{-# LANGUAGE CPP #-}

module HsLua.Module.System (

-- * Module

documentedModule

-- ** Fields

, arch

, compiler_name

, compiler_version

, os

-- ** Functions

, cmd

, cp

, cputime

, env

, exists

, getenv

, getwd

, ls

, mkdir

, read_file

, rename

, rm

, rmdir

, setenv

, setwd

, times

, tmpdirname

, with_env

, with_tmpdir

, with_wd

, write_file

, xdg

)

import Control.Monad ((>=>), forM_)

import Control.Monad.Catch (bracket)

import Data.Maybe (fromMaybe)

import Data.Text (Text)

import Data.Version (versionBranch)

import HsLua.Core

import HsLua.List (newListMetatable)

import HsLua.Marshalling

import HsLua.Packaging

import HsLua.Module.SystemUtils

import qualified Data.ByteString as B

import qualified Data.Text as T

import qualified Data.Time as Time

import qualified Data.Time.Format.ISO8601 as ISO8601

import qualified HsLua.Core.Utf8 as Utf8

import qualified System.CPUTime as CPUTime

import qualified System.Directory as Directory

import qualified System.Environment as Env

import qualified System.Exit as Exit

import qualified System.Info as Info

import qualified System.IO.Temp as Temp

import qualified System.Process as Process

-- | The "system" module.

documentedModule :: LuaError e => Module e

documentedModule = defmodule "system"

`withFields`

[ arch

, compiler_name

, compiler_version

, cputime_precision

, os

]

`withFunctions`

[ cmd

, cp

, cputime

, env

, exists

, getenv

, getwd

, ls

, mkdir

, read_file

, rename

, rm

, rmdir

, setenv

, setwd

, times

, tmpdirname

, with_env

, with_tmpdir

, with_wd

, write_file

, xdg

]

`withDescription`

"Access to the system's information and file functionality."

-- | Module field containing the machine architecture on which the

arch :: Field e

arch = deffield "arch"

`withType`

stringType

`withDescription`

"The machine architecture on which the program is running."

`withValue`

pushString Info.arch

-- | Module field containing the Haskell implementation with which the

compiler_name :: Field e

compiler_name = deffield "compiler_name"

`withType`

stringType

`withDescription`

"The Haskell implementation with which the host program was compiled."

`withValue`

pushString Info.compilerName

-- | Module field containing the version of `compiler_name` with which

compiler_version :: LuaError e => Field e

compiler_version = deffield "compiler_version"

`withType`

stringType

`withDescription`

"The Haskell implementation with which the host program was compiled."

`withValue`

pushList pushIntegral (versionBranch Info.compilerVersion)

-- | Field containing the smallest measurable difference in CPU time.

cputime_precision :: Field e

cputime_precision = deffield "cputime_precision"

`withType` integerType

`withDescription` T.unlines

[ "The smallest measurable difference in CPU time that the"

, "implementation can record, and is given as an integral number of"

, "picoseconds."

]

`withValue` pushIntegral CPUTime.cpuTimePrecision

-- | Field containing the operating system on which the program is

os :: Field e

os = deffield "os"

`withType` "string"

`withDescription` T.unlines

[ "The operating system on which the program is running."

, "The most common values are `darwin` (macOS), `freebsd`, `linux`,"

, "`linux-android`, `mingw32` (Windows), `netbsd`, `openbsd`."

]

`withValue` pushString Info.os

-- | Run a system command

cmd :: LuaError e => DocumentedFunction e

cmd = defun "cmd"

### (\command args minput opts -> do

let input = fromMaybe "" minput

let cp_opts = (Process.proc command args)

{ Process.env = processOptsEnv =<< opts

, Process.cwd = processOptsCwd =<< opts

}

liftIO $ Process.readCreateProcessWithExitCode cp_opts input)

<#> filepathParam "command" "command to execute"

<#> parameter (peekList peekString) "{string,...}" "args" "command arguments"

<#> opt (parameter peekString "string" "input" "input on stdin")

<#> opt (parameter peekProcessOptions "table" "opts" "process options")

=#> (functionResult (pushExitCode . (\(a,_,_) -> a)) "integer|boolean"

"exit code – `false` on success, an integer otherwise" <>

functionResult (pushString . \(_,b,_) -> b) "string" "stdout" <>

functionResult (pushString . \(_,_,c) -> c) "string" "stderr")

#? T.unlines

[ "Executes a system command with the given arguments and `input`"

, "on *stdin*."

]

-- | Copy a file

cp :: LuaError e => DocumentedFunction e

cp = defun "cp"

### (\src tgt -> ioToLua $ Directory.copyFile src tgt)

<#> filepathParam "source" "source file"

<#> filepathParam "target" "target destination"

=#> []

#? T.unlines

[ "Copy a file with its permissions."

, "If the destination file already exists, it is overwritten."

]

-- | Access the CPU time, e.g. for benchmarking.

cputime :: LuaError e => DocumentedFunction e

cputime = defun "cputime"

### ioToLua CPUTime.getCPUTime

=#> functionResult pushIntegral "integer" "CPU time in picoseconds"

#? T.unlines

[ "Returns the number of picoseconds CPU time used by the current"

, "program. The precision of this result may vary in different"

, "versions and on different platforms."

]

-- | Retrieve the entire environment

env :: LuaError e => DocumentedFunction e

env = defun "env"

### ioToLua Env.getEnvironment

=#> functionResult (pushKeyValuePairs pushString pushString) "table"

"A table mapping environment variable names to their value."

#? "Retrieves the entire environment as a string-indexed table."

-- | Check the existence of a file path.

exists :: LuaError e => DocumentedFunction e

exists = defun "exists"

### (\fp mbType -> do

case T.toLower <$> mbType of

Nothing ->

-- any file type is fine

ioToLua $ Directory.doesPathExist fp

Just "directory" ->

-- must be a directory or a symlink pointing to one

ioToLua $ Directory.doesDirectoryExist fp

Just "file" ->

-- must be a file or a symlink pointing to one

ioToLua $ Directory.doesFileExist fp

Just "symlink" ->

-- must exist and be a symlink

ioToLua $ (&&) <$> Directory.doesPathExist fp

<*> Directory.pathIsSymbolicLink fp

Just otherType ->

failLua $

"Unsupported filesystem object type: " <> T.unpack otherType)

<#> filepathParam "path" "file path to check"

<#> opt (textParam "type" "the required type of the filesystem object")

=#> functionResult pushBool "boolean"

"whether a filesystem object of type `type` exists at `path`."

#? T.unlines

[ "Check whether there exists a filesystem object at the given path."

, "If `type` is given and either *directory* or *file*, then the"

, "function returns `true` if and only if the file system object has"

, "the given type, or if it's a symlink pointing to an object of that"

, "type. Passing *symlink* as type requires the path itself to be a"

, "symlink. Types other than those will cause an error."

]

-- | Return the current working directory as an absolute path.

getwd :: LuaError e => DocumentedFunction e

getwd = defun "getwd"

### ioToLua Directory.getCurrentDirectory

=#> filepathResult "The current working directory."

#? "Obtain the current working directory as an absolute path."

-- | Returns the value of an environment variable

getenv :: LuaError e => DocumentedFunction e

getenv = defun "getenv"

### ioToLua . Env.lookupEnv

<#> parameter peekString "string" "var" "name of the environment"

=#> functionResult (maybe pushnil pushString) "string or nil"

"value of the variable, or nil if the variable is not defined."

#? T.unwords

[ "Return the value of the environment variable `var`, or `nil` "

, "if there is no such value." ]

-- | List the contents of a directory.

ls :: LuaError e => DocumentedFunction e

ls = defun "ls"

### ioToLua . Directory.listDirectory . fromMaybe "."

<#> opt (stringParam "directory"

("Path of the directory whose contents should be listed. "

`T.append` "Defaults to `.`."))

=#> functionResult pushFilePathList "table"

("A table of all entries in `directory`, except for the "

`T.append` "special entries (`.` and `..`).")

#? "List the contents of a directory."

-- | Create a new directory which is initially empty, or as near to

mkdir :: LuaError e => DocumentedFunction e

mkdir = defun "mkdir"

### (\fp createParent ->

if createParent == Just True

then ioToLua (Directory.createDirectoryIfMissing True fp)

else ioToLua (Directory.createDirectory fp))

<#> filepathParam "dirname" "name of the new directory"

<#> opt (boolParam "create_parent" "create parent directory if necessary")

=#> []

#? T.concat

[ "Create a new directory which is initially empty, or as near "

, "to empty as the operating system allows. The function throws "

, "an error if the directory cannot be created, e.g., if the "

, "parent directory does not exist or if a directory of the "

, "same name is already present.\n"

, "\n"

, "If the optional second parameter is provided and truthy, "

, "then all directories, including parent directories, are "

, "created as necessary.\n"

]

-- | Returns the contents of a file.

read_file :: LuaError e => DocumentedFunction e

read_file = defun "read_file"

### (ioToLua . B.readFile)

<#> filepathParam "filepath" "File to read"

=#> functionResult pushByteString "string" "file contents"

-- | Rename a file path.

rename :: LuaError e => DocumentedFunction e

rename = defun "rename"

### (\old new -> ioToLua $ do

isDir <- Directory.doesDirectoryExist old

if isDir

then Directory.renameDirectory old new

else Directory.renameFile old new)

<#> filepathParam "old" "original path"

<#> filepathParam "new" "new path"

=#> []

#? T.unlines

[ "Change the name of an existing path from `old` to `new`."

, ""

, "If `old` is a directory and `new` is a directory that already"

, "exists, then `new` is atomically replaced by the `old` directory."

, "On Win32 platforms, this function fails if `new` is an existing"

, "directory."

, ""

, "If `old` does not refer to a directory, then neither may `new`."

, ""

, "Renaming may not work across file system boundaries or due to"

, "other system-specific reasons. It's generally more robust to"

, "copy the source path to its destination before deleting the"

, "source."

]

-- | Remove a file.

rm :: LuaError e => DocumentedFunction e

rm = defun "rm"

### ioToLua . Directory.removeFile

<#> filepathParam "filename" "file to remove"

=#> []

#? "Removes the directory entry for an existing file."

-- | Remove an existing directory.

rmdir :: LuaError e => DocumentedFunction e

rmdir = defun "rmdir"

### (\fp recursive ->

if recursive == Just True

then ioToLua (Directory.removeDirectoryRecursive fp)

else ioToLua (Directory.removeDirectory fp))

<#> filepathParam "dirname" "name of the directory to delete"

<#> opt (boolParam "recursive" "delete content recursively")

=#> []

#?("Remove an existing, empty directory. If `recursive` is given, "

`T.append` "then delete the directory and its contents recursively.")

-- | Set the specified environment variable to a new value.

setenv :: LuaError e => DocumentedFunction e

setenv = defun "setenv"

### (\name value -> ioToLua (Env.setEnv name value))

<#> parameter peekString "string" "name"

"name of the environment variable"

<#> parameter peekString "string" "value" "new value"

=#> []

#? "Set the specified environment variable to a new value."

-- | Change current working directory.

setwd :: LuaError e => DocumentedFunction e

setwd = defun "setwd"

### ioToLua . Directory.setCurrentDirectory

<#> filepathParam "directory" "Path of the new working directory"

=#> []

#? "Change the working directory to the given path."

-- | Get the modification time and access time of a file.

times :: LuaError e => DocumentedFunction e

times = defun "times"

### (\filepath -> ioToLua $

(,) <$> Directory.getModificationTime filepath

<*> Directory.getAccessTime filepath)

<#> filepathParam "filepath" "file or directory path"

=#> (functionResult (pushUTCTime . fst) "table"

"time at which the file or directory was last modified" <>

functionResult (pushUTCTime . snd) "table"

"time at which the file or directory was last accessed")

#? T.unlines

[ "Obtain the modification and access time of a file or directory."

, "The times are returned as strings using the ISO 8601 format."

]

-- | Get the current directory for temporary files.

tmpdirname :: LuaError e => DocumentedFunction e

tmpdirname = defun "tmpdirname"

### ioToLua Directory.getTemporaryDirectory

=#> functionResult pushString "string"

"The current directory for temporary files."

#? mconcat

[ "Returns the current directory for temporary files.\n"

, "\n"

, "On Unix, `tmpdirname()` returns the value of the `TMPDIR` "

, "environment variable or \"/tmp\" if the variable isn't defined. "

, "On Windows, the function checks for the existence of environment "

, "variables in the following order and uses the first path found:\n"

, "\n"

, "- TMP environment variable.\n"

, "- TEMP environment variable.\n"

, "- USERPROFILE environment variable.\n"

, "- The Windows directory\n"

, "\n"

, "The operation may fail if the operating system has no notion of "

, "temporary directory.\n"

, "\n"

, "The function doesn't verify whether the path exists.\n"

]

-- | Run an action in a different directory, then restore the old

with_wd :: LuaError e => DocumentedFunction e

with_wd = defun "with_wd"

### (\fp callback ->

bracket (ioToLua Directory.getCurrentDirectory)

(ioToLua . Directory.setCurrentDirectory)

(\_ -> do

ioToLua (Directory.setCurrentDirectory fp)

callback `invokeWithFilePath` fp))

<#> filepathParam "directory"

"Directory in which the given `callback` should be executed"

<#> parameter peekCallback "function" "callback"

"Action to execute in the given directory"

=?> "The results of the call to `callback`."

#? T.unwords

[ "Run an action within a different directory. This function will"

, "change the working directory to `directory`, execute `callback`,"

, "then switch back to the original working directory, even if an"

, "error occurs while running the callback action."

]

-- | Run an action, then restore the old environment variable values.

with_env :: LuaError e => DocumentedFunction e

with_env = defun "with_env"

### (\environment callback ->

bracket (ioToLua Env.getEnvironment)

setEnvironment

(\_ -> setEnvironment environment *> invoke callback))

<#> parameter (peekKeyValuePairs peekString peekString) "table"

"environment"

("Environment variables and their values to be set before "

`T.append` "running `callback`")

<#> parameter peekCallback "function" "callback"

"Action to execute in the custom environment"

=?> "The results of the call to `callback`."

#? T.unwords

[ "Run an action within a custom environment. Only the environment"

, "variables given by `environment` will be set, when `callback` is"

, "called. The original environment is restored after this function"

, "finishes, even if an error occurs while running the callback"

, "action."

]

where

setEnvironment newEnv = ioToLua $ do

-- Crude, but fast enough: delete all entries in new environment,

-- then restore old environment one-by-one.

curEnv <- Env.getEnvironment

forM_ curEnv (Env.unsetEnv . fst)

forM_ newEnv (uncurry Env.setEnv)

-- | Provides a temporary directory for the given action.

with_tmpdir :: LuaError e => DocumentedFunction e

with_tmpdir = defun "with_tmpdir"

### (\mParentDir tmpl callback -> case mParentDir of

Nothing -> do

Temp.withSystemTempDirectory tmpl $

invokeWithFilePath callback

Just parentDir -> do

Temp.withTempDirectory parentDir tmpl $

invokeWithFilePath callback)

<#> parameter peekParentDir "string" "parent_dir"

(mconcat

[ "Parent directory to create the directory in. If this "

, "parameter is omitted, the system's canonical temporary "

, "directory is used."

])

<#> stringParam "templ" "Directory name template."

<#> parameter peekCallback "function" "callback"

("Function which takes the name of the temporary directory as "

`T.append` "its first argument.")

=?> "The results of the call to `callback`."

#? T.unlines

[ "Create and use a temporary directory inside the given directory."

, "The directory is deleted after the callback returns."

]

where

peekParentDir idx = do

args <- liftLua gettop

if args < 3

then liftLua $ do

pushnil

insert idx

return Nothing

else Just <$> peekString idx

-- | Write a string to a file.

write_file :: LuaError e => DocumentedFunction e

write_file = defun "write_file"

### (\filepath contents ->

ioToLua $ B.writeFile filepath contents)

<#> filepathParam "filepath" "path to target file"

<#> parameter peekByteString "string" "contents" "file contents"

=#> []

#? "Writes a string to a file."

-- | Obtain the paths to special directories.

xdg :: LuaError e => DocumentedFunction e

xdg = defun "xdg"

### (\xdgDirTypeOrList mfp->

case xdgDirTypeOrList of

Left xdgDirType -> Left <$>

let fp = fromMaybe "" mfp

in ioToLua $ Directory.getXdgDirectory xdgDirType fp

Right xdgDirList ->

ioToLua $ Right <$> Directory.getXdgDirectoryList xdgDirList)

<#> parameter peekXdgDirectory "string" "xdg_directory_type"

(T.unlines

[ "The type of the XDG directory or search path."

, "Must be one of `config`, `data`, `cache`, `state`,"

, "`datadirs`, or `configdirs`."

, ""

, "Matching is case-insensitive, and underscores and `XDG`"

, "prefixes are ignored, so a value like"

, "`XDG_DATA_DIRS` is also acceptable."

, ""

, "The `state` directory might not be available, depending"

, "on the version of the underlying Haskell library."

])

<#> opt (filepathParam "filepath"

("relative path that is appended to the path; ignored " <>

"if the result is a list of search paths."))

=#> functionResult (either pushString pushFilePathList)

"string|{string,...}"

"Either a single file path, or a list of search paths."

#? T.unlines

[ "Access special directories and directory search paths."

, ""

, "Special directories for storing user-specific application"

, "data, configuration, and cache files, as specified by the"

, "[XDG Base Directory Specification](" <>

"https://specifications.freedesktop.org/basedir-spec/latest/)."

]

-- | Filepath function parameter.

filepathParam :: Text -- ^ name

-> Text -- ^ description

-> Parameter e FilePath

filepathParam = stringParam

-- | Result of a function returning a file path.

filepathResult :: Text -- ^ Description

-> [FunctionResult e FilePath]

filepathResult = functionResult pushString "string"

-- | Process options

data ProcessOpts = ProcessOpts

{ processOptsEnv :: Maybe [(String, String)]

, processOptsCwd :: Maybe FilePath

}

-- | Peek process creation options

peekProcessOptions :: LuaError e => Peeker e ProcessOpts

peekProcessOptions = typeChecked "table" istable $ \idx -> do

let peekEnv = peekKeyValuePairs peekString peekString

env' <- peekFieldRaw (peekNilOr peekEnv) "env" idx

cwd' <- peekFieldRaw (peekNilOr peekString) "cwd" idx

return $ ProcessOpts

{ processOptsEnv = env'

, processOptsCwd = cwd'

}

-- | Pushes an exit code; failure codes are pushed as integers, and

pushExitCode :: Pusher e Exit.ExitCode

pushExitCode = \case

Exit.ExitSuccess -> pushBool False

Exit.ExitFailure n -> pushIntegral n

-- | Pushes a time as ISO 8601 string.

pushUTCTime :: Pusher e Time.UTCTime

pushUTCTime = pushString . ISO8601.iso8601Show

-- | Get an XDG directory type identifier.

peekXdgDirectory :: Peeker e

(Either Directory.XdgDirectory Directory.XdgDirectoryList)

peekXdgDirectory =

(fmap cleanupXdgSpec . peekText) >=> \case

"cache" -> pure (Left Directory.XdgCache)

"config" -> pure (Left Directory.XdgConfig)

"data" -> pure (Left Directory.XdgData)

#if MIN_VERSION_directory(1,3,7)

"state" -> pure (Left Directory.XdgState)

"datadirs" -> pure (Right Directory.XdgDataDirs)

"configdirs" -> pure (Right Directory.XdgConfigDirs)

s -> failPeek $

"Expected 'cache', 'config', 'data', or 'state', got: " <>

Utf8.fromText s

where

-- Cleanup the XDG directory specifier as to make matching easier

-- while keeping things permissive.

-- Remove underscores, any 'xdg' prefix, and

-- make sure everything is lowercase

cleanupXdgSpec =

(\s -> fromMaybe s $ T.stripPrefix "xdg" s)

. T.filter (/= '_')

. T.toLower

-- | Pushes a list of file paths.

pushFilePathList :: LuaError e => Pusher e [FilePath]

pushFilePathList fps = do

pushList pushString fps

newListMetatable "FilePath list" (pure ())

setmetatable (nth 2)