#!/usr/bin/env ruby

DockerBinaryLocation = `which docker`.chomp

def cmd(*args)
  io = IO.popen(args, err: '/dev/null')
  io.read.split("\n")
end

def docker(*args)
  cmd(DockerBinaryLocation, *args)
end

tasks = [:remove_containers, :remove_volumes, :remove_images]
container_filter = [:running]
image_filter = [:untagged]

while task_pattern = ARGV.shift
  case task_pattern.intern
  when :all
    container_filter = []
    image_filter = []
  when :running
    container_filter -= [:running]
  when :volumes
    #
  when :images
    image_filter -= [:untagged]
  end
end


containers = docker('ps', '-a', '-q').sort

if container_filter.include? :running
  running_containers = docker('ps', '-q').sort
  containers = containers - running_containers
end


images = docker('images')[1..-1].map do |ln|
  parts = ln.split(' ').map{ |part| part unless part == '<none>' }
  image_name = (parts[0] and parts[1]) ? "#{parts[0]}:#{parts[1]}" : nil
  {id: parts[2], name: image_name}
end

if image_filter.include? :untagged
  images = images.delete_if{ |image| image[:name] }
end



if tasks.include? :remove_containers and containers.length.nonzero?
  puts "removing containers"
  containers.each do |cid|
    docker 'kill', cid
    docker 'rm', cid

    puts "  #{cid}"
  end
end

if tasks.include? :remove_images and images.length.nonzero?
  puts "removing image layers"
  images.each do |image|
    docker 'rmi', '-f', image[:id]

    puts "  #{image[:name]} #{image[:id]}"
  end
end