{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE ScopedTypeVariables #-}

module Distribution.Types.GenericPackageDescription
  ( GenericPackageDescription (..)
  , emptyGenericPackageDescription
  ) where

import Distribution.Compat.Prelude
import Prelude ()

-- lens
import Distribution.Compat.Lens as L
import qualified Distribution.Types.BuildInfo.Lens as L

import Distribution.Types.PackageDescription

import Distribution.Package
import Distribution.Types.Benchmark
import Distribution.Types.CondTree
import Distribution.Types.ConfVar
import Distribution.Types.Executable
import Distribution.Types.Flag
import Distribution.Types.ForeignLib
import Distribution.Types.Library
import Distribution.Types.TestSuite
import Distribution.Types.UnqualComponentName
import Distribution.Version

-- ---------------------------------------------------------------------------
-- The 'GenericPackageDescription' type

data GenericPackageDescription = GenericPackageDescription
  { packageDescription :: PackageDescription
  , gpdScannedVersion :: Maybe Version
  -- ^ This is a version as specified in source.
  --   We populate this field in index reading for dummy GPDs,
  --   only when GPD reading failed, but scanning haven't.
  --
  --   Cabal-the-library never produces GPDs with Just as gpdScannedVersion.
  --
  --   Perfectly, PackageIndex should have sum type, so we don't need to
  --   have dummy GPDs.
  , genPackageFlags :: [PackageFlag]
  , condLibrary :: Maybe (CondTree ConfVar [Dependency] Library)
  , condSubLibraries
      :: [ ( UnqualComponentName
           , CondTree ConfVar [Dependency] Library
           )
         ]
  , condForeignLibs
      :: [ ( UnqualComponentName
           , CondTree ConfVar [Dependency] ForeignLib
           )
         ]
  , condExecutables
      :: [ ( UnqualComponentName
           , CondTree ConfVar [Dependency] Executable
           )
         ]
  , condTestSuites
      :: [ ( UnqualComponentName
           , CondTree ConfVar [Dependency] TestSuite
           )
         ]
  , condBenchmarks
      :: [ ( UnqualComponentName
           , CondTree ConfVar [Dependency] Benchmark
           )
         ]
  }
  deriving (Show, Eq, Data, Generic)

instance Package GenericPackageDescription where
  packageId = packageId . packageDescription

instance Binary GenericPackageDescription
instance Structured GenericPackageDescription
instance NFData GenericPackageDescription where rnf = genericRnf

emptyGenericPackageDescription :: GenericPackageDescription
emptyGenericPackageDescription = GenericPackageDescription emptyPackageDescription Nothing [] Nothing [] [] [] [] []

-- -----------------------------------------------------------------------------
-- Traversal Instances

instance L.HasBuildInfos GenericPackageDescription where
  traverseBuildInfos f (GenericPackageDescription p v a1 x1 x2 x3 x4 x5 x6) =
    GenericPackageDescription
      <$> L.traverseBuildInfos f p
      <*> pure v
      <*> pure a1
      <*> (traverse . traverseCondTreeBuildInfo) f x1
      <*> (traverse . L._2 . traverseCondTreeBuildInfo) f x2
      <*> (traverse . L._2 . traverseCondTreeBuildInfo) f x3
      <*> (traverse . L._2 . traverseCondTreeBuildInfo) f x4
      <*> (traverse . L._2 . traverseCondTreeBuildInfo) f x5
      <*> (traverse . L._2 . traverseCondTreeBuildInfo) f x6

-- We use this traversal to keep [Dependency] field in CondTree up to date.
traverseCondTreeBuildInfo
  :: forall f comp v
   . (Applicative f, L.HasBuildInfo comp)
  => LensLike' f (CondTree v [Dependency] comp) L.BuildInfo
traverseCondTreeBuildInfo g = node
  where
    mkCondNode :: comp -> [CondBranch v [Dependency] comp] -> CondTree v [Dependency] comp
    mkCondNode comp = CondNode comp (view L.targetBuildDepends comp)

    node (CondNode comp _ branches) =
      mkCondNode
        <$> L.buildInfo g comp
        <*> traverse branch branches

    branch (CondBranch v x y) =
      CondBranch v
        <$> node x
        <*> traverse node y
