#!/bin/perl
# 
# This script is designed to identify hard drives and decide where and how to partition it for installation 
# during a kickstart install. 
# 
# Exit codes;
# 0 - Success
# 1 - Target type not specified.
# 2 - Failed to find a drive to install on.
# 
# NOTE: This is restricted to what is available during an anaconda install session. That is to same, bare 
#       minimum.
# TODO: If multiple matching drives are found (same medium and size, build an appropriate RAID array.
# 

use strict;
use warnings;

my $debug = 0;
my $type  = defined $ARGV[0] ? $ARGV[0] : "";
#print "Type: [".$type."]\n";
if ($type =~ /striker/i)
{
	print "Finding install drive for a Striker dashboard.\n";
	$type = "striker";
}
elsif ($type =~ /node/i)
{
	print "Finding install drive for an Anvil! node.\n";
	$type = "node";
}
elsif ($type =~ /dr/i)
{
	print "Finding install drive for a DR (disaster recovery) host.\n";
	$type = "dr";
}
else
{
	print "Error: Target type not specified.\n";
	print "Usage: ".$0." [striker,node,dr]\n";
	exit(1);
}

my $device = {};

# We might want to add HCTL (Host:Channel:Target:Lun for SCSI) and/or SUBSYSTEMS later
my $target = "";
my $lsblk  = system_call("/bin/lsblk --bytes --paths --pairs --output NAME,RM,HOTPLUG,TYPE,SIZE,TRAN,ROTA");
foreach my $line (split/\n/, $lsblk)
{
	### NOTE: If a drive has no transport, is not removable, but is hotplugable and the device path is 
	###       mmcblk0, it is probably an SDCard. It doesn't seem to be a directly divinable state. We 
	###       don't currently plan to use them, but it might come to pass later.
	print __LINE__."; [ Debug ] - lsblk: [".$line."]\n" if $debug;
	my ($path, $removable, $hotplug, $type, $size, $transport, $rotational) = ($line =~ /NAME="(.*?)" RM="(\d)" HOTPLUG="(\d)" TYPE="(.*?)" SIZE="(\d+)" TRAN="(.*?)" ROTA="(\d)"/);
	print __LINE__."; [ Debug ] - Device: [".$path."], type: [".$type."], remvoable? [".$removable."], hotplug? [".$hotplug."], rotational? [".$rotational."], transport: [".$transport."], size: [".$size."]\n" if $debug;
	next if (($removable) or ($hotplug) or ($type ne "disk"));
	$device->{$path} = {
		type       => $type,
		size       => $size, 
		transport  => $transport, 
		rotational => $rotational, 
	};
	if ($device->{$path}{rotational})
	{
		print "Analyzing platter drive: [".$path."], using the transport: [".$device->{$path}{transport}."], of the size: [".$device->{$path}{size}." (".hr_size($device->{$path}{size}).")]\n";
	}
	else
	{
		print "Analyzing solid-state drive: [".$path."], using the transport: [".$device->{$path}{transport}."], of the size: [".$device->{$path}{size}." (".hr_size($device->{$path}{size}).")]\n";
	}
}

### Usage selection priority
# on Striker, we'll simply use whatever is the biggest avalable drive.
# on Node and DR, we'll prefer slowest first (rotational, sata before nvme/scsi), and smallest second. 
my $use_drive = "";
if ($type eq "striker")
{
	my $biggest_size = 0;
	foreach my $path (sort {$a cmp $b} keys %{$device})
	{
		print __LINE__."; [ Debug ] - path: [".$path."], ${path}::size: [".$device->{$path}{size}." (".hr_size($device->{$path}{size}).")] < biggest_size: [".$biggest_size." (".hr_size($biggest_size).")]\n" if $debug;
		if ($device->{$path}{size} > $biggest_size)
		{
			$biggest_size = $device->{$path}{size}; 
			$use_drive    = $path;
			print __LINE__."; [ Debug ] - use_drive: [".$use_drive."], biggest_size: [".$biggest_size." (".hr_size($biggest_size).")]\n" if $debug;
		}
	}
	if ($use_drive)
	{
		print "Selected the largest disk: [".$use_drive."], which has a capacity of: [".hr_size($device->{$use_drive}{size})."]\n";
	}
}
else
{
	# Node and DR are handled the same
	my $first_disk_seen     = 0;
	my $smallest_size       = 0;
	my $selected_is_platter = 0;
	foreach my $path (sort {$a cmp $b} keys %{$device})
	{
		print __LINE__."; [ Debug ] - first_disk_seen: [".$first_disk_seen."], path: [".$path."], ${path}::rotational: [".$device->{$path}{rotational}."]\n" if $debug;
		if (not $first_disk_seen)
		{
			# Select this one
			$first_disk_seen     = 1;
			$use_drive           = $path;
			$smallest_size       = $device->{$path}{size};
			$selected_is_platter = $device->{$path}{rotational};
			print __LINE__."; [ Debug ] - first_disk_seen: [".$first_disk_seen."], use_drive: [".$use_drive."], selected_is_platter: [".$selected_is_platter."], smallest_size: [".$smallest_size." (".hr_size($smallest_size).")]\n" if $debug;
		}
		elsif ($device->{$path}{rotational})
		{
			# This takes priority 
			print __LINE__."; [ Debug ] - selected_is_platter: [".$selected_is_platter."]\n" if $debug;
			if ($selected_is_platter)
			{
				# Was the previously seen drive bigger?
				print __LINE__."; [ Debug ] - ".$path."::size: [".$first_disk_seen." (".hr_size($first_disk_seen).")], smallest_size: [".$smallest_size." (".hr_size($smallest_size).")]\n" if $debug;
				if ($device->{$path}{size} < $smallest_size)
				{
					# This is smaller, use it.
					$use_drive     = $path;
					$smallest_size = $device->{$path}{size};
					print __LINE__."; [ Debug ] - use_drive: [".$use_drive."], smallest_size: [".$smallest_size." (".hr_size($smallest_size).")]\n" if $debug;
				}
			}
			else
			{
				# The previous drive is an SSD, so use this one regardless
				$use_drive           = $path;
				$smallest_size       = $device->{$path}{size};
				$selected_is_platter = $device->{$path}{rotational};
				print __LINE__."; [ Debug ] - use_drive: [".$use_drive."], selected_is_platter: [".$selected_is_platter."], smallest_size: [".$smallest_size." (".hr_size($smallest_size).")]\n" if $debug;
			}
		}
		elsif (not $selected_is_platter)
		{
			# This is an SSD, but we haven't seen a platter drive yet, so use it if it is 
			# smaller.
			print __LINE__."; [ Debug ] - ".$path."::size: [".$first_disk_seen." (".hr_size($first_disk_seen).")], smallest_size: [".$smallest_size." (".hr_size($smallest_size).")]\n" if $debug;
			if ($device->{$path}{size} < $smallest_size)
			{
				# This is smaller, use it.
				$use_drive     = $path;
				$smallest_size = $device->{$path}{size};
				print __LINE__."; [ Debug ] - use_drive: [".$use_drive."], smallest_size: [".$smallest_size." (".hr_size($smallest_size).")]\n" if $debug;
			}
		}
	}
	
	# Did we find a drive?
	if ($use_drive)
	{
		if ($selected_is_platter)
		{
			print "Selected the smallest platter drive: [".$use_drive."], which has a capacity of: [".hr_size($device->{$use_drive}{size})."]\n";
		}
		else
		{
			print "Selected the smallest solid-state drive: [".$use_drive."], which has a capacity of: [".hr_size($device->{$use_drive}{size})."] (no platter drives found)\n";
		}
	}
}

# Did we find a disk to use?
if (not $use_drive)
{
	print "[ Error ] - Failed to find any fixed drives (platter or USB, not removable) to install onto. Unable to proceed.\n";
	exit(2);
}

# Finally, we've got our output.
my $partition_file = "/tmp/partition_plan";
my $partition_body = "";
if ($type eq "striker")
{
	$partition_body = "
zerombr
clearpart --all --drives=".$use_drive."
ignoredisk --only-use=".$use_drive."
bootloader --location=mbr --driveorder=".$use_drive."

part     /boot --fstype ext4 --size=1024  --asprimary --ondisk=".$use_drive."
part     swap  --fstype swap --size=4096  --asprimary --ondisk=".$use_drive."
part     /     --fstype ext4 --size=100   --asprimary --ondisk=".$use_drive." --grow
";
}
else
{
	$partition_body = "
zerombr
clearpart --all --drives=".$use_drive."
ignoredisk --only-use=".$use_drive."
bootloader --location=mbr --driveorder=".$use_drive."

part     /boot --fstype ext4 --size=1024  --asprimary --ondisk=".$use_drive."
part     swap  --fstype swap --size=4096  --asprimary --ondisk=".$use_drive."
part     /     --fstype ext4 --size=100   --asprimary --ondisk=".$use_drive."
";
}

print "Writing out the partition plan to: [".$partition_file."]\n";
#print __LINE__."; [ Debug ] - partition_body: [".$partition_body."]\n" if $debug;
print __LINE__."; [ Debug ] - partition_body: [".$partition_body."]\n";

exit(0);

sub hr_size
{
	my ($size) = @_;
	
	my $hr_size = $size;
	
	if ($size < 1023)
	{
		# Bytes
		$hr_size .= " B";
	}
	elsif ($size < (2 ** 20))
	{
		# Kibibyte
		$hr_size = sprintf("%.1f", ($size /= (2 ** 10)))." KiB";
	}
	elsif ($size < (2 ** 30))
	{
		# Mebibyte
		$hr_size = sprintf("%.2f", ($size /= (2 ** 20)))." MiB";
	}
	elsif ($size < (2 ** 40))
	{
		# Gibibyte
		$hr_size = sprintf("%.2f", ($size /= (2 ** 30)))." GiB";
	}
	elsif ($size < (2 ** 50))
	{
		# Tebibyte
		$hr_size = sprintf("%.2f", ($size /= (2 ** 40)))." TiB";
	}
	else
	{
		# Pebibyte or higher
		$hr_size = sprintf("%.3f", ($size /= (2 ** 40)))." PiB";
	}
	
	return($hr_size);
}

sub system_call
{
	my ($command) = @_;
	my $output = "";
	open (my $file_handle, $command." 2>&1 |") or die "Failed to call: [".$command."], error was: [".$!."]\n";
	while (<$file_handle>)
	{
		chomp;
		my $line =  $_;
      		   $line =~ s/\n$//;
      		   $line =~ s/\r$//;
		$output .= $line."\n";
	}
	close $file_handle;
	$output =~ s/\n$//s;

	return($output);
}