/*
 * Copyright (C) 2020 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 LOG_TAG "pixelstats-uevent: BatteryCapacityFG"

#include <log/log.h>
#include <time.h>
#include <utils/Timers.h>
#include <cmath>

#include <android-base/file.h>

#include <pixelstats/BatteryCapacityReporter.h>
#include <pixelstats/StatsHelper.h>

#include <hardware/google/pixel/pixelstats/pixelatoms.pb.h>

namespace android {
namespace hardware {
namespace google {
namespace pixel {

using aidl::android::frameworks::stats::IStats;
using aidl::android::frameworks::stats::VendorAtom;
using aidl::android::frameworks::stats::VendorAtomValue;
using android::base::ReadFileToString;
using android::hardware::google::pixel::PixelAtoms::BatteryCapacityFG;

#define ONE_HOUR_SECS (60 * 60)

BatteryCapacityReporter::BatteryCapacityReporter() {
    // Remove the need for a translation function/table, while removing the dependency on the
    // generated <pixelatoms.pb.h> in BatteryCapacityReporter.h.
    static_assert(static_cast<int>(BatteryCapacityReporter::LOG_REASON_UNKNOWN) ==
                  static_cast<int>(BatteryCapacityFG::LOG_REASON_UNKNOWN));
    static_assert(static_cast<int>(BatteryCapacityReporter::LOG_REASON_CONNECTED) ==
                  static_cast<int>(BatteryCapacityFG::LOG_REASON_CONNECTED));
    static_assert(static_cast<int>(BatteryCapacityReporter::LOG_REASON_DISCONNECTED) ==
                  static_cast<int>(BatteryCapacityFG::LOG_REASON_DISCONNECTED));
    static_assert(static_cast<int>(BatteryCapacityReporter::LOG_REASON_FULL_CHARGE) ==
                  static_cast<int>(BatteryCapacityFG::LOG_REASON_FULL_CHARGE));
    static_assert(static_cast<int>(BatteryCapacityReporter::LOG_REASON_PERCENT_SKIP) ==
                  static_cast<int>(BatteryCapacityFG::LOG_REASON_PERCENT_SKIP));
    static_assert(static_cast<int>(BatteryCapacityReporter::LOG_REASON_DIVERGING_FG) ==
                  static_cast<int>(BatteryCapacityFG::LOG_REASON_DIVERGING_FG));
}

void BatteryCapacityReporter::checkAndReport(const std::shared_ptr<IStats> &stats_client,
                                             const std::string &path) {
    if (parse(path)) {
        if (checkLogEvent()) {
            reportEvent(stats_client);
        }
    }
}

int64_t BatteryCapacityReporter::getTimeSecs(void) {
    return nanoseconds_to_seconds(systemTime(SYSTEM_TIME_BOOTTIME));
}

bool BatteryCapacityReporter::parse(const std::string &path) {
    std::string batterySSOCContents;
    if (!ReadFileToString(path, &batterySSOCContents)) {
        ALOGE("Unable to read ssoc_details path: %s - %s", path.c_str(), strerror(errno));
        return false;
    }

    // Parse file. Example format:
    // soc: l=97% gdf=97.72 uic=97.72 rl=97.72
    // curve:[15.00 15.00][97.87 97.87][100.00 100.00]
    // status: ct=1 rl=0 s=1
    if (sscanf(batterySSOCContents.c_str(),
               "soc: %*s gdf=%f %*s rl=%f\n"
               "curve:[%*f %*f][%f %f][%*f %*f]\n"
               "status: %*s %*s s=%d",
               &gdf_, &ssoc_, &gdf_curve_, &ssoc_curve_, &status_) != 5) {
        ALOGE("Unable to parse ssoc_details [%s] from file %s to int.", batterySSOCContents.c_str(),
              path.c_str());
        return false;
    }

    return true;
}

bool BatteryCapacityReporter::shouldReportEvent(void) {
    const int64_t current_time = getTimeSecs();
    if (current_time == 0) {
        ALOGE("Current boot time is zero!");
        return false;
    }

    /* Perform cleanup of events that are older than 1 hour */
    for (int i = 0; i < MAX_LOG_EVENTS_PER_HOUR; i++) {
        if (log_event_time_secs_[i] != 0 && /* Non-empty */
            log_event_time_secs_[i] + ONE_HOUR_SECS < current_time) {
            log_event_time_secs_[i] = 0;
            num_events_in_last_hour_--;
        }
    }

    /* Log event if there hasn't been many events in the past hour */
    if (num_events_in_last_hour_ < MAX_LOG_EVENTS_PER_HOUR) {
        for (int i = 0; i < MAX_LOG_EVENTS_PER_HOUR; i++) {
            if (log_event_time_secs_[i] == 0) { /* Empty */
                log_event_time_secs_[i] = current_time;
                num_events_in_last_hour_++;
                return true;
            }
        }
    } else {
        ALOGD("Too many log events in past hour; event ignored.");
    }

    return false;
}

/**
 * @return true if a log should be reported, else false
 */
bool BatteryCapacityReporter::checkLogEvent(void) {
    LogReason log_reason = LOG_REASON_UNKNOWN;
    if (status_previous_ != status_) {
        // Handle nominal events

        if (status_ == SOC_STATUS_CONNECTED) {
            log_reason = LOG_REASON_CONNECTED;

        } else if (status_ == SOC_STATUS_DISCONNECTED) {
            log_reason = LOG_REASON_DISCONNECTED;

        } else if (status_ == SOC_STATUS_FULL) {
            log_reason = LOG_REASON_FULL_CHARGE;
        }

        status_previous_ = status_;

    } else {
        // Handle abnormal events
        const float diff = fabsf(ssoc_ - gdf_);

        if (fabsf(ssoc_ - ssoc_previous_) >= 2.0f) {
            log_reason = LOG_REASON_PERCENT_SKIP;

            // Every +- 1% when above a 4% SOC difference (w/ timer)
        } else if (static_cast<int>(round(ssoc_gdf_diff_previous_)) !=
                           static_cast<int>(round(diff)) &&
                   diff >= 4.0f) {
            log_reason = LOG_REASON_DIVERGING_FG;

            ssoc_gdf_diff_previous_ = diff;
        }
    }
    ssoc_previous_ = ssoc_;
    log_reason_ = log_reason;

    if (log_reason != LOG_REASON_UNKNOWN) {
        /* Found new log event! */
        /* Check if we should actually report the event */
        return shouldReportEvent();
    }

    return false;
}

void BatteryCapacityReporter::reportEvent(const std::shared_ptr<IStats> &stats_client) {
    // Load values array
    std::vector<VendorAtomValue> values(5);
    VendorAtomValue tmp;
    tmp.set<VendorAtomValue::intValue>(log_reason_);
    values[BatteryCapacityFG::kCapacityLogReasonFieldNumber - kVendorAtomOffset] = tmp;
    tmp.set<VendorAtomValue::floatValue>(gdf_);
    values[BatteryCapacityFG::kCapacityGdfFieldNumber - kVendorAtomOffset] = tmp;
    tmp.set<VendorAtomValue::floatValue>(ssoc_);
    values[BatteryCapacityFG::kCapacitySsocFieldNumber - kVendorAtomOffset] = tmp;
    tmp.set<VendorAtomValue::floatValue>(gdf_curve_);
    values[BatteryCapacityFG::kCapacityGdfCurveFieldNumber - kVendorAtomOffset] = tmp;
    tmp.set<VendorAtomValue::floatValue>(ssoc_curve_);
    values[BatteryCapacityFG::kCapacitySsocCurveFieldNumber - kVendorAtomOffset] = tmp;

    // Send vendor atom to IStats HAL
    VendorAtom event = {.reverseDomainName = PixelAtoms::ReverseDomainNames().pixel(),
                        .atomId = PixelAtoms::Atom::kFgCapacity,
                        .values = std::move(values)};
    const ndk::ScopedAStatus ret = stats_client->reportVendorAtom(event);
    if (!ret.isOk())
        ALOGE("Unable to report to IStats service");
}

}  // namespace pixel
}  // namespace google
}  // namespace hardware
}  // namespace android