content: {-| Implementation of the Ganeti Query2 basic types.
  
  These are types internal to the library, and for example clients that
  use the library should not need to import it.
  
   -}
  
  {-
  
  Copyright (C) 2012, 2013 Google Inc.
  All rights reserved.
  
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  modification, are permitted provided that the following conditions are
  met:
  
  1. Redistributions of source code must retain the above copyright notice,
  this list of conditions and the following disclaimer.
  
  2. Redistributions in binary form must reproduce the above copyright
  notice, this list of conditions and the following disclaimer in the
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  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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  -}
  
  module Ganeti.Query.Types
    ( FieldGetter(..)
    , QffMode(..)
    , FieldData
    , FieldList
    , FieldMap
    , isRuntimeField
    , fieldListToFieldMap
    ) where
  
  import qualified Data.Map as Map
  
  import Ganeti.Query.Language
  import Ganeti.Objects
  
  -- | The type of field getters. The \"a\" type represents the type
  -- we're querying, whereas the \"b\" type represents the \'runtime\'
  -- data for that type (if any). Note that we don't support multiple
  -- runtime sources, and we always consider the entire configuration as
  -- a given (so no equivalent for Python's /*_CONFIG/ and /*_GROUP/;
  -- configuration accesses are cheap for us).
  data FieldGetter a b = FieldSimple        (a -> ResultEntry)
                       | FieldRuntime       (b -> a -> ResultEntry)
                       | FieldConfig        (ConfigData -> a -> ResultEntry)
                       | FieldConfigRuntime (ConfigData -> b -> a -> ResultEntry)
                       | FieldUnknown
  
  -- | Type defining how the value of a field is used in filtering. This
  -- implements the equivalent to Python's QFF_ flags, except that we
  -- don't use OR-able values.
  data QffMode = QffNormal     -- ^ Value is used as-is in filters
               | QffTimestamp  -- ^ Value is a timestamp tuple, convert to float
               | QffHostname   -- ^ Value is a hostname, compare it smartly
                 deriving (Show, Eq)
  
  
  -- | Alias for a field data (definition and getter).
  type FieldData a b = (FieldDefinition, FieldGetter a b, QffMode)
  
  -- | Alias for a field data list.
  type FieldList a b = [FieldData a b]
  
  -- | Alias for field maps.
  type FieldMap a b = Map.Map String (FieldData a b)
  
  -- | Helper function to check if a getter is a runtime one.
  isRuntimeField :: FieldGetter a b -> Bool
  isRuntimeField FieldRuntime {}       = True
  isRuntimeField FieldConfigRuntime {} = True
  isRuntimeField _                     = False
  
  -- | Helper function to obtain a FieldMap from the corresponding FieldList.
  fieldListToFieldMap :: FieldList a b -> FieldMap a b
  fieldListToFieldMap = Map.fromList . map (\v@(f, _, _) -> (fdefName f, v))
  