
	if (!@ARGV) {
		&Usage();
		exit 0;
	}

	# Process input arguments
	$fail = 0;
	GetOptions(
		"device=s", \$::arg_device,
		"help|?",   \$arg_help
	) || GetOptionsMessage();

	# Print help documentation if user has selected -help
	&ListHelp() if (defined $arg_help);

	# Give warning messages and usage when parameters are specified incorrectly.
	if (!( defined $::arg_device)) {
		warn "$SCRIPT: Input error: must specify --device <dev>n.\n";
		$fail = 1;
	}
	if ($fail == 1) {
		# touch variables here to make silly warning go away
		&Usage();
		exit 1;
	}

	$::arg_device ||= 'sda';

	# Assume remaining options are filenames
	@::arg_files    = @ARGV;
}

sub GetOptionsMessage {
	# Print out a warning message and then print program usage.
	warn "$SCRIPT: Error processing input arguments.\n";
	&Usage();
	exit 1;
}

sub Usage {
	# Print out program usage.
	printf "Usage: $SCRIPT OPTIONS file1 file2 file3.gz ...\n";
	printf "\t[--device <pattern>] ...\n";
	printf "\t[--help | -?]\n";
}

sub ListHelp {
	# Print out tool help
	printf "$SCRIPT  -- parses 'iostat' data for matching device name\n";
	&Usage();
	printf "\nOptional input arguments:\n";
	printf "  --device <pattern>  : match device name\n";
	printf "  --help                   : this help information\n";
	printf "\n";
	exit 0;
}

1;