/* 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 <prthread.h>
#include <stdio.h>
#include <stdlib.h>

#include "gtest/gtest.h"
#include "mozilla/UniquePtr.h"
#include "nsComponentManagerUtils.h"
#include "nsDirectoryServiceDefs.h"
#include "nsDirectoryServiceUtils.h"
#include "nsExpirationTracker.h"
#include "nsString.h"
#include "nsThreadUtils.h"
#include "nsXPCOM.h"
#include "prinrval.h"

namespace TestExpirationTracker {

struct Object {
  Object() : mExpired(false) { Touch(); }
  void Touch() {
    mLastUsed = PR_IntervalNow();
    mExpired = false;
  }

  nsExpirationState mExpiration;
  nsExpirationState* GetExpirationState() { return &mExpiration; }

  PRIntervalTime mLastUsed;
  bool mExpired;
};

static bool error;
static uint32_t periodMS = 100;
static uint32_t ops = 1000;
static uint32_t iterations = 2;
static bool logging = 0;
static uint32_t sleepPeriodMS = 50;
static uint32_t upperBoundSlackMS = 1200;  // allow this much error
static uint32_t lowerBoundSlackMS = 60;

template <uint32_t K>
class Tracker : public nsExpirationTracker<Object, K> {
 public:
  Tracker() : nsExpirationTracker<Object, K>(periodMS, "Tracker"_ns) {
    Object* obj = new Object();
    mUniverse.AppendElement(obj);
    LogAction(obj, "Created");
  }

  nsTArray<mozilla::UniquePtr<Object>> mUniverse;

  void LogAction(Object* aObj, const char* aAction) {
    if (logging) {
      printf("%d %p(%d): %s\n", PR_IntervalNow(), static_cast<void*>(aObj),
             aObj->mLastUsed, aAction);
    }
  }

  void DoRandomOperation() {
    using mozilla::UniquePtr;

    Object* obj;
    switch (rand() & 0x7) {
      case 0: {
        if (mUniverse.Length() < 50) {
          obj = new Object();
          mUniverse.AppendElement(obj);
          nsExpirationTracker<Object, K>::AddObject(obj);
          LogAction(obj, "Created and added");
        }
        break;
      }
      case 4: {
        if (mUniverse.Length() < 50) {
          obj = new Object();
          mUniverse.AppendElement(obj);
          LogAction(obj, "Created");
        }
        break;
      }
      case 1: {
        UniquePtr<Object>& objref =
            mUniverse[uint32_t(rand()) % mUniverse.Length()];
        if (objref->mExpiration.IsTracked()) {
          nsExpirationTracker<Object, K>::RemoveObject(objref.get());
          LogAction(objref.get(), "Removed");
        }
        break;
      }
      case 2: {
        UniquePtr<Object>& objref =
            mUniverse[uint32_t(rand()) % mUniverse.Length()];
        if (!objref->mExpiration.IsTracked()) {
          objref->Touch();
          nsExpirationTracker<Object, K>::AddObject(objref.get());
          LogAction(objref.get(), "Added");
        }
        break;
      }
      case 3: {
        UniquePtr<Object>& objref =
            mUniverse[uint32_t(rand()) % mUniverse.Length()];
        if (objref->mExpiration.IsTracked()) {
          objref->Touch();
          nsExpirationTracker<Object, K>::MarkUsed(objref.get());
          LogAction(objref.get(), "Marked used");
        }
        break;
      }
    }
  }

 protected:
  void NotifyExpired(Object* aObj) override {
    LogAction(aObj, "Expired");
    PRIntervalTime now = PR_IntervalNow();
    uint32_t timeDiffMS = (now - aObj->mLastUsed) * 1000 / PR_TicksPerSecond();
    // See the comment for NotifyExpired in nsExpirationTracker.h for these
    // bounds
    uint32_t lowerBoundMS = (K - 1) * periodMS - lowerBoundSlackMS;
    uint32_t upperBoundMS = K * (periodMS + sleepPeriodMS) + upperBoundSlackMS;
    if (logging) {
      printf("Checking: %d-%d = %d [%d,%d]\n", now, aObj->mLastUsed, timeDiffMS,
             lowerBoundMS, upperBoundMS);
    }
    if (timeDiffMS < lowerBoundMS || timeDiffMS > upperBoundMS) {
      EXPECT_LT(timeDiffMS, periodMS);
      EXPECT_TRUE(aObj->mExpired);
    }
    aObj->Touch();
    aObj->mExpired = true;
    DoRandomOperation();
    DoRandomOperation();
    DoRandomOperation();
  }
};

template <uint32_t K>
static bool test_random() {
  srand(K);
  error = false;

  for (uint32_t j = 0; j < iterations; ++j) {
    Tracker<K> tracker;

    uint32_t i = 0;
    for (i = 0; i < ops; ++i) {
      if ((rand() & 0xF) == 0) {
        // Simulate work that takes time
        if (logging) {
          printf("SLEEPING for %dms (%d)\n", sleepPeriodMS, PR_IntervalNow());
        }
        PR_Sleep(PR_MillisecondsToInterval(sleepPeriodMS));
        // Process pending timer events
        NS_ProcessPendingEvents(nullptr);
      }
      tracker.DoRandomOperation();
    }
  }

  return !error;
}

static bool test_random3() { return test_random<3>(); }
static bool test_random4() { return test_random<4>(); }
static bool test_random8() { return test_random<8>(); }

typedef bool (*TestFunc)();
#define DECL_TEST(name) {#name, name}

static const struct Test {
  const char* name;
  TestFunc func;
} tests[] = {DECL_TEST(test_random3),
             DECL_TEST(test_random4),
             DECL_TEST(test_random8),
             {nullptr, nullptr}};

TEST(ExpirationTracker, main)
{
  for (const TestExpirationTracker::Test* t = tests; t->name != nullptr; ++t) {
    EXPECT_TRUE(t->func());
  }
}

}  // namespace TestExpirationTracker
