/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "gtest/gtest.h"
#include "gmock/gmock.h"
#include "mozilla/AbstractThread.h"
#include "mozilla/Preferences.h"
#include "mozilla/dom/DocGroup.h"
#include "mozilla/dom/TabGroup.h"
#include "mozilla/SchedulerGroup.h"
#include "mozilla/TaskCategory.h"
#include "mozilla/PerformanceCounter.h"
#include "nsThreadUtils.h"
#include "nsServiceManagerUtils.h"
#include "nsThread.h"

using namespace mozilla;
using mozilla::Runnable;

class MockSchedulerGroup : public SchedulerGroup {
 public:
  explicit MockSchedulerGroup(mozilla::dom::DocGroup* aDocGroup)
      : mDocGroup(aDocGroup) {}
  NS_INLINE_DECL_REFCOUNTING(MockSchedulerGroup);

  MOCK_METHOD1(SetValidatingAccess, void(ValidationType aType));
  mozilla::dom::DocGroup* DocGroup() { return mDocGroup; }

 protected:
  virtual ~MockSchedulerGroup() = default;

 private:
  mozilla::dom::DocGroup* mDocGroup;
};

typedef testing::NiceMock<MockSchedulerGroup> MSchedulerGroup;

/* Timed runnable which simulates some execution time
 * and can run a nested runnable.
 */
class TimedRunnable final : public Runnable {
 public:
  explicit TimedRunnable(uint32_t aExecutionTime1, uint32_t aExecutionTime2,
                         uint32_t aSubExecutionTime)
      : Runnable("TimedRunnable"),
        mExecutionTime1(aExecutionTime1),
        mExecutionTime2(aExecutionTime2),
        mSubExecutionTime(aSubExecutionTime) {}
  NS_IMETHODIMP Run() {
    PR_Sleep(PR_MillisecondsToInterval(mExecutionTime1 + 5));
    if (mSubExecutionTime > 0) {
      // Dispatch another runnable so nsThread::ProcessNextEvent is called
      // recursively
      nsCOMPtr<nsIThread> thread = do_GetMainThread();
      nsCOMPtr<nsIRunnable> runnable =
          new TimedRunnable(mSubExecutionTime, 0, 0);
      thread->Dispatch(runnable, NS_DISPATCH_NORMAL);
      (void)NS_ProcessNextEvent(thread, false);
    }
    PR_Sleep(PR_MillisecondsToInterval(mExecutionTime2 + 5));
    return NS_OK;
  }

 private:
  uint32_t mExecutionTime1;
  uint32_t mExecutionTime2;
  uint32_t mSubExecutionTime;
};

/* test class used for all metrics tests
 *
 * - sets up the enable_scheduler_timing pref
 * - provides a function to dispatch runnables and spin the loop
 */

class ThreadMetrics : public ::testing::Test {
 public:
  explicit ThreadMetrics() = default;

 protected:
  virtual void SetUp() {
    // building the TabGroup/DocGroup structure
    nsCString key = NS_LITERAL_CSTRING("key");
    RefPtr<dom::Document> doc;
    RefPtr<dom::TabGroup> tabGroup = new dom::TabGroup(false);
    mDocGroup = tabGroup->AddDocument(key, doc);
    mSchedulerGroup = new MSchedulerGroup(mDocGroup);
    mCounter = mDocGroup->GetPerformanceCounter();
    mThreadMgr = do_GetService("@mozilla.org/thread-manager;1");
    mOther = DispatchCategory(TaskCategory::Other).GetValue();
    mDispatchCount = (uint32_t)TaskCategory::Other + 1;
  }

  virtual void TearDown() {
    // and remove the document from the doc group (actually, a nullptr)
    mDocGroup->RemoveDocument(nullptr);
    mDocGroup = nullptr;
    ProcessAllEvents();
  }

  // this is used to get rid of transient events
  void initScheduler() { ProcessAllEvents(); }

  nsresult Dispatch(uint32_t aExecutionTime1, uint32_t aExecutionTime2,
                    uint32_t aSubExecutionTime) {
    ProcessAllEvents();
    nsCOMPtr<nsIRunnable> runnable =
        new TimedRunnable(aExecutionTime1, aExecutionTime2, aSubExecutionTime);
    runnable = new SchedulerGroup::Runnable(runnable.forget(), mSchedulerGroup,
                                            mDocGroup);
    return mDocGroup->Dispatch(TaskCategory::Other, runnable.forget());
  }

  void ProcessAllEvents() { mThreadMgr->SpinEventLoopUntilEmpty(); }

  uint32_t mOther;
  bool mOldPref;
  RefPtr<MSchedulerGroup> mSchedulerGroup;
  RefPtr<mozilla::dom::DocGroup> mDocGroup;
  RefPtr<mozilla::PerformanceCounter> mCounter;
  nsCOMPtr<nsIThreadManager> mThreadMgr;
  uint32_t mDispatchCount;
};

TEST_F(ThreadMetrics, CollectMetrics) {
  nsresult rv;
  initScheduler();

  // Dispatching a runnable that will last for +50ms
  rv = Dispatch(25, 25, 0);
  ASSERT_TRUE(NS_SUCCEEDED(rv));

  // Flush the queue
  ProcessAllEvents();

  // Let's look at the task category "other" counter
  ASSERT_EQ(mCounter->GetDispatchCounter()[mOther], 1u);

  // other counters should stay empty
  for (uint32_t i = 0; i < mDispatchCount; i++) {
    if (i != mOther) {
      ASSERT_EQ(mCounter->GetDispatchCounter()[i], 0u);
    }
  }

  // Did we get incremented in the docgroup ?
  uint64_t duration = mCounter->GetExecutionDuration();
  ASSERT_GE(duration, 50000u);
}

TEST_F(ThreadMetrics, CollectRecursiveMetrics) {
  nsresult rv;

  initScheduler();

  // Dispatching a runnable that will last for +50ms
  // and run another one recursively that lasts for 400ms
  rv = Dispatch(25, 25, 400);
  ASSERT_TRUE(NS_SUCCEEDED(rv));

  // Flush the queue
  ProcessAllEvents();

  // let's look at the counters
  ASSERT_EQ(mCounter->GetDispatchCounter()[mOther], 1u);

  // other counters should stay empty
  for (uint32_t i = 0; i < mDispatchCount; i++) {
    if (i != mOther) {
      ASSERT_EQ(mCounter->GetDispatchCounter()[i], 0u);
    }
  }

  // did we get incremented in the docgroup ?
  uint64_t duration = mCounter->GetExecutionDuration();
  ASSERT_GE(duration, 50000u);

  // let's make sure we don't count the time spent in recursive calls
  ASSERT_LT(duration, 300000u);
}