{-| Implementation of the Ganeti Query2 instance queries.

-}

{-

Copyright (C) 2013 Google Inc.
All rights reserved.

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-}

module Ganeti.Query.Instance
  ( Runtime
  , fieldsMap
  , collectLiveData
  , getInstanceInfo
  , instanceFields
  , instanceAliases
  ) where

import Control.Applicative
import Control.Monad (liftM, (>=>))
import qualified Data.ByteString.UTF8 as UTF8
import Data.Either
import Data.List
import Data.Maybe
import Data.Monoid
import qualified Data.Map as Map
import Data.Ord (comparing)
import qualified Text.JSON as J
import Text.Printf

import Ganeti.BasicTypes
import Ganeti.Common
import Ganeti.Config
import qualified Ganeti.Constants as C
import qualified Ganeti.ConstantUtils as C
import Ganeti.Errors
import Ganeti.JSON (MaybeForJSON(..), fromContainer)
import Ganeti.Objects
import Ganeti.Query.Common
import Ganeti.Query.Language
import Ganeti.Query.Types
import Ganeti.Rpc
import Ganeti.Storage.Utils
import Ganeti.Types
import Ganeti.Utils (formatOrdinal)

-- | The LiveInfo consists of two entries whose presence is independent.
-- The 'InstanceInfo' is the live instance information, accompanied by a bool
-- signifying if it was found on its designated primary node or not.
-- The 'InstanceConsoleInfo' describes how to connect to an instance.
-- Any combination of these may or may not be present, depending on node and
-- instance availability.
type LiveInfo = (Maybe (InstanceInfo, Bool), Maybe InstanceConsoleInfo)

-- | Runtime containing the 'LiveInfo'. See the genericQuery function in
-- the Query.hs file for an explanation of the terms used.
type Runtime = Either RpcError LiveInfo

-- | The instance fields map.
fieldsMap :: FieldMap Instance Runtime
fieldsMap = fieldListToFieldMap aliasedFields

-- | The instance aliases.
instanceAliases :: [(FieldName, FieldName)]
instanceAliases =
  [ ("vcpus", "be/vcpus")
  , ("be/memory", "be/maxmem")
  , ("sda_size", "disk.size/0")
  , ("sdb_size", "disk.size/1")
  , ("ip", "nic.ip/0")
  , ("mac", "nic.mac/0")
  , ("bridge", "nic.bridge/0")
  , ("nic_mode", "nic.mode/0")
  , ("nic_link", "nic.link/0")
  , ("nic_network", "nic.network/0")
  ]

-- | The aliased instance fields.
aliasedFields :: FieldList Instance Runtime
aliasedFields = aliasFields instanceAliases instanceFields

-- | The instance fields.
instanceFields :: FieldList Instance Runtime
instanceFields =
  -- Simple fields
  [ (FieldDefinition "admin_state" "InstanceState" QFTText
     "Desired state of instance",
     FieldSimple (rsMaybeNoData . liftM adminStateToRaw . instAdminState),
     QffNormal)
  , (FieldDefinition "admin_state_source" "InstanceStateSource" QFTText
     "Who last changed the desired state of the instance",
     FieldSimple (rsMaybeNoData . liftM adminStateSourceToRaw
                  . instAdminStateSource),
     QffNormal)
  , (FieldDefinition "admin_up" "Autostart" QFTBool
     "Desired state of instance",
     FieldSimple (rsMaybeNoData . liftM (== AdminUp) . instAdminState),
     QffNormal)
  , (FieldDefinition "disks_active" "DisksActive" QFTBool
     "Desired state of instance disks",
     FieldSimple (rsMaybeNoData . instDisksActive), QffNormal)
  , (FieldDefinition "name" "Instance" QFTText
     "Instance name",
     FieldSimple (rsMaybeNoData . instName), QffHostname)
  , (FieldDefinition "hypervisor" "Hypervisor" QFTText
     "Hypervisor name",
     FieldSimple (rsMaybeNoData . instHypervisor), QffNormal)
  , (FieldDefinition "network_port" "Network_port" QFTOther
     "Instance network port if available (e.g. for VNC console)",
     FieldSimple (rsMaybeUnavail . instNetworkPort), QffNormal)
  , (FieldDefinition "os" "OS" QFTText
     "Operating system",
     FieldSimple (rsMaybeNoData . instOs), QffNormal)
  , (FieldDefinition "pnode" "Primary_node" QFTText
     "Primary node",
     FieldConfig getPrimaryNodeName, QffHostname)
  , (FieldDefinition "pnode.group" "PrimaryNodeGroup" QFTText
     "Primary node's group",
     FieldConfig getPrimaryNodeGroupName, QffNormal)
  , (FieldDefinition "pnode.group.uuid" "PrimaryNodeGroupUUID" QFTText
     "Primary node's group UUID",
     FieldConfig getPrimaryNodeGroupUuid, QffNormal)
  , (FieldDefinition "snodes" "Secondary_Nodes" QFTOther
     "Secondary nodes; usually this will just be one node",
     FieldConfig (getSecondaryNodeAttribute nodeName), QffNormal)
  , (FieldDefinition "snodes.group" "SecondaryNodesGroups" QFTOther
     "Node groups of secondary nodes",
     FieldConfig (getSecondaryNodeGroupAttribute groupName), QffNormal)
  , (FieldDefinition "snodes.group.uuid" "SecondaryNodesGroupsUUID" QFTOther
     "Node group UUIDs of secondary nodes",
     FieldConfig (getSecondaryNodeGroupAttribute uuidOf), QffNormal)
  ] ++

  -- Instance parameter fields, whole
  [ (FieldDefinition "hvparams" "HypervisorParameters" QFTOther
     "Hypervisor parameters (merged)",
     FieldConfig
       ((rsNormal .) . getFilledInstHvParams (C.toList C.hvcGlobals)),
     QffNormal),

    (FieldDefinition "beparams" "BackendParameters" QFTOther
     "Backend parameters (merged)",
     FieldConfig ((rsErrorNoData .) . getFilledInstBeParams), QffNormal)
  , (FieldDefinition "osparams" "OpSysParameters" QFTOther
     "Operating system parameters (merged)",
     FieldConfig ((rsNormal .) . getFilledInstOsParams), QffNormal)
  , (FieldDefinition "custom_hvparams" "CustomHypervisorParameters" QFTOther
     "Custom hypervisor parameters",
     FieldSimple (rsNormal . instHvparams), QffNormal)
  , (FieldDefinition "custom_beparams" "CustomBackendParameters" QFTOther
     "Custom backend parameters",
     FieldSimple (rsNormal . instBeparams), QffNormal)
  , (FieldDefinition "custom_osparams" "CustomOpSysParameters" QFTOther
     "Custom operating system parameters",
     FieldSimple (rsNormal . instOsparams), QffNormal)
  , (FieldDefinition "custom_nicparams" "CustomNicParameters" QFTOther
     "Custom network interface parameters",
     FieldSimple (rsNormal . map nicNicparams . instNics), QffNormal)
  ] ++

  -- Instance parameter fields, generated
  map (buildBeParamField beParamGetter) allBeParamFields ++
  map (buildHvParamField hvParamGetter)
      (C.toList C.hvsParameters \\ C.toList C.hvcGlobals) ++

  -- disk parameter fields
  [ (FieldDefinition "disk_usage" "DiskUsage" QFTUnit
     "Total disk space used by instance on each of its nodes; this is not the\
     \ disk size visible to the instance, but the usage on the node",
     FieldConfig getDiskSizeRequirements, QffNormal)
  , (FieldDefinition "disk.count" "Disks" QFTNumber
     "Number of disks",
     FieldSimple (rsNormal . length . instDisks), QffNormal)
  , (FieldDefinition "disk.sizes" "Disk_sizes" QFTOther
     "List of disk sizes", FieldConfig getDiskSizes, QffNormal)
  , (FieldDefinition "disk.spindles" "Disk_spindles" QFTOther
     "List of disk spindles",
     FieldConfig getDiskSpindles, QffNormal)
  , (FieldDefinition "disk.names" "Disk_names" QFTOther
     "List of disk names",
     FieldConfig getDiskNames, QffNormal)
  , (FieldDefinition "disk.uuids" "Disk_UUIDs" QFTOther
     "List of disk UUIDs",
     FieldConfig getDiskUuids, QffNormal)
    -- For pre-2.14 backwards compatibility
  , (FieldDefinition "disk_template" "Disk_template" QFTText
     "Instance disk template",
     FieldConfig getDiskTemplate, QffNormal)
  ] ++

  -- Per-disk parameter fields
  instantiateIndexedFields C.maxDisks
  [ (fieldDefinitionCompleter "disk.size/%d" "Disk/%d" QFTUnit
    "Disk size of %s disk",
    getIndexedOptionalConfField getInstDisksFromObj diskSize,
    QffNormal)
  , (fieldDefinitionCompleter "disk.spindles/%d" "DiskSpindles/%d" QFTNumber
    "Spindles of %s disk",
    getIndexedOptionalConfField getInstDisksFromObj diskSpindles,
    QffNormal)
  , (fieldDefinitionCompleter "disk.name/%d" "DiskName/%d" QFTText
    "Name of %s disk",
    getIndexedOptionalConfField getInstDisksFromObj diskName, QffNormal)
  , (fieldDefinitionCompleter "disk.uuid/%d" "DiskUUID/%d" QFTText
    "UUID of %s disk",
    getIndexedConfField getInstDisksFromObj uuidOf, QffNormal)
  ] ++

  -- Aggregate nic parameter fields
  [ (FieldDefinition "nic.count" "NICs" QFTNumber
     "Number of network interfaces",
     FieldSimple (rsNormal . length . instNics), QffNormal)
  , (FieldDefinition "nic.macs" "NIC_MACs" QFTOther
     (nicAggDescPrefix ++ "MAC address"),
     FieldSimple (rsNormal . map nicMac . instNics), QffNormal)
  , (FieldDefinition "nic.ips" "NIC_IPs" QFTOther
     (nicAggDescPrefix ++ "IP address"),
     FieldSimple (rsNormal . map (MaybeForJSON . nicIp) . instNics),
     QffNormal)
  , (FieldDefinition "nic.names" "NIC_Names" QFTOther
     (nicAggDescPrefix ++ "name"),
     FieldSimple (rsNormal . map (MaybeForJSON . nicName) . instNics),
     QffNormal)
  , (FieldDefinition "nic.uuids" "NIC_UUIDs" QFTOther
     (nicAggDescPrefix ++ "UUID"),
     FieldSimple (rsNormal . map uuidOf . instNics), QffNormal)
  , (FieldDefinition "nic.modes" "NIC_modes" QFTOther
     (nicAggDescPrefix ++ "mode"),
     FieldConfig (\cfg -> rsNormal . map
       (nicpMode . fillNicParamsFromConfig cfg . nicNicparams)
       . instNics),
     QffNormal)
  , (FieldDefinition "nic.vlans" "NIC_VLANs" QFTOther
     (nicAggDescPrefix ++ "VLAN"),
     FieldConfig (\cfg -> rsNormal . map (MaybeForJSON . getNicVlan .
       fillNicParamsFromConfig cfg . nicNicparams) . instNics),
     QffNormal)
  , (FieldDefinition "nic.bridges" "NIC_bridges" QFTOther
     (nicAggDescPrefix ++ "bridge"),
     FieldConfig (\cfg -> rsNormal . map (MaybeForJSON . getNicBridge .
       fillNicParamsFromConfig cfg . nicNicparams) . instNics),
     QffNormal)
  , (FieldDefinition "nic.links" "NIC_links" QFTOther
     (nicAggDescPrefix ++ "link"),
     FieldConfig (\cfg -> rsNormal . map
       (nicpLink . fillNicParamsFromConfig cfg . nicNicparams)
       . instNics), QffNormal)
  , (FieldDefinition "nic.networks" "NIC_networks" QFTOther
     "List containing each interface's network",
     FieldSimple (rsNormal . map (MaybeForJSON . nicNetwork) . instNics),
     QffNormal)
  , (FieldDefinition "nic.networks.names" "NIC_networks_names" QFTOther
     "List containing the name of each interface's network",
     FieldConfig (\cfg -> rsNormal . map
       (\x -> MaybeForJSON (getNetworkName cfg <$> nicNetwork x))
       . instNics),
     QffNormal)
  ] ++

  -- Per-nic parameter fields
  instantiateIndexedFields C.maxNics
  [ (fieldDefinitionCompleter "nic.ip/%d" "NicIP/%d" QFTText
     ("IP address" ++ nicDescSuffix),
     getIndexedOptionalField instNics nicIp, QffNormal)
  , (fieldDefinitionCompleter "nic.uuid/%d" "NicUUID/%d" QFTText
     ("UUID address" ++ nicDescSuffix),
     getIndexedField instNics uuidOf, QffNormal)
  , (fieldDefinitionCompleter "nic.mac/%d" "NicMAC/%d" QFTText
     ("MAC address" ++ nicDescSuffix),
     getIndexedField instNics nicMac, QffNormal)
  , (fieldDefinitionCompleter "nic.name/%d" "NicName/%d" QFTText
     ("Name address" ++ nicDescSuffix),
     getIndexedOptionalField instNics nicName, QffNormal)
  , (fieldDefinitionCompleter "nic.network/%d" "NicNetwork/%d" QFTText
     ("Network" ++ nicDescSuffix),
     getIndexedOptionalField instNics nicNetwork, QffNormal)
  , (fieldDefinitionCompleter "nic.mode/%d" "NicMode/%d" QFTText
     ("Mode" ++ nicDescSuffix),
     getIndexedNicField nicpMode, QffNormal)
  , (fieldDefinitionCompleter "nic.link/%d" "NicLink/%d" QFTText
     ("Link" ++ nicDescSuffix),
     getIndexedNicField nicpLink, QffNormal)
  , (fieldDefinitionCompleter "nic.vlan/%d" "NicVLAN/%d" QFTText
     ("VLAN" ++ nicDescSuffix),
     getOptionalIndexedNicField getNicVlan, QffNormal)
  , (fieldDefinitionCompleter "nic.network.name/%d" "NicNetworkName/%d" QFTText
     ("Network name" ++ nicDescSuffix),
     getIndexedNicNetworkNameField, QffNormal)
  , (fieldDefinitionCompleter "nic.bridge/%d" "NicBridge/%d" QFTText
     ("Bridge" ++ nicDescSuffix),
     getOptionalIndexedNicField getNicBridge, QffNormal)
  ] ++

  -- Live fields using special getters
  [ (FieldDefinition "status" "Status" QFTText
     statusDocText,
     FieldConfigRuntime statusExtract, QffNormal)
  , (FieldDefinition "oper_state" "Running" QFTBool
     "Actual state of instance",
     FieldRuntime operStatusExtract, QffNormal),

    (FieldDefinition "console" "Console" QFTOther
     "Instance console information",
     FieldRuntime consoleExtract, QffNormal)
  ] ++

  -- Simple live fields
  map instanceLiveFieldBuilder instanceLiveFieldsDefs ++

  -- Common fields
  timeStampFields ++
  serialFields "Instance" ++
  uuidFields "Instance" ++
  forthcomingFields "Instance" ++
  tagsFields

-- * Helper functions for node property retrieval

-- | Constant suffix of network interface field descriptions.
nicDescSuffix ::String
nicDescSuffix = " of %s network interface"

-- | Almost-constant suffix of aggregate network interface field descriptions.
nicAggDescPrefix ::String
nicAggDescPrefix = "List containing each network interface's "

-- | Given a network name id, returns the network's name.
getNetworkName :: ConfigData -> String -> NonEmptyString
getNetworkName cfg = networkName . (Map.!) (fromContainer $ configNetworks cfg)
                     . UTF8.fromString

-- | Gets the bridge of a NIC.
getNicBridge :: FilledNicParams -> Maybe String
getNicBridge nicParams
  | nicpMode nicParams == NMBridged = Just $ nicpLink nicParams
  | otherwise                       = Nothing

-- | Gets the VLAN of a NIC.
getNicVlan :: FilledNicParams -> Maybe String
getNicVlan params
  | nicpMode params == NMOvs = Just $ nicpVlan params
  | otherwise                = Nothing

-- | Fill partial NIC params by using the defaults from the configuration.
fillNicParamsFromConfig :: ConfigData -> PartialNicParams -> FilledNicParams
fillNicParamsFromConfig cfg = fillParams (getDefaultNicParams cfg)

-- | Retrieves the default network interface parameters.
getDefaultNicParams :: ConfigData -> FilledNicParams
getDefaultNicParams cfg =
  (Map.!) (fromContainer . clusterNicparams . configCluster $ cfg)
    $ UTF8.fromString C.ppDefault

-- | Retrieves the real disk size requirements for all the disks of the
-- instance. This includes the metadata etc. and is different from the values
-- visible to the instance.
getDiskSizeRequirements :: ConfigData -> Instance -> ResultEntry
getDiskSizeRequirements cfg inst =
  rsErrorNoData . liftA (sum . map getSize) . getInstDisksFromObj cfg $ inst
 where
  diskType x = lidDiskType <$> diskLogicalId x
  getSize :: Disk -> Int
  getSize disk =
    let dt = diskType disk
    in case dt of
         Just DTDrbd8    -> fromMaybe 0 (diskSize disk) + C.drbdMetaSize
         Just DTDiskless -> 0
         Just DTBlock    -> 0
         _               -> fromMaybe 0 (diskSize disk)

-- | Get a list of disk sizes for an instance
getDiskSizes :: ConfigData -> Instance -> ResultEntry
getDiskSizes cfg =
  rsErrorNoData . liftA (map $ MaybeForJSON . diskSize)
  . getInstDisksFromObj cfg

-- | Get a list of disk spindles
getDiskSpindles :: ConfigData -> Instance -> ResultEntry
getDiskSpindles cfg =
  rsErrorNoData . liftA (map (MaybeForJSON . diskSpindles)) .
    getInstDisksFromObj cfg

-- | Get a list of disk names for an instance
getDiskNames :: ConfigData -> Instance -> ResultEntry
getDiskNames cfg =
  rsErrorNoData . liftA (map (MaybeForJSON . diskName)) .
    getInstDisksFromObj cfg

-- | Get a list of disk UUIDs for an instance
getDiskUuids :: ConfigData -> Instance -> ResultEntry
getDiskUuids cfg =
  rsErrorNoData . liftA (map uuidOf) . getInstDisksFromObj cfg

-- | Creates a functions which produces a FieldConfig 'FieldGetter' when fed
-- an index. Works for fields that may not return a value, expressed through
-- the Maybe monad.
getIndexedOptionalConfField :: (J.JSON b)
                            => (ConfigData -> Instance -> ErrorResult [a])
                                              -- ^ Extracts a list of objects
                            -> (a -> Maybe b) -- ^ Possibly gets a property
                                              -- from an object
                            -> Int            -- ^ Index in list to use
                            -> FieldGetter Instance Runtime -- ^ Result
getIndexedOptionalConfField extractor optPropertyGetter index =
  let getProperty x = maybeAt index x >>= optPropertyGetter
  in FieldConfig (\cfg ->
    rsErrorMaybeUnavail . liftA getProperty . extractor cfg)

-- | Creates a function which produces a FieldConfig 'FieldGetter' when fed
-- an index. Works only for fields that surely return a value.
getIndexedConfField :: (J.JSON b)
                    => (ConfigData -> Instance -> ErrorResult [a])
                                  -- ^ Extracts a list of objects
                    -> (a -> b)   -- ^ Gets a property from an object
                    -> Int        -- ^ Index in list to use
                    -> FieldGetter Instance Runtime -- ^ Result
getIndexedConfField extractor propertyGetter index =
  let optPropertyGetter = Just . propertyGetter
  in getIndexedOptionalConfField extractor optPropertyGetter index

-- | Returns a field that retrieves a given NIC's network name.
getIndexedNicNetworkNameField :: Int -> FieldGetter Instance Runtime
getIndexedNicNetworkNameField index =
  FieldConfig (\cfg inst -> rsMaybeUnavail $ do
    nicObj <- maybeAt index $ instNics inst
    nicNetworkId <- nicNetwork nicObj
    return $ getNetworkName cfg nicNetworkId)

-- | Gets a fillable NIC field.
getIndexedNicField :: (J.JSON a)
                   => (FilledNicParams -> a)
                   -> Int
                   -> FieldGetter Instance Runtime
getIndexedNicField getter =
  getOptionalIndexedNicField (\x -> Just . getter $ x)

-- | Gets an optional fillable NIC field.
getOptionalIndexedNicField :: (J.JSON a)
                           => (FilledNicParams -> Maybe a)
                           -> Int
                           -> FieldGetter Instance Runtime
getOptionalIndexedNicField =
  getIndexedFieldWithDefault
    (map nicNicparams . instNics) (\x _ -> getDefaultNicParams x) fillParams

-- | Creates a function which produces a 'FieldGetter' when fed an index. Works
-- for fields that should be filled out through the use of a default.
getIndexedFieldWithDefault :: (J.JSON c)
  => (Instance -> [a])             -- ^ Extracts a list of incomplete objects
  -> (ConfigData -> Instance -> b) -- ^ Extracts the default object
  -> (b -> a -> b)                 -- ^ Fills the default object
  -> (b -> Maybe c)                -- ^ Extracts an obj property
  -> Int                           -- ^ Index in list to use
  -> FieldGetter Instance Runtime  -- ^ Result
getIndexedFieldWithDefault
  listGetter defaultGetter fillFn propertyGetter index =
  FieldConfig (\cfg inst -> rsMaybeUnavail $ do
                              incompleteObj <- maybeAt index $ listGetter inst
                              let defaultObj = defaultGetter cfg inst
                                  completeObj = fillFn defaultObj incompleteObj
                              propertyGetter completeObj)

-- | Creates a function which produces a 'FieldGetter' when fed an index. Works
-- for fields that may not return a value, expressed through the Maybe monad.
getIndexedOptionalField :: (J.JSON b)
                        => (Instance -> [a]) -- ^ Extracts a list of objects
                        -> (a -> Maybe b)    -- ^ Possibly gets a property
                                             -- from an object
                        -> Int               -- ^ Index in list to use
                        -> FieldGetter Instance Runtime -- ^ Result
getIndexedOptionalField extractor optPropertyGetter index =
  FieldSimple(\inst -> rsMaybeUnavail $ do
                         obj <- maybeAt index $ extractor inst
                         optPropertyGetter obj)

-- | Creates a function which produces a 'FieldGetter' when fed an index.
-- Works only for fields that surely return a value.
getIndexedField :: (J.JSON b)
                => (Instance -> [a]) -- ^ Extracts a list of objects
                -> (a -> b)          -- ^ Gets a property from an object
                -> Int               -- ^ Index in list to use
                -> FieldGetter Instance Runtime -- ^ Result
getIndexedField extractor propertyGetter index =
  let optPropertyGetter = Just . propertyGetter
  in getIndexedOptionalField extractor optPropertyGetter index

-- | Retrieves a value from an array at an index, using the Maybe monad to
-- indicate failure.
maybeAt :: Int -> [a] -> Maybe a
maybeAt index list
  | index >= length list = Nothing
  | otherwise            = Just $ list !! index

-- | Primed with format strings for everything but the type, it consumes two
-- values and uses them to complete the FieldDefinition.
-- Warning: a bit unsafe as it uses printf. Handle with care.
fieldDefinitionCompleter :: (PrintfArg t1) => (PrintfArg t2)
                         => FieldName
                         -> FieldTitle
                         -> FieldType
                         -> FieldDoc
                         -> t1
                         -> t2
                         -> FieldDefinition
fieldDefinitionCompleter fName fTitle fType fDoc firstVal secondVal =
  FieldDefinition (printf fName firstVal)
                  (printf fTitle firstVal)
                  fType
                  (printf fDoc secondVal)

-- | Given an incomplete field definition and values that can complete it,
-- return a fully functional FieldData. Cannot work for all cases, should be
-- extended as necessary.
fillIncompleteFields :: (t1 -> t2 -> FieldDefinition,
                         t1 -> FieldGetter a b,
                         QffMode)
                     -> t1
                     -> t2
                     -> FieldData a b
fillIncompleteFields (iDef, iGet, mode) firstVal secondVal =
  (iDef firstVal secondVal, iGet firstVal, mode)

-- | Given indexed fields that describe lists, complete / instantiate them for
-- a given list size.
instantiateIndexedFields :: (Show t1, Integral t1)
                         => Int            -- ^ The size of the list
                         -> [(t1 -> String -> FieldDefinition,
                              t1 -> FieldGetter a b,
                              QffMode)]    -- ^ The indexed fields
                         -> FieldList a b  -- ^ A list of complete fields
instantiateIndexedFields listSize fields = do
  index <- take listSize [0..]
  field <- fields
  return . fillIncompleteFields field index . formatOrdinal $ index + 1

-- * Various helper functions for property retrieval

-- | Helper function for primary node retrieval
getPrimaryNode :: ConfigData -> Instance -> ErrorResult Node
getPrimaryNode cfg = maybe (Bad $ ParameterError "no primary node") return
                       . instName
                     >=> getInstPrimaryNode cfg

-- | Get primary node hostname
getPrimaryNodeName :: ConfigData -> Instance -> ResultEntry
getPrimaryNodeName cfg inst =
  rsErrorNoData $ nodeName <$> getPrimaryNode cfg inst

-- | Get primary node group
getPrimaryNodeGroup :: ConfigData -> Instance -> ErrorResult NodeGroup
getPrimaryNodeGroup cfg inst = do
  pNode <- getPrimaryNode cfg inst
  maybeToError "Configuration missing" $ getGroupOfNode cfg pNode

-- | Get primary node group name
getPrimaryNodeGroupName :: ConfigData -> Instance -> ResultEntry
getPrimaryNodeGroupName cfg inst =
  rsErrorNoData $ groupName <$> getPrimaryNodeGroup cfg inst

-- | Get primary node group uuid
getPrimaryNodeGroupUuid :: ConfigData -> Instance -> ResultEntry
getPrimaryNodeGroupUuid cfg inst =
  rsErrorNoData $ uuidOf <$> getPrimaryNodeGroup cfg inst

-- | Get secondary nodes - the configuration objects themselves
getSecondaryNodes :: ConfigData -> Instance -> ErrorResult [Node]
getSecondaryNodes cfg inst = do
  pNode <- getPrimaryNode cfg inst
  iname <- maybe (Bad $ ParameterError "no name") return $ instName inst
  allNodes <- getInstAllNodes cfg iname
  return $ delete pNode allNodes

-- | Get attributes of the secondary nodes
getSecondaryNodeAttribute :: (J.JSON a)
                          => (Node -> a)
                          -> ConfigData
                          -> Instance
                          -> ResultEntry
getSecondaryNodeAttribute getter cfg inst =
  rsErrorNoData $ map (J.showJSON . getter) <$> getSecondaryNodes cfg inst

-- | Get secondary node groups
getSecondaryNodeGroups :: ConfigData -> Instance -> ErrorResult [NodeGroup]
getSecondaryNodeGroups cfg inst = do
  sNodes <- getSecondaryNodes cfg inst
  return . catMaybes $ map (getGroupOfNode cfg) sNodes

-- | Get attributes of secondary node groups
getSecondaryNodeGroupAttribute :: (J.JSON a)
                               => (NodeGroup -> a)
                               -> ConfigData
                               -> Instance
                               -> ResultEntry
getSecondaryNodeGroupAttribute getter cfg inst =
  rsErrorNoData $ map (J.showJSON . getter) <$> getSecondaryNodeGroups cfg inst

-- | Beparam getter builder: given a field, it returns a FieldConfig
-- getter, that is a function that takes the config and the object and
-- returns the Beparam field specified when the getter was built.
beParamGetter :: String       -- ^ The field we are building the getter for
              -> ConfigData   -- ^ The configuration object
              -> Instance     -- ^ The instance configuration object
              -> ResultEntry  -- ^ The result
beParamGetter field config inst =
  case getFilledInstBeParams config inst of
    Ok beParams -> dictFieldGetter field $ Just beParams
    Bad       _ -> rsNoData

-- | Hvparam getter builder: given a field, it returns a FieldConfig
-- getter, that is a function that takes the config and the object and
-- returns the Hvparam field specified when the getter was built.
hvParamGetter :: String -- ^ The field we're building the getter for
              -> ConfigData -> Instance -> ResultEntry
hvParamGetter field cfg inst =
  rsMaybeUnavail . Map.lookup (UTF8.fromString field) . fromContainer $
    getFilledInstHvParams (C.toList C.hvcGlobals) cfg inst

-- * Live fields functionality

-- | List of node live fields.
instanceLiveFieldsDefs :: [(FieldName, FieldTitle, FieldType, String, FieldDoc)]
instanceLiveFieldsDefs =
  [ ("oper_ram", "Memory", QFTUnit, "oper_ram",
     "Actual memory usage as seen by hypervisor")
  , ("oper_vcpus", "VCPUs", QFTNumber, "oper_vcpus",
     "Actual number of VCPUs as seen by hypervisor")
  ]

-- | Map each name to a function that extracts that value from the RPC result.
instanceLiveFieldExtract :: FieldName -> InstanceInfo -> Instance -> J.JSValue
instanceLiveFieldExtract "oper_ram"   info _ = J.showJSON $ instInfoMemory info
instanceLiveFieldExtract "oper_vcpus" info _ = J.showJSON $ instInfoVcpus info
instanceLiveFieldExtract n _ _ = J.showJSON $
  "The field " ++ n ++ " is not an expected or extractable live field!"

-- | Helper for extracting an instance live field from the RPC results.
instanceLiveRpcCall :: FieldName -> Runtime -> Instance -> ResultEntry
instanceLiveRpcCall fname (Right (Just (res, _), _)) inst =
  case instanceLiveFieldExtract fname res inst of
    J.JSNull -> rsNoData
    x        -> rsNormal x
instanceLiveRpcCall _ (Right (Nothing, _)) _ = rsUnavail
instanceLiveRpcCall _ (Left err) _ =
  ResultEntry (rpcErrorToStatus err) Nothing

-- | Builder for node live fields.
instanceLiveFieldBuilder :: (FieldName, FieldTitle, FieldType, String, FieldDoc)
                         -> FieldData Instance Runtime
instanceLiveFieldBuilder (fname, ftitle, ftype, _, fdoc) =
  ( FieldDefinition fname ftitle ftype fdoc
  , FieldRuntime $ instanceLiveRpcCall fname
  , QffNormal)

-- * Functionality related to status and operational status extraction

-- | The documentation text for the instance status field
statusDocText :: String
statusDocText =
  let si = show . instanceStatusToRaw :: InstanceStatus -> String
  in  "Instance status; " ++
      si Running ++
      " if instance is set to be running and actually is, " ++
      si StatusDown ++
      " if instance is stopped and is not running, " ++
      si WrongNode ++
      " if instance running, but not on its designated primary node, " ++
      si ErrorUp ++
      " if instance should be stopped, but is actually running, " ++
      si ErrorDown ++
      " if instance should run, but doesn't, " ++
      si NodeDown ++
      " if instance's primary node is down, " ++
      si NodeOffline ++
      " if instance's primary node is marked offline, " ++
      si StatusOffline ++
      " if instance is offline and does not use dynamic resources"

-- | Checks if the primary node of an instance is offline
isPrimaryOffline :: ConfigData -> Instance -> Bool
isPrimaryOffline cfg inst =
  let pNodeResult = maybe (Bad $ ParameterError "no primary node") return
                          (instPrimaryNode inst)
                    >>= getNode cfg
  in case pNodeResult of
     Ok pNode -> nodeOffline pNode
     Bad    _ -> error "Programmer error - result assumed to be OK is Bad!"

-- | Determines if user shutdown reporting is enabled
userShutdownEnabled :: ConfigData -> Bool
userShutdownEnabled = clusterEnabledUserShutdown . configCluster

-- | Determines the status of a live instance
liveInstanceStatus :: ConfigData
                   -> (InstanceInfo, Bool)
                   -> Instance
                   -> InstanceStatus
liveInstanceStatus cfg (instInfo, foundOnPrimary) inst
  | not foundOnPrimary = WrongNode
  | otherwise =
    case instanceState of
      InstanceStateRunning
        | adminState == Just AdminUp -> Running
        | otherwise -> ErrorUp
      InstanceStateShutdown
        | adminState == Just AdminUp && allowDown -> UserDown
        | adminState == Just AdminUp -> ErrorDown
        | otherwise -> StatusDown
  where adminState = instAdminState inst
        instanceState = instInfoState instInfo

        hvparams =
          fromContainer $ getFilledInstHvParams (C.toList C.hvcGlobals) cfg inst

        allowDown =
          userShutdownEnabled cfg &&
          (instHypervisor inst /= Just Kvm ||
           (Map.member (UTF8.fromString C.hvKvmUserShutdown) hvparams &&
            hvparams Map.! UTF8.fromString C.hvKvmUserShutdown
              == J.JSBool True))

-- | Determines the status of a dead instance.
deadInstanceStatus :: ConfigData -> Instance -> InstanceStatus
deadInstanceStatus cfg inst =
  case instAdminState inst of
    Just AdminUp -> ErrorDown
    Just AdminDown | wasCleanedUp && userShutdownEnabled cfg -> UserDown
                   | otherwise -> StatusDown
    Just AdminOffline -> StatusOffline
    Nothing -> StatusDown
  where wasCleanedUp = instAdminStateSource inst == Just UserSource

-- | Determines the status of the instance, depending on whether it is possible
-- to communicate with its primary node, on which node it is, and its
-- configuration.
determineInstanceStatus :: ConfigData      -- ^ The configuration data
                        -> Runtime         -- ^ All the data from the live call
                        -> Instance        -- ^ Static instance configuration
                        -> InstanceStatus  -- ^ Result
determineInstanceStatus cfg res inst
  | isPrimaryOffline cfg inst = NodeOffline
  | otherwise = case res of
      Left _                   -> NodeDown
      Right (Just liveData, _) -> liveInstanceStatus cfg liveData inst
      Right (Nothing, _)       -> deadInstanceStatus cfg inst

-- | Extracts the instance status, retrieving it using the functions above and
-- transforming it into a 'ResultEntry'.
statusExtract :: ConfigData -> Runtime -> Instance -> ResultEntry
statusExtract cfg res inst =
  rsNormal . J.showJSON . instanceStatusToRaw $
    determineInstanceStatus cfg res inst

-- | Extracts the operational status of the instance.
operStatusExtract :: Runtime -> Instance -> ResultEntry
operStatusExtract res _ =
  rsMaybeNoData $ J.showJSON <$>
    case res of
      Left _       -> Nothing
      Right (x, _) -> Just $ isJust x

-- | Extracts the console connection information
consoleExtract :: Runtime -> Instance -> ResultEntry
consoleExtract (Left err) _ = ResultEntry (rpcErrorToStatus err) Nothing
consoleExtract (Right (_, val)) _ = rsMaybeNoData val

-- * Helper functions extracting information as necessary for the generic query
-- interfaces

-- | This function checks if a node with a given uuid has experienced an error
-- or not.
checkForNodeError :: [(String, ERpcError a)]
                  -> String
                  -> Maybe RpcError
checkForNodeError uuidList uuid =
  case snd <$> pickPairUnique uuid uuidList of
    Just (Left err) -> Just err
    Just (Right _)  -> Nothing
    Nothing         -> Just . RpcResultError $
                         "Node response not present"

-- | Finds information about the instance in the info delivered by a node
findInfoInNodeResult :: Instance
                     -> ERpcError RpcResultAllInstancesInfo
                     -> Maybe InstanceInfo
findInfoInNodeResult inst nodeResponse =
  case nodeResponse of
    Left  _err    -> Nothing
    Right allInfo ->
      let instances = rpcResAllInstInfoInstances allInfo
          maybeMatch = instName inst >>= (`pickPairUnique` instances)
      in snd <$> maybeMatch

-- | Retrieves the instance information if it is present anywhere in the all
-- instances RPC result. Notes if it originates from the primary node.
-- An error is delivered if there is no result, and the primary node is down.
getInstanceInfo :: [(String, ERpcError RpcResultAllInstancesInfo)]
                -> Instance
                -> ERpcError (Maybe (InstanceInfo, Bool))
getInstanceInfo uuidList inst =
  case instPrimaryNode inst of
    Nothing -> Right Nothing
    Just pNodeUuid ->
      let primarySearchResult =
            pickPairUnique pNodeUuid uuidList >>= findInfoInNodeResult inst
                                                    . snd
      in case primarySearchResult of
           Just instInfo -> Right . Just $ (instInfo, True)
           Nothing       ->
             let allSearchResult =
                   getFirst . mconcat $ map
                   (First . findInfoInNodeResult inst . snd) uuidList
             in case allSearchResult of
                  Just instInfo -> Right . Just $ (instInfo, False)
                  Nothing       ->
                    case checkForNodeError uuidList pNodeUuid of
                      Just err -> Left err
                      Nothing  -> Right Nothing

-- | Retrieves the console information if present anywhere in the given results
getConsoleInfo :: [(String, ERpcError RpcResultInstanceConsoleInfo)]
               -> Instance
               -> Maybe InstanceConsoleInfo
getConsoleInfo uuidList inst =
  let allValidResults = concatMap rpcResInstConsInfoInstancesInfo .
                        rights . map snd $ uuidList
  in snd <$> (instName inst >>= flip pickPairUnique allValidResults)

-- | Extracts all the live information that can be extracted.
extractLiveInfo :: [(Node, ERpcError RpcResultAllInstancesInfo)]
                -> [(Node, ERpcError RpcResultInstanceConsoleInfo)]
                -> Instance
                -> Runtime
extractLiveInfo nodeResultList nodeConsoleList inst =
  let uuidConvert     = map (\(x, y) -> (uuidOf x, y))
      uuidResultList  = uuidConvert nodeResultList
      uuidConsoleList = uuidConvert nodeConsoleList
  in case getInstanceInfo uuidResultList inst of
    -- If we can't get the instance info, we can't get the console info either.
    -- Best to propagate the error further.
    Left err  -> Left err
    Right res -> Right (res, getConsoleInfo uuidConsoleList inst)

-- | Retrieves all the parameters for the console calls.
getAllConsoleParams :: ConfigData
                    -> [Instance]
                    -> ErrorResult [InstanceConsoleInfoParams]
getAllConsoleParams cfg = mapM $ \i ->
  InstanceConsoleInfoParams i
    <$> getPrimaryNode cfg i
    <*> getPrimaryNodeGroup cfg i
    <*> pure (getFilledInstHvParams [] cfg i)
    <*> getFilledInstBeParams cfg i

-- | Compares two params according to their node, needed for grouping.
compareParamsByNode :: InstanceConsoleInfoParams
                    -> InstanceConsoleInfoParams
                    -> Bool
compareParamsByNode x y = instConsInfoParamsNode x == instConsInfoParamsNode y

-- | Groups instance information calls heading out to the same nodes.
consoleParamsToCalls :: [InstanceConsoleInfoParams]
                     -> [(Node, RpcCallInstanceConsoleInfo)]
consoleParamsToCalls params =
  let sortedParams = sortBy
        (comparing (instPrimaryNode . instConsInfoParamsInstance)) params
      groupedParams = groupBy compareParamsByNode sortedParams
  in map (\x -> case x of
            [] -> error "Programmer error: group must have one or more members"
            paramGroup@(y:_) ->
              let node = instConsInfoParamsNode y
                  packer z = do
                              name <- instName $ instConsInfoParamsInstance z
                              return (name, z)
              in (node, RpcCallInstanceConsoleInfo . mapMaybe packer
                          $ paramGroup)
         ) groupedParams

-- | Retrieves a list of all the hypervisors and params used by the given
-- instances.
getHypervisorSpecs :: ConfigData -> [Instance] -> [(Hypervisor, HvParams)]
getHypervisorSpecs cfg instances =
  let hvs = nub . mapMaybe instHypervisor $ instances
      hvParamMap = (fromContainer . clusterHvparams . configCluster $ cfg)
  in zip hvs . map ((Map.!) hvParamMap) $ hvs

-- | Collect live data from RPC query if enabled.
collectLiveData :: Bool        -- ^ Live queries allowed
                -> ConfigData  -- ^ The cluster config
                -> [String]    -- ^ The requested fields
                -> [Instance]  -- ^ The instance objects
                -> IO [(Instance, Runtime)]
collectLiveData liveDataEnabled cfg fields instances
  | not liveDataEnabled = return . zip instances . repeat . Left .
                            RpcResultError $ "Live data disabled"
  | otherwise = do
      let hvSpecs = getHypervisorSpecs cfg instances
          instanceNodes =
            nub . justOk
                $ map ( maybe (Bad $ ParameterError "no primary node") return
                       . instPrimaryNode
                       >=> getNode cfg) instances
          goodNodes = nodesWithValidConfig cfg instanceNodes
      instInfoRes <- executeRpcCall goodNodes (RpcCallAllInstancesInfo hvSpecs)
      consInfoRes <-
        if "console" `elem` fields
          then case getAllConsoleParams cfg instances of
            Ok  p -> executeRpcCalls $ consoleParamsToCalls p
            Bad _ -> return . zip goodNodes . repeat . Left $
              RpcResultError "Cannot construct parameters for console info call"
          else return [] -- The information is not necessary
      return . zip instances .
        map (extractLiveInfo instInfoRes consInfoRes) $ instances

-- | An aggregate disk attribute for backward compatibility.
getDiskTemplate :: ConfigData -> Instance -> ResultEntry
getDiskTemplate cfg inst =
  let disks = getInstDisksFromObj cfg inst
      getDt x = lidDiskType <$> diskLogicalId x
      disk_types :: ErrorResult [DiskTemplate]
      disk_types = nub <$> catMaybes <$> map getDt <$> disks
      mix :: [DiskTemplate] -> J.JSValue
      mix []  = J.showJSON C.dtDiskless
      mix [t] = J.showJSON t
      mix _   = J.showJSON C.dtMixed
  in case mix <$> disk_types of
       Ok t -> rsNormal t
       Bad _ -> rsNoData