-- Copyright 2016 TensorFlow authors.
--
-- Licensed under the Apache License, Version 2.0 (the "License");
-- you may not use this file except in compliance with the License.
-- You may obtain a copy of the License at
--
--     http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.

{-# LANGUAGE OverloadedStrings #-}

module Main where

import Control.Monad.IO.Class (liftIO)
import Data.Int (Int32, Int64)
import Google.Test (googleTest)
import Lens.Family2 ((.~))
import System.IO.Temp (withSystemTempDirectory)
import Test.Framework (Test)
import Test.Framework.Providers.HUnit (testCase)
import Test.HUnit ((@=?))
import qualified Data.ByteString.Char8 as B8

import qualified Data.Vector as V
import qualified TensorFlow.Build as TF
import qualified TensorFlow.Nodes as TF
import qualified TensorFlow.Ops as TF
import qualified TensorFlow.Session as TF
import qualified TensorFlow.Tensor as TF
import qualified TensorFlow.Types as TF

-- | Test that one can easily determine number of elements in the tensor.
testSize :: Test
testSize = testCase "testSize" $ do
    x <- eval $ TF.size (TF.constant (TF.Shape [2, 3]) [0..5 :: Float])
    TF.Scalar (2 * 3 :: Int32) @=? x

eval :: TF.Fetchable t a => t -> IO a
eval = TF.runSession . TF.run

-- | Confirms that the original example from Python code works.
testReducedShape :: Test
testReducedShape = testCase "testReducedShape" $ do
    x <- eval $ TF.reducedShape (TF.vector [2, 3, 5, 7 :: Int64])
                                (TF.vector [1, 2 :: Int32])
    V.fromList [2, 1, 1, 7 :: Int32] @=? x

testSaveRestore :: Test
testSaveRestore = testCase "testSaveRestore" $
    withSystemTempDirectory "" $ \dirPath -> do
        let path = B8.pack $ dirPath ++ "/checkpoint"
            var :: TF.MonadBuild m => m (TF.Tensor TF.Ref Float)
            var = TF.render =<<
                  TF.zeroInitializedVariable' (TF.opName .~ "a")
                                        (TF.Shape [])
        TF.runSession $ do
            v <- var
            TF.assign v 134 >>= TF.run_
            TF.save path [v] >>= TF.run_
        result <- TF.runSession $ do
            v <- var
            TF.restore path v >>= TF.run_
            TF.run v
        liftIO $ TF.Scalar 134 @=? result


main :: IO ()
main = googleTest [ testSaveRestore
                  , testSize
                  , testReducedShape
                  ]