// Copyright 2019 The Abseil 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
//
//      https://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.

#ifdef _WIN32
#include <windows.h>
#endif

#include "gtest/gtest.h"
#include "absl/base/internal/scoped_set_env.h"

namespace {

using absl::base_internal::ScopedSetEnv;

std::string GetEnvVar(const char* name) {
#ifdef _WIN32
  char buf[1024];
  auto get_res = GetEnvironmentVariable(name, buf, sizeof(buf));
  if (get_res == sizeof(buf)) {
    return "TOO_BIG";
  }

  if (get_res == 0) {
    return "UNSET";
  }

  return std::string(buf, get_res);
#else
  const char* val = ::getenv(name);
  if (val == nullptr) {
    return "UNSET";
  }

  return val;
#endif
}

TEST(ScopedSetEnvTest, SetNonExistingVarToString) {
  EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "UNSET");

  {
    ScopedSetEnv scoped_set("SCOPED_SET_ENV_TEST_VAR", "value");

    EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "value");
  }

  EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "UNSET");
}

TEST(ScopedSetEnvTest, SetNonExistingVarToNull) {
  EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "UNSET");

  {
    ScopedSetEnv scoped_set("SCOPED_SET_ENV_TEST_VAR", nullptr);

    EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "UNSET");
  }

  EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "UNSET");
}

TEST(ScopedSetEnvTest, SetExistingVarToString) {
  ScopedSetEnv scoped_set("SCOPED_SET_ENV_TEST_VAR", "value");
  EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "value");

  {
    ScopedSetEnv scoped_set("SCOPED_SET_ENV_TEST_VAR", "new_value");

    EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "new_value");
  }

  EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "value");
}

TEST(ScopedSetEnvTest, SetExistingVarToNull) {
  ScopedSetEnv scoped_set("SCOPED_SET_ENV_TEST_VAR", "value");
  EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "value");

  {
    ScopedSetEnv scoped_set("SCOPED_SET_ENV_TEST_VAR", nullptr);

    EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "UNSET");
  }

  EXPECT_EQ(GetEnvVar("SCOPED_SET_ENV_TEST_VAR"), "value");
}

}  // namespace
