{-# LANGUAGE DataKinds #-}

{-|
Module      : System.XDG
Description : XDG Basedir functions

These functions implement the [XDG Base Directory Specification](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html).


When an environment variable is missing that must be defined, they will
raise a `MissingEnv` exception. This applies to @$HOME@ and @$XDG_RUNTIME_DIR@.
-}
module System.XDG where

import           Data.ByteString.Lazy           ( ByteString )
import           Data.Either                    ( fromRight )
import           Polysemy
import           Polysemy.Error                 ( runError )
import           Polysemy.Operators
import           System.XDG.Env
import           System.XDG.Error
import           System.XDG.FileSystem
import qualified System.XDG.Internal           as In


{-| Returns the content of @$XDG_DATA_HOME@ or its default value. -}
getDataHome :: IO FilePath
getDataHome :: IO FilePath
getDataHome = forall a. XDGReader ByteString a -> IO a
In.runXDGIO Env -@> FilePath
In.getDataHome

{-| Returns the content of @$XDG_CONFIG_HOME@ or its default value. -}
getConfigHome :: IO FilePath
getConfigHome :: IO FilePath
getConfigHome = forall a. XDGReader ByteString a -> IO a
In.runXDGIO Env -@> FilePath
In.getConfigHome

{-| Returns the content of @$XDG_STATE_HOME@ or its default value. -}
getStateHome :: IO FilePath
getStateHome :: IO FilePath
getStateHome = forall a. XDGReader ByteString a -> IO a
In.runXDGIO Env -@> FilePath
In.getStateHome

{-| Returns the content of @$XDG_CACHE_HOME@ or its default value. -}
getCacheHome :: IO FilePath
getCacheHome :: IO FilePath
getCacheHome = forall a. XDGReader ByteString a -> IO a
In.runXDGIO Env -@> FilePath
In.getCacheHome

{-| Returns the content of @$XDG_RUNTIME_DIR@. -}
getRuntimeDir :: IO FilePath
getRuntimeDir :: IO FilePath
getRuntimeDir = forall a. XDGReader ByteString a -> IO a
In.runXDGIO '[Env, Error XDGError] >@> FilePath
In.getRuntimeDir

{-| Returns the list of data dirs taken from @$XDG_DATA_HOME@ and
@$XDG_DATA_DIRS@ or their default values. -}
getDataDirs :: IO [FilePath]
getDataDirs :: IO [FilePath]
getDataDirs = forall a. XDGReader ByteString a -> IO a
In.runXDGIO Env -@> [FilePath]
In.getDataDirs

{-| Returns the content of the first readable file in the data dirs if there is one.
It will try the files in order of decreasing imporance.


To read @$XDG_DATA_DIRS\/subdir\/filename@:

@
> readDataFile "subdir/filename"
@
-}
readDataFile :: FilePath -> IO (Maybe ByteString)
readDataFile :: FilePath -> IO (Maybe ByteString)
readDataFile FilePath
file = forall a. XDGReader ByteString a -> IO a
In.runXDGIO forall a b. (a -> b) -> a -> b
$ forall a. XDGReader a a -> XDGReader a (Maybe a)
In.maybeRead forall a b. (a -> b) -> a -> b
$ forall a. FilePath -> '[Env, Error XDGError, ReadFile a] >@> a
In.readDataFile FilePath
file

{-| Parse all readable data files into a monoid and append them.
The append operation will operate left to right in the order of decreasing importance. -}
readData :: Monoid b => (ByteString -> b) -> FilePath -> IO b
readData :: forall b. Monoid b => (ByteString -> b) -> FilePath -> IO b
readData ByteString -> b
parse FilePath
file = forall a. XDGReader ByteString a -> IO a
In.runXDGIO forall a b. (a -> b) -> a -> b
$ forall b a. Monoid b => (a -> b) -> FilePath -> XDGReader a b
In.readData ByteString -> b
parse FilePath
file

{-| Returns the list of config dirs taken from @$XDG_CONFIG_HOME@ and
@$XDG_CONFIG_DIRS@ or their default values. -}
getConfigDirs :: IO [FilePath]
getConfigDirs :: IO [FilePath]
getConfigDirs = forall a. XDGReader ByteString a -> IO a
In.runXDGIO Env -@> [FilePath]
In.getConfigDirs

{-| Returns the content of the first readable file in the config dirs if there is one.
It will try the files in order of decreasing imporance.


To read @$XDG_CONFIG_DIRS\/subdir\/filename@:

@
> readConfigFile "subdir/filename"
@
-}
readConfigFile :: FilePath -> IO (Maybe ByteString)
readConfigFile :: FilePath -> IO (Maybe ByteString)
readConfigFile FilePath
file = forall a. XDGReader ByteString a -> IO a
In.runXDGIO forall a b. (a -> b) -> a -> b
$ forall a. XDGReader a a -> XDGReader a (Maybe a)
In.maybeRead forall a b. (a -> b) -> a -> b
$ forall a. FilePath -> '[Env, Error XDGError, ReadFile a] >@> a
In.readConfigFile FilePath
file

{-| Parse all readable config files into a monoid and append them.
The append operation will operate left to right in the order of decreasing importance. -}
readConfig :: Monoid b => (ByteString -> b) -> FilePath -> IO b
readConfig :: forall b. Monoid b => (ByteString -> b) -> FilePath -> IO b
readConfig ByteString -> b
parse FilePath
file = forall a. XDGReader ByteString a -> IO a
In.runXDGIO forall a b. (a -> b) -> a -> b
$ forall b a. Monoid b => (a -> b) -> FilePath -> XDGReader a b
In.readConfig ByteString -> b
parse FilePath
file

{-| Returns the content of the cache file if it exists.

@
> readCacheFile "subdir/filename"
@
-}
readCacheFile :: FilePath -> IO (Maybe ByteString)
readCacheFile :: FilePath -> IO (Maybe ByteString)
readCacheFile FilePath
file = forall a. XDGReader ByteString a -> IO a
In.runXDGIO forall a b. (a -> b) -> a -> b
$ forall a. XDGReader a a -> XDGReader a (Maybe a)
In.maybeRead forall a b. (a -> b) -> a -> b
$ forall a. FilePath -> '[Env, Error XDGError, ReadFile a] >@> a
In.readCacheFile FilePath
file

{-| Returns the content of the state file if it exists.

@
> readStateFile "subdir/filename"
@
-}
readStateFile :: FilePath -> IO (Maybe ByteString)
readStateFile :: FilePath -> IO (Maybe ByteString)
readStateFile FilePath
file = forall a. XDGReader ByteString a -> IO a
In.runXDGIO forall a b. (a -> b) -> a -> b
$ forall a. XDGReader a a -> XDGReader a (Maybe a)
In.maybeRead forall a b. (a -> b) -> a -> b
$ forall a. FilePath -> '[Env, Error XDGError, ReadFile a] >@> a
In.readStateFile FilePath
file

{-| Returns the content of the runtime file if it exists.

@
> readRuntimeFile "subdir/filename"
@
-}
readRuntimeFile :: FilePath -> IO (Maybe ByteString)
readRuntimeFile :: FilePath -> IO (Maybe ByteString)
readRuntimeFile FilePath
file = forall a. XDGReader ByteString a -> IO a
In.runXDGIO forall a b. (a -> b) -> a -> b
$ forall a. XDGReader a a -> XDGReader a (Maybe a)
In.maybeRead forall a b. (a -> b) -> a -> b
$ forall a. FilePath -> '[Env, Error XDGError, ReadFile a] >@> a
In.readStateFile FilePath
file