{- git-annex command
 -
 - Copyright 2025 Joey Hess <id@joeyh.name>
 -
 - Licensed under the GNU AGPL version 3 or higher.
 -}

{-# LANGUAGE OverloadedStrings #-}

module Command.AddComputed where

import Command
import qualified Git
import qualified Annex
import qualified Remote.Compute
import qualified Types.Remote as Remote
import Annex.CatFile
import Annex.Content.Presence
import Annex.Ingest
import Types.KeySource
import Messages.Progress
import Logs.Location
import Utility.Metered
import Utility.MonotonicClock
import Backend.URL (fromUrl)

import qualified Data.Map as M
import Data.Time.Clock

cmd :: Command
cmd = notBareRepo $ 
	command "addcomputed" SectionCommon "add computed files to annex"
		(paramRepeating paramExpression)
		(seek <$$> optParser)

data AddComputedOptions = AddComputedOptions
	{ computeParams :: CmdParams
	, computeRemote :: DeferredParse Remote
	, reproducible :: Maybe Reproducible
	}

optParser :: CmdParamsDesc -> Parser AddComputedOptions
optParser desc = AddComputedOptions
	<$> cmdParams desc
	<*> (mkParseRemoteOption <$> parseToOption)
	<*> parseReproducible

newtype Reproducible = Reproducible { isReproducible :: Bool }

parseReproducible :: Parser (Maybe Reproducible)
parseReproducible = r <|> unr
  where
	r  = flag Nothing (Just (Reproducible True))
		( long "reproducible"
		<> short 'r'
		<> help "computation is fully reproducible"
		)
	unr = flag Nothing (Just (Reproducible False))
		( long "unreproducible"
		<> short 'u'
		<> help "computation is not fully reproducible"
		)

seek :: AddComputedOptions -> CommandSeek
seek o = startConcurrency commandStages (seek' o)

seek' :: AddComputedOptions -> CommandSeek
seek' o = do
	r <- getParsed (computeRemote o)
	unless (Remote.Compute.isComputeRemote r) $
		giveup "That is not a compute remote."

	commandAction $ start o r

start :: AddComputedOptions -> Remote -> CommandStart
start o r = starting "addcomputed" ai si $ perform o r
  where
	ai = ActionItemUUID (Remote.uuid r) (UnquotedString (Remote.name r))
	si = SeekInput (computeParams o)

perform :: AddComputedOptions -> Remote -> CommandPerform
perform o r = do
	program <- Remote.Compute.getComputeProgram r
	repopath <- fromRepo Git.repoPath
	subdir <- liftIO $ relPathDirToFile repopath (literalOsPath ".")
	let state = Remote.Compute.ComputeState
		{ Remote.Compute.computeParams = computeParams o ++
			Remote.Compute.defaultComputeParams r
		, Remote.Compute.computeInputs = mempty
		, Remote.Compute.computeOutputs = mempty
		, Remote.Compute.computeSubdir = subdir
		, Remote.Compute.computeReproducible = False
		}
	fast <- Annex.getRead Annex.fast
	starttime <- liftIO currentMonotonicTimestamp
	showOutput
	Remote.Compute.runComputeProgram program state
		(Remote.Compute.ImmutableState False)
		(getInputContent fast)
		(go starttime fast)
	next $ return True
  where
	go starttime fast state tmpdir = do
		endtime <- liftIO currentMonotonicTimestamp
		let ts = calcduration starttime endtime
		let outputs = Remote.Compute.computeOutputs state
		when (M.null outputs) $
			giveup "The computation succeeded, but it did not generate any files."
		oks <- forM (M.keys outputs) $ \outputfile -> do
			showAction $ "adding " <> QuotedPath outputfile
			k <- catchNonAsync (addfile fast state tmpdir outputfile)
				(\err -> giveup $ "Failed to ingest output file " ++ fromOsPath outputfile ++ ": " ++ show err)
			return (outputfile, Just k)
		let state' = state
			{ Remote.Compute.computeOutputs = M.fromList oks
			}
		forM_ (mapMaybe snd oks) $ \k -> do
			Remote.Compute.setComputeState
				(Remote.remoteStateHandle r)
				k ts state'
			logChange NoLiveUpdate k (Remote.uuid r) InfoPresent
	
	addfile fast state tmpdir outputfile
		| fast = do
			addSymlink outputfile stateurlk Nothing
			return stateurlk
		| isreproducible state = do
			sz <- liftIO $ getFileSize outputfile'
			metered Nothing sz Nothing $ \_ p ->
				ingestwith $ ingestAdd p (Just ld)
		| otherwise = ingestwith $
			ingestAdd' nullMeterUpdate (Just ld) (Just stateurlk)
	  where
	  	stateurl = Remote.Compute.computeStateUrl r state outputfile
		stateurlk = fromUrl stateurl Nothing True
		outputfile' = tmpdir </> outputfile
		ld = LockedDown ldc $ KeySource
				{ keyFilename = outputfile
				, contentLocation = outputfile'
				, inodeCache = Nothing
				}
		ingestwith a = a >>= \case
			Nothing -> giveup "key generation failed"
			Just k -> do
				logStatus NoLiveUpdate k InfoPresent
				return k

	ldc = LockDownConfig
		{ lockingFile = True
		, hardlinkFileTmpDir = Nothing
		, checkWritePerms = True
		}
	
	calcduration (MonotonicTimestamp starttime) (MonotonicTimestamp endtime) =
		fromIntegral (endtime - starttime) :: NominalDiffTime
	
	isreproducible state = case reproducible o of
		Just v -> isReproducible v
		Nothing -> Remote.Compute.computeReproducible state
	
getInputContent :: Bool -> OsPath -> Annex (Key, Maybe OsPath)
getInputContent fast p = catKeyFile p >>= \case
	Just inputkey -> do
		obj <- calcRepo (gitAnnexLocation inputkey)
		if fast
			then return (inputkey, Nothing)
			else ifM (inAnnex inputkey)
				( return (inputkey, Just obj)
				, giveup $ "The computation needs the content of a file which is not present: " ++ fromOsPath p
				)
	Nothing -> ifM (liftIO $ doesFileExist p)
		( giveup $ "The computation needs an input file that is not an annexed file: " ++ fromOsPath p 
		, giveup $ "The computation needs an input file which does not exist: " ++ fromOsPath p
		)