namespace :tunnel do

  tunnel_ns = namespace :tunnel do
    # Courtesy of Christopher Haupt
    # http://www.BuildingWebApps.com
    # http://www.LearningRails.com
    desc "Create a reverse ssh tunnel from a public server to a private development server."
    task :start => [ :environment, :config ] do
      puts @notification
      system @ssh_command
    end

    desc "Create a reverse ssh tunnel in the background. Requires ssh keys to be setup."
    task :background_start => [ :environment, :config ] do
      puts @notification
      system "#{@ssh_command} > /dev/null 2>&1 &"
    end

    # Adapted from Evan Weaver: http://blog.evanweaver.com/articles/2007/07/13/developing-a-facebook-app-locally/
    desc "Check if reverse tunnel is running"
    task :status => [ :environment, :config ] do
     if `ssh #{@public_host} -l #{@public_host_username} netstat -an | egrep "tcp.*:#{@public_port}.*LISTEN" | wc`.to_i > 0
       puts "Seems ok"
     else
       puts "Down"
     end
    end

    task :config => :environment do
     tunnel_config = File.join(RAILS_ROOT, 'config', 'tunnel.yml')
     TUNNEL = YAML.load(ERB.new(File.read(tunnel_config)).result)[RAILS_ENV]
     @public_host_username = TUNNEL['tunnel']['public_host_username']
     @public_host = TUNNEL['tunnel']['public_host']
     @public_port = TUNNEL['tunnel']['public_port']
     @local_port = TUNNEL['tunnel']['local_port']
     @ssh_port = TUNNEL['tunnel']['ssh_port'] || 22
     @server_alive_interval = TUNNEL['tunnel']['server_alive_interval'] || 0
     @notification = "Starting tunnel #{@public_host}:#{@public_port} to 0.0.0.0:#{@local_port}"
     @notification << " using SSH port #{@ssh_port}" unless @ssh_port == 22
     # "GatewayPorts yes" needs to be enabled in the remote's sshd config
     @ssh_command = %Q[ssh -v -p #{@ssh_port} -nNT4 -o "ServerAliveInterval #{@server_alive_interval}" -R *:#{@public_port}:localhost:#{@local_port} #{@public_host_username}@#{@public_host}]
    end
  end
  desc "Create a reverse ssh tunnel from a public server to a private development server."
  task :tunnel => tunnel_ns[:start]
end
