//
// Copyright (C) 2015 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 "shill/process_manager.h"

#include <memory>
#include <string>
#include <utility>
#include <vector>

#include <base/bind.h>
#include <brillo/minijail/mock_minijail.h>
#include <gmock/gmock.h>
#include <gtest/gtest.h>

#include "shill/mock_event_dispatcher.h"

using base::Bind;
using base::Callback;
using base::CancelableClosure;
using base::Closure;
using base::Unretained;
using std::string;
using std::vector;
using testing::_;
using testing::DoAll;
using testing::Return;
using testing::SetArgPointee;
using testing::StrEq;

namespace shill {

class ProcessManagerTest : public testing::Test {
 public:
  ProcessManagerTest() : process_manager_(ProcessManager::GetInstance()) {}

  void SetUp() override {
    process_manager_->dispatcher_ = &dispatcher_;
    process_manager_->minijail_ = &minijail_;
  }

  void TearDown() override {
    process_manager_->watched_processes_.clear();
    process_manager_->pending_termination_processes_.clear();
  }

  void AddWatchedProcess(pid_t pid, const Callback<void(int)>& callback) {
    process_manager_->watched_processes_.emplace(pid, callback);
  }

  void AddTerminateProcess(pid_t pid,
                           std::unique_ptr<CancelableClosure> timeout_handler) {
    process_manager_->pending_termination_processes_.emplace(
        pid, std::move(timeout_handler));
  }

  void AssertEmptyWatchedProcesses() {
    EXPECT_TRUE(process_manager_->watched_processes_.empty());
  }

  void AssertNonEmptyWatchedProcesses() {
    EXPECT_FALSE(process_manager_->watched_processes_.empty());
  }

  void AssertEmptyTerminateProcesses() {
    EXPECT_TRUE(process_manager_->pending_termination_processes_.empty());
  }

  void OnProcessExited(pid_t pid, int exit_status) {
    siginfo_t info;
    info.si_status = exit_status;
    process_manager_->OnProcessExited(pid, info);
  }

  void OnTerminationTimeout(pid_t pid, bool kill_signal) {
    process_manager_->ProcessTerminationTimeoutHandler(pid, kill_signal);
  }

 protected:
  class CallbackObserver {
   public:
    CallbackObserver()
        : exited_callback_(
              Bind(&CallbackObserver::OnProcessExited, Unretained(this))),
          termination_timeout_callback_(
              Bind(&CallbackObserver::OnTerminationTimeout,
                   Unretained(this))) {}
    virtual ~CallbackObserver() {}

    MOCK_METHOD1(OnProcessExited, void(int exit_status));
    MOCK_METHOD0(OnTerminationTimeout, void());

    Callback<void(int)> exited_callback_;
    Closure termination_timeout_callback_;
  };

  MockEventDispatcher dispatcher_;
  brillo::MockMinijail minijail_;
  ProcessManager* process_manager_;
};

MATCHER_P2(IsProcessArgs, program, args, "") {
  if (string(arg[0]) != program) {
    return false;
  }
  int index = 1;
  for (const auto& option : args) {
    if (string(arg[index++]) != option) {
      return false;
    }
  }
  return arg[index] == nullptr;
}

TEST_F(ProcessManagerTest, WatchedProcessExited) {
  const pid_t kPid = 123;
  const int kExitStatus = 1;
  CallbackObserver observer;
  AddWatchedProcess(kPid, observer.exited_callback_);

  EXPECT_CALL(observer, OnProcessExited(kExitStatus)).Times(1);
  OnProcessExited(kPid, kExitStatus);
  AssertEmptyWatchedProcesses();
}

TEST_F(ProcessManagerTest, TerminateProcessExited) {
  const pid_t kPid = 123;
  CallbackObserver observer;
  auto timeout_handler = std::make_unique<CancelableClosure>(
      observer.termination_timeout_callback_);
  AddTerminateProcess(kPid, std::move(timeout_handler));

  EXPECT_CALL(observer, OnTerminationTimeout()).Times(0);
  OnProcessExited(kPid, 1);
  AssertEmptyTerminateProcesses();
}

TEST_F(ProcessManagerTest,
       StartProcessInMinijailWithPipesReturnsPidAndWatchesChild) {
  const string kProgram = "/usr/bin/dump";
  const vector<string> kArgs = { "-b", "-g" };
  const string kUser = "user";
  const string kGroup = "group";
  const uint64_t kCapMask = 1;
  const pid_t kPid = 123;
  int stdin_fd;
  int stdout_fd;
  int stderr_fd;

  EXPECT_CALL(minijail_, DropRoot(_, StrEq(kUser), StrEq(kGroup)))
      .WillOnce(Return(true));
  EXPECT_CALL(minijail_, UseCapabilities(_, kCapMask)).Times(1);
  EXPECT_CALL(minijail_,
              RunPipesAndDestroy(_,  // minijail*
                                 IsProcessArgs(kProgram, kArgs),
                                 _,  // pid_t*
                                 &stdin_fd,
                                 &stdout_fd,
                                 &stderr_fd))
      .WillOnce(DoAll(SetArgPointee<2>(kPid), Return(true)));
  struct std_file_descriptors std_fds { &stdin_fd, &stdout_fd, &stderr_fd };
  pid_t actual_pid =
      process_manager_->StartProcessInMinijailWithPipes(
          FROM_HERE,
          base::FilePath(kProgram),
          kArgs,
          kUser,
          kGroup,
          kCapMask,
          false,
          Callback<void(int)>(),
          std_fds);
  EXPECT_EQ(kPid, actual_pid);
  AssertNonEmptyWatchedProcesses();
}

TEST_F(ProcessManagerTest,
       StartProcessInMinijailWithPipesHandlesFailureOfDropRoot) {
  const string kProgram = "/usr/bin/dump";
  const vector<string> kArgs = { "-b", "-g" };
  const string kUser = "user";
  const string kGroup = "group";
  const uint64_t kCapMask = 1;

  EXPECT_CALL(minijail_, DropRoot(_, StrEq(kUser), StrEq(kGroup)))
      .WillOnce(Return(false));
  EXPECT_CALL(minijail_,
              RunPipesAndDestroy(_, IsProcessArgs(kProgram, kArgs), _, _, _, _))
      .Times(0);
  struct std_file_descriptors std_fds = { nullptr, nullptr, nullptr };
  pid_t actual_pid =
      process_manager_->StartProcessInMinijailWithPipes(
          FROM_HERE,
          base::FilePath(kProgram),
          kArgs,
          kUser,
          kGroup,
          kCapMask,
          false,
          Callback<void(int)>(),
          std_fds);
  EXPECT_EQ(-1, actual_pid);
  AssertEmptyWatchedProcesses();
}

TEST_F(ProcessManagerTest,
       StartProcessInMinijailWithPipesHandlesFailureOfRunAndDestroy) {
  const string kProgram = "/usr/bin/dump";
  const vector<string> kArgs = { "-b", "-g" };
  const string kUser = "user";
  const string kGroup = "group";
  const uint64_t kCapMask = 1;

  EXPECT_CALL(minijail_, DropRoot(_, StrEq(kUser), StrEq(kGroup)))
      .WillOnce(Return(true));
  EXPECT_CALL(minijail_, UseCapabilities(_, kCapMask)).Times(1);
  EXPECT_CALL(minijail_,
              RunPipesAndDestroy(_, IsProcessArgs(kProgram, kArgs), _, _, _, _))
      .WillOnce(Return(false));
  struct std_file_descriptors std_fds = { nullptr, nullptr, nullptr };
  pid_t actual_pid =
      process_manager_->StartProcessInMinijailWithPipes(
          FROM_HERE,
          base::FilePath(kProgram),
          kArgs,
          kUser,
          kGroup,
          kCapMask,
          false,
          Callback<void(int)>(),
          std_fds);
  EXPECT_EQ(-1, actual_pid);
  AssertEmptyWatchedProcesses();
}

TEST_F(ProcessManagerTest, UpdateExitCallbackUpdatesCallback) {
  const pid_t kPid = 123;
  const int kExitStatus = 1;
  CallbackObserver original_observer;
  AddWatchedProcess(kPid, original_observer.exited_callback_);

  CallbackObserver new_observer;
  EXPECT_CALL(original_observer, OnProcessExited(_)).Times(0);
  EXPECT_TRUE(process_manager_->UpdateExitCallback(
      kPid,
      new_observer.exited_callback_));
  EXPECT_CALL(new_observer, OnProcessExited(_)).Times(1);
  OnProcessExited(kPid, kExitStatus);
}

}  // namespace shill