/* Copyright Statement:
 *
 * This software/firmware and related documentation ("MediaTek Software") are
 * protected under relevant copyright laws. The information contained herein is
 * confidential and proprietary to MediaTek Inc. and/or its licensors. Without
 * the prior written permission of MediaTek inc. and/or its licensors, any
 * reproduction, modification, use or disclosure of MediaTek Software, and
 * information contained herein, in whole or in part, shall be strictly
 * prohibited.
 *
 * MediaTek Inc. (C) 2022. All rights reserved.
 *
 * BY OPENING THIS FILE, RECEIVER HEREBY UNEQUIVOCALLY ACKNOWLEDGES AND AGREES
 * THAT THE SOFTWARE/FIRMWARE AND ITS DOCUMENTATIONS ("MEDIATEK SOFTWARE")
 * RECEIVED FROM MEDIATEK AND/OR ITS REPRESENTATIVES ARE PROVIDED TO RECEIVER
 * ON AN "AS-IS" BASIS ONLY. MEDIATEK EXPRESSLY DISCLAIMS ANY AND ALL
 * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NONINFRINGEMENT. NEITHER DOES MEDIATEK PROVIDE ANY WARRANTY WHATSOEVER WITH
 * RESPECT TO THE SOFTWARE OF ANY THIRD PARTY WHICH MAY BE USED BY,
 * INCORPORATED IN, OR SUPPLIED WITH THE MEDIATEK SOFTWARE, AND RECEIVER AGREES
 * TO LOOK ONLY TO SUCH THIRD PARTY FOR ANY WARRANTY CLAIM RELATING THERETO.
 * RECEIVER EXPRESSLY ACKNOWLEDGES THAT IT IS RECEIVER'S SOLE RESPONSIBILITY TO
 * OBTAIN FROM ANY THIRD PARTY ALL PROPER LICENSES CONTAINED IN MEDIATEK
 * SOFTWARE. MEDIATEK SHALL ALSO NOT BE RESPONSIBLE FOR ANY MEDIATEK SOFTWARE
 * RELEASES MADE TO RECEIVER'S SPECIFICATION OR TO CONFORM TO A PARTICULAR
 * STANDARD OR OPEN FORUM. RECEIVER'S SOLE AND EXCLUSIVE REMEDY AND MEDIATEK'S
 * ENTIRE AND CUMULATIVE LIABILITY WITH RESPECT TO THE MEDIATEK SOFTWARE
 * RELEASED HEREUNDER WILL BE, AT MEDIATEK'S OPTION, TO REVISE OR REPLACE THE
 * MEDIATEK SOFTWARE AT ISSUE, OR REFUND ANY SOFTWARE LICENSE FEES OR SERVICE
 * CHARGE PAID BY RECEIVER TO MEDIATEK FOR SUCH MEDIATEK SOFTWARE AT ISSUE.
 *
 * The following software/firmware and/or related documentation ("MediaTek
 * Software") have been modified by MediaTek Inc. All revisions are subject to
 * any receiver's applicable license agreements with MediaTek Inc.
 */

#pragma once

#define ATRACE_TAG ATRACE_TAG_GRAPHICS

#include <log/log.h>
#include <thread>
#include <utils/Trace.h>
#include <utils/Mutex.h>
#include <android-base/properties.h>

#define MAX_DELAY_COUNT 5

namespace android {
// ---------------------------------------------------------------------------
class ScheduleHelper
{
public:
    bool mDebug;
    int64_t mDelayTransactionThreshold;
    size_t mPendingTransactionsCount;
    size_t mLocklessTransactionsCount;
    int64_t mSfWorkDuration;
    int64_t mVsyncPeriod;
    int64_t mLastScheduledPresentTime;

    std::vector<int64_t> mDelayedTimesForPending;
    std::vector<int64_t> mDelayedTimesForLockless;

    Mutex mPendings;
    Mutex mLockless;
    Mutex mGeneral;
    static ScheduleHelper& getInstance() {
        static ScheduleHelper gInstance;
        return gInstance;
    }

    ~ScheduleHelper() {};

    int64_t getDelayTimeForTransaction(bool isauto, int64_t desiredTime) {
        int64_t delayed_time = 0;
        if (!isauto) {
            Mutex::Autolock lock(mGeneral);
            const auto now = systemTime();
            // we add 2ms to cover slight shift of presentTime
            const auto nextPredictedPresentTime = mLastScheduledPresentTime + mVsyncPeriod + ms2ns(2);
            const auto delayedWakeUpTime = desiredTime - mSfWorkDuration;
            delayed_time = delayedWakeUpTime - now;
            if (desiredTime <= nextPredictedPresentTime || // don't delay if it is in next vsync.
                delayed_time > mDelayTransactionThreshold) { // don't delay too much
                delayed_time = 0;
            }
        }
        ATRACE_INT64("delayedTransaction", delayed_time);
        return delayed_time;
    }

    int64_t checkDelayTimeForPendingTransaction(bool isauto, int64_t desiredTime) {
        int64_t delayTime = getDelayTimeForTransaction(isauto, desiredTime);
        Mutex::Autolock lock(mPendings);
        if (delayTime > 0 && mDelayedTimesForPending.size() < MAX_DELAY_COUNT) {
            if (mDelayedTimesForPending.size() < MAX_DELAY_COUNT) {
                mDelayedTimesForPending.push_back(delayTime);
            } else {
                ALOGW("can't delay more pending transaction");
            }
        }
        return delayTime;
    }

    int64_t checkDelayForLocklessTransaction(bool isauto, int64_t desiredTime) {
        return getDelayTimeForTransaction(isauto, desiredTime);
    }

    void queueDelayTimeForLocklessTransaction(int64_t delayTime) {
        Mutex::Autolock lock(mLockless);
        mLocklessTransactionsCount+=1;
        if (delayTime > 0 && mDelayedTimesForLockless.size() < MAX_DELAY_COUNT) {
            if (mDelayedTimesForLockless.size() < MAX_DELAY_COUNT) {
                mDelayedTimesForLockless.push_back(delayTime);
            } else {
                ALOGW("can't delay more lockless transaction");
            }
        }
    }

    int64_t getNextDelayedTimeOfPendingTransactions() {
        Mutex::Autolock lock(mPendings);
        if (mDelayedTimesForPending.empty()) return 0;
        int64_t delayTime = mDelayedTimesForPending.back();
        mDelayedTimesForPending.pop_back();
        return delayTime;
    }

    void updateDurationVsync(int64_t sfduration, int64_t vsync) {
        Mutex::Autolock lock(mGeneral);
        mSfWorkDuration = sfduration;
        mVsyncPeriod = vsync;
    }

    void updateLastSchedulePresentTime(int64_t time) {
        Mutex::Autolock lock(mGeneral);
        mLastScheduledPresentTime = time;
    }

    void resetLocklessCount() {
        Mutex::Autolock lock(mLockless);
        mDelayedTimesForLockless.clear();
        mLocklessTransactionsCount = 0;
    }

    void increasePendingTransactionsCount() {
        Mutex::Autolock lock(mPendings);
        mPendingTransactionsCount += 1;
    }

    void resetPendingTransactionsCount() {
        Mutex::Autolock lock(mPendings);
        mPendingTransactionsCount = 0;
    }

    bool hasPendingTransactions() {
        Mutex::Autolock lock1(mPendings);
        Mutex::Autolock lock2(mLockless);
        // If all pending transactions are delayed and all lockless transactions
        // are delayed, there is no pending transactions.
        if (mDebug) {
            ATRACE_INT("PendingTransactionsCount", static_cast<int>(mPendingTransactionsCount));
            ATRACE_INT("DelayedTimesForPending", static_cast<int>(mDelayedTimesForPending.size()));
            ATRACE_INT("LocklessTransactionsCount", static_cast<int>(mLocklessTransactionsCount));
            ATRACE_INT("DelayedTimesForLockless", static_cast<int>(mDelayedTimesForLockless.size()));
        }
        if ((mPendingTransactionsCount - mDelayedTimesForPending.size() == 0) &&
            (mLocklessTransactionsCount - mDelayedTimesForLockless.size() ==0)) {
            return false;
        }
        return true;
    }

private:
    ScheduleHelper() {
        mDebug = base::GetBoolProperty("debug.sf.schedule_helper", false);
        mDelayTransactionThreshold = base::GetIntProperty("debug.sf.mDelayTransactionThreshold", 500000000);
        mDelayedTimesForPending.reserve(MAX_DELAY_COUNT);
        mDelayedTimesForLockless.reserve(MAX_DELAY_COUNT);
        mPendingTransactionsCount = 0;
        mLocklessTransactionsCount = 0;
        mSfWorkDuration = 0;
        mVsyncPeriod = 0;
        mLastScheduledPresentTime = 0;
    }
};
// ---------------------------------------------------------------------------
}; // namespace android