{-# LANGUAGE NamedFieldPuns    #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards   #-}
{-# LANGUAGE ViewPatterns      #-}

-- | This module contains the implementation of the @dhall freeze@ subcommand

module Dhall.Freeze
    ( -- * Freeze
      freeze
    , freezeWithManager
    , freezeExpression
    , freezeExpressionWithManager
    , freezeImport
    , freezeImportWithManager
    , freezeRemoteImport
    , freezeRemoteImportWithManager

      -- * Types
    , Scope(..)
    , Intent(..)
    ) where

import Data.Foldable       (for_)
import Dhall.Pretty        (CharacterSet)
import Dhall.Syntax
    ( Expr (..)
    , Import (..)
    , ImportHashed (..)
    , ImportType (..)
    )
import Dhall.Util
    ( Censor
    , CheckFailed (..)
    , Header (..)
    , OutputMode (..)
    , PossiblyTransitiveInput (..)
    , Transitivity (..)
    )
import System.Console.ANSI (hSupportsANSI)

import qualified Control.Exception                         as Exception
import qualified Control.Monad.Trans.State.Strict          as State
import qualified Data.Text.IO                              as Text.IO
import qualified Data.Text.Prettyprint.Doc                 as Pretty
import qualified Data.Text.Prettyprint.Doc.Render.Terminal as Pretty
import qualified Data.Text.Prettyprint.Doc.Render.Text     as Pretty.Text
import qualified Dhall.Core                                as Core
import qualified Dhall.Import
import qualified Dhall.Optics
import qualified Dhall.Pretty
import qualified Dhall.TypeCheck
import qualified Dhall.Util                                as Util
import qualified System.AtomicWrite.Writer.LazyText        as AtomicWrite.LazyText
import qualified System.FilePath
import qualified System.IO

-- | Retrieve an `Import` and update the hash to match the latest contents
freezeImport
    :: FilePath
    -- ^ Current working directory
    -> Import
    -> IO Import
freezeImport :: FilePath -> Import -> IO Import
freezeImport = IO Manager -> FilePath -> Import -> IO Import
freezeImportWithManager IO Manager
Dhall.Import.defaultNewManager

-- | See 'freezeImport'.
freezeImportWithManager
    :: IO Dhall.Import.Manager
    -> FilePath
    -> Import
    -> IO Import
freezeImportWithManager :: IO Manager -> FilePath -> Import -> IO Import
freezeImportWithManager IO Manager
newManager FilePath
directory Import
import_ = do
    let unprotectedImport :: Import
unprotectedImport =
            Import
import_
                { importHashed :: ImportHashed
importHashed =
                    (Import -> ImportHashed
importHashed Import
import_)
                        { hash :: Maybe SHA256Digest
hash = Maybe SHA256Digest
forall a. Maybe a
Nothing
                        }
                }

    let status :: Status
status = IO Manager -> FilePath -> Status
Dhall.Import.emptyStatusWithManager IO Manager
newManager FilePath
directory

    Expr Src Void
expression <- StateT Status IO (Expr Src Void) -> Status -> IO (Expr Src Void)
forall (m :: * -> *) s a. Monad m => StateT s m a -> s -> m a
State.evalStateT (Expr Src Import -> StateT Status IO (Expr Src Void)
Dhall.Import.loadWith (Import -> Expr Src Import
forall s a. a -> Expr s a
Embed Import
unprotectedImport)) Status
status

    case Expr Src Void -> Either (TypeError Src Void) (Expr Src Void)
forall s. Expr s Void -> Either (TypeError s Void) (Expr s Void)
Dhall.TypeCheck.typeOf Expr Src Void
expression of
        Left  TypeError Src Void
exception -> TypeError Src Void -> IO ()
forall e a. Exception e => e -> IO a
Exception.throwIO TypeError Src Void
exception
        Right Expr Src Void
_         -> () -> IO ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()

    let normalizedExpression :: Expr s Void
normalizedExpression = Expr s Void -> Expr s Void
forall s a. Expr s a -> Expr s a
Core.alphaNormalize (Expr Src Void -> Expr s Void
forall a s t. Eq a => Expr s a -> Expr t a
Core.normalize Expr Src Void
expression)

    -- make sure the frozen import is present in the semantic cache
    Expr Void Void -> IO ()
Dhall.Import.writeExpressionToSemanticCache (Expr Src Void -> Expr Void Void
forall s a t. Expr s a -> Expr t a
Core.denote Expr Src Void
expression)

    let expressionHash :: SHA256Digest
expressionHash = Expr Void Void -> SHA256Digest
Dhall.Import.hashExpression Expr Void Void
forall s. Expr s Void
normalizedExpression

    let newImportHashed :: ImportHashed
newImportHashed = (Import -> ImportHashed
importHashed Import
import_) { hash :: Maybe SHA256Digest
hash = SHA256Digest -> Maybe SHA256Digest
forall a. a -> Maybe a
Just SHA256Digest
expressionHash }

    let newImport :: Import
newImport = Import
import_ { importHashed :: ImportHashed
importHashed = ImportHashed
newImportHashed }

    Import -> IO Import
forall (m :: * -> *) a. Monad m => a -> m a
return Import
newImport

-- | Freeze an import only if the import is a `Remote` import
freezeRemoteImport
    :: FilePath
    -- ^ Current working directory
    -> Import
    -> IO Import
freezeRemoteImport :: FilePath -> Import -> IO Import
freezeRemoteImport = IO Manager -> FilePath -> Import -> IO Import
freezeRemoteImportWithManager IO Manager
Dhall.Import.defaultNewManager

-- | See 'freezeRemoteImport'.
freezeRemoteImportWithManager
    :: IO Dhall.Import.Manager
    -> FilePath
    -> Import
    -> IO Import
freezeRemoteImportWithManager :: IO Manager -> FilePath -> Import -> IO Import
freezeRemoteImportWithManager IO Manager
newManager FilePath
directory Import
import_ =
    case ImportHashed -> ImportType
importType (Import -> ImportHashed
importHashed Import
import_) of
        Remote {} -> IO Manager -> FilePath -> Import -> IO Import
freezeImportWithManager IO Manager
newManager FilePath
directory Import
import_
        ImportType
_         -> Import -> IO Import
forall (m :: * -> *) a. Monad m => a -> m a
return Import
import_

-- | Specifies which imports to freeze
data Scope
    = OnlyRemoteImports
    -- ^ Freeze only remote imports (i.e. URLs)
    | AllImports
    -- ^ Freeze all imports (including paths and environment variables)

-- | Specifies why we are adding semantic integrity checks
data Intent
    = Secure
    -- ^ Protect imports with an integrity check without a fallback so that
    --   import resolution fails if the import changes
    | Cache
    -- ^ Protect imports with an integrity check and also add a fallback import
    --   import without an integrity check.  This is useful if you only want to
    --   cache imports when possible but still gracefully degrade to resolving
    --   them if the semantic integrity check has changed.

-- | Implementation of the @dhall freeze@ subcommand
freeze
    :: OutputMode
    -> PossiblyTransitiveInput
    -> Scope
    -> Intent
    -> CharacterSet
    -> Censor
    -> IO ()
freeze :: OutputMode
-> PossiblyTransitiveInput
-> Scope
-> Intent
-> CharacterSet
-> Censor
-> IO ()
freeze = IO Manager
-> OutputMode
-> PossiblyTransitiveInput
-> Scope
-> Intent
-> CharacterSet
-> Censor
-> IO ()
freezeWithManager IO Manager
Dhall.Import.defaultNewManager

-- | See 'freeze'.
freezeWithManager
    :: IO Dhall.Import.Manager
    -> OutputMode
    -> PossiblyTransitiveInput
    -> Scope
    -> Intent
    -> CharacterSet
    -> Censor
    -> IO ()
freezeWithManager :: IO Manager
-> OutputMode
-> PossiblyTransitiveInput
-> Scope
-> Intent
-> CharacterSet
-> Censor
-> IO ()
freezeWithManager IO Manager
newManager OutputMode
outputMode PossiblyTransitiveInput
input0 Scope
scope Intent
intent CharacterSet
characterSet Censor
censor = PossiblyTransitiveInput -> IO ()
go PossiblyTransitiveInput
input0
  where
    go :: PossiblyTransitiveInput -> IO ()
go PossiblyTransitiveInput
input = do
        let directory :: FilePath
directory = case PossiblyTransitiveInput
input of
                PossiblyTransitiveInput
NonTransitiveStandardInput ->
                    FilePath
"."
                PossiblyTransitiveInputFile file _ ->
                    FilePath -> FilePath
System.FilePath.takeDirectory FilePath
file

        let status :: Status
status = IO Manager -> FilePath -> Status
Dhall.Import.emptyStatusWithManager IO Manager
newManager FilePath
directory

        (Text
originalText, Transitivity
transitivity) <- case PossiblyTransitiveInput
input of
            PossiblyTransitiveInputFile FilePath
file Transitivity
transitivity -> do
                Text
text <- FilePath -> IO Text
Text.IO.readFile FilePath
file

                (Text, Transitivity) -> IO (Text, Transitivity)
forall (m :: * -> *) a. Monad m => a -> m a
return (Text
text, Transitivity
transitivity)

            PossiblyTransitiveInput
NonTransitiveStandardInput -> do
                Text
text <- IO Text
Text.IO.getContents

                (Text, Transitivity) -> IO (Text, Transitivity)
forall (m :: * -> *) a. Monad m => a -> m a
return (Text
text, Transitivity
NonTransitive)

        (Header Text
header, Expr Src Import
parsedExpression) <- Censor -> Text -> IO (Header, Expr Src Import)
Util.getExpressionAndHeaderFromStdinText Censor
censor Text
originalText

        case Transitivity
transitivity of
            Transitivity
Transitive ->
                Expr Src Import -> (Import -> IO ()) -> IO ()
forall (t :: * -> *) (f :: * -> *) a b.
(Foldable t, Applicative f) =>
t a -> (a -> f b) -> f ()
for_ Expr Src Import
parsedExpression ((Import -> IO ()) -> IO ()) -> (Import -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \Import
import_ -> do
                    Maybe FilePath
maybeFilepath <- Status -> Import -> IO (Maybe FilePath)
Dhall.Import.dependencyToFile Status
status Import
import_

                    Maybe FilePath -> (FilePath -> IO ()) -> IO ()
forall (t :: * -> *) (f :: * -> *) a b.
(Foldable t, Applicative f) =>
t a -> (a -> f b) -> f ()
for_ Maybe FilePath
maybeFilepath ((FilePath -> IO ()) -> IO ()) -> (FilePath -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \FilePath
filepath ->
                        PossiblyTransitiveInput -> IO ()
go (FilePath -> Transitivity -> PossiblyTransitiveInput
PossiblyTransitiveInputFile FilePath
filepath Transitivity
Transitive)

            Transitivity
NonTransitive ->
                () -> IO ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()

        Expr Src Import
frozenExpression <- IO Manager
-> FilePath
-> Scope
-> Intent
-> Expr Src Import
-> IO (Expr Src Import)
forall s.
IO Manager
-> FilePath
-> Scope
-> Intent
-> Expr s Import
-> IO (Expr s Import)
freezeExpressionWithManager IO Manager
newManager FilePath
directory Scope
scope Intent
intent Expr Src Import
parsedExpression

        let doc :: Doc Ann
doc =  Text -> Doc Ann
forall a ann. Pretty a => a -> Doc ann
Pretty.pretty Text
header
                Doc Ann -> Doc Ann -> Doc Ann
forall a. Semigroup a => a -> a -> a
<> CharacterSet -> Expr Src Import -> Doc Ann
forall a. Pretty a => CharacterSet -> Expr Src a -> Doc Ann
Dhall.Pretty.prettyCharacterSet CharacterSet
characterSet Expr Src Import
frozenExpression
                Doc Ann -> Doc Ann -> Doc Ann
forall a. Semigroup a => a -> a -> a
<> Doc Ann
"\n"

        let stream :: SimpleDocStream Ann
stream = Doc Ann -> SimpleDocStream Ann
forall ann. Doc ann -> SimpleDocStream ann
Dhall.Pretty.layout Doc Ann
doc

        let modifiedText :: Text
modifiedText = SimpleDocStream Ann -> Text
forall ann. SimpleDocStream ann -> Text
Pretty.Text.renderStrict SimpleDocStream Ann
stream

        case OutputMode
outputMode of
            OutputMode
Write -> do
                let unAnnotated :: SimpleDocStream xxx
unAnnotated = SimpleDocStream Ann -> SimpleDocStream xxx
forall ann xxx. SimpleDocStream ann -> SimpleDocStream xxx
Pretty.unAnnotateS SimpleDocStream Ann
stream

                case PossiblyTransitiveInput
input of
                    PossiblyTransitiveInputFile FilePath
file Transitivity
_ ->
                        if Text
originalText Text -> Text -> Bool
forall a. Eq a => a -> a -> Bool
== Text
modifiedText
                            then () -> IO ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()
                            else
                                FilePath -> Text -> IO ()
AtomicWrite.LazyText.atomicWriteFile
                                    FilePath
file
                                    (SimpleDocStream Any -> Text
forall ann. SimpleDocStream ann -> Text
Pretty.Text.renderLazy SimpleDocStream Any
forall xxx. SimpleDocStream xxx
unAnnotated)

                    PossiblyTransitiveInput
NonTransitiveStandardInput -> do
                        Bool
supportsANSI <- Handle -> IO Bool
System.Console.ANSI.hSupportsANSI Handle
System.IO.stdout
                        if Bool
supportsANSI
                           then
                             Handle -> SimpleDocStream AnsiStyle -> IO ()
Pretty.renderIO Handle
System.IO.stdout (Ann -> AnsiStyle
Dhall.Pretty.annToAnsiStyle (Ann -> AnsiStyle)
-> SimpleDocStream Ann -> SimpleDocStream AnsiStyle
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> SimpleDocStream Ann
stream)
                           else
                             Handle -> SimpleDocStream AnsiStyle -> IO ()
Pretty.renderIO Handle
System.IO.stdout SimpleDocStream AnsiStyle
forall xxx. SimpleDocStream xxx
unAnnotated

            OutputMode
Check ->
                if Text
originalText Text -> Text -> Bool
forall a. Eq a => a -> a -> Bool
== Text
modifiedText
                    then () -> IO ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()
                    else do
                        let command :: Text
command = Text
"freeze"

                        let modified :: Text
modified = Text
"frozen"

                        CheckFailed -> IO ()
forall e a. Exception e => e -> IO a
Exception.throwIO CheckFailed :: Text -> Text -> CheckFailed
CheckFailed{Text
modified :: Text
command :: Text
modified :: Text
command :: Text
..}

{-| Slightly more pure version of the `freeze` function

    This still requires `IO` to freeze the import, but now the input and output
    expression are passed in explicitly
-}
freezeExpression
    :: FilePath
    -- ^ Starting directory
    -> Scope
    -> Intent
    -> Expr s Import
    -> IO (Expr s Import)
freezeExpression :: FilePath -> Scope -> Intent -> Expr s Import -> IO (Expr s Import)
freezeExpression = IO Manager
-> FilePath
-> Scope
-> Intent
-> Expr s Import
-> IO (Expr s Import)
forall s.
IO Manager
-> FilePath
-> Scope
-> Intent
-> Expr s Import
-> IO (Expr s Import)
freezeExpressionWithManager IO Manager
Dhall.Import.defaultNewManager

-- | See 'freezeExpression'.
freezeExpressionWithManager
    :: IO Dhall.Import.Manager
    -> FilePath
    -> Scope
    -> Intent
    -> Expr s Import
    -> IO (Expr s Import)
freezeExpressionWithManager :: IO Manager
-> FilePath
-> Scope
-> Intent
-> Expr s Import
-> IO (Expr s Import)
freezeExpressionWithManager IO Manager
newManager FilePath
directory Scope
scope Intent
intent Expr s Import
expression = do
    let freezeScope :: IO Manager -> FilePath -> Import -> IO Import
freezeScope =
            case Scope
scope of
                Scope
AllImports        -> IO Manager -> FilePath -> Import -> IO Import
freezeImportWithManager
                Scope
OnlyRemoteImports -> IO Manager -> FilePath -> Import -> IO Import
freezeRemoteImportWithManager

    let freezeFunction :: Import -> IO Import
freezeFunction = IO Manager -> FilePath -> Import -> IO Import
freezeScope IO Manager
newManager FilePath
directory

    let cache :: Expr s Import -> IO (Expr s Import)
cache
            -- This case is necessary because `transformOf` is a bottom-up
            -- rewrite rule.   Without this rule, if you were to transform a
            -- file that already has a cached expression, like this:
            --
            --     someImport sha256:… ? someImport
            --
            -- ... then you would get:
            --
            --       (someImport sha256:… ? someImport)
            --     ? (someImport sha256:… ? someImport)
            --
            -- ... and this rule fixes that by collapsing that back to:
            --
            --       (someImport sha256:… ? someImport)
            (ImportAlt
                (Expr s Import -> Expr s Import
forall s a. Expr s a -> Expr s a
Core.shallowDenote -> ImportAlt
                    (Expr s Import -> Expr s Import
forall s a. Expr s a -> Expr s a
Core.shallowDenote -> Embed
                        Import{ importHashed :: Import -> ImportHashed
importHashed = ImportHashed{ hash :: ImportHashed -> Maybe SHA256Digest
hash = Just SHA256Digest
_expectedHash } }
                    )
                    (Expr s Import -> Expr s Import
forall s a. Expr s a -> Expr s a
Core.shallowDenote -> Embed
                        Import{ importHashed :: Import -> ImportHashed
importHashed = ImportHashed{ hash :: ImportHashed -> Maybe SHA256Digest
hash = Maybe SHA256Digest
Nothing } }
                    )
                )
                import_ :: Expr s Import
import_@(Expr s Import -> Expr s Import
forall s a. Expr s a -> Expr s a
Core.shallowDenote -> ImportAlt
                    (Expr s Import -> Expr s Import
forall s a. Expr s a -> Expr s a
Core.shallowDenote -> Embed
                        Import{ importHashed :: Import -> ImportHashed
importHashed = ImportHashed{ hash :: ImportHashed -> Maybe SHA256Digest
hash = Just SHA256Digest
_actualHash } }
                    )
                    (Expr s Import -> Expr s Import
forall s a. Expr s a -> Expr s a
Core.shallowDenote -> Embed
                        Import{ importHashed :: Import -> ImportHashed
importHashed = ImportHashed{ hash :: ImportHashed -> Maybe SHA256Digest
hash = Maybe SHA256Digest
Nothing } }
                    )
                )
            ) =
                {- Here we could actually compare the `_expectedHash` and
                   `_actualHash` to see if they differ, but we choose not to do
                   so and instead automatically accept the `_actualHash`.  This
                   is done for the same reason that the `freeze*` functions
                   ignore hash mismatches: the user intention when using `dhall
                   freeze` is to update the hash, which they expect to possibly
                   change.
                -}
                Expr s Import -> IO (Expr s Import)
forall (m :: * -> *) a. Monad m => a -> m a
return Expr s Import
import_
        cache
            (Embed import_ :: Import
import_@(Import { importHashed :: Import -> ImportHashed
importHashed = ImportHashed { hash :: ImportHashed -> Maybe SHA256Digest
hash = Maybe SHA256Digest
Nothing } })) = do
                Import
frozenImport <- Import -> IO Import
freezeFunction Import
import_

                {- The two imports can be the same if the import is local and
                   `freezeFunction` only freezes remote imports by default
                -}
                if Import
frozenImport Import -> Import -> Bool
forall a. Eq a => a -> a -> Bool
/= Import
import_
                    then Expr s Import -> IO (Expr s Import)
forall (m :: * -> *) a. Monad m => a -> m a
return (Expr s Import -> Expr s Import -> Expr s Import
forall s a. Expr s a -> Expr s a -> Expr s a
ImportAlt (Import -> Expr s Import
forall s a. a -> Expr s a
Embed Import
frozenImport) (Import -> Expr s Import
forall s a. a -> Expr s a
Embed Import
import_))
                    else Expr s Import -> IO (Expr s Import)
forall (m :: * -> *) a. Monad m => a -> m a
return (Import -> Expr s Import
forall s a. a -> Expr s a
Embed Import
import_)
        cache
            (Embed import_ :: Import
import_@(Import { importHashed :: Import -> ImportHashed
importHashed = ImportHashed { hash :: ImportHashed -> Maybe SHA256Digest
hash = Just SHA256Digest
_ } })) = do
                -- Regenerate the integrity check, just in case it's wrong
                Import
frozenImport <- Import -> IO Import
freezeFunction Import
import_

                -- `dhall freeze --cache` also works the other way around, adding an
                -- unprotected fallback import to imports that are already
                -- protected
                let thawedImport :: Import
thawedImport = Import
import_
                        { importHashed :: ImportHashed
importHashed = (Import -> ImportHashed
importHashed Import
import_)
                            { hash :: Maybe SHA256Digest
hash = Maybe SHA256Digest
forall a. Maybe a
Nothing
                            }
                        }

                Expr s Import -> IO (Expr s Import)
forall (m :: * -> *) a. Monad m => a -> m a
return (Expr s Import -> Expr s Import -> Expr s Import
forall s a. Expr s a -> Expr s a -> Expr s a
ImportAlt (Import -> Expr s Import
forall s a. a -> Expr s a
Embed Import
frozenImport) (Import -> Expr s Import
forall s a. a -> Expr s a
Embed Import
thawedImport))
        cache Expr s Import
expression_ =
            Expr s Import -> IO (Expr s Import)
forall (m :: * -> *) a. Monad m => a -> m a
return Expr s Import
expression_

    case Intent
intent of
        Intent
Secure ->
            (Import -> IO Import) -> Expr s Import -> IO (Expr s Import)
forall (t :: * -> *) (f :: * -> *) a b.
(Traversable t, Applicative f) =>
(a -> f b) -> t a -> f (t b)
traverse Import -> IO Import
freezeFunction Expr s Import
expression
        Intent
Cache  ->
            LensLike
  (WrappedMonad IO)
  (Expr s Import)
  (Expr s Import)
  (Expr s Import)
  (Expr s Import)
-> (Expr s Import -> IO (Expr s Import))
-> Expr s Import
-> IO (Expr s Import)
forall (m :: * -> *) a b.
Monad m =>
LensLike (WrappedMonad m) a b a b -> (b -> m b) -> a -> m b
Dhall.Optics.transformMOf LensLike
  (WrappedMonad IO)
  (Expr s Import)
  (Expr s Import)
  (Expr s Import)
  (Expr s Import)
forall (f :: * -> *) s a.
Applicative f =>
(Expr s a -> f (Expr s a)) -> Expr s a -> f (Expr s a)
Core.subExpressions Expr s Import -> IO (Expr s Import)
forall s. Expr s Import -> IO (Expr s Import)
cache Expr s Import
expression