#!/usr/bin/env ruby

require 'pathname'
require 'lxc'
require 'etc'

require_relative 'ns'
require_relative 'cborio'
require_relative 'lxc_extend'
require_relative 'authorized_keys'

class AuthorizedKeysCollector
  def initialize
  end

  def forked wr
    LXC.running_containers do |ct|
      pid = ct.init_pid
      NS.change pid, :pid, :mnt do
        name = ct.config_item( 'lxc.uts.name')
        conf = Hash.new {|h,k| h[k] = []}
        IO.popen %w[sshd -T], err: "/dev/null" do |s|
          s.each_line do |l|
            k, v = l.chomp.split( ' ', 2)
            conf[k.to_sym].push v
          end
        end
        akf = conf[:authorizedkeysfile].flat_map {|e| e.split ' ' }
        akf.map! do |pn|
          pn = "%h/#{pn}"  if Pathname.new( pn).relative?
          pn.gsub( /%h/, "%<home>s").gsub( /%u/, "%<name>s")
        end
        while pw = Etc.getpwent
          wr.write [
            :authkeys, ct.name, pw.name,
            akf.each.flat_map do |pn|
              pn = Pathname.new pn % {name: pw.name, home: pw.dir}
              pn.exist? ? pn.readlines.map( &:chomp) : []
            end
          ]
        end
        Etc.endpwent
      end
    end
  end

  def collect
    pid, io = CBORIO.popen {|io| forked io }
    io.map do |l|
      case l[0].to_sym
      when :authkeys
        host, user, keys = l[1..3]
        keys.map! {|k| AuthorizedKeys.parse k }
        {host: host, user: user, keys: keys}
      end
    end
  end
end

if Pathname.new( __FILE__).expand_path == Pathname.new( $0).expand_path
  AuthorizedKeysCollector.new.collect.each {|e| p e }
end