#include "flatbuffers/grpc.h"
#include "monster_test_generated.h"
#include "test_assert.h"
#include "test_builder.h"

using MyGame::Example::Any_NONE;
using MyGame::Example::CreateStat;
using MyGame::Example::Vec3;

bool verify(flatbuffers::grpc::Message<Monster> &msg,
            const std::string &expected_name, Color expected_color) {
  const Monster *monster = msg.GetRoot();
  const auto name = monster->name()->str();
  const auto color = monster->color();
  TEST_EQ(name, expected_name);
  TEST_EQ(color, expected_color);
  return (name == expected_name) && (color == expected_color);
}

bool release_n_verify(flatbuffers::grpc::MessageBuilder &mbb,
                      const std::string &expected_name, Color expected_color) {
  flatbuffers::grpc::Message<Monster> msg = mbb.ReleaseMessage<Monster>();
  return verify(msg, expected_name, expected_color);
}

void builder_move_assign_after_releaseraw_test(
    flatbuffers::grpc::MessageBuilder dst) {
  auto root_offset1 = populate1(dst);
  dst.Finish(root_offset1);
  size_t size, offset;
  grpc_slice slice;
  dst.ReleaseRaw(size, offset, slice);
  flatbuffers::FlatBufferBuilder src;
  auto root_offset2 = populate2(src);
  src.Finish(root_offset2);
  auto src_size = src.GetSize();
  // Move into a released builder.
  dst = std::move(src);
  TEST_EQ(dst.GetSize(), src_size);
  TEST_ASSERT(release_n_verify(dst, m2_name(), m2_color()));
  TEST_EQ(src.GetSize(), 0);
  grpc_slice_unref(slice);
}

template<class SrcBuilder>
struct BuilderReuseTests<flatbuffers::grpc::MessageBuilder, SrcBuilder> {
  static void builder_reusable_after_release_message_test(
      TestSelector selector) {
    if (!selector.count(REUSABLE_AFTER_RELEASE_MESSAGE)) { return; }

    flatbuffers::grpc::MessageBuilder mb;
    std::vector<flatbuffers::grpc::Message<Monster>> buffers;
    for (int i = 0; i < 5; ++i) {
      auto root_offset1 = populate1(mb);
      mb.Finish(root_offset1);
      buffers.push_back(mb.ReleaseMessage<Monster>());
      TEST_ASSERT_FUNC(verify(buffers[i], m1_name(), m1_color()));
    }
  }

  static void builder_reusable_after_release_test(TestSelector selector) {
    if (!selector.count(REUSABLE_AFTER_RELEASE)) { return; }

    // FIXME: Populate-Release loop fails assert(GRPC_SLICE_IS_EMPTY(slice_)) in
    // SliceAllocator::allocate in the second iteration.

    flatbuffers::grpc::MessageBuilder mb;
    std::vector<flatbuffers::DetachedBuffer> buffers;
    for (int i = 0; i < 2; ++i) {
      auto root_offset1 = populate1(mb);
      mb.Finish(root_offset1);
      buffers.push_back(mb.Release());
      TEST_ASSERT_FUNC(verify(buffers[i], m1_name(), m1_color()));
    }
  }

  static void builder_reusable_after_releaseraw_test(TestSelector selector) {
    if (!selector.count(REUSABLE_AFTER_RELEASE_RAW)) { return; }

    flatbuffers::grpc::MessageBuilder mb;
    for (int i = 0; i < 5; ++i) {
      auto root_offset1 = populate1(mb);
      mb.Finish(root_offset1);
      size_t size, offset;
      grpc_slice slice;
      const uint8_t *buf = mb.ReleaseRaw(size, offset, slice);
      TEST_ASSERT_FUNC(verify(buf, offset, m1_name(), m1_color()));
      grpc_slice_unref(slice);
    }
  }

  static void builder_reusable_after_release_and_move_assign_test(
      TestSelector selector) {
    if (!selector.count(REUSABLE_AFTER_RELEASE_AND_MOVE_ASSIGN)) { return; }

    // FIXME: Release-move_assign loop fails assert(p ==
    // GRPC_SLICE_START_PTR(slice_)) in DetachedBuffer destructor after all the
    // iterations

    flatbuffers::grpc::MessageBuilder dst;
    std::vector<flatbuffers::DetachedBuffer> buffers;

    for (int i = 0; i < 2; ++i) {
      auto root_offset1 = populate1(dst);
      dst.Finish(root_offset1);
      buffers.push_back(dst.Release());
      TEST_ASSERT_FUNC(verify(buffers[i], m1_name(), m1_color()));

      // bring dst back to life.
      SrcBuilder src;
      dst = std::move(src);
      TEST_EQ_FUNC(dst.GetSize(), 0);
      TEST_EQ_FUNC(src.GetSize(), 0);
    }
  }

  static void builder_reusable_after_release_message_and_move_assign_test(
      TestSelector selector) {
    if (!selector.count(REUSABLE_AFTER_RELEASE_MESSAGE_AND_MOVE_ASSIGN)) {
      return;
    }

    flatbuffers::grpc::MessageBuilder dst;
    std::vector<flatbuffers::grpc::Message<Monster>> buffers;

    for (int i = 0; i < 5; ++i) {
      auto root_offset1 = populate1(dst);
      dst.Finish(root_offset1);
      buffers.push_back(dst.ReleaseMessage<Monster>());
      TEST_ASSERT_FUNC(verify(buffers[i], m1_name(), m1_color()));

      // bring dst back to life.
      SrcBuilder src;
      dst = std::move(src);
      TEST_EQ_FUNC(dst.GetSize(), 0);
      TEST_EQ_FUNC(src.GetSize(), 0);
    }
  }

  static void builder_reusable_after_releaseraw_and_move_assign_test(
      TestSelector selector) {
    if (!selector.count(REUSABLE_AFTER_RELEASE_RAW_AND_MOVE_ASSIGN)) { return; }

    flatbuffers::grpc::MessageBuilder dst;
    for (int i = 0; i < 5; ++i) {
      auto root_offset1 = populate1(dst);
      dst.Finish(root_offset1);
      size_t size, offset;
      grpc_slice slice = grpc_empty_slice();
      const uint8_t *buf = dst.ReleaseRaw(size, offset, slice);
      TEST_ASSERT_FUNC(verify(buf, offset, m1_name(), m1_color()));
      grpc_slice_unref(slice);

      SrcBuilder src;
      dst = std::move(src);
      TEST_EQ_FUNC(dst.GetSize(), 0);
      TEST_EQ_FUNC(src.GetSize(), 0);
    }
  }

  static void run_tests(TestSelector selector) {
    builder_reusable_after_release_test(selector);
    builder_reusable_after_release_message_test(selector);
    builder_reusable_after_releaseraw_test(selector);
    builder_reusable_after_release_and_move_assign_test(selector);
    builder_reusable_after_releaseraw_and_move_assign_test(selector);
    builder_reusable_after_release_message_and_move_assign_test(selector);
  }
};

void slice_allocator_tests() {
  // move-construct no-delete test
  {
    size_t size = 2048;
    flatbuffers::grpc::SliceAllocator sa1;
    uint8_t *buf = sa1.allocate(size);
    TEST_ASSERT_FUNC(buf != 0);
    buf[0] = 100;
    buf[size - 1] = 200;
    flatbuffers::grpc::SliceAllocator sa2(std::move(sa1));
    // buf should not be deleted after move-construct
    TEST_EQ_FUNC(buf[0], 100);
    TEST_EQ_FUNC(buf[size - 1], 200);
    // buf is freed here
  }

  // move-assign test
  {
    flatbuffers::grpc::SliceAllocator sa1, sa2;
    uint8_t *buf = sa1.allocate(2048);
    sa1 = std::move(sa2);
    // sa1 deletes previously allocated memory in move-assign.
    // So buf is no longer usable here.
    TEST_ASSERT_FUNC(buf != 0);
  }
}

/// This function does not populate exactly the first half of the table. But it
/// could.
void populate_first_half(MyGame::Example::MonsterBuilder &wrapper,
                         flatbuffers::Offset<flatbuffers::String> name_offset) {
  wrapper.add_name(name_offset);
  wrapper.add_color(m1_color());
}

/// This function does not populate exactly the second half of the table. But it
/// could.
void populate_second_half(MyGame::Example::MonsterBuilder &wrapper) {
  wrapper.add_hp(77);
  wrapper.add_mana(88);
  Vec3 vec3;
  wrapper.add_pos(&vec3);
}

/// This function is a hack to update the FlatBufferBuilder reference (fbb_) in
/// the MonsterBuilder object. This function will break if fbb_ is not the first
/// member in MonsterBuilder. In that case, some offset must be added. This
/// function is used exclusively for testing correctness of move operations
/// between FlatBufferBuilders. If MonsterBuilder had a fbb_ pointer, this hack
/// would be unnecessary. That involves a code-generator change though.
void test_only_hack_update_fbb_reference(
    MyGame::Example::MonsterBuilder &monsterBuilder,
    flatbuffers::grpc::MessageBuilder &mb) {
  *reinterpret_cast<flatbuffers::FlatBufferBuilder **>(&monsterBuilder) = &mb;
}

/// This test validates correctness of move conversion of FlatBufferBuilder to a
/// MessageBuilder DURING a table construction. Half of the table is constructed
/// using FlatBufferBuilder and the other half of the table is constructed using
/// a MessageBuilder.
void builder_move_ctor_conversion_before_finish_half_n_half_table_test() {
  for (size_t initial_size = 4; initial_size <= 2048; initial_size *= 2) {
    flatbuffers::FlatBufferBuilder fbb(initial_size);
    auto name_offset = fbb.CreateString(m1_name());
    MyGame::Example::MonsterBuilder monsterBuilder(
        fbb);  // starts a table in FlatBufferBuilder
    populate_first_half(monsterBuilder, name_offset);
    flatbuffers::grpc::MessageBuilder mb(std::move(fbb));
    test_only_hack_update_fbb_reference(monsterBuilder, mb);  // hack
    populate_second_half(monsterBuilder);
    mb.Finish(monsterBuilder.Finish());  // ends the table in MessageBuilder
    TEST_ASSERT_FUNC(release_n_verify(mb, m1_name(), m1_color()));
    TEST_EQ_FUNC(fbb.GetSize(), 0);
  }
}

/// This test populates a COMPLETE inner table before move conversion and later
/// populates more members in the outer table.
void builder_move_ctor_conversion_before_finish_test() {
  for (size_t initial_size = 1; initial_size <= 2048; initial_size += 1) {
    flatbuffers::FlatBufferBuilder fbb(initial_size);
    auto stat_offset = CreateStat(fbb, fbb.CreateString("SomeId"), 0, 0);
    flatbuffers::grpc::MessageBuilder mb(std::move(fbb));
    auto monster_offset =
        CreateMonster(mb, 0, 150, 100, mb.CreateString(m1_name()), 0, m1_color(),
                      Any_NONE, 0, 0, 0, 0, 0, 0, stat_offset);
    mb.Finish(monster_offset);
    {
      auto mon = flatbuffers::GetRoot<Monster>(mb.GetBufferPointer());
      TEST_NOTNULL(mon);
      TEST_NOTNULL(mon->name());
      TEST_EQ_STR(mon->name()->c_str(), m1_name().c_str());
      TEST_EQ(mon->color(), m1_color());
    }
    TEST_EQ(1, MyGame::Example::Color_Red);    
    TEST_EQ(1, m1_color());
    TEST_ASSERT_FUNC(release_n_verify(mb, m1_name(), m1_color()));
    TEST_EQ_FUNC(fbb.GetSize(), 0);
  }
}

/// This test validates correctness of move conversion of FlatBufferBuilder to a
/// MessageBuilder DURING a table construction. Half of the table is constructed
/// using FlatBufferBuilder and the other half of the table is constructed using
/// a MessageBuilder.
void builder_move_assign_conversion_before_finish_half_n_half_table_test() {
  flatbuffers::FlatBufferBuilder fbb;
  flatbuffers::grpc::MessageBuilder mb;

  for (int i = 0; i < 5; ++i) {
    flatbuffers::FlatBufferBuilder fbb;
    auto name_offset = fbb.CreateString(m1_name());
    MyGame::Example::MonsterBuilder monsterBuilder(
        fbb);  // starts a table in FlatBufferBuilder
    populate_first_half(monsterBuilder, name_offset);
    mb = std::move(fbb);
    test_only_hack_update_fbb_reference(monsterBuilder, mb);  // hack
    populate_second_half(monsterBuilder);
    mb.Finish(monsterBuilder.Finish());  // ends the table in MessageBuilder
    TEST_ASSERT_FUNC(release_n_verify(mb, m1_name(), m1_color()));
    TEST_EQ_FUNC(fbb.GetSize(), 0);
  }
}

/// This test populates a COMPLETE inner table before move conversion and later
/// populates more members in the outer table.
void builder_move_assign_conversion_before_finish_test() {
  flatbuffers::FlatBufferBuilder fbb;
  flatbuffers::grpc::MessageBuilder mb;

  for (int i = 0; i < 5; ++i) {
    auto stat_offset = CreateStat(fbb, fbb.CreateString("SomeId"), 0, 0);
    mb = std::move(fbb);
    auto monster_offset =
        CreateMonster(mb, 0, 150, 100, mb.CreateString(m1_name()), 0, m1_color(),
                      Any_NONE, 0, 0, 0, 0, 0, 0, stat_offset);
    mb.Finish(monster_offset);
    TEST_ASSERT_FUNC(release_n_verify(mb, m1_name(), m1_color()));
    TEST_EQ_FUNC(fbb.GetSize(), 0);
  }
}

/// This test populates data, finishes the buffer, and does move conversion
/// after.
void builder_move_ctor_conversion_after_finish_test() {
  flatbuffers::FlatBufferBuilder fbb;
  fbb.Finish(populate1(fbb));
  flatbuffers::grpc::MessageBuilder mb(std::move(fbb));
  TEST_ASSERT_FUNC(release_n_verify(mb, m1_name(), m1_color()));
  TEST_EQ_FUNC(fbb.GetSize(), 0);
}

/// This test populates data, finishes the buffer, and does move conversion
/// after.
void builder_move_assign_conversion_after_finish_test() {
  flatbuffers::FlatBufferBuilder fbb;
  flatbuffers::grpc::MessageBuilder mb;

  for (int i = 0; i < 5; ++i) {
    fbb.Finish(populate1(fbb));
    mb = std::move(fbb);
    TEST_ASSERT_FUNC(release_n_verify(mb, m1_name(), m1_color()));
    TEST_EQ_FUNC(fbb.GetSize(), 0);
  }
}

void message_builder_tests() {
  using flatbuffers::FlatBufferBuilder;
  using flatbuffers::grpc::MessageBuilder;

  slice_allocator_tests();

#ifndef __APPLE__
  builder_move_ctor_conversion_before_finish_half_n_half_table_test();
  builder_move_assign_conversion_before_finish_half_n_half_table_test();
#endif  // __APPLE__
  builder_move_ctor_conversion_before_finish_test();
  builder_move_assign_conversion_before_finish_test();

  builder_move_ctor_conversion_after_finish_test();
  builder_move_assign_conversion_after_finish_test();

  BuilderTests<MessageBuilder, MessageBuilder>::all_tests();
  BuilderTests<MessageBuilder, FlatBufferBuilder>::all_tests();

  BuilderReuseTestSelector tests[6] = {
    // REUSABLE_AFTER_RELEASE,                 // Assertion failed:
    // (GRPC_SLICE_IS_EMPTY(slice_))
    // REUSABLE_AFTER_RELEASE_AND_MOVE_ASSIGN, // Assertion failed: (p ==
    // GRPC_SLICE_START_PTR(slice_)

    REUSABLE_AFTER_RELEASE_RAW, REUSABLE_AFTER_RELEASE_MESSAGE,
    REUSABLE_AFTER_RELEASE_MESSAGE_AND_MOVE_ASSIGN,
    REUSABLE_AFTER_RELEASE_RAW_AND_MOVE_ASSIGN
  };

  BuilderReuseTests<MessageBuilder, MessageBuilder>::run_tests(
      TestSelector(tests, tests + 6));
  BuilderReuseTests<MessageBuilder, FlatBufferBuilder>::run_tests(
      TestSelector(tests, tests + 6));
}
