{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE DerivingStrategies #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE ViewPatterns #-}

-- | Copyright: (c) 2021 berberman
-- SPDX-License-Identifier: MIT
-- Maintainer: berberman <berberman@yandex.com>
-- Stability: experimental
-- Portability: portable
--
-- Types used in this program.
module NvFetcher.Types
  ( -- * Common types
    Version (..),
    SHA256 (..),
    NixExpr,
    VersionChange (..),
    WithPackageKey (..),
    Core (..),

    -- * Nvchecker types
    VersionSource (..),
    NvcheckerResult (..),

    -- * Nix fetcher types
    NixFetcher (..),
    Prefetch (..),
    PrefetchResult,

    -- * Package types
    PackageName,
    PackageFetcher,
    Package (..),
    PackageKey (..),
  )
where

import qualified Data.Aeson as A
import Data.Coerce (coerce)
import Data.Maybe (fromMaybe)
import Data.String (IsString)
import Data.Text (Text)
import qualified Data.Text as T
import Development.Shake
import Development.Shake.Classes
import GHC.Generics (Generic)

--------------------------------------------------------------------------------

-- | Package version
newtype Version = Version Text
  deriving newtype (Eq, Show, Ord, IsString, Semigroup, Monoid, A.FromJSON, A.ToJSON)
  deriving stock (Typeable, Generic)
  deriving anyclass (Hashable, Binary, NFData)

-- | SHA 256 sum
newtype SHA256 = SHA256 Text
  deriving newtype (Show, Eq)
  deriving stock (Typeable, Generic)
  deriving anyclass (Hashable, Binary, NFData)

-- | Version change of a package
--
-- >>> VersionChange "foo" Nothing "2.3.3"
-- foo: ∅ → 2.3.3
--
-- >>> VersionChange "bar" (Just "2.2.2") "2.3.3"
-- bar: 2.2.2 → 2.3.3
data VersionChange = VersionChange
  { vcName :: PackageName,
    vcOld :: Maybe Version,
    vcNew :: Version
  }
  deriving (Eq)

instance Show VersionChange where
  show VersionChange {..} =
    T.unpack $ vcName <> ": " <> fromMaybe "∅" (coerce vcOld) <> " → " <> coerce vcNew

-- | Nix expression
type NixExpr = Text

--------------------------------------------------------------------------------

-- | The input of nvchecker
data VersionSource
  = GitHubRelease {_owner :: Text, _repo :: Text}
  | Git {_vurl :: Text}
  | Pypi {_pypi :: Text}
  | ArchLinux {_archpkg :: Text}
  | Aur {_aur :: Text}
  | Manual {_manual :: Text}
  | Repology {_repology :: Text, _repo :: Text}
  deriving (Show, Typeable, Eq, Ord, Generic, Hashable, Binary, NFData)

-- | The result of running nvchecker
data NvcheckerResult = NvcheckerResult
  { nvNow :: Version,
    -- | nvchecker doesn't give this value, but shake restores it from last run
    nvOld :: Maybe Version
  }
  deriving (Show, Typeable, Eq, Generic, Hashable, Binary, NFData)

instance A.FromJSON NvcheckerResult where
  parseJSON = A.withObject "NvcheckerResult" $ \o ->
    NvcheckerResult <$> o A..: "version" <*> pure Nothing

type instance RuleResult VersionSource = NvcheckerResult

--------------------------------------------------------------------------------

-- | If the package is prefetched, then we can obtain the SHA256
data NixFetcher (k :: Prefetch)
  = FetchGit
      { _furl :: Text,
        _rev :: Version,
        _branch :: Maybe Text,
        _deepClone :: Bool,
        _fetchSubmodules :: Bool,
        _leaveDotGit :: Bool,
        _sha256 :: PrefetchResult k
      }
  | FetchUrl {_furl :: Text, _sha256 :: PrefetchResult k}
  deriving (Typeable, Generic)

-- | Prefetch status
data Prefetch = Fresh | Prefetched

-- | Prefetched fetchers hold hashes
type family PrefetchResult (k :: Prefetch) where
  PrefetchResult Fresh = ()
  PrefetchResult Prefetched = SHA256

type instance RuleResult (NixFetcher Fresh) = NixFetcher Prefetched

deriving instance Show (PrefetchResult k) => Show (NixFetcher k)

deriving instance Eq (PrefetchResult k) => Eq (NixFetcher k)

deriving instance Ord (PrefetchResult k) => Ord (NixFetcher k)

deriving instance Hashable (PrefetchResult k) => Hashable (NixFetcher k)

deriving instance Binary (PrefetchResult k) => Binary (NixFetcher k)

deriving instance NFData (PrefetchResult k) => NFData (NixFetcher k)

--------------------------------------------------------------------------------

-- | Package name, used in generating nix expr
type PackageName = Text

-- | How to create package source fetcher given a version
type PackageFetcher = Version -> NixFetcher Fresh

-- | A package is defined with:
--
-- 1. its name
-- 2. how to track its version
-- 3. how to fetch it as we have the version
--
-- /INVARIANT: 'Version' passed to 'PackageFetcher' MUST be used textually,/
-- /i.e. can only be concatenated with other strings,/
-- /in case we can't check the equality between fetcher functions./
data Package = Package
  { _pname :: PackageName,
    _pversion :: VersionSource,
    _pfetcher :: PackageFetcher
  }

-- | Package key is the name of a package.
-- We use this type to index packages.
newtype PackageKey = PackageKey PackageName
  deriving newtype (Eq, Show, Ord)
  deriving stock (Typeable, Generic)
  deriving anyclass (Hashable, Binary, NFData)

-- | The key type of nvfetcher rule. See "NvFetcher.Core"
data Core = Core
  deriving (Eq, Show, Ord, Typeable, Generic, Hashable, Binary, NFData)

type instance RuleResult Core = NixExpr

--------------------------------------------------------------------------------

-- | Decorate a rule's key with 'PackageKey'
newtype WithPackageKey k = WithPackageKey (k, PackageKey)
  deriving newtype (Eq, Hashable, Binary, NFData)

instance Show k => Show (WithPackageKey k) where
  show (WithPackageKey (k, n)) = show k <> " (" <> show n <> ")"

type instance RuleResult (WithPackageKey k) = RuleResult k