defmodule Meta.OpenNebula.VM do
  @moduledoc """
  OpenNebula VM: http://docs.opennebula.io/5.12/integration/system_interfaces/api.html#one-vm-info
  """
  alias Meta.OpenNebula, as: ONE
  alias Meta.OpenNebula.Schema

  @states [
    {:any, -2},
    {:any_except_done, -1},
    {:init, 0},
    {:pending, 1},
    {:hold, 2},
    {:active, 3},
    {:stopped, 4},
    {:suspended, 5},
    {:done, 6},
    {:failure, 7},
    {:poweroff, 8},
    {:undeployed, 9},
    {:cloning, 10},
    {:cloning_failure, 11}
  ]

  @lcm_states [
    {:LCM_INIT                       , 0},
    {:PROLOG                         , 1},
    {:BOOT                           , 2},
    {:RUNNING                        , 3},
    {:MIGRATE                        , 4},
    {:SAVE_STOP                      , 5},
    {:SAVE_SUSPEND                   , 6},
    {:SAVE_MIGRATE                   , 7},
    {:PROLOG_MIGRATE                 , 8},
    {:PROLOG_RESUME                  , 9},
    {:EPILOG_STOP                    , 10},
    {:EPILOG                         , 11},
    {:SHUTDOWN                       , 12},
    {:CLEANUP_RESUBMIT               , 15},
    {:UNKNOWN                        , 16},
    {:HOTPLUG                        , 17},
    {:SHUTDOWN_POWEROFF              , 18},
    {:BOOT_UNKNOWN                   , 19},
    {:BOOT_POWEROFF                  , 20},
    {:BOOT_SUSPENDED                 , 21},
    {:BOOT_STOPPED                   , 22},
    {:CLEANUP_DELETE                 , 23},
    {:HOTPLUG_SNAPSHOT               , 24},
    {:HOTPLUG_NIC                    , 25},
    {:HOTPLUG_SAVEAS                 , 26},
    {:HOTPLUG_SAVEAS_POWEROFF        , 27},
    {:HOTPLUG_SAVEAS_SUSPENDED       , 28},
    {:SHUTDOWN_UNDEPLOY              , 29},
    {:EPILOG_UNDEPLOY                , 30},
    {:PROLOG_UNDEPLOY                , 31},
    {:BOOT_UNDEPLOY                  , 32},
    {:HOTPLUG_PROLOG_POWEROFF        , 33},
    {:HOTPLUG_EPILOG_POWEROFF        , 34},
    {:BOOT_MIGRATE                   , 35},
    {:BOOT_FAILURE                   , 36},
    {:BOOT_MIGRATE_FAILURE           , 37},
    {:PROLOG_MIGRATE_FAILURE         , 38},
    {:PROLOG_FAILURE                 , 39},
    {:EPILOG_FAILURE                 , 40},
    {:EPILOG_STOP_FAILURE            , 41},
    {:EPILOG_UNDEPLOY_FAILURE        , 42},
    {:PROLOG_MIGRATE_POWEROFF        , 43},
    {:PROLOG_MIGRATE_POWEROFF_FAILURE, 44},
    {:PROLOG_MIGRATE_SUSPEND         , 45},
    {:PROLOG_MIGRATE_SUSPEND_FAILURE , 46},
    {:BOOT_UNDEPLOY_FAILURE          , 47},
    {:BOOT_STOPPED_FAILURE           , 48},
    {:PROLOG_RESUME_FAILURE          , 49},
    {:PROLOG_UNDEPLOY_FAILURE        , 50},
    {:DISK_SNAPSHOT_POWEROFF         , 51},
    {:DISK_SNAPSHOT_REVERT_POWEROFF  , 52},
    {:DISK_SNAPSHOT_DELETE_POWEROFF  , 53},
    {:DISK_SNAPSHOT_SUSPENDED        , 54},
    {:DISK_SNAPSHOT_REVERT_SUSPENDED , 55},
    {:DISK_SNAPSHOT_DELETE_SUSPENDED , 56},
    {:DISK_SNAPSHOT                  , 57},
    {:DISK_SNAPSHOT_DELETE           , 59},
    {:PROLOG_MIGRATE_UNKNOWN         , 60},
    {:PROLOG_MIGRATE_UNKNOWN_FAILURE , 61},
    ]

  @actions [
    "terminate-hard",
    "terminate",
    "undeploy-hard",
    "undeploy",
    "poweroff-hard",
    "poweroff",
    "reboot-hard",
    "reboot",
    "hold",
    "release",
    "stop",
    "suspend",
    "resume",
    "resched",
    "unresched"
  ]

  @events [
    {:NONE_ACTION                 , 0},
    {:MIGRATE_ACTION              , 1},
    {:LIVE_MIGRATE_ACTION         , 2},
    {:SHUTDOWN_ACTION             , 3},
    {:SHUTDOWN_HARD_ACTION        , 4},
    {:UNDEPLOY_ACTION             , 5},
    {:UNDEPLOY_HARD_ACTION        , 6},
    {:HOLD_ACTION                 , 7},
    {:RELEASE_ACTION              , 8},
    {:STOP_ACTION                 , 9},
    {:SUSPEND_ACTION              , 10},
    {:RESUME_ACTION               , 11},
    {:BOOT_ACTION                 , 12},
    {:DELETE_ACTION               , 13},
    {:DELETE_RECREATE_ACTION      , 14},
    {:REBOOT_ACTION               , 15},
    {:REBOOT_HARD_ACTION          , 16},
    {:RESCHED_ACTION              , 17},
    {:UNRESCHED_ACTION            , 18},
    {:POWEROFF_ACTION             , 19},
    {:POWEROFF_HARD_ACTION        , 20},
    {:DISK_ATTACH_ACTION          , 21},
    {:DISK_DETACH_ACTION          , 22},
    {:NIC_ATTACH_ACTION           , 23},
    {:NIC_DETACH_ACTION           , 24},
    {:DISK_SNAPSHOT_CREATE_ACTION , 25},
    {:DISK_SNAPSHOT_DELETE_ACTION , 26},
    {:TERMINATE_ACTION            , 27},
    {:TERMINATE_HARD_ACTION       , 28},
    {:DISK_RESIZE_ACTION          , 29},
    {:DEPLOY_ACTION               , 30},
    {:CHOWN_ACTION                , 31},
    {:CHMOD_ACTION                , 32},
    {:UPDATECONF_ACTION           , 33},
    {:RENAME_ACTION               , 34},
    {:RESIZE_ACTION               , 35},
    {:UPDATE_ACTION               , 36},
    {:SNAPSHOT_CREATE_ACTION      , 37},
    {:SNAPSHOT_DELETE_ACTION      , 38},
    {:SNAPSHOT_REVERT_ACTION      , 39},
    {:DISK_SAVEAS_ACTION          , 40},
    {:DISK_SNAPSHOT_REVERT_ACTION , 41},
    {:RECOVER_ACTION              , 42},
    {:RETRY_ACTION                , 43},
    {:MONITOR_ACTION              , 44},
    {:DISK_SNAPSHOT_RENAME_ACTION , 45},
    {:ALIAS_ATTACH_ACTION         , 46},
    {:ALIAS_DETACH_ACTION         , 47},
    ]

  defp find(table, state) when is_integer(state) do
    case Enum.find(table, fn {_atom, value} -> value == state end) do
      {atom, _value} -> atom
      nil -> nil
    end
  end

  def state_for(state) when is_atom(state), do: @states |> Keyword.get(state)
  def state_for(state) when is_integer(state), do: find(@states, state)
  def lcm_state_for(state) when is_integer(state), do: find(@lcm_states, state)

  def event_for(event) when is_integer(event) do
    case Enum.find(@events, fn {_atom, value} -> value == event end) do
      {atom, _value} -> atom
      nil -> nil
    end
  end

  def get(id) do
    fn location ->
      case ONE.query(location, "one.vm.info", [id]) do
        {:ok, raw} ->
          data = raw
                 |> Schema.scan("vm")
                 |> Schema.map_record
          {:ok, data}
        {:error, err} -> {:error, err}
      end
    end
  end

  def execute(vm_id, action) when action in @actions do
    fn location ->
      case ONE.query(location, "one.vm.action", [action, vm_id]) do
        {:ok, _raw} -> :ok
        {:error, err} -> {:error, err}
      end
    end
  end
end