module DevLXC

# File lib/dev-lxc.rb, line 108
def self.append_line_to_file(file_name, line)
  content = IO.readlines(file_name)
  content[-1] = content[-1].chomp + "\n" unless content.empty?
  content << line
  IO.write(file_name, content.join)
end

# File lib/dev-lxc.rb, line 9
def self.create_base_container(base_container_name, base_container_options)
  base_container = DevLXC::Container.new(base_container_name)
  if base_container.defined?
    puts "Base container '#{base_container.name}' already exists"
    return base_container
  end
  puts "Creating base container '#{base_container.name}'"
  template = "download"
  case base_container.name
  when "b-ubuntu-1204"
    options = ["-d", "ubuntu", "-r", "precise", "-a", "amd64"]
  when "b-ubuntu-1404"
    options = ["-d", "ubuntu", "-r", "trusty", "-a", "amd64"]
  when "b-ubuntu-1604"
    options = ["-d", "ubuntu", "-r", "xenial", "-a", "amd64"]
  when "b-centos-5"
    template = "centos"
    options = ["-R", "5"]
  when "b-centos-6"
    options = ["-d", "centos", "-r", "6", "-a", "amd64"]
  when "b-centos-7"
    options = ["-d", "centos", "-r", "7", "-a", "amd64"]
  end
  options.concat(base_container_options.split) unless base_container_options.nil?
  base_container.create(template, "btrfs", {}, 0, options)

  # if base container is centos then `/etc/hosts` file needs to be modified so `hostname -f`
  # provides the FQDN instead of `localhost`
  if base_container.name.start_with?('b-centos-')
    IO.write("#{base_container.config_item('lxc.rootfs')}/etc/hosts", "127.0.0.1 localhost\n127.0.1.1 #{base_container.name}\n")
  end

  # Centos 7 needs setpcap capabilities
  # ref: https://bugzilla.redhat.com/show_bug.cgi?id=1176816
  # ref: https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1339781
  # ref: http://vfamilyserver.org/blog/2015/05/centos-7-lxc-container-slow-boot/
  if base_container.name == "b-centos-7"
    DevLXC.search_file_replace(base_container.config_file_name, /centos.common.conf/, 'fedora.common.conf')
    base_container.clear_config
    base_container.load_config
  end

  unless base_container.config_item("lxc.mount.auto").nil?
    base_container.set_config_item("lxc.mount.auto", "proc:rw sys:rw")
  end
  if base_container.config_item("lxc.network.0.hwaddr").nil?
    hwaddr = '00:16:3e:' + Digest::SHA1.hexdigest(Time.now.to_s).slice(0..5).unpack('a2a2a2').join(':')
    puts "Setting '#{base_container.name}' base container's lxc.network.hwaddr to #{hwaddr}"
    base_container.set_config_item("lxc.network.hwaddr", hwaddr)
  end
  base_container.save_config
  base_container.start
  puts "Installing packages in base container '#{base_container.name}'"
  case base_container.name
  when "b-ubuntu-1204", "b-ubuntu-1404"
    base_container.run_command("apt-get update")
    base_container.run_command("apt-get install -y standard^ server^ vim-nox emacs23-nox tree openssh-server")
    IO.write("#{base_container.config_item('lxc.rootfs')}/etc/rc.local", "#!/usr/bin/env bash\n\n/usr/sbin/dpkg-reconfigure openssh-server\n")
    FileUtils.chmod(0755, "#{base_container.config_item('lxc.rootfs')}/etc/rc.local")
  when "b-ubuntu-1604"
    base_container.run_command("apt-get update")
    base_container.run_command("apt-get install -y standard^ server^ vim-nox emacs24-nox tree openssh-server")
    IO.write("#{base_container.config_item('lxc.rootfs')}/etc/rc.local", "#!/usr/bin/env bash\n\n/usr/sbin/dpkg-reconfigure openssh-server\n")
    FileUtils.chmod(0755, "#{base_container.config_item('lxc.rootfs')}/etc/rc.local")
  when "b-centos-5"
    # downgrade openssl temporarily to overcome an install bug
    # reference: http://www.hack.net.br/blog/2014/02/12/openssl-conflicts-with-file-from-package-openssl/
    base_container.run_command("yum downgrade -y openssl")
    base_container.run_command("yum install -y @base @core vim-enhanced emacs-nox tree openssh-server")
    FileUtils.mkdir_p("#{base_container.config_item('lxc.rootfs')}/etc/sudoers.d")
    FileUtils.chmod(0750, "#{base_container.config_item('lxc.rootfs')}/etc/sudoers.d")
    append_line_to_file("#{base_container.config_item('lxc.rootfs')}/etc/sudoers", "\n#includedir /etc/sudoers.d\n")
  when "b-centos-6"
    base_container.run_command("yum install -y @base @core vim-enhanced emacs-nox tree openssh-server")
  when "b-centos-7"
    base_container.run_command("yum install -y @base @core vim-enhanced emacs-nox tree openssh-server")
  end
  base_container.run_command("useradd --create-home --shell /bin/bash --password $6$q3FDMpMZ$zfahCxEWHbzuEV98QPzhGZ7fLtGcLNZrbKK7OAYGXmJXZc07WbcxVnDwrMyX/cL6vSp4/IjlrVUZFBp7Orhyu1 dev-lxc")

  FileUtils.mkdir_p("#{base_container.config_item('lxc.rootfs')}/home/dev-lxc/.ssh")
  FileUtils.chmod(0700, "#{base_container.config_item('lxc.rootfs')}/home/dev-lxc/.ssh")
  FileUtils.touch("#{base_container.config_item('lxc.rootfs')}/home/dev-lxc/.ssh/authorized_keys")
  FileUtils.chmod(0600, "#{base_container.config_item('lxc.rootfs')}/home/dev-lxc/.ssh/authorized_keys")
  base_container.run_command("chown -R dev-lxc:dev-lxc /home/dev-lxc/.ssh")

  IO.write("#{base_container.config_item('lxc.rootfs')}/etc/sudoers.d/dev-lxc", "dev-lxc   ALL=NOPASSWD:ALL\n")
  FileUtils.chmod(0440, "#{base_container.config_item('lxc.rootfs')}/etc/sudoers.d/dev-lxc")
  base_container.shutdown
  return base_container
end

# File lib/dev-lxc.rb, line 100
def self.reload_dnsmasq
  system("pkill -HUP dnsmasq")
end

# File lib/dev-lxc.rb, line 104
def self.search_file_delete_line(file_name, regex)
  IO.write(file_name, IO.readlines(file_name).delete_if {|line| line.match(Regexp.new(regex))}.join)
end

# File lib/dev-lxc.rb, line 115
def self.search_file_replace(file_name, regex, replace)
  IO.write(file_name, IO.readlines(file_name).map {|line| line.gsub(Regexp.new(regex), replace)}.join)
end