require "log4r"

module VagrantPlugins
  module ProviderVirtualBox
    class Provider < Vagrant.plugin("2", :provider)
      attr_reader :driver

      def initialize(machine)
        @logger  = Log4r::Logger.new("vagrant::provider::virtualbox")
        @machine = machine

        # This method will load in our driver, so we call it now to
        # initialize it.
        machine_id_changed
      end

      # @see Vagrant::Plugin::V1::Provider#action
      def action(name)
        # Attempt to get the action method from the Action class if it
        # exists, otherwise return nil to show that we don't support the
        # given action.
        action_method = "action_#{name}"
        return Action.send(action_method) if Action.respond_to?(action_method)
        nil
      end

      # If the machine ID changed, then we need to rebuild our underlying
      # driver.
      def machine_id_changed
        id = @machine.id

        begin
          @logger.debug("Instantiating the driver for machine ID: #{@machine.id.inspect}")
          @driver = Driver::Meta.new(id)
        rescue Driver::Meta::VMNotFound
          # The virtual machine doesn't exist, so we probably have a stale
          # ID. Just clear the id out of the machine and reload it.
          @logger.debug("VM not found! Clearing saved machine ID and reloading.")
          id = nil
          retry
        end
      end

      # Returns the SSH info for accessing the VirtualBox VM.
      def ssh_info
        # If the VM is not created then we cannot possibly SSH into it, so
        # we return nil.
        return nil if state == :not_created

        # Return what we know. The host is always "127.0.0.1" because
        # VirtualBox VMs are always local. The port we try to discover
        # by reading the forwarded ports.
        return {
          :host => "127.0.0.1",
          :port => @driver.ssh_port(@machine.config.ssh.guest_port)
        }
      end

      # Return the state of VirtualBox virtual machine by actually
      # querying VBoxManage.
      #
      # @return [Symbol]
      def state
        # XXX: What happens if we destroy the VM but the UUID is still
        # set here?
        return :not_created if !@driver.uuid
        state = @driver.read_state
        return :unknown if !state
        state
      end

      # Returns a human-friendly string version of this provider which
      # includes the machine's ID that this provider represents, if it
      # has one.
      #
      # @return [String]
      def to_s
        id = @machine.id ? @machine.id : "new VM"
        "VirtualBox (#{id})"
      end
    end
  end
end