{-# LANGUAGE DataKinds #-}
{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeOperators #-}

module Cachix.Client.Commands
  ( authtoken,
    generateKeypair,
    push,
    watchStore,
    watchExec,
    use,
  )
where

import qualified Cachix.API as API
import Cachix.API.Error
import Cachix.Client.CNix (filterInvalidStorePath)
import Cachix.Client.Config
  ( BinaryCacheConfig (BinaryCacheConfig),
    Config (..),
    mkConfig,
    writeConfig,
  )
import qualified Cachix.Client.Config as Config
import Cachix.Client.Env (Env (..))
import Cachix.Client.Exception (CachixException (..))
import Cachix.Client.HumanSize (humanSize)
import qualified Cachix.Client.InstallationMode as InstallationMode
import qualified Cachix.Client.NixConf as NixConf
import Cachix.Client.NixVersion (assertNixVersion)
import Cachix.Client.OptionsParser
  ( CachixOptions (..),
    PushArguments (..),
    PushOptions (..),
  )
import Cachix.Client.Push
import Cachix.Client.Retry (retryAll)
import Cachix.Client.Secrets
  ( SigningKey (SigningKey),
    exportSigningKey,
  )
import Cachix.Client.Servant
import qualified Cachix.Client.WatchStore as WatchStore
import qualified Cachix.Types.SigningKeyCreate as SigningKeyCreate
import Control.Exception.Safe (throwM)
import Control.Retry (RetryStatus (rsIterNumber))
import Crypto.Sign.Ed25519 (PublicKey (PublicKey), createKeypair)
import qualified Data.ByteString.Base64 as B64
import Data.String.Here
import qualified Data.Text as T
import qualified Data.Text.IO as T.IO
import GHC.IO.Handle (hDuplicate, hDuplicateTo)
import Hercules.CNix.Store (Store, StorePath, followLinksToStorePath, isValidPath, storePathToPath)
import Network.HTTP.Types (status401, status404)
import Protolude hiding (toS)
import Protolude.Conv
import Servant.API (NoContent)
import Servant.Auth.Client
import Servant.Client.Streaming
import Servant.Conduit ()
import System.Directory (doesFileExist)
import System.IO (hIsTerminalDevice)
import qualified System.Posix.Signals as Signals
import qualified System.Process

authtoken :: Env -> Maybe Text -> IO ()
authtoken env (Just token) = do
  -- TODO: check that token actually authenticates!
  writeConfig (configPath (cachixoptions env)) $ case config env of
    Just cfg -> Config.setAuthToken cfg $ Token (toS token)
    Nothing -> mkConfig token
authtoken env Nothing = authtoken env . Just . T.strip =<< T.IO.getContents

generateKeypair :: Env -> Text -> IO ()
generateKeypair env name = do
  cachixAuthToken <- Config.getAuthTokenRequired (config env)
  (PublicKey pk, sk) <- createKeypair
  let signingKey = exportSigningKey $ SigningKey sk
      signingKeyCreate = SigningKeyCreate.SigningKeyCreate (toS $ B64.encode pk)
      bcc = BinaryCacheConfig name signingKey
  -- we first validate if key can be added to the binary cache
  (_ :: NoContent) <-
    escalate <=< retryAll $ \_ ->
      (`runClientM` clientenv env) $
        API.createKey cachixClient cachixAuthToken name signingKeyCreate
  -- if key was successfully added, write it to the config
  -- TODO: warn if binary cache with the same key already exists
  let cfg = case config env of
        Just it -> it
        Nothing -> Config.mkConfig $ toS $ getToken cachixAuthToken
  writeConfig (configPath (cachixoptions env)) $
    cfg {binaryCaches = binaryCaches cfg <> [bcc]}
  putStrLn
    ( [iTrim|
Secret signing key has been saved in the file above. To populate
your binary cache:

    $ nix-build | cachix push ${name}

Or if you'd like to use the signing key on another machine or CI:

    $ export CACHIX_SIGNING_KEY=${signingKey}
    $ nix-build | cachix push ${name}

To instruct Nix to use the binary cache:

    $ cachix use ${name}

IMPORTANT: Make sure to make a backup for the signing key above, as you have the only copy.
  |] ::
        Text
    )

notAuthenticatedBinaryCache :: Text -> CachixException
notAuthenticatedBinaryCache name =
  AccessDeniedBinaryCache $
    "Binary cache " <> name <> " doesn't exist or it's private. " <> Config.noAuthTokenError

accessDeniedBinaryCache :: Text -> CachixException
accessDeniedBinaryCache name =
  AccessDeniedBinaryCache $ "Binary cache " <> name <> " doesn't exist or it's private and you don't have access it"

use :: Env -> Text -> InstallationMode.UseOptions -> IO ()
use env name useOptions = do
  cachixAuthToken <- Config.getAuthTokenOptional (config env)
  -- 1. get cache public key
  res <- retryAll $ \_ -> (`runClientM` clientenv env) $ API.getCache cachixClient cachixAuthToken name
  case res of
    Left err
      | isErr err status401 && isJust (config env) -> throwM $ accessDeniedBinaryCache name
      | isErr err status401 -> throwM $ notAuthenticatedBinaryCache name
      | isErr err status404 -> throwM $ BinaryCacheNotFound $ "Binary cache" <> name <> " does not exist."
      | otherwise -> throwM err
    Right binaryCache -> do
      () <- escalateAs UnsupportedNixVersion =<< assertNixVersion
      user <- InstallationMode.getUser
      nc <- NixConf.read NixConf.Global
      isTrusted <- InstallationMode.isTrustedUser $ NixConf.readLines (catMaybes [nc]) NixConf.isTrustedUsers
      isNixOS <- doesFileExist "/run/current-system/nixos-version"
      let nixEnv =
            InstallationMode.NixEnv
              { InstallationMode.isRoot = user == "root",
                InstallationMode.isTrusted = isTrusted,
                InstallationMode.isNixOS = isNixOS
              }
      InstallationMode.addBinaryCache (config env) binaryCache useOptions $
        InstallationMode.getInstallationMode nixEnv useOptions

push :: Env -> PushArguments -> IO ()
push env (PushPaths opts name cliPaths) = do
  hasStdin <- not <$> hIsTerminalDevice stdin
  inputStorePaths <-
    case (hasStdin, cliPaths) of
      (False, []) -> throwIO $ NoInput "You need to specify store paths either as stdin or as an command argument"
      (True, []) -> T.words <$> getContents
      -- If we get both stdin and cli args, prefer cli args.
      -- This avoids hangs in cases where stdin is non-interactive but unused by caller
      -- some programming environments always create a (non-interactive) stdin
      -- that may or may not be written to by the caller.
      -- This is somewhat like the behavior of `cat` for example.
      (_, paths) -> return paths
  pushParams <- getPushParams env opts name
  normalized <-
    liftIO $
      for inputStorePaths $ \path -> do
        storePath <- followLinksToStorePath (pushParamsStore pushParams) (encodeUtf8 path)
        filterInvalidStorePath (pushParamsStore pushParams) storePath

  pushedPaths <-
    pushClosure
      (mapConcurrentlyBounded (numJobs opts))
      pushParams
      (catMaybes normalized)
  case (length normalized, length pushedPaths) of
    (0, _) -> putText "Nothing to push."
    (_, 0) -> putText "Nothing to push - all store paths are already on Cachix."
    _ -> putText "All done."
push _ _ =
  throwIO $
    DeprecatedCommand "DEPRECATED: cachix watch-store has replaced cachix push --watch-store."

watchStore :: Env -> PushOptions -> Text -> IO ()
watchStore env opts name = do
  pushParams <- getPushParams env opts name
  WatchStore.startWorkers (pushParamsStore pushParams) (numJobs opts) pushParams

watchExec :: Env -> PushOptions -> Text -> Text -> [Text] -> IO ()
watchExec env pushOpts name cmd args = do
  pushParams <- getPushParams env pushOpts name
  stdoutOriginal <- hDuplicate stdout
  let process = (System.Process.proc (toS cmd) (toS <$> args)) {System.Process.std_out = System.Process.UseHandle stdoutOriginal}
      watch = do
        hDuplicateTo stderr stdout -- redirect all stdout to stderr
        WatchStore.startWorkers (pushParamsStore pushParams) (numJobs pushOpts) pushParams

  (_, exitCode) <- concurrently watch $ do
    (_, _, _, processHandle) <- System.Process.createProcess process
    exitCode <- System.Process.waitForProcess processHandle
    Signals.raiseSignal Signals.sigINT
    return exitCode
  exitWith exitCode

retryText :: RetryStatus -> Text
retryText retrystatus =
  if rsIterNumber retrystatus == 0
    then ""
    else "(retry #" <> show (rsIterNumber retrystatus) <> ") "

pushStrategy :: Store -> Env -> PushOptions -> Text -> StorePath -> PushStrategy IO ()
pushStrategy store env opts name storePath =
  PushStrategy
    { onAlreadyPresent = pass,
      on401 =
        if isJust (config env)
          then throwM $ accessDeniedBinaryCache name
          else throwM $ notAuthenticatedBinaryCache name,
      onError = throwM,
      onAttempt = \retrystatus size -> do
        path <- decodeUtf8With lenientDecode <$> storePathToPath store storePath
        -- we append newline instead of putStrLn due to https://github.com/haskell/text/issues/242
        putStr $ retryText retrystatus <> "compressing and pushing " <> path <> " (" <> humanSize (fromIntegral size) <> ")\n",
      onDone = pass,
      withXzipCompressor = defaultWithXzipCompressorWithLevel (compressionLevel opts),
      Cachix.Client.Push.omitDeriver = Cachix.Client.OptionsParser.omitDeriver opts
    }

getPushParams :: Env -> PushOptions -> Text -> IO (PushParams IO ())
getPushParams env pushOpts name = do
  pushSecret <- findPushSecret (config env) name
  store <- wait (storeAsync env)
  return $
    PushParams
      { pushParamsName = name,
        pushParamsSecret = pushSecret,
        pushParamsClientEnv = clientenv env,
        pushParamsStrategy = pushStrategy store env pushOpts name,
        pushParamsStore = store
      }