{-# LANGUAGE AllowAmbiguousTypes   #-}
{-# LANGUAGE FlexibleContexts      #-}
{-# LANGUAGE FlexibleInstances     #-}
{-# LANGUAGE LambdaCase            #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE MultiWayIf            #-}
{-# LANGUAGE NoImplicitPrelude     #-}
{-# LANGUAGE OverloadedStrings     #-}
{-# LANGUAGE QuasiQuotes           #-}
{-# LANGUAGE RecordWildCards       #-}
{-# LANGUAGE ScopedTypeVariables   #-}
{-# LANGUAGE StrictData            #-}
{-# LANGUAGE TemplateHaskell       #-}
{-# LANGUAGE TupleSections         #-}
{-# LANGUAGE TypeApplications      #-}
{-# LANGUAGE ViewPatterns          #-}

{-|
Module      : Headroom.Command.Run
Description : Handler for the @run@ command.
Copyright   : (c) 2019-2021 Vaclav Svejcar
License     : BSD-3-Clause
Maintainer  : vaclav.svejcar@gmail.com
Stability   : experimental
Portability : POSIX

Module representing the @run@ command, the core command of /Headroom/, which is
responsible for license header management.
-}

module Headroom.Command.Run
  ( commandRun
  , loadTemplateRefs
  , typeOfTemplate
    -- * License Header Post-processing
  , postProcessHeader'
  )
where

import           Control.Monad.Extra                 ( ifM )
import           Data.String.Interpolate             ( i
                                                     , iii
                                                     )
import           Data.Time.Calendar                  ( toGregorian )
import           Data.Time.Clock                     ( getCurrentTime )
import           Data.Time.Clock.POSIX               ( getPOSIXTime )
import           Data.Time.LocalTime                 ( getCurrentTimeZone
                                                     , localDay
                                                     , utcToLocalTime
                                                     )
import           Data.VCS.Ignore                     ( Git
                                                     , Repo(..)
                                                     , findRepo
                                                     )
import           Headroom.Command.Types              ( CommandRunOptions(..) )
import           Headroom.Command.Utils              ( bootstrap )
import           Headroom.Configuration              ( loadConfiguration
                                                     , makeConfiguration
                                                     , parseConfiguration
                                                     )
import           Headroom.Configuration.Types        ( Configuration(..)
                                                     , CtConfiguration
                                                     , CtPostProcessConfigs
                                                     , HeaderConfig(..)
                                                     , HeaderSyntax(..)
                                                     , PtConfiguration
                                                     , RunMode(..)
                                                     )
import           Headroom.Data.EnumExtra             ( EnumExtra(..) )
import           Headroom.Data.Has                   ( Has(..) )
import           Headroom.Data.Lens                  ( suffixLenses
                                                     , suffixLensesFor
                                                     )
import           Headroom.Embedded                   ( defaultConfig
                                                     , licenseTemplate
                                                     )
import           Headroom.FileSupport                ( analyzeSourceCode
                                                     , fileSupport
                                                     )
import           Headroom.FileType                   ( fileTypeByExt )
import           Headroom.FileType.Types             ( FileType(..) )
import           Headroom.Header                     ( addHeader
                                                     , dropHeader
                                                     , extractHeaderInfo
                                                     , extractHeaderTemplate
                                                     , replaceHeader
                                                     )
import           Headroom.Header.Sanitize            ( sanitizeSyntax )
import           Headroom.Header.Types               ( HeaderInfo(..)
                                                     , HeaderTemplate(..)
                                                     )
import           Headroom.IO.FileSystem              ( FileSystem(..)
                                                     , excludePaths
                                                     , fileExtension
                                                     , mkFileSystem
                                                     )
import           Headroom.IO.Network                 ( Network(..)
                                                     , mkNetwork
                                                     )
import           Headroom.Meta                       ( TemplateType
                                                     , configFileName
                                                     , productInfo
                                                     )
import           Headroom.PostProcess                ( mkConfiguredEnv
                                                     , postProcessHeader
                                                     )
import           Headroom.SourceCode                 ( SourceCode
                                                     , toText
                                                     )
import           Headroom.Template                   ( Template(..) )
import           Headroom.Template.TemplateRef       ( TemplateRef(..)
                                                     , renderRef
                                                     )
import           Headroom.Types                      ( CurrentYear(..) )
import           Headroom.UI                         ( Progress(..)
                                                     , zipWithProgress
                                                     )
import           Headroom.UI.Table                   ( Table2(..) )
import           Headroom.Variables                  ( compileVariables
                                                     , dynamicVariables
                                                     , parseVariables
                                                     )
import           Headroom.Variables.Types            ( Variables(..) )
import           RIO
import           RIO.FilePath                        ( takeBaseName )
import qualified RIO.List                           as L
import qualified RIO.Map                            as M
import qualified RIO.Text                           as T


suffixLensesFor ["cPostProcessConfigs"] ''Configuration


-- | Action to be performed based on the selected 'RunMode'.
data RunAction = RunAction
  { raProcessed    :: Bool -- ^ whether the given file was processed
  , raFunc         :: SourceCode -> SourceCode -- ^ function to process the file
  , raProcessedMsg :: Text -- ^ message to show when file was processed
  , raSkippedMsg   :: Text -- ^ message to show when file was skipped
  }


-- | Initial /RIO/ startup environment for the /Run/ command.
data StartupEnv = StartupEnv
  { envLogFunc    :: LogFunc           -- ^ logging function
  , envRunOptions :: CommandRunOptions -- ^ options
  }

suffixLenses ''StartupEnv

-- | Full /RIO/ environment for the /Run/ command.
data Env = Env
  { envEnv           :: StartupEnv           -- ^ startup /RIO/ environment
  , envConfiguration :: CtConfiguration      -- ^ application configuration
  , envCurrentYear   :: CurrentYear          -- ^ current year
  , envNetwork       :: Network (RIO Env)    -- ^ network operations
  , envFileSystem    :: FileSystem (RIO Env) -- ^ file system operations
  }

suffixLenses ''Env

instance Has CtConfiguration Env where
  hasLens = envConfigurationL

instance Has CtPostProcessConfigs Env where
  hasLens = envConfigurationL . cPostProcessConfigsL

instance Has StartupEnv StartupEnv where
  hasLens = id

instance Has StartupEnv Env where
  hasLens = envEnvL

instance HasLogFunc StartupEnv where
  logFuncL = envLogFuncL

instance HasLogFunc Env where
  logFuncL = hasLens @StartupEnv . logFuncL

instance Has CommandRunOptions StartupEnv where
  hasLens = envRunOptionsL

instance Has CommandRunOptions Env where
  hasLens = hasLens @StartupEnv . hasLens

instance Has CurrentYear Env where
  hasLens = envCurrentYearL

instance Has (Network (RIO Env)) Env where
  hasLens = envNetworkL

instance Has (FileSystem (RIO Env)) Env where
  hasLens = envFileSystemL


env' :: CommandRunOptions -> LogFunc -> IO Env
env' opts logFunc = do
  let envEnv        = StartupEnv { envLogFunc = logFunc, envRunOptions = opts }
      envNetwork    = mkNetwork
      envFileSystem = mkFileSystem
  envConfiguration <- runRIO envEnv finalConfiguration
  envCurrentYear   <- currentYear
  pure Env { .. }


-- | Handler for /Run/ command.
commandRun :: CommandRunOptions -- ^ /Run/ command options
           -> IO ()             -- ^ execution result
commandRun opts = bootstrap (env' opts) (croDebug opts) $ do
  CommandRunOptions {..} <- viewL
  Configuration {..}     <- viewL @CtConfiguration
  let isCheck = cRunMode == Check
  warnOnDryRun
  startTS            <- liftIO getPOSIXTime
  templates          <- loadTemplates
  sourceFiles        <- findSourceFiles (M.keys templates)
  _                  <- logInfo "-----"
  (total, processed) <- processSourceFiles @TemplateType templates sourceFiles
  endTS              <- liftIO getPOSIXTime
  when (processed > 0) $ logStickyDone "-----"
  logStickyDone $ mconcat
    [ "Done: "
    , if isCheck then "outdated " else "modified "
    , display processed
    , if isCheck then ", up-to-date " else ", skipped "
    , display (total - processed)
    , " files in "
    , displayShow (endTS - startTS)
    , " seconds."
    ]
  warnOnDryRun
  when (not croDryRun && isCheck && processed > 0) (exitWith $ ExitFailure 1)


warnOnDryRun :: (HasLogFunc env, Has CommandRunOptions env) => RIO env ()
warnOnDryRun = do
  CommandRunOptions {..} <- viewL
  when croDryRun $ logWarn "[!] Running with '--dry-run', no files are changed!"


findSourceFiles :: ( Has CtConfiguration env
                   , Has (FileSystem (RIO env)) env
                   , HasLogFunc env
                   )
                => [FileType]
                -> RIO env [FilePath]
findSourceFiles fileTypes = do
  Configuration {..} <- viewL
  FileSystem {..}    <- viewL
  logDebug $ "Using source paths: " <> displayShow cSourcePaths
  files <-
    mconcat <$> mapM (fsFindFilesByTypes cLicenseHeaders fileTypes) cSourcePaths
  notIgnored <- excludePaths cExcludedPaths <$> excludeIgnored files
  logInfo [iii|
      Found #{length notIgnored} files to process
      (excluded #{length files - length notIgnored})
    |]
  pure notIgnored


excludeIgnored :: ( Has CtConfiguration env
                  , Has (FileSystem (RIO env)) env
                  , HasLogFunc env
                  )
               => [FilePath]
               -> RIO env [FilePath]
excludeIgnored paths = do
  Configuration {..} <- viewL @CtConfiguration
  FileSystem {..}    <- viewL
  currentDir         <- fsGetCurrentDirectory
  maybeRepo          <- ifM (pure cExcludeIgnoredPaths)
                            (findRepo' currentDir)
                            (pure Nothing)
  case maybeRepo of
    Just repo -> filterM (fmap not . isIgnored repo) paths
    Nothing   -> pure paths
 where
  findRepo' = \dir -> do
    logInfo "Searching for VCS repository to extract exclude patterns from..."
    maybeRepo <- findRepo @_ @Git dir
    case maybeRepo of
      Just r -> logInfo [i|Found #{repoName r} repository in: #{dir}|]
      _      -> logInfo [i|No VCS repository found in: #{dir}|]
    pure maybeRepo


processSourceFiles :: forall a env
                    . ( Template a
                      , Has CtConfiguration env
                      , Has CtPostProcessConfigs env
                      , Has CommandRunOptions env
                      , Has CurrentYear env
                      , HasLogFunc env
                      )
                   => Map FileType HeaderTemplate
                   -> [FilePath]
                   -> RIO env (Int, Int)
processSourceFiles templates paths = do
  Configuration {..} <- viewL
  year               <- viewL
  let dVars        = dynamicVariables year
      withTemplate = mapMaybe (template cLicenseHeaders) paths
  cVars     <- compileVariables @a (dVars <> cVariables)
  processed <- mapM (process cVars dVars) (zipWithProgress withTemplate)
  pure (length withTemplate, length . filter (== True) $ processed)
 where
  fileType c p = fileExtension p >>= fileTypeByExt c
  template c p = (, p) <$> (fileType c p >>= \ft -> M.lookup ft templates)
  process cVars dVars (pr, (ht, p)) = processSourceFile @a cVars dVars pr ht p


processSourceFile :: forall a env
                   . ( Template a
                     , Has CommandRunOptions env
                     , Has CtConfiguration env
                     , Has CtPostProcessConfigs env
                     , Has CurrentYear env
                     , HasLogFunc env
                     )
                  => Variables
                  -> Variables
                  -> Progress
                  -> HeaderTemplate
                  -> FilePath
                  -> RIO env Bool
processSourceFile cVars dVars progress ht@HeaderTemplate {..} path = do
  Configuration {..}     <- viewL @CtConfiguration
  CommandRunOptions {..} <- viewL
  fileContent            <- readFileUtf8 path
  let fs                         = fileSupport htFileType
      source                     = analyzeSourceCode fs fileContent
      headerInfo@HeaderInfo {..} = extractHeaderInfo ht source
      variables                  = dVars <> cVars <> hiVariables
      syntax                     = hcHeaderSyntax hiHeaderConfig
  header'        <- renderTemplate variables htTemplate
  header         <- postProcessHeader' @a syntax variables header'
  RunAction {..} <- chooseAction headerInfo header
  let result  = raFunc source
      changed = raProcessed && (source /= result)
      message = if changed then raProcessedMsg else raSkippedMsg
      logFn   = if changed then logInfo else logSticky
      isCheck = cRunMode == Check
  logDebug $ "Header info: " <> displayShow headerInfo
  logFn $ mconcat [display progress, " ", display message, fromString path]
  when (not croDryRun && not isCheck && changed)
       (writeFileUtf8 path $ toText result)
  pure changed


chooseAction :: (Has CtConfiguration env)
             => HeaderInfo
             -> Text
             -> RIO env RunAction
chooseAction info header = do
  Configuration {..} <- viewL @CtConfiguration
  let hasHeader = isJust $ hiHeaderPos info
  pure $ go cRunMode hasHeader
 where
  go runMode hasHeader = case runMode of
    Add     -> aAction hasHeader
    Check   -> cAction hasHeader
    Drop    -> dAction hasHeader
    Replace -> rAction hasHeader
  aAction hasHeader = RunAction (not hasHeader)
                                (addHeader info header)
                                (justify "Adding header to:")
                                (justify "Header already exists in:")
  cAction hasHeader = (rAction hasHeader)
    { raProcessedMsg = justify "Outdated header found in:"
    , raSkippedMsg   = justify "Header up-to-date in:"
    }
  dAction hasHeader = RunAction hasHeader
                                (dropHeader info)
                                (justify "Dropping header from:")
                                (justify "No header exists in:")
  rAction hasHeader = if hasHeader then rAction' else go Add hasHeader
  rAction' = RunAction True
                       (replaceHeader info header)
                       (justify "Replacing header in:")
                       (justify "Header up-to-date in:")
  justify = T.justifyLeft 30 ' '


-- | Loads templates using given template references. If multiple sources define
-- template for the same 'FileType', then the preferred one (based on ordering
-- of 'TemplateRef' is selected).
loadTemplateRefs :: forall a env
                  . ( Template a
                    , Has (Network (RIO env)) env
                    , Has (FileSystem (RIO env)) env
                    , HasLogFunc env
                    )
                 => [TemplateRef]            -- ^ template references
                 -> RIO env (Map FileType a) -- ^ map of templates
loadTemplateRefs refs = do
  fileSystem <- viewL
  network    <- viewL
  allRefs    <- concat <$> mapM (getAllRefs fileSystem) refs
  refsWTp    <- (\rs -> [ (ft, ref) | (Just ft, ref) <- rs ]) <$> zipRs allRefs
  refsWCtn   <- mapM (loadContent fileSystem network) (filterPreferred refsWTp)
  M.fromList <$> mapM loadTemplate refsWCtn
 where
  zipRs      = \rs -> fmap (`zip` rs) . mapM getFileType $ rs
  exts       = toList $ templateExtensions @a
  getAllRefs = \fs ref -> case ref of
    LocalTemplateRef p -> fmap LocalTemplateRef <$> fsFindFilesByExts fs p exts
    _                  -> pure [ref]
  loadContent = \fs n (ft, ref) -> (ft, ref, ) <$> case ref of
    InlineRef        content -> pure content
    LocalTemplateRef path    -> fsLoadFile fs path
    UriTemplateRef   uri     -> nDownloadContent n uri
    BuiltInRef lt ft'        -> pure $ licenseTemplate lt ft'
  loadTemplate = \(ft, ref, T.strip -> c) -> (ft, ) <$> parseTemplate @a ref c
  getFileType  = \case
    InlineRef _     -> pure Nothing
    BuiltInRef _ ft -> pure . Just $ ft
    other           -> typeOfTemplate . T.unpack . renderRef $ other
  filterPreferred rs =
    mapMaybe (L.headMaybe . L.sort) . L.groupBy (\x y -> fst x == fst y) $ rs


loadTemplates :: ( Has CtConfiguration env
                 , Has (FileSystem (RIO env)) env
                 , Has (Network (RIO env)) env
                 , HasLogFunc env
                 )
              => RIO env (Map FileType HeaderTemplate)
loadTemplates = do
  Configuration {..} <- viewL @CtConfiguration
  let allRefs = builtInRefs cBuiltInTemplates <> cTemplateRefs
  templates <- loadTemplateRefs @TemplateType allRefs
  logInfo . display . stats . M.toList $ templates
  pure $ M.mapWithKey (extractHeaderTemplate cLicenseHeaders) templates
 where
  stats = Table2 . fmap
    (\(ft, t) -> ([i|Using #{ft} template:|], renderRef . templateRef $ t))
  builtInRefs = \case
    Just lt -> fmap (BuiltInRef lt) $ allValues @FileType
    _       -> []


-- | Takes path to the template file and returns detected type of the template.
typeOfTemplate :: HasLogFunc env
               => FilePath                 -- ^ path to the template file
               -> RIO env (Maybe FileType) -- ^ detected template type
typeOfTemplate path = do
  let fileType = textToEnum . T.pack . takeBaseName $ path
  when (isNothing fileType)
       (logWarn $ "Skipping unrecognized template type: " <> fromString path)
  pure fileType


loadConfigurationSafe :: (HasLogFunc env)
                      => FilePath
                      -> RIO env (Maybe PtConfiguration)
loadConfigurationSafe path = catch (Just <$> loadConfiguration path) onError
 where
  onError err = do
    logDebug $ displayShow (err :: IOException)
    logInfo $ mconcat
      [ "Configuration file '"
      , fromString path
      , "' not found. You can either specify all required parameter by "
      , "command line arguments, or generate one using "
      , "'headroom gen -c >"
      , configFileName
      , "'. See official documentation "
      , "for more details."
      ]
    pure Nothing


finalConfiguration :: (HasLogFunc env, Has CommandRunOptions env)
                   => RIO env CtConfiguration
finalConfiguration = do
  logInfo $ display productInfo
  defaultConfig' <- Just <$> parseConfiguration defaultConfig
  cmdLineConfig  <- Just <$> optionsToConfiguration
  yamlConfig     <- loadConfigurationSafe configFileName
  let mergedConfig =
        mconcat . catMaybes $ [defaultConfig', yamlConfig, cmdLineConfig]
  config <- makeConfiguration mergedConfig
  logDebug $ "Default config: " <> displayShow defaultConfig'
  logDebug $ "YAML config: " <> displayShow yamlConfig
  logDebug $ "CmdLine config: " <> displayShow cmdLineConfig
  logDebug $ "Merged config: " <> displayShow mergedConfig
  logDebug $ "Final config: " <> displayShow config
  pure config


optionsToConfiguration :: (Has CommandRunOptions env) => RIO env PtConfiguration
optionsToConfiguration = do
  CommandRunOptions {..} <- viewL
  variables              <- parseVariables croVariables
  pure Configuration
    { cRunMode             = maybe mempty pure croRunMode
    , cSourcePaths         = ifNot null croSourcePaths
    , cExcludedPaths       = ifNot null croExcludedPaths
    , cExcludeIgnoredPaths = ifNot (== False) croExcludeIgnoredPaths
    , cBuiltInTemplates    = pure croBuiltInTemplates
    , cTemplateRefs        = croTemplateRefs
    , cVariables           = variables
    , cLicenseHeaders      = mempty
    , cPostProcessConfigs  = mempty
    }
  where ifNot cond value = if cond value then mempty else pure value


currentYear :: (MonadIO m) => m CurrentYear
currentYear = do
  now      <- liftIO getCurrentTime
  timezone <- liftIO getCurrentTimeZone
  let zoneNow      = utcToLocalTime timezone now
      (year, _, _) = toGregorian $ localDay zoneNow
  pure $ CurrentYear year


-- | Performs post-processing on rendered /license header/, based on given
-- configuration. Currently the main points are to:
--
--  1. sanitize possibly corrupted comment syntax ('sanitizeSyntax')
--  2. apply /post-processors/ ('postProcessHeader')
postProcessHeader' :: forall a env
                    . ( Template a
                      , Has CtPostProcessConfigs env
                      , Has CurrentYear env
                      )
                   => HeaderSyntax -- ^ syntax of the license header comments
                   -> Variables    -- ^ template variables
                   -> Text         -- ^ /license header/ to post-process
                   -> RIO env Text -- ^ post-processed /license header/
postProcessHeader' syntax vars rawHeader = do
  configs <- viewL @CtPostProcessConfigs
  year    <- viewL
  cEnv    <- mkConfiguredEnv @a year vars configs
  pure . sanitizeSyntax syntax . postProcessHeader cEnv $ rawHeader