#! /usr/bin/env ruby
require "tempfile"
usbdisks=`for devlink in /dev/disk/by-id/usb*; do readlink -f ${devlink}; done`
raws=usbdisks.split("\n")
parts=[]
for disk in raws
  if /(\w+)\d+/.match disk
    parts.push disk
  end
end
for disk in raws
  if /(\w+)\d+/.match disk
    raws.delete("/dev/#{$1}")
  end
end
if raws.length==0
  puts "No disks detected. Aborting."
  exit 1
end
if parts.length>1
  puts "Multiple partitions detected."
  i=0
  for part in parts
    puts "#{i}: #{part}"
    i+=1
  end
  print "Please choose partition to install to:"
  num=gets.chomp.to_i
  part=parts[num]
  /(\w+)\d+/.match part
  raw="/dev/#{$1}"
elsif parts.length==0
  puts "No partitions detected."
  i=0
  for raw in raws
    puts "#{i}: #{raw}"
    i+=1
  end
  print "Please choose disk to install to:"
  num=gets.chomp.to_i
  raw=raws[num]
  print "Getting disk size..."
  origsize=`sudo blockdev --getsize64 #{raw}`.chomp.to_i
  unit="MB"
  fullsize=(origsize/1024.to_f)/1024
  if fullsize%1024==0 or fullsize>2048
    fullsize=fullsize/1024.to_f
    unit="GB"
  end
  fullsize=fullsize.floor(1)
  puts "#{fullsize}#{unit}"
  print "Partition size: (return for whole disk)"
  size=gets.chomp.downcase
  if size.match /(\d)+m/ or size.match /(\d+)mb/
    size=(size.to_i)*1024*1024
  elsif size.match /(\d)+g/ or size.match /(\d+)gb/
    size=(size.to_i)*1024*1024*1024
  elsif size==""
    size=origsize
  else
    puts "Could not parse size. Aborting."
    exit 1
  end
  sfdisk_input="label: dos\n- #{size/1024}KiB L"
  tmp=Tempfile.new("myosinstall")
  tmp.puts sfdisk_input
  tmp.close
  print "Partitioning..."
  `cat #{tmp.path} | sudo sfdisk #{raw} 2>/dev/null`
  puts "Done"
  tmp.unlink
  exit 1
  puts `sudo mkfs.ext2 #{raw}`
  part="#{raw}1"
  raw="#{raw}"
else
  part=parts[0]
  /(\w+)\d+/.match parts[0]
  raw="/dev/#{$1}"
end
`mkdir -p usb`
print "Mounting the disk..."
`sudo mount #{part} usb`
puts "Done"
if !File.exists?("usb/boot")
  puts "Installing GRUB..."
  `sudo grub-install --boot-directory=usb/boot #{raw}`
end
print "Installing the OS..."
`sudo cp -r /vagrant/sysroot/* usb`
puts "Done"
print "Umounting disk..."
`sudo umount usb`
puts "Done"