/*
 * Copyright (C) 2019 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 "src/trace_processor/importers/common/clock_tracker.h"

#include <cstdint>
#include <memory>
#include <optional>
#include <random>
#include <tuple>

#include "perfetto/base/logging.h"
#include "perfetto/ext/base/utils.h"
#include "src/trace_processor/importers/common/global_metadata_tracker.h"
#include "src/trace_processor/importers/common/global_stats_tracker.h"
#include "src/trace_processor/importers/common/import_logs_tracker.h"
#include "src/trace_processor/importers/common/machine_tracker.h"
#include "src/trace_processor/importers/common/metadata_tracker.h"
#include "src/trace_processor/importers/common/stats_tracker.h"
#include "src/trace_processor/storage/trace_storage.h"
#include "src/trace_processor/types/trace_processor_context.h"
#include "src/trace_processor/types/trace_processor_context_ptr.h"
#include "src/trace_processor/util/clock_synchronizer.h"
#include "test/gtest_and_gmock.h"

#include "protos/perfetto/common/builtin_clock.pbzero.h"
#include "protos/perfetto/trace/clock_snapshot.pbzero.h"

namespace perfetto::trace_processor {

class ClockTrackerTest : public ::testing::Test {
 public:
  ClockTrackerTest() {
    context_.storage.reset(new TraceStorage());
    context_.global_stats_tracker =
        std::make_unique<GlobalStatsTracker>(context_.storage.get());
    context_.global_args_tracker.reset(
        new GlobalArgsTracker(context_.storage.get()));
    context_.global_metadata_tracker.reset(
        new GlobalMetadataTracker(context_.storage.get()));
    context_.trace_state =
        TraceProcessorContextPtr<TraceProcessorContext::TraceState>::MakeRoot(
            TraceProcessorContext::TraceState{TraceId(0)});
    context_.machine_tracker =
        std::make_unique<MachineTracker>(&context_, kDefaultMachineId);
    context_.stats_tracker = std::make_unique<StatsTracker>(&context_);
    context_.metadata_tracker.reset(new MetadataTracker(&context_));
    context_.import_logs_tracker.reset(
        new ImportLogsTracker(&context_, TraceId(1)));
    context_.trace_time_state = std::make_unique<TraceTimeState>(
        ClockId::Machine(protos::pbzero::BUILTIN_CLOCK_BOOTTIME));
    primary_sync_ = std::make_unique<ClockSynchronizer>(
        context_.trace_time_state.get(),
        std::make_unique<ClockSynchronizerListenerImpl>(&context_));
    ct_ = std::make_unique<ClockTracker>(
        &context_, std::make_unique<ClockSynchronizerListenerImpl>(&context_),
        primary_sync_.get(), true);
  }
  std::optional<int64_t> Convert(ClockTracker::ClockId src_clock_id,
                                 int64_t src_timestamp,
                                 ClockTracker::ClockId target_clock_id) {
    return ct_->Convert(src_clock_id, src_timestamp, target_clock_id, {});
  }

  TraceProcessorContext context_;
  std::unique_ptr<ClockSynchronizer> primary_sync_;
  std::unique_ptr<ClockTracker> ct_;
};

namespace {

using ::testing::NiceMock;
using Clock = protos::pbzero::ClockSnapshot::Clock;

constexpr ClockTracker::ClockId REALTIME =
    ClockId::Machine(protos::pbzero::BUILTIN_CLOCK_REALTIME);
constexpr ClockTracker::ClockId BOOTTIME =
    ClockId::Machine(protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
constexpr ClockTracker::ClockId MONOTONIC =
    ClockId::Machine(protos::pbzero::BUILTIN_CLOCK_MONOTONIC);
constexpr ClockTracker::ClockId MONOTONIC_COARSE =
    ClockId::Machine(protos::pbzero::BUILTIN_CLOCK_MONOTONIC_COARSE);
constexpr ClockTracker::ClockId MONOTONIC_RAW =
    ClockId::Machine(protos::pbzero::BUILTIN_CLOCK_MONOTONIC_RAW);

TEST_F(ClockTrackerTest, ClockDomainConversions) {
  EXPECT_FALSE(ct_->ToTraceTime(REALTIME, 0).has_value());

  ct_->AddSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}});
  ct_->AddSnapshot({{REALTIME, 20}, {BOOTTIME, 20220}});
  ct_->AddSnapshot({{REALTIME, 30}, {BOOTTIME, 30030}});
  ct_->AddSnapshot({{MONOTONIC, 1000}, {BOOTTIME, 100000}});

  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 0), 10000);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 1), 10001);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 9), 10009);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 10), 10010);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 11), 10011);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 19), 10019);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 20), 20220);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 21), 20221);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 29), 20229);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 30), 30030);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 40), 30040);

  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 0), 100000 - 1000);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 999), 100000 - 1);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 1000), 100000);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 1e6),
            static_cast<int64_t>(100000 - 1000 + 1e6));
}

TEST_F(ClockTrackerTest, ToTraceTimeFromSnapshot) {
  EXPECT_FALSE(ct_->ToTraceTime(REALTIME, 0).has_value());

  EXPECT_EQ(*ct_->ToTraceTimeFromSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}}),
            10010);
  EXPECT_EQ(ct_->ToTraceTimeFromSnapshot({{MONOTONIC, 10}, {REALTIME, 10010}}),
            std::nullopt);
}

// When a clock moves backwards conversions *from* that clock are forbidden
// but conversions *to* that clock should still work.
// Think to the case of REALTIME going backwards from 3AM to 2AM during DST day.
// You can't convert 2.10AM REALTIME to BOOTTIME because there are two possible
// answers, but you can still unambiguosly convert BOOTTIME into REALTIME.
TEST_F(ClockTrackerTest, RealTimeClockMovingBackwards) {
  ct_->AddSnapshot({{BOOTTIME, 10010}, {REALTIME, 10}});

  // At this point conversions are still possible in both ways because we
  // haven't broken monotonicity yet.
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 11), 10011);

  ct_->AddSnapshot({{BOOTTIME, 10020}, {REALTIME, 20}});
  ct_->AddSnapshot({{BOOTTIME, 30040}, {REALTIME, 40}});
  ct_->AddSnapshot({{BOOTTIME, 40030}, {REALTIME, 30}});

  // Now only BOOTIME -> REALTIME conversion should be possible.
  EXPECT_FALSE(ct_->ToTraceTime(REALTIME, 11).has_value());
  EXPECT_EQ(*Convert(BOOTTIME, 10011, REALTIME), 11);
  EXPECT_EQ(*Convert(BOOTTIME, 10029, REALTIME), 29);
  EXPECT_EQ(*Convert(BOOTTIME, 40030, REALTIME), 30);
  EXPECT_EQ(*Convert(BOOTTIME, 40040, REALTIME), 40);

  ct_->AddSnapshot({{BOOTTIME, 50000}, {REALTIME, 50}});
  EXPECT_EQ(*Convert(BOOTTIME, 50005, REALTIME), 55);

  ct_->AddSnapshot({{BOOTTIME, 60020}, {REALTIME, 20}});
  EXPECT_EQ(*Convert(BOOTTIME, 60020, REALTIME), 20);
}

// Simulate the following scenario:
// MONOTONIC = MONOTONIC_COARSE + 10
// BOOTTIME = MONOTONIC + 1000 (until T=200)
// BOOTTIME = MONOTONIC + 2000 (from T=200)
// Then resolve MONOTONIC_COARSE. This requires a two-level resolution:
// MONOTONIC_COARSE -> MONOTONIC -> BOOTTIME.
TEST_F(ClockTrackerTest, ChainedResolutionSimple) {
  ct_->AddSnapshot({{MONOTONIC_COARSE, 1}, {MONOTONIC, 11}});
  ct_->AddSnapshot({{MONOTONIC, 100}, {BOOTTIME, 1100}});
  ct_->AddSnapshot({{MONOTONIC, 200}, {BOOTTIME, 2200}});

  // MONOTONIC_COARSE@100 == MONOTONIC@110 == BOOTTIME@1100.
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 110), 1110);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC_COARSE, 100), 100 + 10 + 1000);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC_COARSE, 202), 202 + 10 + 2000);
}

TEST_F(ClockTrackerTest, ChainedResolutionHard) {
  // MONOTONIC_COARSE = MONOTONIC_RAW - 1.
  ct_->AddSnapshot({{MONOTONIC_RAW, 10}, {MONOTONIC_COARSE, 9}});

  // MONOTONIC = MONOTONIC_COARSE - 50.
  ct_->AddSnapshot({{MONOTONIC_COARSE, 100}, {MONOTONIC, 50}});

  // BOOTTIME = MONOTONIC + 1000 until T=100 (see below).
  ct_->AddSnapshot({{MONOTONIC, 1}, {BOOTTIME, 1001}, {REALTIME, 10001}});

  // BOOTTIME = MONOTONIC + 2000 from T=100.
  // At the same time, REALTIME goes backwards.
  ct_->AddSnapshot({{MONOTONIC, 101}, {BOOTTIME, 2101}, {REALTIME, 9101}});

  // 1-hop conversions.
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 2, MONOTONIC_COARSE), 1);
  EXPECT_EQ(*Convert(MONOTONIC_COARSE, 1, MONOTONIC_RAW), 2);
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 100001, MONOTONIC_COARSE), 100000);
  EXPECT_EQ(*Convert(MONOTONIC_COARSE, 100000, MONOTONIC_RAW), 100001);

  // 2-hop conversions (MONOTONIC_RAW <-> MONOTONIC_COARSE <-> MONOTONIC).
  // From above, MONOTONIC = (MONOTONIC_RAW - 1) - 50.
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 53, MONOTONIC), 53 - 1 - 50);
  EXPECT_EQ(*Convert(MONOTONIC, 2, MONOTONIC_RAW), 2 + 1 + 50);

  // 3-hop conversions (as above + BOOTTIME)
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 53, BOOTTIME), 53 - 1 - 50 + 1000);
  EXPECT_EQ(*Convert(BOOTTIME, 1002, MONOTONIC_RAW), 1002 - 1000 + 1 + 50);

  EXPECT_EQ(*Convert(MONOTONIC_RAW, 753, BOOTTIME), 753 - 1 - 50 + 2000);
  EXPECT_EQ(*Convert(BOOTTIME, 2702, MONOTONIC_RAW), 2702 - 2000 + 1 + 50);

  // 3-hop conversion to REALTIME, one way only (REALTIME goes backwards).
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 53, REALTIME), 53 - 1 - 50 + 10000);
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 753, REALTIME), 753 - 1 - 50 + 9000);
}

// Regression test for b/158182858. When taking two snapshots back-to-back,
// MONOTONIC_COARSE might be stuck to the last value. We should still be able
// to convert both ways in this case.
TEST_F(ClockTrackerTest, NonStrictlyMonotonic) {
  ct_->AddSnapshot({{BOOTTIME, 101}, {MONOTONIC, 51}, {MONOTONIC_COARSE, 50}});
  ct_->AddSnapshot({{BOOTTIME, 105}, {MONOTONIC, 55}, {MONOTONIC_COARSE, 50}});

  // This last snapshot is deliberately identical to the previous one. This
  // is to simulate the case of taking two snapshots so close to each other
  // that all clocks are identical.
  ct_->AddSnapshot({{BOOTTIME, 105}, {MONOTONIC, 55}, {MONOTONIC_COARSE, 50}});

  EXPECT_EQ(*Convert(MONOTONIC_COARSE, 49, MONOTONIC), 50);
  EXPECT_EQ(*Convert(MONOTONIC_COARSE, 50, MONOTONIC), 55);
  EXPECT_EQ(*Convert(MONOTONIC_COARSE, 51, MONOTONIC), 56);

  EXPECT_EQ(*Convert(MONOTONIC_COARSE, 40, BOOTTIME), 91);
  EXPECT_EQ(*Convert(MONOTONIC_COARSE, 50, BOOTTIME), 105);
  EXPECT_EQ(*Convert(MONOTONIC_COARSE, 55, BOOTTIME), 110);

  EXPECT_EQ(*Convert(BOOTTIME, 91, MONOTONIC_COARSE), 40);
  EXPECT_EQ(*Convert(BOOTTIME, 105, MONOTONIC_COARSE), 50);
  EXPECT_EQ(*Convert(BOOTTIME, 110, MONOTONIC_COARSE), 55);
}

TEST_F(ClockTrackerTest, SequenceScopedClocks) {
  ct_->AddSnapshot({{MONOTONIC, 1000}, {BOOTTIME, 100000}});

  ClockTracker::ClockId c64_1 = ClockId::Sequence(0, 1, 64);
  ClockTracker::ClockId c65_1 = ClockId::Sequence(0, 1, 65);
  ClockTracker::ClockId c66_1 = ClockId::Sequence(0, 1, 66);
  ClockTracker::ClockId c66_2 = ClockId::Sequence(0, 2, 64);

  ct_->AddSnapshot({{MONOTONIC, 10000},
                    {c64_1, 100000},
                    {c65_1, 100, /*unit=*/1000, /*incremental=*/false},
                    {c66_1, 10, /*unit=*/1000, /*incremental=*/true}});

  // c64_1 is non-incremental and in nanos.
  EXPECT_EQ(*Convert(c64_1, 150000, MONOTONIC), 60000);
  EXPECT_EQ(*Convert(c64_1, 150000, BOOTTIME), 159000);
  EXPECT_EQ(*ct_->ToTraceTime(c64_1, 150000), 159000);

  // c65_1 is non-incremental and in micros.
  EXPECT_EQ(*Convert(c65_1, 150, MONOTONIC), 60000);
  EXPECT_EQ(*Convert(c65_1, 150, BOOTTIME), 159000);
  EXPECT_EQ(*ct_->ToTraceTime(c65_1, 150), 159000);

  // c66_1 is incremental and in micros.
  EXPECT_EQ(*Convert(c66_1, 1 /* abs 11 */, MONOTONIC), 11000);
  EXPECT_EQ(*Convert(c66_1, 1 /* abs 12 */, MONOTONIC), 12000);
  EXPECT_EQ(*Convert(c66_1, 1 /* abs 13 */, BOOTTIME), 112000);
  EXPECT_EQ(*ct_->ToTraceTime(c66_1, 2 /* abs 15 */), 114000);

  ct_->AddSnapshot(
      {{MONOTONIC, 20000}, {c66_1, 20, /*unit=*/1000, /*incremental=*/true}});
  ct_->AddSnapshot(
      {{MONOTONIC, 20000}, {c66_2, 20, /*unit=*/1000, /*incremental=*/true}});

  // c66_1 and c66_2 are both incremental and in micros, but shouldn't affect
  // each other.
  EXPECT_EQ(*Convert(c66_1, 1 /* abs 21 */, MONOTONIC), 21000);
  EXPECT_EQ(*Convert(c66_2, 2 /* abs 22 */, MONOTONIC), 22000);
  EXPECT_EQ(*Convert(c66_1, 1 /* abs 22 */, MONOTONIC), 22000);
  EXPECT_EQ(*Convert(c66_2, 2 /* abs 24 */, MONOTONIC), 24000);
  EXPECT_EQ(*Convert(c66_1, 1 /* abs 23 */, BOOTTIME), 122000);
  EXPECT_EQ(*Convert(c66_2, 2 /* abs 26 */, BOOTTIME), 125000);
  EXPECT_EQ(*ct_->ToTraceTime(c66_1, 2 /* abs 25 */), 124000);
  EXPECT_EQ(*ct_->ToTraceTime(c66_2, 4 /* abs 30 */), 129000);
}

// Tests that the cache doesn't affect the results of Convert() in unexpected
// ways.
TEST_F(ClockTrackerTest, CacheDoesntAffectResults) {
  std::minstd_rand rnd;
  int last_mono = 0;
  int last_boot = 0;
  int last_raw = 0;
  static const int increments[] = {1, 2, 10};
  for (int i = 0; i < 1000; i++) {
    last_mono += increments[rnd() % base::ArraySize(increments)];
    last_boot += increments[rnd() % base::ArraySize(increments)];
    ct_->AddSnapshot({{MONOTONIC, last_mono}, {BOOTTIME, last_boot}});

    last_raw += increments[rnd() % base::ArraySize(increments)];
    last_boot += increments[rnd() % base::ArraySize(increments)];
    ct_->AddSnapshot({{MONOTONIC_RAW, last_raw}, {BOOTTIME, last_boot}});
  }

  for (int i = 0; i < 1000; i++) {
    int64_t val = static_cast<int64_t>(rnd()) % 10000;
    for (int j = 0; j < 5; j++) {
      ClockTracker::ClockId src;
      ClockTracker::ClockId tgt;
      if (j == 0) {
        std::tie(src, tgt) = std::make_tuple(MONOTONIC, BOOTTIME);
      } else if (j == 1) {
        std::tie(src, tgt) = std::make_tuple(MONOTONIC_RAW, BOOTTIME);
      } else if (j == 2) {
        std::tie(src, tgt) = std::make_tuple(BOOTTIME, MONOTONIC);
      } else if (j == 3) {
        std::tie(src, tgt) = std::make_tuple(BOOTTIME, MONOTONIC_RAW);
      } else if (j == 4) {
        std::tie(src, tgt) = std::make_tuple(MONOTONIC_RAW, MONOTONIC);
      } else {
        PERFETTO_FATAL("j out of bounds");
      }
      // It will still write the cache, just not lookup.
      ct_->set_cache_lookups_disabled_for_testing(true);
      auto not_cached = Convert(src, val, tgt);

      // This should 100% hit the cache.
      ct_->set_cache_lookups_disabled_for_testing(false);
      auto cached = Convert(src, val, tgt);

      ASSERT_EQ(not_cached.value(), cached.value());
    }
  }
}

TEST_F(ClockTrackerTest, CacheDoesntAffectResultsTwoStep) {
  std::minstd_rand rnd;
  int last_raw = 0;
  int last_mono = 0;
  int last_boot = 0;
  static const int increments[] = {1, 2, 10};
  for (int i = 0; i < 1000; i++) {
    last_raw += increments[rnd() % base::ArraySize(increments)];
    last_mono += increments[rnd() % base::ArraySize(increments)];
    ct_->AddSnapshot({{MONOTONIC_RAW, last_raw}, {MONOTONIC, last_mono}});

    last_mono += increments[rnd() % base::ArraySize(increments)];
    last_boot += increments[rnd() % base::ArraySize(increments)];
    ct_->AddSnapshot({{MONOTONIC, last_mono}, {BOOTTIME, last_boot}});
  }

  for (int i = 0; i < 1000; i++) {
    int64_t val = static_cast<int64_t>(rnd()) % 10000;
    ClockTracker::ClockId src = MONOTONIC_RAW;
    ClockTracker::ClockId tgt = BOOTTIME;

    // It will still write the cache, just not lookup.
    ct_->set_cache_lookups_disabled_for_testing(true);
    auto not_cached = Convert(src, val, tgt);

    // This should 100% hit the cache.
    ct_->set_cache_lookups_disabled_for_testing(false);
    auto cached = Convert(src, val, tgt);

    ASSERT_EQ(not_cached.value(), cached.value());
  }
}

// Test clock conversion with offset to the host.
TEST_F(ClockTrackerTest, ClockOffset) {
  EXPECT_FALSE(ct_->ToTraceTime(REALTIME, 0).has_value());

  context_.machine_tracker =
      std::make_unique<MachineTracker>(&context_, 0x1001);

  // Client-to-host BOOTTIME offset is -10000 ns.
  ct_->SetRemoteClockOffset(BOOTTIME, -10000);

  ct_->AddSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}});
  ct_->AddSnapshot({{REALTIME, 20}, {BOOTTIME, 20220}});
  ct_->AddSnapshot({{REALTIME, 30}, {BOOTTIME, 30030}});
  ct_->AddSnapshot({{MONOTONIC, 1000}, {BOOTTIME, 100000}});

  auto seq_clock_1 = ClockId::Sequence(0, 1, 64);
  auto seq_clock_2 = ClockId::Sequence(0, 2, 64);
  ct_->AddSnapshot({{MONOTONIC, 2000}, {seq_clock_1, 1200}});
  ct_->AddSnapshot({{seq_clock_1, 1300}, {seq_clock_2, 2000, 10, false}});

  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 0), 20000);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 1), 20001);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 9), 20009);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 10), 20010);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 11), 20011);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 19), 20019);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 20), 30220);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 21), 30221);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 29), 30229);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 30), 40030);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 40), 40040);

  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 0), 100000 - 1000 + 10000);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 999), 100000 - 1 + 10000);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 1000), 100000 + 10000);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 1e6),
            static_cast<int64_t>(100000 - 1000 + 1e6 + 10000));

  // seq_clock_1 -> MONOTONIC -> BOOTTIME -> apply offset.
  EXPECT_EQ(*ct_->ToTraceTime(seq_clock_1, 1100), -100 + 1000 + 100000 + 10000);
  // seq_clock_2 -> seq_clock_1 -> MONOTONIC -> BOOTTIME -> apply offset.
  EXPECT_EQ(*ct_->ToTraceTime(seq_clock_2, 2100),
            (100 * 10) + 100 + 1000 + 100000 + 10000);
}

// Test conversion of remote machine timestamps without offset. This can happen
// if timestamp conversion for remote machines is done by trace data
// post-processing.
TEST_F(ClockTrackerTest, RemoteNoClockOffset) {
  context_.machine_tracker =
      std::make_unique<MachineTracker>(&context_, 0x1001);

  ct_->AddSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}});
  ct_->AddSnapshot({{REALTIME, 20}, {BOOTTIME, 20220}});
  ct_->AddSnapshot({{MONOTONIC, 1000}, {BOOTTIME, 100000}});

  auto seq_clock_1 = ClockId::Sequence(0, 1, 64);
  auto seq_clock_2 = ClockId::Sequence(0, 2, 64);
  ct_->AddSnapshot({{MONOTONIC, 2000}, {seq_clock_1, 1200}});
  ct_->AddSnapshot({{seq_clock_1, 1300}, {seq_clock_2, 2000, 10, false}});

  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 0), 10000);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 9), 10009);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 10), 10010);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 11), 10011);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 19), 10019);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 20), 20220);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 21), 20221);

  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 0), 100000 - 1000);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 999), 100000 - 1);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 1000), 100000);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 1e6),
            static_cast<int64_t>(100000 - 1000 + 1e6));

  // seq_clock_1 -> MONOTONIC -> BOOTTIME.
  EXPECT_EQ(*ct_->ToTraceTime(seq_clock_1, 1100), -100 + 1000 + 100000);
  // seq_clock_2 -> seq_clock_1 -> MONOTONIC -> BOOTTIME.
  EXPECT_EQ(*ct_->ToTraceTime(seq_clock_2, 2100),
            (100 * 10) + 100 + 1000 + 100000);
}

// Test clock offset of non-defualt trace time clock domain.
TEST_F(ClockTrackerTest, NonDefaultTraceTimeClock) {
  context_.machine_tracker =
      std::make_unique<MachineTracker>(&context_, 0x1001);

  ct_->SetGlobalClock(MONOTONIC);
  ct_->SetRemoteClockOffset(MONOTONIC, -2000);
  ct_->SetRemoteClockOffset(BOOTTIME, -10000);  // This doesn't take effect.

  ct_->AddSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}});
  ct_->AddSnapshot({{MONOTONIC, 1000}, {BOOTTIME, 100000}});

  auto seq_clock_1 = ClockId::Sequence(0, 1, 64);
  ct_->AddSnapshot({{MONOTONIC, 2000}, {seq_clock_1, 1200}});

  int64_t realtime_to_trace_time_delta = -10 + 10010 - 100000 + 1000 - (-2000);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 9), 9 + realtime_to_trace_time_delta);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 10), 10 + realtime_to_trace_time_delta);
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 20), 20 + realtime_to_trace_time_delta);

  int64_t mono_to_trace_time_delta = -2000;
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 0), 0 - mono_to_trace_time_delta);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 999), 999 - mono_to_trace_time_delta);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 1000),
            1000 - mono_to_trace_time_delta);
  EXPECT_EQ(*ct_->ToTraceTime(MONOTONIC, 1e6),
            static_cast<int64_t>(1e6) - mono_to_trace_time_delta);

  // seq_clock_1 -> MONOTONIC.
  EXPECT_EQ(*ct_->ToTraceTime(seq_clock_1, 1100), 1100 - 1200 + 2000 - (-2000));
}

TEST_F(ClockTrackerTest, MultiHopCacheIsHit) {
  // Path: MONOTONIC_RAW -> MONOTONIC -> BOOTTIME
  ct_->AddSnapshot({{MONOTONIC_RAW, 100}, {MONOTONIC, 200}});
  ct_->AddSnapshot({{MONOTONIC, 300}, {BOOTTIME, 4000}});

  // First conversion should be a cache miss.
  uint32_t hits = ct_->cache_hits_for_testing();
  int64_t expected_ts = 10 + (200 - 100) + (4000 - 300);
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 10, BOOTTIME), expected_ts);
  EXPECT_EQ(ct_->cache_hits_for_testing(), hits);

  // Second conversion should be a cache hit.
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 10, BOOTTIME), expected_ts);
  EXPECT_EQ(ct_->cache_hits_for_testing(), hits + 1);

  // Another conversion within the same range.
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 20, BOOTTIME), expected_ts + 10);
  EXPECT_EQ(ct_->cache_hits_for_testing(), hits + 2);

  // Add a new snapshot. This should clear the cache.
  ct_->AddSnapshot({{MONOTONIC, 500}, {BOOTTIME, 6000}});

  // This conversion should now cause another cache miss.
  hits = ct_->cache_hits_for_testing();
  EXPECT_EQ(*Convert(MONOTONIC_RAW, 10, BOOTTIME), expected_ts);
  EXPECT_EQ(ct_->cache_hits_for_testing(), hits);
}

TEST_F(ClockTrackerTest, CacheBoundaries) {
  ct_->AddSnapshot({{MONOTONIC, 100}, {BOOTTIME, 1000}});
  ct_->AddSnapshot({{MONOTONIC, 200}, {BOOTTIME, 2000}});
  ct_->AddSnapshot({{MONOTONIC, 300}, {BOOTTIME, 3000}});

  // Test points around the first snapshot.
  EXPECT_EQ(*Convert(MONOTONIC, 99, BOOTTIME), 999);
  EXPECT_EQ(*Convert(MONOTONIC, 100, BOOTTIME), 1000);
  EXPECT_EQ(*Convert(MONOTONIC, 101, BOOTTIME), 1001);

  // Test points around the second snapshot.
  EXPECT_EQ(*Convert(MONOTONIC, 199, BOOTTIME), 1099);
  EXPECT_EQ(*Convert(MONOTONIC, 200, BOOTTIME), 2000);
  EXPECT_EQ(*Convert(MONOTONIC, 201, BOOTTIME), 2001);

  // Test points around the third snapshot.
  EXPECT_EQ(*Convert(MONOTONIC, 299, BOOTTIME), 2099);
  EXPECT_EQ(*Convert(MONOTONIC, 300, BOOTTIME), 3000);
  EXPECT_EQ(*Convert(MONOTONIC, 301, BOOTTIME), 3001);
}

TEST_F(ClockTrackerTest, CacheInvalidationAndPathReoptimization) {
  // 1. Set up a 2-hop path and convert through it.
  ct_->AddSnapshot({{MONOTONIC, 100}, {MONOTONIC_RAW, 200}});
  ct_->AddSnapshot({{MONOTONIC_RAW, 300}, {BOOTTIME, 4000}});

  // First conversion is a miss.
  EXPECT_EQ(*Convert(MONOTONIC, 50, BOOTTIME), 50 + (200 - 100) + (4000 - 300));
  EXPECT_EQ(ct_->cache_hits_for_testing(), 0u);

  // Second conversion should be a cache hit.
  EXPECT_EQ(*Convert(MONOTONIC, 50, BOOTTIME), 50 + (200 - 100) + (4000 - 300));
  EXPECT_EQ(ct_->cache_hits_for_testing(), 1u);

  // 2. Add a direct, more optimal path. This will clear the cache.
  ct_->AddSnapshot({{MONOTONIC, 500}, {BOOTTIME, 6000}});

  // 3. Convert again. It should be a miss, and the new, more optimal path
  // should be used for the conversion.
  EXPECT_EQ(*Convert(MONOTONIC, 400, BOOTTIME), 400 + (6000 - 500));
  EXPECT_EQ(ct_->cache_hits_for_testing(), 1u);

  // The new path should now be cached.
  EXPECT_EQ(*Convert(MONOTONIC, 400, BOOTTIME), 400 + (6000 - 500));
  EXPECT_EQ(ct_->cache_hits_for_testing(), 2u);
}

TEST_F(ClockTrackerTest, ThreeHopConversion) {
  // Path: REALTIME -> MONOTONIC_RAW -> MONOTONIC -> BOOTTIME
  ct_->AddSnapshot({{REALTIME, 1000}, {MONOTONIC_RAW, 100}});
  ct_->AddSnapshot({{MONOTONIC_RAW, 200}, {MONOTONIC, 3000}});
  ct_->AddSnapshot({{MONOTONIC, 4000}, {BOOTTIME, 50000}});

  // First conversion should be a cache miss.
  uint32_t hits = ct_->cache_hits_for_testing();
  int64_t expected_ts = 10 + (100 - 1000) + (3000 - 200) + (50000 - 4000);
  EXPECT_EQ(*Convert(REALTIME, 10, BOOTTIME), expected_ts);
  EXPECT_EQ(ct_->cache_hits_for_testing(), hits);

  // Second conversion should be a cache hit.
  EXPECT_EQ(*Convert(REALTIME, 10, BOOTTIME), expected_ts);
  EXPECT_EQ(ct_->cache_hits_for_testing(), hits + 1);

  // Another conversion within the same range.
  EXPECT_EQ(*Convert(REALTIME, 20, BOOTTIME), expected_ts + 10);
  EXPECT_EQ(ct_->cache_hits_for_testing(), hits + 2);
}

// Tests for multi-trace clock isolation (shared_sync fallback).
TEST_F(ClockTrackerTest, NonPrimaryUsesSharedSnapshots) {
  // Set up a shared ClockSynchronizer (simulating the per-machine shared sync).
  ClockSynchronizer shared_sync(
      context_.trace_time_state.get(),
      std::make_unique<ClockSynchronizerListenerImpl>(&context_));
  // Add snapshots to the shared sync (primary trace's snapshots).
  shared_sync.AddSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}});
  shared_sync.AddSnapshot({{MONOTONIC, 1000}, {BOOTTIME, 100000}});

  // Create a non-primary ClockTracker that falls back to shared_sync.
  auto non_primary = std::make_unique<ClockTracker>(
      &context_, std::make_unique<ClockSynchronizerListenerImpl>(&context_),
      &shared_sync, /*is_primary=*/false);

  // Non-primary should be able to convert using the shared snapshots.
  EXPECT_EQ(*non_primary->ToTraceTime(REALTIME, 10), 10010);
  EXPECT_EQ(*non_primary->ToTraceTime(REALTIME, 20), 10020);
  EXPECT_EQ(*non_primary->ToTraceTime(MONOTONIC, 1000), 100000);
}

TEST_F(ClockTrackerTest, NonPrimarySwitchesToOwnOnAddSnapshot) {
  ClockSynchronizer shared_sync(
      context_.trace_time_state.get(),
      std::make_unique<ClockSynchronizerListenerImpl>(&context_));
  shared_sync.AddSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}});

  auto non_primary = std::make_unique<ClockTracker>(
      &context_, std::make_unique<ClockSynchronizerListenerImpl>(&context_),
      &shared_sync, /*is_primary=*/false);

  // Before own snapshot: uses shared snapshots.
  EXPECT_EQ(*non_primary->ToTraceTime(REALTIME, 10), 10010);

  // Add own snapshot with different offset.
  non_primary->AddSnapshot({{REALTIME, 100}, {BOOTTIME, 200100}});

  // After own snapshot: uses own sync, not shared.
  EXPECT_EQ(*non_primary->ToTraceTime(REALTIME, 100), 200100);
  EXPECT_EQ(*non_primary->ToTraceTime(REALTIME, 110), 200110);
}

TEST_F(ClockTrackerTest, PrimaryTraceAlwaysUsesSharedSync) {
  ClockSynchronizer shared_sync(
      context_.trace_time_state.get(),
      std::make_unique<ClockSynchronizerListenerImpl>(&context_));

  // Create primary trace ClockTracker pointing to shared_sync.
  auto primary = std::make_unique<ClockTracker>(
      &context_, std::make_unique<ClockSynchronizerListenerImpl>(&context_),
      &shared_sync, /*is_primary=*/true);

  // Primary adds snapshots — they should go to shared_sync.
  primary->AddSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}});

  // Primary converts using shared_sync.
  EXPECT_EQ(*primary->ToTraceTime(REALTIME, 10), 10010);

  // A non-primary trace should also see the primary's snapshots.
  auto non_primary = std::make_unique<ClockTracker>(
      &context_, std::make_unique<ClockSynchronizerListenerImpl>(&context_),
      &shared_sync, /*is_primary=*/false);
  EXPECT_EQ(*non_primary->ToTraceTime(REALTIME, 10), 10010);
}

// --- TraceTimeSetup state machine tests ---

TEST_F(ClockTrackerTest, SetTraceTimeClockBehavior) {
  ct_->SetGlobalClock(BOOTTIME);
  ct_->AddSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}});
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 10), 10010);
}

TEST_F(ClockTrackerTest, AddDeferredIdentitySync_InjectsEdge) {
  // AddDeferredIdentitySync injects a zero-offset edge between the given clock
  // and the trace time clock (BOOTTIME in test fixture).
  constexpr ClockTracker::ClockId TRACE_FILE = ClockId::TraceFile(0);
  ct_->AddDeferredIdentitySync(TRACE_FILE);

  // The identity edge allows conversion: TRACE_FILE timestamps pass through.
  EXPECT_EQ(*ct_->ToTraceTime(TRACE_FILE, 42), 42);
  EXPECT_EQ(*ct_->ToTraceTime(TRACE_FILE, 100), 100);
}

TEST_F(ClockTrackerTest, SetTraceDefaultClock_SetsDefaultClock) {
  constexpr ClockTracker::ClockId TRACE_FILE = ClockId::TraceFile(0);
  ct_->SetTraceDefaultClock(TRACE_FILE);

  ASSERT_TRUE(ct_->trace_default_clock().has_value());
  EXPECT_EQ(*ct_->trace_default_clock(), TRACE_FILE);
}

TEST_F(ClockTrackerTest, AddDeferredIdentitySync_MatchesTraceTimeClock) {
  // If the identity clock IS the trace time clock, no edge needed.
  ct_->AddDeferredIdentitySync(BOOTTIME);

  ct_->AddSnapshot({{REALTIME, 10}, {BOOTTIME, 10010}});
  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 10), 10010);
  EXPECT_EQ(*ct_->ToTraceTime(BOOTTIME, 42), 42);
}

TEST_F(ClockTrackerTest, AddDeferredIdentitySync_WithExplicitSnapshot) {
  // AddDeferredIdentitySync creates a zero-offset edge TRACE_FILE ↔ BOOTTIME
  // (since BOOTTIME is the global trace time clock in the test fixture).
  constexpr ClockTracker::ClockId TRACE_FILE = ClockId::TraceFile(0);
  ct_->AddDeferredIdentitySync(TRACE_FILE);

  // Without any other snapshot, TRACE_FILE converts to BOOTTIME at offset 0.
  EXPECT_EQ(*ct_->ToTraceTime(TRACE_FILE, 42), 42);

  // An explicit snapshot overrides the identity edge with real data.
  ct_->AddSnapshot({{TRACE_FILE, 100}, {BOOTTIME, 1100}});
  EXPECT_EQ(*ct_->ToTraceTime(TRACE_FILE, 100), 1100);
  EXPECT_EQ(*ct_->ToTraceTime(BOOTTIME, 1100), 1100);
}

TEST_F(ClockTrackerTest,
       AddDeferredIdentitySync_DoesNotChangeGlobalTraceClock) {
  // Trace time starts as BOOTTIME (test fixture default).
  constexpr ClockTracker::ClockId TRACE_FILE = ClockId::TraceFile(0);
  ct_->AddDeferredIdentitySync(TRACE_FILE);

  // AddDeferredIdentitySync does NOT change the global trace time clock.
  EXPECT_EQ(context_.trace_time_state->clock_id, BOOTTIME);
}

TEST_F(ClockTrackerTest, SetGlobalClock_ChangesGlobalClock) {
  ct_->SetGlobalClock(MONOTONIC);
  ct_->AddSnapshot({{REALTIME, 10}, {MONOTONIC, 500}});

  EXPECT_EQ(*ct_->ToTraceTime(REALTIME, 10), 500);
  EXPECT_EQ(context_.trace_time_state->clock_id, MONOTONIC);
}

TEST_F(ClockTrackerTest, SetGlobalClock_DoesNotSetTraceDefaultClock) {
  ct_->SetGlobalClock(MONOTONIC);

  EXPECT_FALSE(ct_->trace_default_clock().has_value());
}

TEST_F(ClockTrackerTest, SetTraceDefaultClock_DoesNotChangeGlobalClock) {
  ct_->SetTraceDefaultClock(MONOTONIC);

  // Global clock should still be BOOTTIME (test fixture default).
  EXPECT_EQ(context_.trace_time_state->clock_id, BOOTTIME);
}

}  // namespace
}  // namespace perfetto::trace_processor
