/*
 * Copyright (C) 2020 The Android Open Source Project
 *
 * 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.
 */

#include "apexd_session.h"

#include <android-base/file.h>
#include <android-base/result-gmock.h>
#include <android-base/result.h>
#include <android-base/scopeguard.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <errno.h>
#include <gmock/gmock.h>
#include <gtest/gtest.h>

#include <algorithm>
#include <filesystem>
#include <fstream>
#include <string>

#include "apexd_test_utils.h"
#include "apexd_utils.h"
#include "session_state.pb.h"

namespace android {
namespace apex {
namespace {

using android::base::Join;
using android::base::make_scope_guard;
using android::base::testing::Ok;
using ::apex::proto::SessionState;
using ::testing::Not;
using ::testing::UnorderedElementsAre;

// TODO(b/170329726): add unit tests for apexd_sessions.h

TEST(ApexdSessionTest, GetSessionsDirSessionsStoredInMetadata) {
  if (access("/metadata", F_OK) != 0) {
    GTEST_SKIP() << "Device doesn't have /metadata partition";
  }

  std::string result = GetSessionsDir();
  ASSERT_EQ(result, "/metadata/apex/sessions");
}

TEST(ApexdSessionTest, GetSessionsDirNoMetadataPartitionFallbackToData) {
  if (access("/metadata", F_OK) == 0) {
    GTEST_SKIP() << "Device has /metadata partition";
  }

  std::string result = GetSessionsDir();
  ASSERT_EQ(result, "/data/apex/sessions");
}

TEST(ApexdSessionTest, MigrateToMetadataSessionsDir) {
  namespace fs = std::filesystem;

  if (access("/metadata", F_OK) != 0) {
    GTEST_SKIP() << "Device doesn't have /metadata partition";
  }

  // This is ugly, but does the job. To have a truly hermetic unit tests we
  // need to refactor ApexSession class.
  for (const auto& entry : fs::directory_iterator("/metadata/apex/sessions")) {
    fs::remove_all(entry.path());
  }

  // This is a very ugly test set up, but to have something better we need to
  // refactor ApexSession class.
  class TestApexSession {
   public:
    TestApexSession(int id, const SessionState::State& state) {
      path_ = "/data/apex/sessions/" + std::to_string(id);
      if (auto status = CreateDirIfNeeded(path_, 0700); !status.ok()) {
        ADD_FAILURE() << "Failed to create " << path_ << " : "
                      << status.error();
      }
      SessionState session;
      session.set_id(id);
      session.set_state(state);
      std::fstream state_file(
          path_ + "/state", std::ios::out | std::ios::trunc | std::ios::binary);
      if (!session.SerializeToOstream(&state_file)) {
        ADD_FAILURE() << "Failed to write to " << path_;
      }
    }

    ~TestApexSession() { fs::remove_all(path_); }

   private:
    std::string path_;
  };

  auto deleter = make_scope_guard([&]() {
    fs::remove_all("/metadata/apex/sessions/239");
    fs::remove_all("/metadata/apex/sessions/1543");
  });

  TestApexSession session1(239, SessionState::SUCCESS);
  TestApexSession session2(1543, SessionState::ACTIVATION_FAILED);

  ASSERT_RESULT_OK(ApexSession::MigrateToMetadataSessionsDir());

  auto sessions = ApexSession::GetSessions();
  ASSERT_EQ(2u, sessions.size()) << Join(sessions, ',');

  auto migrated_session_1 = ApexSession::GetSession(239);
  ASSERT_RESULT_OK(migrated_session_1);
  ASSERT_EQ(SessionState::SUCCESS, migrated_session_1->GetState());

  auto migrated_session_2 = ApexSession::GetSession(1543);
  ASSERT_RESULT_OK(migrated_session_2);
  ASSERT_EQ(SessionState::ACTIVATION_FAILED, migrated_session_2->GetState());
}

TEST(ApexSessionManagerTest, CreateSession) {
  TemporaryDir td;
  auto manager = ApexSessionManager::Create(std::string(td.path));

  auto session = manager->CreateSession(239);
  ASSERT_RESULT_OK(session);
  ASSERT_EQ(239, session->GetId());
  std::string session_dir = std::string(td.path) + "/239";
  ASSERT_EQ(session_dir, session->GetSessionDir());
}

TEST(ApexSessionManagerTest, GetSessionsNoSessionReturnsError) {
  TemporaryDir td;
  auto manager = ApexSessionManager::Create(std::string(td.path));

  ASSERT_THAT(manager->GetSession(37), Not(Ok()));
}

TEST(ApexSessionManagerTest, GetSessionsReturnsErrorSessionNotCommitted) {
  TemporaryDir td;
  auto manager = ApexSessionManager::Create(std::string(td.path));

  auto session = manager->CreateSession(73);
  ASSERT_RESULT_OK(session);
  ASSERT_THAT(manager->GetSession(73), Not(Ok()));
}

TEST(ApexSessionManagerTest, CreateCommitGetSession) {
  TemporaryDir td;
  auto manager = ApexSessionManager::Create(std::string(td.path));

  auto session = manager->CreateSession(23);
  ASSERT_RESULT_OK(session);
  session->SetErrorMessage("error");
  ASSERT_RESULT_OK(session->UpdateStateAndCommit(SessionState::STAGED));

  auto same_session = manager->GetSession(23);
  ASSERT_RESULT_OK(same_session);
  ASSERT_EQ(23, same_session->GetId());
  ASSERT_EQ("error", same_session->GetErrorMessage());
  ASSERT_EQ(SessionState::STAGED, same_session->GetState());
}

TEST(ApexSessionManagerTest, GetSessionsNoSessionsCommitted) {
  TemporaryDir td;
  auto manager = ApexSessionManager::Create(std::string(td.path));

  ASSERT_RESULT_OK(manager->CreateSession(3));

  auto sessions = manager->GetSessions();
  ASSERT_EQ(0u, sessions.size());
}

TEST(ApexSessionManager, GetSessionsCommittedSessions) {
  TemporaryDir td;
  auto manager = ApexSessionManager::Create(std::string(td.path));

  auto session1 = manager->CreateSession(1543);
  ASSERT_RESULT_OK(session1);
  ASSERT_RESULT_OK(session1->UpdateStateAndCommit(SessionState::ACTIVATED));

  auto session2 = manager->CreateSession(179);
  ASSERT_RESULT_OK(session2);
  ASSERT_RESULT_OK(session2->UpdateStateAndCommit(SessionState::SUCCESS));

  // This sessions is not committed, it won't be returned in GetSessions.
  ASSERT_RESULT_OK(manager->CreateSession(101));

  auto sessions = manager->GetSessions();
  std::sort(
      sessions.begin(), sessions.end(),
      [](const auto& s1, const auto& s2) { return s1.GetId() < s2.GetId(); });

  ASSERT_EQ(2u, sessions.size());

  ASSERT_EQ(179, sessions[0].GetId());
  ASSERT_EQ(SessionState::SUCCESS, sessions[0].GetState());

  ASSERT_EQ(1543, sessions[1].GetId());
  ASSERT_EQ(SessionState::ACTIVATED, sessions[1].GetState());
}

TEST(ApexSessionManager, GetSessionsInState) {
  TemporaryDir td;
  auto manager = ApexSessionManager::Create(std::string(td.path));

  auto session1 = manager->CreateSession(43);
  ASSERT_RESULT_OK(session1);
  ASSERT_RESULT_OK(session1->UpdateStateAndCommit(SessionState::ACTIVATED));

  auto session2 = manager->CreateSession(41);
  ASSERT_RESULT_OK(session2);
  ASSERT_RESULT_OK(session2->UpdateStateAndCommit(SessionState::SUCCESS));

  auto session3 = manager->CreateSession(23);
  ASSERT_RESULT_OK(session3);
  ASSERT_RESULT_OK(session3->UpdateStateAndCommit(SessionState::SUCCESS));

  auto sessions = manager->GetSessionsInState(SessionState::SUCCESS);
  std::sort(
      sessions.begin(), sessions.end(),
      [](const auto& s1, const auto& s2) { return s1.GetId() < s2.GetId(); });

  ASSERT_EQ(2u, sessions.size());

  ASSERT_EQ(23, sessions[0].GetId());
  ASSERT_EQ(SessionState::SUCCESS, sessions[0].GetState());

  ASSERT_EQ(41, sessions[1].GetId());
  ASSERT_EQ(SessionState::SUCCESS, sessions[1].GetState());
}

TEST(ApexSessionManager, MigrateFromOldSessionsDir) {
  TemporaryDir td;
  auto old_manager = ApexSessionManager::Create(std::string(td.path));

  auto session1 = old_manager->CreateSession(239);
  ASSERT_RESULT_OK(session1);
  ASSERT_RESULT_OK(session1->UpdateStateAndCommit(SessionState::STAGED));

  auto session2 = old_manager->CreateSession(13);
  ASSERT_RESULT_OK(session2);
  ASSERT_RESULT_OK(session2->UpdateStateAndCommit(SessionState::SUCCESS));

  auto session3 = old_manager->CreateSession(31);
  ASSERT_RESULT_OK(session3);
  ASSERT_RESULT_OK(session3->UpdateStateAndCommit(SessionState::ACTIVATED));

  TemporaryDir td2;
  auto new_manager = ApexSessionManager::Create(std::string(td2.path));

  ASSERT_RESULT_OK(
      new_manager->MigrateFromOldSessionsDir(std::string(td.path)));

  auto sessions = new_manager->GetSessions();
  std::sort(
      sessions.begin(), sessions.end(),
      [](const auto& s1, const auto& s2) { return s1.GetId() < s2.GetId(); });

  ASSERT_EQ(3u, sessions.size());

  ASSERT_EQ(13, sessions[0].GetId());
  ASSERT_EQ(SessionState::SUCCESS, sessions[0].GetState());

  ASSERT_EQ(31, sessions[1].GetId());
  ASSERT_EQ(SessionState::ACTIVATED, sessions[1].GetState());

  ASSERT_EQ(239, sessions[2].GetId());
  ASSERT_EQ(SessionState::STAGED, sessions[2].GetState());

  // Check that old manager directory doesn't have anything
  auto old_sessions = old_manager->GetSessions();
  ASSERT_TRUE(old_sessions.empty());
}

TEST(ApexSessionManager, MigrateFromOldSessionsDirSameDir) {
  TemporaryDir td;
  auto old_manager = ApexSessionManager::Create(std::string(td.path));

  auto session1 = old_manager->CreateSession(239);
  ASSERT_RESULT_OK(session1);
  ASSERT_RESULT_OK(session1->UpdateStateAndCommit(SessionState::STAGED));

  auto session2 = old_manager->CreateSession(13);
  ASSERT_RESULT_OK(session2);
  ASSERT_RESULT_OK(session2->UpdateStateAndCommit(SessionState::SUCCESS));

  auto session3 = old_manager->CreateSession(31);
  ASSERT_RESULT_OK(session3);
  ASSERT_RESULT_OK(session3->UpdateStateAndCommit(SessionState::ACTIVATED));

  auto new_manager = ApexSessionManager::Create(std::string(td.path));

  ASSERT_RESULT_OK(
      new_manager->MigrateFromOldSessionsDir(std::string(td.path)));

  auto sessions = new_manager->GetSessions();
  std::sort(
      sessions.begin(), sessions.end(),
      [](const auto& s1, const auto& s2) { return s1.GetId() < s2.GetId(); });

  ASSERT_EQ(3u, sessions.size());

  ASSERT_EQ(13, sessions[0].GetId());
  ASSERT_EQ(SessionState::SUCCESS, sessions[0].GetState());

  ASSERT_EQ(31, sessions[1].GetId());
  ASSERT_EQ(SessionState::ACTIVATED, sessions[1].GetState());

  ASSERT_EQ(239, sessions[2].GetId());
  ASSERT_EQ(SessionState::STAGED, sessions[2].GetState());

  // Directory is the same, so using old_manager should also work.
  auto old_sessions = old_manager->GetSessions();
  std::sort(
      old_sessions.begin(), old_sessions.end(),
      [](const auto& s1, const auto& s2) { return s1.GetId() < s2.GetId(); });

  ASSERT_EQ(3u, old_sessions.size());

  ASSERT_EQ(13, old_sessions[0].GetId());
  ASSERT_EQ(SessionState::SUCCESS, old_sessions[0].GetState());

  ASSERT_EQ(31, old_sessions[1].GetId());
  ASSERT_EQ(SessionState::ACTIVATED, old_sessions[1].GetState());

  ASSERT_EQ(239, old_sessions[2].GetId());
  ASSERT_EQ(SessionState::STAGED, old_sessions[2].GetState());
}

TEST(ApexSessionManagerTest, GetStagedApexDirsSelf) {
  TemporaryDir td;
  auto manager = ApexSessionManager::Create(std::string(td.path));

  auto session = manager->CreateSession(239);
  ASSERT_RESULT_OK(session);

  ASSERT_THAT(session->GetStagedApexDirs("/path/to/staged_session_dir"),
              UnorderedElementsAre("/path/to/staged_session_dir/session_239"));
}

TEST(ApexSessionManagerTest, GetStagedApexDirsChildren) {
  TemporaryDir td;
  auto manager = ApexSessionManager::Create(std::string(td.path));

  auto session = manager->CreateSession(239);
  ASSERT_RESULT_OK(session);
  auto child_session_1 = manager->CreateSession(240);
  ASSERT_RESULT_OK(child_session_1);
  auto child_session_2 = manager->CreateSession(241);
  ASSERT_RESULT_OK(child_session_2);
  session->SetChildSessionIds({240, 241});

  ASSERT_THAT(session->GetStagedApexDirs("/path/to/staged_session_dir"),
              UnorderedElementsAre("/path/to/staged_session_dir/session_240",
                                   "/path/to/staged_session_dir/session_241"));
}

}  // namespace
}  // namespace apex
}  // namespace android