{-# OPTIONS_GHC -fno-warn-incomplete-patterns -fno-warn-incomplete-uni-patterns #-}
{-# LANGUAGE OverloadedStrings #-}

module System.GPIO.Linux.Sysfs.MockSpec (spec) where

import Prelude hiding (readFile, writeFile)
import Control.Exception (fromException)
import Data.List (sort)
import GHC.IO.Exception (IOErrorType(..))
import System.GPIO.Linux.Sysfs.Mock
import System.GPIO.Types (Pin(..), PinValue(..))
import System.IO.Error (ioeGetErrorType, isDoesNotExistError, isPermissionError)
import Test.Hspec

isInappropriateTypeErrorType :: IOErrorType -> Bool
isInappropriateTypeErrorType InappropriateType = True
isInappropriateTypeErrorType _ = False

isInappropriateTypeError :: IOError -> Bool
isInappropriateTypeError = isInappropriateTypeErrorType . ioeGetErrorType

evalSysfsMock' :: SysfsMock a -> MockWorld -> [MockGpioChip] -> Either (Maybe IOError) a
evalSysfsMock' a w c = either (Left . fromException) Right $ evalSysfsMock a w c

evalSysfsMockME :: SysfsMock a -> MockWorld -> [MockGpioChip] -> Either (Maybe MockFSException) a
evalSysfsMockME a w c = either (Left . fromException) Right $ evalSysfsMock a w c

execSysfsMock' :: SysfsMock a -> MockWorld -> [MockGpioChip] -> Either (Maybe IOError) MockWorld
execSysfsMock' a w c = either (Left . fromException) Right $ execSysfsMock a w c

spec :: Spec
spec =
  do
    describe "MockPinState" $ do
      it "logicalValue returns the correct pin value" $
        let pinState = defaultMockPinState {_value = Low, _activeLow = False}
        in do
          logicalValue pinState `shouldBe` Low
          logicalValue (pinState {_value = High}) `shouldBe` High
          logicalValue (pinState {_activeLow = True}) `shouldBe` High
          logicalValue (pinState {_value = High, _activeLow = True}) `shouldBe` Low
      it "setLogicalValue sets the correct pin value" $
        let pinState = defaultMockPinState {_value = Low, _activeLow = False}
            activeLowPinState = defaultMockPinState {_value = Low, _activeLow = True}
        in do
          setLogicalValue Low pinState `shouldBe` pinState
          setLogicalValue High pinState `shouldBe` pinState {_value = High}
          setLogicalValue Low activeLowPinState `shouldBe` activeLowPinState {_value = High}
          setLogicalValue High activeLowPinState `shouldBe` activeLowPinState {_value = Low}

    describe "SysfsMockT" $ do

      context "doesDirectoryExist" $ do
        it "relative paths are relative to the initial zipper's working directory" $ do
          evalSysfsMock' (doesDirectoryExist "sys/class/gpio") initialMockWorld [] `shouldBe` Right True
        it "absolute paths work regardless of the initial zipper's working directory" $ do
          evalSysfsMock' (doesDirectoryExist "/sys/class/gpio") initialMockWorld [] `shouldBe` Right True
        it "doesn't change the initial zipper's state" $ do
          execSysfsMock' (doesDirectoryExist "/sys/class/gpio") initialMockWorld [] `shouldBe` Right initialMockWorld
        it "returns False on files" $ do
          evalSysfsMock' (doesDirectoryExist "/sys/class/gpio/export") initialMockWorld [] `shouldBe` Right False
        it "returns False on non-existent names" $ do
          evalSysfsMock' (doesDirectoryExist "/sys/class/foobar") initialMockWorld [] `shouldBe` Right False

      context "doesFileExist" $ do
        it "relative paths are relative to the initial zipper's working directory" $ do
          evalSysfsMock' (doesFileExist "sys/class/gpio/export") initialMockWorld [] `shouldBe` Right True
        it "absolute paths work regardless of the initial zipper's working directory" $ do
          evalSysfsMock' (doesFileExist "/sys/class/gpio/export") initialMockWorld [] `shouldBe` Right True
        it "doesn't change the initial zipper's state" $ do
          execSysfsMock' (doesFileExist "/sys/class/gpio/export") initialMockWorld [] `shouldBe` Right initialMockWorld
        it "returns False on directories" $ do
          evalSysfsMock' (doesFileExist "/sys/class/gpio") initialMockWorld [] `shouldBe` Right False
        it "returns False on non-existent names" $ do
          evalSysfsMock' (doesFileExist "/sys/class/foobar") initialMockWorld [] `shouldBe` Right False

      context "getDirectoryContents" $ do
        it "relative paths are relative to the initial zipper's working directory" $ do
          fmap sort (evalSysfsMock' (getDirectoryContents "sys/class") initialMockWorld []) `shouldBe` Right ["gpio"]
          fmap sort (evalSysfsMock' (getDirectoryContents "sys/class/gpio") initialMockWorld []) `shouldBe` (Right $ sort ["export", "unexport"])
        it "absolute paths work regardless of the initial zipper's working directory" $ do
          fmap sort (evalSysfsMock' (getDirectoryContents "/sys/class") initialMockWorld []) `shouldBe` Right ["gpio"]
          fmap sort (evalSysfsMock' (getDirectoryContents "/sys/class/gpio") initialMockWorld []) `shouldBe` (Right $ sort ["export", "unexport"])
        it "doesn't change the initial zipper's state" $ do
          execSysfsMock' (getDirectoryContents "/sys/class/gpio") initialMockWorld [] `shouldBe` Right initialMockWorld
        it "returns failure on files" $ do
          do let Left (Just result) = evalSysfsMock' (getDirectoryContents "/sys/class/gpio/export") initialMockWorld []
             isInappropriateTypeError result `shouldBe` True
        it "returns failure on non-existent names" $ do
          do let Left (Just result) = evalSysfsMock' (getDirectoryContents "/sys/class/foobar") initialMockWorld []
             isDoesNotExistError result `shouldBe` True

      context "readFile" $ do
        -- Note: most interesting cases are already checked by the
        -- tests in 'SysfsGpioMockSpec.hs' and it would be a bit silly
        -- to try to test them here due to the amount of setup
        -- required to get the filesystem into the necessary state.
        -- (We would basically end up rewriting large chunks of the
        -- mock GPIO code.)
        it "works with 'constant' files" $
          let chip0 = MockGpioChip "chip0" 0 (replicate 16 defaultMockPinState)
          in evalSysfsMock' (readFile "/sys/class/gpio/gpiochip0/base") initialMockWorld [chip0] `shouldBe` Right "0\n"
        it "fails on /sys/class/gpio/export" $
          do let Left (Just result) = evalSysfsMock' (readFile "/sys/class/gpio/export") initialMockWorld []
             isPermissionError result `shouldBe` True
        it "fails on /sys/class/gpio/unexport" $
          do let Left (Just result) = evalSysfsMock' (readFile "/sys/class/gpio/unexport") initialMockWorld []
             isPermissionError result `shouldBe` True
        it "fails on non-existent file" $
          do let Left (Just result) = evalSysfsMock' (readFile "/sys/class/gpio/foo") initialMockWorld []
             isDoesNotExistError result `shouldBe` True
        it "fails on a directory" $
          do let Left (Just result) = evalSysfsMock' (readFile "/sys/class/gpio") initialMockWorld []
             isInappropriateTypeError result `shouldBe` True

      context "writeFile" $
        it "does the right thing" $
          pendingWith "Not implemented" -- See notes for 'readFile'
                                        -- above.

      context "runSysfsMockT" $ do
        let chip0 = MockGpioChip "chip0" 0 (replicate 16 defaultMockPinState)
            chip16 = MockGpioChip "xyz" 16 (replicate 32 defaultMockPinState)
            chip64 = MockGpioChip "abc" 64 (replicate 16 defaultMockPinState)
            invalidChip32 = MockGpioChip "invalid" 32 (replicate 16 defaultMockPinState)
        it "creates the specified gpiochip directories" $ do
          fmap sort (evalSysfsMock' (getDirectoryContents "/sys/class/gpio") initialMockWorld [chip0, chip16, chip64]) `shouldBe` Right ["export", "gpiochip0", "gpiochip16", "gpiochip64", "unexport"]
          evalSysfsMock' (readFile "/sys/class/gpio/gpiochip0/base") initialMockWorld [chip0, chip16, chip64] `shouldBe` Right "0\n"
          evalSysfsMock' (readFile "/sys/class/gpio/gpiochip0/ngpio") initialMockWorld [chip0, chip16, chip64] `shouldBe` Right "16\n"
          evalSysfsMock' (readFile "/sys/class/gpio/gpiochip0/label") initialMockWorld [chip0, chip16, chip64] `shouldBe` Right "chip0\n"
          evalSysfsMock' (readFile "/sys/class/gpio/gpiochip16/base") initialMockWorld [chip0, chip16, chip64] `shouldBe` Right "16\n"
          evalSysfsMock' (readFile "/sys/class/gpio/gpiochip16/ngpio") initialMockWorld [chip0, chip16, chip64] `shouldBe` Right "32\n"
          evalSysfsMock' (readFile "/sys/class/gpio/gpiochip16/label") initialMockWorld [chip0, chip16, chip64] `shouldBe` Right "xyz\n"
          evalSysfsMock' (readFile "/sys/class/gpio/gpiochip64/base") initialMockWorld [chip0, chip16, chip64] `shouldBe` Right "64\n"
          evalSysfsMock' (readFile "/sys/class/gpio/gpiochip64/ngpio") initialMockWorld [chip0, chip16, chip64] `shouldBe` Right "16\n"
          evalSysfsMock' (readFile "/sys/class/gpio/gpiochip64/label") initialMockWorld [chip0, chip16, chip64] `shouldBe` Right "abc\n"
        it "fails when MockGpioChips overlap" $ do
          evalSysfsMockME (readFile "/sys/class/gpio/gpiochip16/ngpio") initialMockWorld [chip0, chip16, invalidChip32] `shouldBe` Left (Just $ GpioChipOverlap $ Pin 47)