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  /*! \internal \file
   * \brief
   * Tests for gmx::InMemorySerializer and InMemoryDeserializer.
   *
   * \author Christian Blau <blau@kth.se>
   * \ingroup module_utility
   */
  
  #include "gmxpre.h"
  
  #include "gromacs/utility/inmemoryserializer.h"
  
  #include <gmock/gmock.h>
  #include <gtest/gtest.h>
  
  namespace gmx
  {
  namespace test
  {
  namespace
  {
  union IntAndFloat32 {
      std::int32_t int32Value_;
      float        floatValue_;
  };
  
  union IntAndFloat64 {
      std::int64_t int64Value_;
      double       doubleValue_;
  };
  
  //! Constants used for testing endian swap operations
  //! \{
  constexpr std::int16_t c_int16Value        = static_cast<std::int16_t>(0x7A2B);
  constexpr std::int16_t c_int16ValueSwapped = static_cast<std::int16_t>(0x2B7A);
  constexpr std::int32_t c_int32Value        = static_cast<std::int32_t>(0x78ABCDEF);
  constexpr std::int32_t c_int32ValueSwapped = static_cast<std::int32_t>(0xEFCDAB78);
  constexpr std::int64_t c_int64Value        = static_cast<std::int64_t>(0x78ABCDEF12345678);
  constexpr std::int64_t c_int64ValueSwapped = static_cast<std::int64_t>(0x78563412EFCDAB78);
  
  constexpr const IntAndFloat32 c_intAndFloat32{ c_int32Value };
  constexpr const IntAndFloat64 c_intAndFloat64{ c_int64Value };
  
  constexpr const IntAndFloat32 c_intAndFloat32Swapped{ c_int32ValueSwapped };
  constexpr const IntAndFloat64 c_intAndFloat64Swapped{ c_int64ValueSwapped };
  //! \}
  
  //! Return the integer used for testing, depending on the size of int.
  constexpr int integerSizeDependentTestingValue()
  {
      return sizeof(int) == 4 ? c_int32Value : sizeof(int) == 8 ? c_int64Value : c_int16Value;
  }
  
  //! Return the endianess-swapped integer used for testing, depending on the size of int.
  constexpr int integerSizeDependentTestingValueEndianessSwapped()
  {
      return sizeof(int) == 4 ? c_int32ValueSwapped
                              : sizeof(int) == 8 ? c_int64ValueSwapped : c_int16ValueSwapped;
  }
  
  class InMemorySerializerTest : public ::testing::Test
  {
  public:
      struct SerializerValues
      {
          bool           boolValue_;
          unsigned char  unsignedCharValue_;
          char           charValue_;
          unsigned short unsignedShortValue_;
          std::int32_t   int32Value_;
          float          floatValue_;
          std::int64_t   int64Value_;
          double         doubleValue_;
          int            intValue_;
          real           realValue_;
      };
  
      static void serialize(ISerializer* serializer, SerializerValues* values)
      {
          EXPECT_FALSE(serializer->reading());
          doValues(serializer, values);
      }
  
      static SerializerValues deserialize(ISerializer* serializer)
      {
          EXPECT_TRUE(serializer->reading());
          SerializerValues result;
          doValues(serializer, &result);
          return result;
      }
  
      static void checkSerializerValuesforEquality(const SerializerValues& lhs, const SerializerValues& rhs)
      {
          EXPECT_EQ(lhs.boolValue_, rhs.boolValue_);
          EXPECT_EQ(lhs.unsignedCharValue_, rhs.unsignedCharValue_);
          EXPECT_EQ(lhs.charValue_, rhs.charValue_);
          EXPECT_EQ(lhs.intValue_, rhs.intValue_);
          EXPECT_EQ(lhs.int32Value_, rhs.int32Value_);
          EXPECT_EQ(lhs.int64Value_, rhs.int64Value_);
          EXPECT_EQ(lhs.unsignedShortValue_, rhs.unsignedShortValue_);
          EXPECT_EQ(lhs.realValue_, rhs.realValue_);
          EXPECT_EQ(lhs.floatValue_, rhs.floatValue_);
          EXPECT_EQ(lhs.doubleValue_, rhs.doubleValue_);
      }
  
  private:
      static void doValues(ISerializer* serializer, SerializerValues* values)
      {
          serializer->doBool(&values->boolValue_);
          serializer->doUChar(&values->unsignedCharValue_);
          serializer->doChar(&values->charValue_);
          serializer->doInt(&values->intValue_);
          serializer->doInt32(&values->int32Value_);
          serializer->doInt64(&values->int64Value_);
          serializer->doUShort(&values->unsignedShortValue_);
          serializer->doReal(&values->realValue_);
          serializer->doFloat(&values->floatValue_);
          serializer->doDouble(&values->doubleValue_);
      }
  
  protected:
      SerializerValues defaultValues_ = { true,
                                          0x78,
                                          0x78,
                                          static_cast<unsigned short>(c_int16Value),
                                          c_int32Value,
                                          c_intAndFloat32.floatValue_,
                                          c_int64Value,
                                          c_intAndFloat64.doubleValue_,
                                          integerSizeDependentTestingValue(),
                                          std::is_same_v<real, double>
                                                  ? static_cast<real>(c_intAndFloat64.doubleValue_)
                                                  : static_cast<real>(c_intAndFloat32.floatValue_) };
  
      SerializerValues endianessSwappedValues_ = {
          true,
          0x78,
          0x78,
          static_cast<unsigned short>(c_int16ValueSwapped),
          c_int32ValueSwapped,
          c_intAndFloat32Swapped.floatValue_,
          c_int64ValueSwapped,
          c_intAndFloat64Swapped.doubleValue_,
          integerSizeDependentTestingValueEndianessSwapped(),
          std::is_same_v<real, float> ? static_cast<real>(c_intAndFloat32Swapped.floatValue_)
                                      : static_cast<real>(c_intAndFloat64Swapped.doubleValue_)
      };
  };
  
  TEST_F(InMemorySerializerTest, Roundtrip)
  {
      InMemorySerializer serializer;
      SerializerValues   values = defaultValues_;
      serialize(&serializer, &values);
  
      auto buffer = serializer.finishAndGetBuffer();
  
      InMemoryDeserializer deserializer(buffer, std::is_same_v<real, double>);
  
      SerializerValues deserialisedValues = deserialize(&deserializer);
  
      checkSerializerValuesforEquality(values, deserialisedValues);
  }
  
  TEST_F(InMemorySerializerTest, RoundtripWithEndianessSwap)
  {
      InMemorySerializer serializerWithSwap(EndianSwapBehavior::Swap);
      SerializerValues   values = defaultValues_;
      serialize(&serializerWithSwap, &values);
  
      auto buffer = serializerWithSwap.finishAndGetBuffer();
  
      InMemoryDeserializer deserializerWithSwap(buffer, std::is_same_v<real, double>,
                                                EndianSwapBehavior::Swap);
  
      SerializerValues deserialisedValues = deserialize(&deserializerWithSwap);
  
      checkSerializerValuesforEquality(values, deserialisedValues);
  }
  
  TEST_F(InMemorySerializerTest, SerializerExplicitEndianessSwap)
  {
      InMemorySerializer serializerWithSwap(EndianSwapBehavior::Swap);
      SerializerValues   values = defaultValues_;
      serialize(&serializerWithSwap, &values);
  
      auto buffer = serializerWithSwap.finishAndGetBuffer();
  
      InMemoryDeserializer deserializerWithOutSwap(buffer, std::is_same_v<real, double>);
  
      SerializerValues deserialisedValues = deserialize(&deserializerWithOutSwap);
      checkSerializerValuesforEquality(endianessSwappedValues_, deserialisedValues);
  }
  
  TEST_F(InMemorySerializerTest, DeserializerExplicitEndianessSwap)
  {
      InMemorySerializer serializer;
      SerializerValues   values = defaultValues_;
      serialize(&serializer, &values);
  
      auto buffer = serializer.finishAndGetBuffer();
  
      InMemoryDeserializer deserializerWithSwap(buffer, std::is_same_v<real, double>,
                                                EndianSwapBehavior::Swap);
  
      SerializerValues deserialisedValues = deserialize(&deserializerWithSwap);
      checkSerializerValuesforEquality(endianessSwappedValues_, deserialisedValues);
  }
  
  TEST_F(InMemorySerializerTest, SizeIsCorrect)
  {
      InMemorySerializer serializer;
      // These types all have well-defined widths in bytes,
      // which we can test below.
      serializer.doBool(&defaultValues_.boolValue_);     // 1 bytes
      serializer.doChar(&defaultValues_.charValue_);     // 1 bytes
      serializer.doInt32(&defaultValues_.int32Value_);   // 4 bytes
      serializer.doInt64(&defaultValues_.int64Value_);   // 8 bytes
      serializer.doFloat(&defaultValues_.floatValue_);   // 4 bytes
      serializer.doDouble(&defaultValues_.doubleValue_); // 8 bytes
      std::vector<char> charBuffer = { 'a', 'b', 'c' };
      serializer.doCharArray(charBuffer.data(), charBuffer.size()); // 3 bytes
      serializer.doOpaque(charBuffer.data(), charBuffer.size());    // 3 bytes
      std::vector<int32_t> int32Buffer = { 0x1BCDEF78, 0x654321FE };
      serializer.doInt32Array(int32Buffer.data(), int32Buffer.size()); // 8 bytes
      std::vector<int64_t> int64Buffer = { 0x1BCDEF78654321FE, 0x3726ABFEAB34716C };
      serializer.doInt64Array(int64Buffer.data(), int64Buffer.size()); // 16 bytes
      auto buffer = serializer.finishAndGetBuffer();
      EXPECT_EQ(buffer.size(), 56);
  }
  
  } // namespace
  } // namespace test
  } // namespace gmx
  