// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <unistd.h>

#include <cstring>
#include <utility>

#include <base/files/file_util.h>
#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include <policy/libpolicy.h>
#include <policy/mock_device_policy.h>

#include "metrics/c_metrics_library.h"
#include "metrics/metrics_library.h"

using base::FilePath;
using ::testing::_;
using ::testing::Return;
using ::testing::AnyNumber;

namespace {
const FilePath kTestUMAEventsFile("test-uma-events");
const char kTestMounts[] = "test-mounts";
const FilePath kTestConsentIdFile("test-consent-id");
const char kValidGuidOld[] = "56ff27bf7f774919b08488416d597fd8";
const char kValidGuid[] = "56ff27bf-7f77-4919-b084-88416d597fd8";
}  // namespace

ACTION_P(SetMetricsPolicy, enabled) {
  *arg0 = enabled;
  return true;
}

class MetricsLibraryTest : public testing::Test {
 protected:
  void SetUp() override {
    lib_.consent_file_ = kTestConsentIdFile.value();
    EXPECT_TRUE(lib_.uma_events_file_.empty());
    lib_.Init();
    EXPECT_FALSE(lib_.uma_events_file_.empty());
    lib_.uma_events_file_ = kTestUMAEventsFile.value();
    EXPECT_EQ(0, WriteFile(kTestUMAEventsFile, "", 0));
    device_policy_ = new policy::MockDevicePolicy();
    EXPECT_CALL(*device_policy_, LoadPolicy())
        .Times(AnyNumber())
        .WillRepeatedly(Return(true));
    EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
        .Times(AnyNumber())
        .WillRepeatedly(SetMetricsPolicy(true));
    lib_.SetPolicyProvider(new policy::PolicyProvider(
        std::unique_ptr<policy::MockDevicePolicy>(device_policy_)));
    // Defeat metrics enabled caching between tests.
    lib_.cached_enabled_time_ = 0;
  }

  void TearDown() override {
    base::DeleteFile(FilePath(kTestMounts), false);
    base::DeleteFile(kTestUMAEventsFile, false);
    base::DeleteFile(kTestConsentIdFile, false);
  }

  void VerifyEnabledCacheHit(bool to_value);
  void VerifyEnabledCacheEviction(bool to_value);

  MetricsLibrary lib_;
  policy::MockDevicePolicy* device_policy_;  // Not owned.
};

// Reject symlinks even if they're to normal files.
TEST_F(MetricsLibraryTest, ConsentIdInvalidSymlinkPath) {
  std::string id;
  base::DeleteFile(kTestConsentIdFile, false);
  ASSERT_EQ(symlink("/bin/sh", kTestConsentIdFile.value().c_str()), 0);
  ASSERT_FALSE(lib_.ConsentId(&id));
}

// Reject non-files (like directories).
TEST_F(MetricsLibraryTest, ConsentIdInvalidDirPath) {
  std::string id;
  base::DeleteFile(kTestConsentIdFile, false);
  ASSERT_EQ(mkdir(kTestConsentIdFile.value().c_str(), 0755), 0);
  ASSERT_FALSE(lib_.ConsentId(&id));
}

// Reject valid files full of invalid uuids.
TEST_F(MetricsLibraryTest, ConsentIdInvalidContent) {
  std::string id;
  base::DeleteFile(kTestConsentIdFile, false);

  ASSERT_EQ(base::WriteFile(kTestConsentIdFile, "", 0), 0);
  ASSERT_FALSE(lib_.ConsentId(&id));

  ASSERT_EQ(base::WriteFile(kTestConsentIdFile, "asdf", 4), 4);
  ASSERT_FALSE(lib_.ConsentId(&id));

  char buf[100];
  memset(buf, '0', sizeof(buf));

  // Reject too long UUIDs that lack dashes.
  ASSERT_EQ(base::WriteFile(kTestConsentIdFile, buf, 36), 36);
  ASSERT_FALSE(lib_.ConsentId(&id));

  // Reject very long UUIDs.
  ASSERT_EQ(base::WriteFile(kTestConsentIdFile, buf, sizeof(buf)), sizeof(buf));
  ASSERT_FALSE(lib_.ConsentId(&id));
}

// Accept old consent ids.
TEST_F(MetricsLibraryTest, ConsentIdValidContentOld) {
  std::string id;
  base::DeleteFile(kTestConsentIdFile, false);
  ASSERT_GT(
      base::WriteFile(kTestConsentIdFile, kValidGuidOld, strlen(kValidGuidOld)),
      0);
  ASSERT_TRUE(lib_.ConsentId(&id));
  ASSERT_EQ(id, kValidGuidOld);
}

// Accept current consent ids.
TEST_F(MetricsLibraryTest, ConsentIdValidContent) {
  std::string id;
  base::DeleteFile(kTestConsentIdFile, false);
  ASSERT_GT(base::WriteFile(kTestConsentIdFile, kValidGuid, strlen(kValidGuid)),
            0);
  ASSERT_TRUE(lib_.ConsentId(&id));
  ASSERT_EQ(id, kValidGuid);
}

// Accept current consent ids (including a newline).
TEST_F(MetricsLibraryTest, ConsentIdValidContentNewline) {
  std::string id;
  std::string outid = std::string(kValidGuid) + "\n";
  base::DeleteFile(kTestConsentIdFile, false);
  ASSERT_GT(base::WriteFile(kTestConsentIdFile, outid.c_str(), outid.size()),
            0);
  ASSERT_TRUE(lib_.ConsentId(&id));
  ASSERT_EQ(id, kValidGuid);
}

// MetricsEnabled policy not present, enterprise managed
// -> AreMetricsEnabled returns true.
TEST_F(MetricsLibraryTest, AreMetricsEnabledTrueNoPolicyManaged) {
  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_)).WillOnce(Return(false));
  EXPECT_CALL(*device_policy_, IsEnterpriseManaged()).WillOnce(Return(true));
  EXPECT_TRUE(lib_.AreMetricsEnabled());
}

// MetricsEnabled policy not present, not enterprise managed
// -> AreMetricsEnabled returns false.
TEST_F(MetricsLibraryTest, AreMetricsEnabledFalseNoPolicyUnmanaged) {
  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_)).WillOnce(Return(false));
  EXPECT_CALL(*device_policy_, IsEnterpriseManaged()).WillOnce(Return(false));
  EXPECT_FALSE(lib_.AreMetricsEnabled());
}

// MetricsEnabled policy set to false -> AreMetricsEnabled returns false.
TEST_F(MetricsLibraryTest, AreMetricsEnabledFalse) {
  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
      .WillOnce(SetMetricsPolicy(false));
  EXPECT_FALSE(lib_.AreMetricsEnabled());
}

// MetricsEnabled policy set to true -> AreMetricsEnabled returns true.
TEST_F(MetricsLibraryTest, AreMetricsEnabledTrue) {
  EXPECT_TRUE(lib_.AreMetricsEnabled());
}

void MetricsLibraryTest::VerifyEnabledCacheHit(bool to_value) {
  // We might step from one second to the next one time, but not 100
  // times in a row.
  for (int i = 0; i < 100; ++i) {
    lib_.cached_enabled_time_ = 0;
    EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
        .WillOnce(SetMetricsPolicy(!to_value));
    ASSERT_EQ(!to_value, lib_.AreMetricsEnabled());
    testing::Mock::VerifyAndClearExpectations(device_policy_);

    ON_CALL(*device_policy_, GetMetricsEnabled(_))
        .WillByDefault(SetMetricsPolicy(to_value));
    if (lib_.AreMetricsEnabled() == !to_value)
      return;
    testing::Mock::VerifyAndClearExpectations(device_policy_);
  }
  ADD_FAILURE() << "Did not see evidence of caching";
}

void MetricsLibraryTest::VerifyEnabledCacheEviction(bool to_value) {
  lib_.cached_enabled_time_ = 0;
  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
      .WillOnce(SetMetricsPolicy(!to_value));
  ASSERT_EQ(!to_value, lib_.AreMetricsEnabled());
  testing::Mock::VerifyAndClearExpectations(device_policy_);

  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
      .WillOnce(SetMetricsPolicy(to_value));
  ASSERT_LT(abs(static_cast<int>(time(nullptr) - lib_.cached_enabled_time_)),
            5);
  // Sleep one second (or cheat to be faster).
  --lib_.cached_enabled_time_;
  ASSERT_EQ(to_value, lib_.AreMetricsEnabled());
}

TEST_F(MetricsLibraryTest, AreMetricsEnabledCaching) {
  VerifyEnabledCacheHit(false);
  VerifyEnabledCacheHit(true);
  VerifyEnabledCacheEviction(false);
  VerifyEnabledCacheEviction(true);
}

class CMetricsLibraryTest : public testing::Test {
 protected:
  void SetUp() override {
    lib_ = CMetricsLibraryNew();
    MetricsLibrary& ml = *reinterpret_cast<MetricsLibrary*>(lib_);
    EXPECT_TRUE(ml.uma_events_file_.empty());
    CMetricsLibraryInit(lib_);
    EXPECT_FALSE(ml.uma_events_file_.empty());
    ml.uma_events_file_ = kTestUMAEventsFile.value();
    EXPECT_EQ(0, WriteFile(kTestUMAEventsFile, "", 0));
    device_policy_ = new policy::MockDevicePolicy();
    EXPECT_CALL(*device_policy_, LoadPolicy())
        .Times(AnyNumber())
        .WillRepeatedly(Return(true));
    EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
        .Times(AnyNumber())
        .WillRepeatedly(SetMetricsPolicy(true));
    ml.SetPolicyProvider(new policy::PolicyProvider(
        std::unique_ptr<policy::MockDevicePolicy>(device_policy_)));
    ml.cached_enabled_time_ = 0;
  }

  void TearDown() override {
    CMetricsLibraryDelete(lib_);
    base::DeleteFile(kTestUMAEventsFile, false);
  }

  CMetricsLibrary lib_;
  policy::MockDevicePolicy* device_policy_;  // Not owned.
};

TEST_F(CMetricsLibraryTest, AreMetricsEnabledFalse) {
  EXPECT_CALL(*device_policy_, GetMetricsEnabled(_))
      .WillOnce(SetMetricsPolicy(false));
  EXPECT_FALSE(CMetricsLibraryAreMetricsEnabled(lib_));
}

TEST_F(CMetricsLibraryTest, AreMetricsEnabledTrue) {
  EXPECT_TRUE(CMetricsLibraryAreMetricsEnabled(lib_));
}

int main(int argc, char** argv) {
  testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}