{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE MultiWayIf #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ViewPatterns #-}

-- | cabal-install CLI command: build
--
module Distribution.Client.CmdInstall (
    -- * The @build@ CLI and action
    installCommand,
    installAction,

    -- * Internals exposed for testing
    TargetProblem(..),
    selectPackageTargets,
    selectComponentTarget
  ) where

import Prelude ()
import Distribution.Client.Compat.Prelude

import Distribution.Client.ProjectOrchestration
import Distribution.Client.CmdErrorMessages
import Distribution.Client.CmdSdist

import Distribution.Client.Setup
         ( GlobalFlags(..), ConfigFlags(..), ConfigExFlags, InstallFlags )
import Distribution.Client.Types
         ( PackageSpecifier(..), PackageLocation(..), UnresolvedSourcePackage )
import qualified Distribution.Client.InstallPlan as InstallPlan
import Distribution.Package
         ( Package(..), mkPackageName )
import Distribution.Types.PackageId
         ( PackageIdentifier(..) )
import Distribution.Client.ProjectConfig.Types
         ( ProjectConfig(..), ProjectConfigShared(..), ProjectConfigBuildOnly(..)
         , PackageConfig(..), getMapLast, getMapMappend
         , projectConfigLogsDir, projectConfigStoreDir, projectConfigShared
         , projectConfigBuildOnly, projectConfigDistDir
         , projectConfigProjectFile, projectConfigConfigFile )
import Distribution.Simple.Program.Db
         ( userSpecifyPaths, userSpecifyArgss, defaultProgramDb
         , modifyProgramSearchPath )
import Distribution.Simple.Program.Find
         ( ProgramSearchPathEntry(..) )       
import Distribution.Client.Config
         ( getCabalDir )
import Distribution.Simple.PackageIndex
         ( lookupUnitId )
import Distribution.Types.InstalledPackageInfo
         ( InstalledPackageInfo(sourcePackageId) )
import Distribution.Client.IndexUtils
         ( getSourcePackages, getInstalledPackages )
import Distribution.Client.ProjectConfig
         ( readGlobalConfig, projectConfigWithBuilderRepoContext
         , resolveBuildTimeSettings
         , BadPackageLocations(..), BadPackageLocation(..)
         , ProjectConfigProvenance(..) )
import Distribution.Client.DistDirLayout
         ( defaultDistDirLayout, DistDirLayout(..), mkCabalDirLayout
         , ProjectRoot(ProjectRootImplicit)
         , storePackageDirectory, cabalStoreDirLayout
         , CabalDirLayout(..), StoreDirLayout(..) )
import Distribution.Client.RebuildMonad
         ( runRebuild )
import Distribution.Client.InstallSymlink
         ( symlinkBinary )
import Distribution.Simple.Setup
         ( Flag(Flag), HaddockFlags, fromFlagOrDefault, flagToMaybe )
import Distribution.Solver.Types.SourcePackage
         ( SourcePackage(..) )
import Distribution.Simple.Command
         ( CommandUI(..), usageAlternatives )
import Distribution.Simple.Configure
         ( configCompilerEx )
import Distribution.Simple.Compiler
         ( Compiler(..), CompilerId(..), CompilerFlavor(..) )
import Distribution.Simple.GHC
         ( ghcPlatformAndVersionString 
         , GhcImplInfo(..), getImplInfo
         , GhcEnvironmentFileEntry(..), renderGhcEnvironmentFile, readEnvironmentFile )
import Distribution.Types.UnitId
         ( UnitId )
import Distribution.Types.UnqualComponentName
         ( UnqualComponentName, unUnqualComponentName )
import Distribution.Verbosity
         ( Verbosity, normal, lessVerbose )
import Distribution.Simple.Utils
         ( wrapText, die', notice
         , withTempDirectory, createDirectoryIfMissingVerbose )
import Distribution.Utils.Generic
         ( writeFileAtomic )

import Control.Exception
         ( catch, throwIO )
import qualified Data.ByteString.Lazy.Char8 as BS
import Data.Either
         ( partitionEithers )
import qualified Data.Map as Map
import Distribution.Utils.NubList
         ( fromNubList )
import qualified Data.Set as Set
import System.Directory 
         ( getHomeDirectory, doesFileExist, createDirectoryIfMissing
         , getTemporaryDirectory, makeAbsolute )
import System.FilePath ( (</>), takeDirectory )

import qualified Distribution.Client.CmdBuild as CmdBuild

installCommand :: CommandUI (ConfigFlags, ConfigExFlags
                            ,InstallFlags, HaddockFlags)
installCommand = CommandUI
  { commandName         = "new-install"
  , commandSynopsis     = "Install packages."
  , commandUsage        = usageAlternatives
                          "new-install" [ "[TARGETS] [FLAGS]" ]
  , commandDescription  = Just $ \_ -> wrapText $
    "Installs one or more packages. This is done by installing them "
    ++ "in the store and symlinking the executables in the directory "
    ++ "specified by the --symlink-bindir flag (`~/.cabal/bin/` by default). "
    ++ "If you want the installed executables to be available globally, "
    ++ "make sure that the PATH environment variable contains that directory. "
    ++ "\n\n"
    ++ "If TARGET is a library, it will be added to the global environment. "
    ++ "When doing this, cabal will try to build a plan that includes all "
    ++ "the previously installed libraries. This is currently not implemented."
  , commandNotes        = Just $ \pname ->
      "Examples:\n"
      ++ "  " ++ pname ++ " new-install\n"
      ++ "    Install the package in the current directory\n"
      ++ "  " ++ pname ++ " new-install pkgname\n"
      ++ "    Install the package named pkgname"
      ++ " (fetching it from hackage if necessary)\n"
      ++ "  " ++ pname ++ " new-install ./pkgfoo\n"
      ++ "    Install the package in the ./pkgfoo directory\n"

      ++ cmdCommonHelpTextNewBuildBeta
  , commandOptions = commandOptions CmdBuild.buildCommand
  , commandDefaultFlags = commandDefaultFlags CmdBuild.buildCommand
  }


-- | The @install@ command actually serves four different needs. It installs:
-- * Nonlocal exes:
--   For example a program from hackage. The behavior is similar to the old
--   install command, except that now conflicts between separate runs of the
--   command are impossible thanks to the store.
--   Exes are installed in the store like a normal dependency, then they are
--   symlinked uin the directory specified by --symlink-bindir.
--   To do this we need a dummy projectBaseContext containing the targets as
--   estra packages and using a temporary dist directory.
-- * Nonlocal libraries (TODO see #4558)
-- * Local exes         (TODO see #4558)
-- * Local libraries    (TODO see #4558)
--
-- For more details on how this works, see the module
-- "Distribution.Client.ProjectOrchestration"
--
installAction :: (ConfigFlags, ConfigExFlags, InstallFlags, HaddockFlags)
            -> [String] -> GlobalFlags -> IO ()
installAction (configFlags, configExFlags, installFlags, haddockFlags)
            targetStrings globalFlags = do
  -- We never try to build tests/benchmarks for remote packages.
  -- So we set them as disabled by default and error if they are explicitly
  -- enabled.
  when (configTests configFlags' == Flag True) $
    die' verbosity $ "--enable-tests was specified, but tests can't "
                  ++ "be enabled in a remote package"
  when (configBenchmarks configFlags' == Flag True) $
    die' verbosity $ "--enable-benchmarks was specified, but benchmarks can't "
                  ++ "be enabled in a remote package"

  let
    withProject = do
      let verbosity' = lessVerbose verbosity

      -- First, we need to learn about what's available to be installed.
      localBaseCtx <- establishProjectBaseContext verbosity' cliConfig
      let localDistDirLayout = distDirLayout localBaseCtx
      pkgDb <- projectConfigWithBuilderRepoContext verbosity' (buildSettings localBaseCtx) (getSourcePackages verbosity)
      targetSelectors <- either (reportTargetSelectorProblems verbosity) return
                     =<< readTargetSelectors (localPackages localBaseCtx) targetStrings

      let
        sdistFlags = defaultSdistFlags
          { sdistVerbosity = Flag verbosity'
          , sdistDistDir = projectConfigDistDir (projectConfigShared cliConfig)
          , sdistProjectFile = projectConfigProjectFile (projectConfigShared cliConfig)
          }
    
      sdistAction sdistFlags ["all"] globalFlags

      (specs, selectors) <- withInstallPlan verbosity' localBaseCtx $ \elaboratedPlan -> do
        -- Split into known targets and hackage packages.
        (targets, hackageNames) <- case
          resolveTargets
            selectPackageTargets
            selectComponentTarget
            TargetProblemCommon
            elaboratedPlan
            (Just pkgDb)
            targetSelectors of
          Right targets -> do
            -- Everything is a local dependency.
            return (targets, [])
          Left errs -> do
            -- Not everything is local.
            let 
              (errs', hackageNames) = partitionEithers . flip fmap errs $ \case
                TargetProblemCommon (TargetAvailableInIndex name) -> Right name
                err -> Left err
            
            when (not . null $ errs') $ reportTargetProblems verbosity errs'
    
            let 
              targetSelectors' = flip filter targetSelectors $ \case
                TargetComponentUnknown name _ _
                  | name `elem` hackageNames -> False
                TargetPackageNamed name _
                  | name `elem` hackageNames -> False
                _ -> True
            
            -- This can't fail, because all of the errors are removed (or we've given up).
            targets <- either (reportTargetProblems verbosity) return $ resolveTargets
                selectPackageTargets
                selectComponentTarget
                TargetProblemCommon
                elaboratedPlan
                Nothing
                targetSelectors'
        
            return (targets, hackageNames)
        
        let
          planMap = InstallPlan.toMap elaboratedPlan
          targetIds = Map.keys targets
    
          sdistize (SpecificSourcePackage spkg@SourcePackage{..}) = SpecificSourcePackage spkg'
            where
              sdistPath = distSdistFile localDistDirLayout packageInfoId TargzFormat
              spkg' = spkg { packageSource = LocalTarballPackage sdistPath }
          sdistize named = named
    
          local = sdistize <$> localPackages localBaseCtx
        
          gatherTargets :: UnitId -> TargetSelector
          gatherTargets targetId = TargetPackageNamed pkgName Nothing
            where          
              Just targetUnit = Map.lookup targetId planMap
              PackageIdentifier{..} = packageId targetUnit
    
          targets' = fmap gatherTargets targetIds 
          
          hackagePkgs :: [PackageSpecifier UnresolvedSourcePackage]
          hackagePkgs = flip NamedPackage [] <$> hackageNames
          hackageTargets :: [TargetSelector]
          hackageTargets = flip TargetPackageNamed Nothing <$> hackageNames
    
        if null targets
          then return (hackagePkgs, hackageTargets)
          else return (local ++ hackagePkgs, targets' ++ hackageTargets)

      return (specs, selectors, projectConfig localBaseCtx)

    withoutProject = do
      let 
        packageNames = mkPackageName <$> targetStrings
        packageSpecifiers = flip NamedPackage [] <$> packageNames
        targetSelectors = flip TargetPackageNamed Nothing <$> packageNames
        globalConfigFlag = projectConfigConfigFile (projectConfigShared cliConfig)
      globalConfig <- runRebuild "" $ readGlobalConfig verbosity globalConfigFlag

      return (packageSpecifiers, targetSelectors, globalConfig <> cliConfig)

  (specs, selectors, config) <- catch withProject
    $ \case
      (BadPackageLocations prov locs) 
        | prov == Set.singleton Implicit
        , let 
          isGlobErr (BadLocGlobEmptyMatch _) = True
          isGlobErr _ = False
        , any isGlobErr locs ->
          withoutProject
      err -> throwIO err

  home <- getHomeDirectory
  let
    ProjectConfig {
      projectConfigShared = ProjectConfigShared {
        projectConfigHcFlavor,
        projectConfigHcPath,
        projectConfigHcPkg
      },
      projectConfigLocalPackages = PackageConfig {
        packageConfigProgramPaths,
        packageConfigProgramArgs,
        packageConfigProgramPathExtra
      }
    } = config

    hcFlavor = flagToMaybe projectConfigHcFlavor
    hcPath   = flagToMaybe projectConfigHcPath
    hcPkg    = flagToMaybe projectConfigHcPkg

    progDb =
        userSpecifyPaths (Map.toList (getMapLast packageConfigProgramPaths))
      . userSpecifyArgss (Map.toList (getMapMappend packageConfigProgramArgs))
      . modifyProgramSearchPath
          (++ [ ProgramSearchPathDir dir
              | dir <- fromNubList packageConfigProgramPathExtra ])
      $ defaultProgramDb
  
  (compiler@Compiler { compilerId = 
    compilerId@(CompilerId compilerFlavor compilerVersion) }, platform, _) <-
      configCompilerEx hcFlavor hcPath hcPkg progDb verbosity

  let 
    envFile = home </> ".ghc" </> ghcPlatformAndVersionString platform compilerVersion
                   </> "environments" </> "default"
    GhcImplInfo{ supportsPkgEnvFiles } = getImplInfo compiler
  envFileExists <- doesFileExist envFile
  
  envEntries <- if 
    | compilerFlavor == GHC || compilerFlavor == GHCJS
    , supportsPkgEnvFiles
    , envFileExists -> readEnvironmentFile envFile
    | otherwise     -> return []

  cabalDir <- getCabalDir
  let
    mstoreDir   = flagToMaybe (globalStoreDir globalFlags)
    mlogsDir    = flagToMaybe (globalLogsDir globalFlags)
    cabalLayout = mkCabalDirLayout cabalDir mstoreDir mlogsDir
    packageDbs  = storePackageDBStack (cabalStoreDirLayout cabalLayout) compilerId

  installedIndex <- getInstalledPackages verbosity compiler packageDbs defaultProgramDb

  let envSpecs = environmentFileToSpecifiers installedIndex envEntries

  -- Second, we need to use a fake project to let Cabal build the
  -- installables correctly. For that, we need a place to put a
  -- temporary dist directory.
  globalTmp <- getTemporaryDirectory
  withTempDirectory
    verbosity
    globalTmp
    "cabal-install."
    $ \tmpDir -> do
    baseCtx <- establishDummyProjectBaseContext
                 verbosity
                 config
                 tmpDir
                 (envSpecs ++ specs)
    
    buildCtx <-
      runProjectPreBuildPhase verbosity baseCtx $ \elaboratedPlan -> do

            -- Interpret the targets on the command line as build targets
            targets <- either (reportTargetProblems verbosity) return
                     $ resolveTargets
                         selectPackageTargets
                         selectComponentTarget
                         TargetProblemCommon
                         elaboratedPlan
                         Nothing
                         selectors

            let elaboratedPlan' = pruneInstallPlanToTargets
                                    TargetActionBuild
                                    targets
                                    elaboratedPlan
            elaboratedPlan'' <-
              if buildSettingOnlyDeps (buildSettings baseCtx)
                then either (reportCannotPruneDependencies verbosity) return $
                     pruneInstallPlanToDependencies (Map.keysSet targets)
                                                    elaboratedPlan'
                else return elaboratedPlan'

            return (elaboratedPlan'', targets)

    printPlan verbosity baseCtx buildCtx

    buildOutcomes <- runProjectBuildPhase verbosity baseCtx buildCtx

    let mkPkgBinDir = (</> "bin") .
                      storePackageDirectory
                         (cabalStoreDirLayout $ cabalDirLayout baseCtx)
                         compilerId

    -- If there are exes, symlink them
    let symlinkBindirUnknown =
          "symlink-bindir is not defined. Set it in your cabal config file "
          ++ "or use --symlink-bindir=<path>"
    symlinkBindir <- fromFlagOrDefault (die' verbosity symlinkBindirUnknown)
                   $ fmap makeAbsolute
                   $ projectConfigSymlinkBinDir
                   $ projectConfigBuildOnly
                   $ projectConfig $ baseCtx
    createDirectoryIfMissingVerbose verbosity False symlinkBindir
    traverse_ (symlinkBuiltPackage verbosity mkPkgBinDir symlinkBindir)
          $ Map.toList $ targetsMap buildCtx
    runProjectPostBuildPhase verbosity baseCtx buildCtx buildOutcomes

    let
      baseEntries =
          GhcEnvFileClearPackageDbStack
        : fmap GhcEnvFilePackageDb packageDbs
      entries = baseEntries ++ entriesForLibraryComponents (targetsMap buildCtx)
    createDirectoryIfMissing True (takeDirectory envFile)
    when supportsPkgEnvFiles $ do
      let 
        entries' = nub (envEntries ++ entries)
        contents' = renderGhcEnvironmentFile entries'
      writeFileAtomic envFile (BS.pack contents')
  where
    configFlags' = disableTestsBenchsByDefault configFlags
    verbosity = fromFlagOrDefault normal (configVerbosity configFlags')
    cliConfig = commandLineFlagsToProjectConfig
                  globalFlags configFlags' configExFlags
                  installFlags haddockFlags

environmentFileToSpecifiers :: InstalledPackageIndex -> [GhcEnvironmentFileEntry] 
                            -> [PackageSpecifier a]
environmentFileToSpecifiers ipi = foldMap $ \case
    (GhcEnvFilePackageId unitId) 
        | Just InstalledPackageInfo{ sourcePackageId = PackageIdentifier{..} }
          <- lookupUnitId ipi unitId ->
            [ NamedPackage pkgName [PackagePropertyVersion (thisVersion pkgVersion)] ]
    _ -> []
                  

-- | Disables tests and benchmarks if they weren't explicitly enabled.
disableTestsBenchsByDefault :: ConfigFlags -> ConfigFlags
disableTestsBenchsByDefault configFlags =
  configFlags { configTests = Flag False <> configTests configFlags
              , configBenchmarks = Flag False <> configBenchmarks configFlags }

-- | Symlink every exe from a package from the store to a given location
symlinkBuiltPackage :: Verbosity
                    -> (UnitId -> FilePath) -- ^ A function to get an UnitId's
                                            -- store directory
                    -> FilePath -- ^ Where to put the symlink
                    -> ( UnitId
                        , [(ComponentTarget, [TargetSelector])] )
                     -> IO ()
symlinkBuiltPackage verbosity mkSourceBinDir destDir (pkg, components) =
  traverse_ (symlinkBuiltExe verbosity (mkSourceBinDir pkg) destDir) exes
  where
    exes = catMaybes $ (exeMaybe . fst) <$> components
    exeMaybe (ComponentTarget (CExeName exe) _) = Just exe
    exeMaybe _ = Nothing

-- | Symlink a specific exe.
symlinkBuiltExe :: Verbosity -> FilePath -> FilePath -> UnqualComponentName -> IO Bool
symlinkBuiltExe verbosity sourceDir destDir exe = do
  notice verbosity $ "Symlinking " ++ unUnqualComponentName exe
  symlinkBinary
    destDir
    sourceDir
    exe
    $ unUnqualComponentName exe

-- | Create 'GhcEnvironmentFileEntry's for packages with exposed libraries.
entriesForLibraryComponents :: TargetsMap -> [GhcEnvironmentFileEntry]
entriesForLibraryComponents = Map.foldrWithKey' (\k v -> mappend (go k v)) []
  where
    hasLib :: (ComponentTarget, [TargetSelector]) -> Bool
    hasLib (ComponentTarget CLibName _,        _) = True
    hasLib (ComponentTarget (CSubLibName _) _, _) = True
    hasLib _                                      = False
    
    go :: UnitId -> [(ComponentTarget, [TargetSelector])] -> [GhcEnvironmentFileEntry]
    go unitId targets
      | any hasLib targets = [GhcEnvFilePackageId unitId]
      | otherwise          = []

-- | Create a dummy project context, without a .cabal or a .cabal.project file
-- (a place where to put a temporary dist directory is still needed)
establishDummyProjectBaseContext
  :: Verbosity
  -> ProjectConfig
  -> FilePath
     -- ^ Where to put the dist directory
  -> [PackageSpecifier UnresolvedSourcePackage]
     -- ^ The packages to be included in the project
  -> IO ProjectBaseContext
establishDummyProjectBaseContext verbosity cliConfig tmpDir localPackages = do

    cabalDir <- getCabalDir

    -- Create the dist directories
    createDirectoryIfMissingVerbose verbosity True $ distDirectory distDirLayout
    createDirectoryIfMissingVerbose verbosity True $
      distProjectCacheDirectory distDirLayout

    globalConfig <- runRebuild ""
                  $ readGlobalConfig verbosity
                  $ projectConfigConfigFile
                  $ projectConfigShared cliConfig
    let projectConfig = globalConfig <> cliConfig

    let ProjectConfigBuildOnly {
          projectConfigLogsDir,
          projectConfigStoreDir
        } = projectConfigBuildOnly projectConfig

        mlogsDir = flagToMaybe projectConfigLogsDir
        mstoreDir = flagToMaybe projectConfigStoreDir
        cabalDirLayout = mkCabalDirLayout cabalDir mstoreDir mlogsDir

        buildSettings = resolveBuildTimeSettings
                          verbosity cabalDirLayout
                          projectConfig

    return ProjectBaseContext {
      distDirLayout,
      cabalDirLayout,
      projectConfig,
      localPackages,
      buildSettings
    }
  where
    mdistDirectory = flagToMaybe
                   $ projectConfigDistDir
                   $ projectConfigShared cliConfig
    projectRoot = ProjectRootImplicit tmpDir
    distDirLayout = defaultDistDirLayout projectRoot
                                         mdistDirectory

-- | This defines what a 'TargetSelector' means for the @bench@ command.
-- It selects the 'AvailableTarget's that the 'TargetSelector' refers to,
-- or otherwise classifies the problem.
--
-- For the @build@ command select all components except non-buildable
-- and disabled tests\/benchmarks, fail if there are no such
-- components
--
selectPackageTargets :: TargetSelector
                     -> [AvailableTarget k] -> Either TargetProblem [k]
selectPackageTargets targetSelector targets

    -- If there are any buildable targets then we select those
  | not (null targetsBuildable)
  = Right targetsBuildable

    -- If there are targets but none are buildable then we report those
  | not (null targets)
  = Left (TargetProblemNoneEnabled targetSelector targets')

    -- If there are no targets at all then we report that
  | otherwise
  = Left (TargetProblemNoTargets targetSelector)
  where
    targets'         = forgetTargetsDetail targets
    targetsBuildable = selectBuildableTargetsWith
                         (buildable targetSelector)
                         targets

    -- When there's a target filter like "pkg:tests" then we do select tests,
    -- but if it's just a target like "pkg" then we don't build tests unless
    -- they are requested by default (i.e. by using --enable-tests)
    buildable (TargetPackage _ _  Nothing) TargetNotRequestedByDefault = False
    buildable (TargetAllPackages  Nothing) TargetNotRequestedByDefault = False
    buildable _ _ = True

-- | For a 'TargetComponent' 'TargetSelector', check if the component can be
-- selected.
--
-- For the @build@ command we just need the basic checks on being buildable etc.
--
selectComponentTarget :: SubComponentTarget
                      -> AvailableTarget k -> Either TargetProblem k
selectComponentTarget subtarget =
    either (Left . TargetProblemCommon) Right
  . selectComponentTargetBasic subtarget


-- | The various error conditions that can occur when matching a
-- 'TargetSelector' against 'AvailableTarget's for the @build@ command.
--
data TargetProblem =
     TargetProblemCommon       TargetProblemCommon

     -- | The 'TargetSelector' matches targets but none are buildable
   | TargetProblemNoneEnabled TargetSelector [AvailableTarget ()]

     -- | There are no targets at all
   | TargetProblemNoTargets   TargetSelector
  deriving (Eq, Show)

reportTargetProblems :: Verbosity -> [TargetProblem] -> IO a
reportTargetProblems verbosity =
    die' verbosity . unlines . map renderTargetProblem

renderTargetProblem :: TargetProblem -> String
renderTargetProblem (TargetProblemCommon problem) =
    renderTargetProblemCommon "build" problem
renderTargetProblem (TargetProblemNoneEnabled targetSelector targets) =
    renderTargetProblemNoneEnabled "build" targetSelector targets
renderTargetProblem(TargetProblemNoTargets targetSelector) =
    renderTargetProblemNoTargets "build" targetSelector

reportCannotPruneDependencies :: Verbosity -> CannotPruneDependencies -> IO a
reportCannotPruneDependencies verbosity =
    die' verbosity . renderCannotPruneDependencies