{-| Implementation of the Ganeti Query2 node group queries.

 -}

{-

Copyright (C) 2012, 2013 Google Inc.
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-}

module Ganeti.Query.Network
  ( getGroupConnection
  , getNetworkUuid
  , instIsConnected
  , fieldsMap
  ) where

-- FIXME: everything except fieldsMap
-- is only exported for testing.

import qualified Data.Map as Map
import Data.Maybe (fromMaybe, mapMaybe)
import Data.List (find, foldl', intercalate)

import Ganeti.JSON
import Ganeti.Network
import Ganeti.Objects
import Ganeti.Query.Language
import Ganeti.Query.Common
import Ganeti.Query.Types
import Ganeti.Types

networkFields :: FieldList Network NoDataRuntime
networkFields =
  [ (FieldDefinition "name" "Network" QFTText "Name",
     FieldSimple (rsNormal . networkName), QffNormal)
  , (FieldDefinition "network" "Subnet" QFTText "IPv4 subnet",
     FieldSimple (rsNormal . networkNetwork), QffNormal)
  , (FieldDefinition "gateway" "Gateway" QFTOther "IPv4 gateway",
     FieldSimple (rsMaybeUnavail . networkGateway), QffNormal)
  , (FieldDefinition "network6" "IPv6Subnet" QFTOther "IPv6 subnet",
     FieldSimple (rsMaybeUnavail . networkNetwork6), QffNormal)
  , (FieldDefinition "gateway6" "IPv6Gateway" QFTOther "IPv6 gateway",
     FieldSimple (rsMaybeUnavail . networkGateway6), QffNormal)
  , (FieldDefinition "mac_prefix" "MacPrefix" QFTOther "MAC address prefix",
     FieldSimple (rsMaybeUnavail . networkMacPrefix), QffNormal)
  , (FieldDefinition "free_count" "FreeCount" QFTNumber "Number of available\
                                                       \ addresses",
     FieldSimple (rsNormal . getFreeCount),
     QffNormal)
  , (FieldDefinition "map" "Map" QFTText "Actual mapping",
     FieldSimple (rsNormal . getMap),
     QffNormal)
  , (FieldDefinition "reserved_count" "ReservedCount" QFTNumber
       "Number of reserved addresses",
     FieldSimple (rsNormal . getReservedCount),
     QffNormal)
  , (FieldDefinition "group_list" "GroupList" QFTOther
       "List of nodegroups (group name, NIC mode, NIC link)",
     FieldConfig (\cfg -> rsNormal . getGroupConnections cfg . networkUuid),
     QffNormal)
  , (FieldDefinition "group_cnt" "NodeGroups" QFTNumber "Number of nodegroups",
     FieldConfig (\cfg -> rsNormal . length . getGroupConnections cfg
       . networkUuid), QffNormal)
  , (FieldDefinition "inst_list" "InstanceList" QFTOther "List of instances",
     FieldConfig (\cfg -> rsNormal . getInstances cfg . networkUuid),
     QffNormal)
  , (FieldDefinition "inst_cnt" "Instances" QFTNumber "Number of instances",
     FieldConfig (\cfg -> rsNormal . length . getInstances cfg
       . networkUuid), QffNormal)
  , (FieldDefinition "external_reservations" "ExternalReservations" QFTText
     "External reservations",
     FieldSimple getExtReservationsString, QffNormal)
  ] ++
  timeStampFields ++
  uuidFields "Network" ++
  serialFields "Network" ++
  tagsFields

-- | The group fields map.
fieldsMap :: FieldMap Network NoDataRuntime
fieldsMap = fieldListToFieldMap networkFields

-- TODO: the following fields are not implemented yet: external_reservations

-- | Given a network's UUID, this function lists all connections from
-- the network to nodegroups including the respective mode and links.
getGroupConnections ::
  ConfigData -> String -> [(String, String, String, String)]
getGroupConnections cfg network_uuid =
  mapMaybe (getGroupConnection network_uuid)
  ((Map.elems . fromContainer . configNodegroups) cfg)

-- | Given a network's UUID and a node group, this function assembles
-- a tuple of the group's name, the mode and the link by which the
-- network is connected to the group. Returns 'Nothing' if the network
-- is not connected to the group.
getGroupConnection ::
  String -> NodeGroup -> Maybe (String, String, String, String)
getGroupConnection network_uuid group =
  let networks = fromContainer . groupNetworks $ group
  in case Map.lookup network_uuid networks of
    Nothing -> Nothing
    Just net ->
      Just (groupName group, getNicMode net, getNicLink net, getNicVlan net)

-- | Retrieves the network's mode and formats it human-readable,
-- also in case it is not available.
getNicMode :: PartialNicParams -> String
getNicMode nic_params =
  maybe "-" nICModeToRaw $ nicpModeP nic_params

-- | Retrieves the network's vlan and formats it human-readable, also in
-- case it it not available.
getNicLink :: PartialNicParams -> String
getNicLink nic_params = fromMaybe "-" (nicpLinkP nic_params)

-- | Retrieves the network's link and formats it human-readable, also in
-- case it it not available.
getNicVlan :: PartialNicParams -> String
getNicVlan nic_params = fromMaybe "-" (nicpVlanP nic_params)

-- | Retrieves the network's instances' names.
getInstances :: ConfigData -> String -> [String]
getInstances cfg network_uuid =
  mapMaybe instName (filter (instIsConnected network_uuid)
    ((Map.elems . fromContainer . configInstances) cfg))

-- | Helper function that checks if an instance is linked to the given network.
instIsConnected :: String -> Instance -> Bool
instIsConnected network_uuid inst =
  network_uuid `elem` mapMaybe nicNetwork (instNics inst)

-- | Helper function to look up a network's UUID by its name
getNetworkUuid :: ConfigData -> String -> Maybe String
getNetworkUuid cfg name =
  let net = find (\n -> name == fromNonEmpty (networkName n))
               ((Map.elems . fromContainer . configNetworks) cfg)
  in fmap networkUuid net

-- | Computes the reservations list for a network.
--
-- This doesn't use the netmask for validation of the length, instead
-- simply iterating over the reservations string.
getReservations :: Ip4Network -> String -> [Ip4Address]
getReservations net =
  reverse .
  fst .
  foldl' (\(accu, addr) c ->
            let addr' = nextIp4Address addr
                accu' = case c of
                          '1' -> addr:accu
                          '0' -> accu
                          _ -> -- FIXME: the reservations string
                               -- should be a proper type
                               accu
            in (accu', addr')) ([], ip4netAddr net)

-- | Computes the external reservations as string for a network.
getExtReservationsString :: Network -> ResultEntry
getExtReservationsString net =
  let addrs = getReservations (networkNetwork net)
              (maybe "" show $ networkExtReservations net)
  in rsNormal . intercalate ", " $ map show addrs
