/*
 * Copyright (C) 2017 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.
 */

#define DEBUG false  // STOPSHIP if true
#include "Log.h"

#include "CountMetricProducer.h"
#include "guardrail/StatsdStats.h"
#include "stats_util.h"
#include "stats_log_util.h"

#include <limits.h>
#include <stdlib.h>

using android::util::FIELD_COUNT_REPEATED;
using android::util::FIELD_TYPE_BOOL;
using android::util::FIELD_TYPE_FLOAT;
using android::util::FIELD_TYPE_INT32;
using android::util::FIELD_TYPE_INT64;
using android::util::FIELD_TYPE_MESSAGE;
using android::util::FIELD_TYPE_STRING;
using android::util::ProtoOutputStream;
using std::map;
using std::string;
using std::unordered_map;
using std::vector;

namespace android {
namespace os {
namespace statsd {

// for StatsLogReport
const int FIELD_ID_ID = 1;
const int FIELD_ID_COUNT_METRICS = 5;
// for CountMetricDataWrapper
const int FIELD_ID_DATA = 1;
// for CountMetricData
const int FIELD_ID_DIMENSION_IN_WHAT = 1;
const int FIELD_ID_DIMENSION_IN_CONDITION = 2;
const int FIELD_ID_BUCKET_INFO = 3;
// for CountBucketInfo
const int FIELD_ID_START_BUCKET_NANOS = 1;
const int FIELD_ID_END_BUCKET_NANOS = 2;
const int FIELD_ID_COUNT = 3;

CountMetricProducer::CountMetricProducer(const ConfigKey& key, const CountMetric& metric,
                                         const int conditionIndex,
                                         const sp<ConditionWizard>& wizard,
                                         const uint64_t startTimeNs)
    : MetricProducer(metric.id(), key, startTimeNs, conditionIndex, wizard) {
    // TODO: evaluate initial conditions. and set mConditionMet.
    if (metric.has_bucket()) {
        mBucketSizeNs = TimeUnitToBucketSizeInMillis(metric.bucket()) * 1000000;
    } else {
        mBucketSizeNs = LLONG_MAX;
    }

    if (metric.has_dimensions_in_what()) {
        translateFieldMatcher(metric.dimensions_in_what(), &mDimensionsInWhat);
    }

    if (metric.has_dimensions_in_condition()) {
        translateFieldMatcher(metric.dimensions_in_condition(), &mDimensionsInCondition);
    }

    if (metric.links().size() > 0) {
        for (const auto& link : metric.links()) {
            Metric2Condition mc;
            mc.conditionId = link.condition();
            translateFieldMatcher(link.fields_in_what(), &mc.metricFields);
            translateFieldMatcher(link.fields_in_condition(), &mc.conditionFields);
            mMetric2ConditionLinks.push_back(mc);
        }
        mConditionSliced = true;
    }

    mConditionSliced = (metric.links().size() > 0) || (mDimensionsInCondition.size() > 0);

    VLOG("metric %lld created. bucket size %lld start_time: %lld", (long long)metric.id(),
         (long long)mBucketSizeNs, (long long)mStartTimeNs);
}

CountMetricProducer::~CountMetricProducer() {
    VLOG("~CountMetricProducer() called");
}

void CountMetricProducer::onSlicedConditionMayChangeLocked(const uint64_t eventTime) {
    VLOG("Metric %lld onSlicedConditionMayChange", (long long)mMetricId);
}

void CountMetricProducer::onDumpReportLocked(const uint64_t dumpTimeNs,
                                             ProtoOutputStream* protoOutput) {
    flushIfNeededLocked(dumpTimeNs);
    if (mPastBuckets.empty()) {
        return;
    }

    protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_ID, (long long)mMetricId);
    long long protoToken = protoOutput->start(FIELD_TYPE_MESSAGE | FIELD_ID_COUNT_METRICS);

    for (const auto& counter : mPastBuckets) {
        const MetricDimensionKey& dimensionKey = counter.first;
        VLOG("  dimension key %s", dimensionKey.c_str());

        long long wrapperToken =
                protoOutput->start(FIELD_TYPE_MESSAGE | FIELD_COUNT_REPEATED | FIELD_ID_DATA);

        // First fill dimension.
        long long dimensionInWhatToken = protoOutput->start(
                FIELD_TYPE_MESSAGE | FIELD_ID_DIMENSION_IN_WHAT);
        writeDimensionToProto(dimensionKey.getDimensionKeyInWhat(), protoOutput);
        protoOutput->end(dimensionInWhatToken);

        if (dimensionKey.hasDimensionKeyInCondition()) {
            long long dimensionInConditionToken = protoOutput->start(
                    FIELD_TYPE_MESSAGE | FIELD_ID_DIMENSION_IN_CONDITION);
            writeDimensionToProto(dimensionKey.getDimensionKeyInCondition(), protoOutput);
            protoOutput->end(dimensionInConditionToken);
        }

        // Then fill bucket_info (CountBucketInfo).
        for (const auto& bucket : counter.second) {
            long long bucketInfoToken = protoOutput->start(
                    FIELD_TYPE_MESSAGE | FIELD_COUNT_REPEATED | FIELD_ID_BUCKET_INFO);
            protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_START_BUCKET_NANOS,
                               (long long)bucket.mBucketStartNs);
            protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_END_BUCKET_NANOS,
                               (long long)bucket.mBucketEndNs);
            protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_COUNT, (long long)bucket.mCount);
            protoOutput->end(bucketInfoToken);
            VLOG("\t bucket [%lld - %lld] count: %lld", (long long)bucket.mBucketStartNs,
                 (long long)bucket.mBucketEndNs, (long long)bucket.mCount);
        }
        protoOutput->end(wrapperToken);
    }

    protoOutput->end(protoToken);

    mPastBuckets.clear();

    // TODO: Clear mDimensionKeyMap once the report is dumped.
}

void CountMetricProducer::onConditionChangedLocked(const bool conditionMet,
                                                   const uint64_t eventTime) {
    VLOG("Metric %lld onConditionChanged", (long long)mMetricId);
    mCondition = conditionMet;
}

bool CountMetricProducer::hitGuardRailLocked(const MetricDimensionKey& newKey) {
    if (mCurrentSlicedCounter->find(newKey) != mCurrentSlicedCounter->end()) {
        return false;
    }
    // ===========GuardRail==============
    // 1. Report the tuple count if the tuple count > soft limit
    if (mCurrentSlicedCounter->size() > StatsdStats::kDimensionKeySizeSoftLimit - 1) {
        size_t newTupleCount = mCurrentSlicedCounter->size() + 1;
        StatsdStats::getInstance().noteMetricDimensionSize(mConfigKey, mMetricId, newTupleCount);
        // 2. Don't add more tuples, we are above the allowed threshold. Drop the data.
        if (newTupleCount > StatsdStats::kDimensionKeySizeHardLimit) {
            ALOGE("CountMetric %lld dropping data for dimension key %s",
                (long long)mMetricId, newKey.c_str());
            return true;
        }
    }

    return false;
}

void CountMetricProducer::onMatchedLogEventInternalLocked(
        const size_t matcherIndex, const MetricDimensionKey& eventKey,
        const ConditionKey& conditionKey, bool condition,
        const LogEvent& event) {
    uint64_t eventTimeNs = event.GetTimestampNs();
    flushIfNeededLocked(eventTimeNs);

    if (condition == false) {
        return;
    }

    auto it = mCurrentSlicedCounter->find(eventKey);
    if (it == mCurrentSlicedCounter->end()) {
        // ===========GuardRail==============
        if (hitGuardRailLocked(eventKey)) {
            return;
        }
        // create a counter for the new key
        (*mCurrentSlicedCounter)[eventKey] = 1;
    } else {
        // increment the existing value
        auto& count = it->second;
        count++;
    }
    for (auto& tracker : mAnomalyTrackers) {
        int64_t countWholeBucket = mCurrentSlicedCounter->find(eventKey)->second;
        auto prev = mCurrentFullCounters->find(eventKey);
        if (prev != mCurrentFullCounters->end()) {
            countWholeBucket += prev->second;
        }
        tracker->detectAndDeclareAnomaly(eventTimeNs, mCurrentBucketNum, eventKey,
                                         countWholeBucket);
    }

    VLOG("metric %lld %s->%lld", (long long)mMetricId, eventKey.c_str(),
         (long long)(*mCurrentSlicedCounter)[eventKey]);
}

// When a new matched event comes in, we check if event falls into the current
// bucket. If not, flush the old counter to past buckets and initialize the new bucket.
void CountMetricProducer::flushIfNeededLocked(const uint64_t& eventTimeNs) {
    uint64_t currentBucketEndTimeNs = getCurrentBucketEndTimeNs();
    if (eventTimeNs < currentBucketEndTimeNs) {
        return;
    }

    flushCurrentBucketLocked(eventTimeNs);
    // Setup the bucket start time and number.
    uint64_t numBucketsForward = 1 + (eventTimeNs - currentBucketEndTimeNs) / mBucketSizeNs;
    mCurrentBucketStartTimeNs = currentBucketEndTimeNs + (numBucketsForward - 1) * mBucketSizeNs;
    mCurrentBucketNum += numBucketsForward;
    VLOG("metric %lld: new bucket start time: %lld", (long long)mMetricId,
         (long long)mCurrentBucketStartTimeNs);
}

void CountMetricProducer::flushCurrentBucketLocked(const uint64_t& eventTimeNs) {
    uint64_t fullBucketEndTimeNs = getCurrentBucketEndTimeNs();
    CountBucket info;
    info.mBucketStartNs = mCurrentBucketStartTimeNs;
    if (eventTimeNs < fullBucketEndTimeNs) {
        info.mBucketEndNs = eventTimeNs;
    } else {
        info.mBucketEndNs = fullBucketEndTimeNs;
    }
    info.mBucketNum = mCurrentBucketNum;
    for (const auto& counter : *mCurrentSlicedCounter) {
        info.mCount = counter.second;
        auto& bucketList = mPastBuckets[counter.first];
        bucketList.push_back(info);
        VLOG("metric %lld, dump key value: %s -> %lld", (long long)mMetricId, counter.first.c_str(),
             (long long)counter.second);
    }

    // If we have finished a full bucket, then send this to anomaly tracker.
    if (eventTimeNs > fullBucketEndTimeNs) {
        // Accumulate partial buckets with current value and then send to anomaly tracker.
        if (mCurrentFullCounters->size() > 0) {
            for (const auto& keyValuePair : *mCurrentSlicedCounter) {
                (*mCurrentFullCounters)[keyValuePair.first] += keyValuePair.second;
            }
            for (auto& tracker : mAnomalyTrackers) {
                tracker->addPastBucket(mCurrentFullCounters, mCurrentBucketNum);
            }
            mCurrentFullCounters = std::make_shared<DimToValMap>();
        } else {
            // Skip aggregating the partial buckets since there's no previous partial bucket.
            for (auto& tracker : mAnomalyTrackers) {
                tracker->addPastBucket(mCurrentSlicedCounter, mCurrentBucketNum);
            }
        }
    } else {
        // Accumulate partial bucket.
        for (const auto& keyValuePair : *mCurrentSlicedCounter) {
            (*mCurrentFullCounters)[keyValuePair.first] += keyValuePair.second;
        }
    }

    // Only resets the counters, but doesn't setup the times nor numbers.
    // (Do not clear since the old one is still referenced in mAnomalyTrackers).
    mCurrentSlicedCounter = std::make_shared<DimToValMap>();
}

// Rough estimate of CountMetricProducer buffer stored. This number will be
// greater than actual data size as it contains each dimension of
// CountMetricData is  duplicated.
size_t CountMetricProducer::byteSizeLocked() const {
    size_t totalSize = 0;
    for (const auto& pair : mPastBuckets) {
        totalSize += pair.second.size() * kBucketSize;
    }
    return totalSize;
}

}  // namespace statsd
}  // namespace os
}  // namespace android