#!/usr/bin/ruby

require 'rubygems'
require 'net/sftp'
require 'net/ssh'

if ARGV.empty?
  STDERR.puts "usage #{__FILE__} <host>"
  Process.exit
end

HOST = ARGV.shift
USER = ENV['USER']

config = "#{HOST}.yml"
config  = File.join(File.dirname(__FILE__), config) unless File.exist? config

require 'yaml'
config = YAML.load(open(config) {|file| file.read})
sections = %w{dirs packages gems gem_sources apache_conf apache_mod rsync}
sections.each {|var| eval "$#{var}=(config[:#{var}] or [])" }

def version string
  string.scan(/[\d.]+/).last.split('.').map {|n| n.to_i}
end

Net::SSH.start(HOST, USER) do |ssh|
  restart_apache = false

  installed = ssh.exec!('dpkg --get-selections').scan(/^\S+/)
  $packages.each do |package|
    unless installed.include? package
      puts "installing #{package}..."
      ssh.exec! "sudo aptitude -y install #{package}"
    end
  end

  Net::SFTP.start(HOST, USER) do |sftp|
    entries = sftp.dir.entries('.')
    $dirs.each do |dir|
      unless entries.any? {|entry| entry.name == dir} 
        puts "mkdir #{dir}"
        sftp.mkdir dir
      end
    end

    entries = sftp.dir.entries('/etc/apache2/conf.d/')
    $apache_conf.each do |conf|
      unless entries.any? {|entry| entry.name == conf} 
        puts "configure apache #{conf}"
        sftp.upload! "/etc/apache2/conf.d/#{conf}", "/tmp/#{conf}"
        ssh.exec! "sudo mv /tmp/#{conf} /etc/apache2/conf.d/#{conf}"
        restart_apache = true
      end
    end

    entries = sftp.dir.entries('/etc/apache2/mods-enabled/')
    $apache_mod.each do |mod|
      unless entries.any? {|entry| entry.name == "#{mod}.load"} 
        puts "enable apache #{mod}"
        ssh.exec! "sudo a2enmod #{mod}"
        restart_apache = true
      end
    end
  end

  if restart_apache
    puts 'restart apache'
    ssh.exec! "sudo /etc/init.d/apache2 restart"
  end

  if $gems.include? 'rubygems-update'
    if -1 == (version(ssh.exec!('gem -v')) <=> version(`gem -v`))
      puts 'installing rubygems-update...'
      ssh.exec! 'sudo gem install rubygems-update'
      ssh.exec! 'sudo /var/lib/gems/1.8/bin/update_rubygems'
    end
    $gems.delete 'rubygems-update'
  end

  gem_env = ssh.exec!('gem env remotesources').split("\n")
  $gem_sources.each do |source|
    unless gem_env.include? source
      puts "add remote gem source #{source}"
      ssh.exec! "sudo gem sources --add #{source}"
    end
  end

  installed = ssh.exec!('gem list').scan(/^\S+/)
  $gems.each do |gem|
    unless installed.include? gem
      puts "installing #{gem}..."
      ssh.exec! "sudo gem install #{gem}"
    end
  end
end

Dir.chdir ENV['HOME']
$rsync.each do |file|
  system "rsync #{file} #{HOST}:."
end