require "log4r"
require "vagrant"

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

      def initialize(machine)
        @logger  = Log4r::Logger.new("vagrant_kvm")
        @machine = machine

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

      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::Driver.new(id)
        rescue Driver::Driver::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 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

        ip_addr = @driver.read_machine_ip
        return {
          :host => ip_addr,
          :port => "22" # XXX should be somewhere in default config
        }
      end

      # Return the state of the VM
      #
      # @return [Symbol]
      def state
        # XXX: What happens if we destroy the VM but the UUID is still
        # set here?

        # Determine the ID of the state here.
        state_id = nil
        state_id = :not_created if !@driver.uuid
        state_id = @driver.read_state if !state_id
        state_id = :unknown if !state_id
        @logger.info("state is now:", state_id)

        # TODO Translate into short/long descriptions
        short = state_id
        long  = I18n.t("vagrant.commands.status.#{state_id}")

        # Return the state
        Vagrant::MachineState.new(state_id, short, long)
      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"
        "QEMU/KVM (#{id})"
      end
    end
  end
end
