/*
 * Copyright (C) 2024 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 "Camera3-Utils"

#include "Utils.h"
#include <android-base/properties.h>
#include <com_android_internal_camera_flags.h>
#include <utils/Errors.h>
#include <utils/Log.h>
#include <vendorsupport/api_level.h>

namespace android {

namespace flags = com::android::internal::camera::flags;

namespace {
constexpr const char* LEGACY_VNDK_VERSION_PROP = "ro.vndk.version";
constexpr const char* BOARD_API_LEVEL_PROP = "ro.board.api_level";
constexpr int MAX_VENDOR_API_LEVEL = 1000000;
constexpr int FIRST_VNDK_VERSION = 202404;

int legacyGetVNDKVersionFromProp(int defaultVersion) {
    if (!flags::use_ro_board_api_level_for_vndk_version()) {
        return base::GetIntProperty(LEGACY_VNDK_VERSION_PROP, defaultVersion);
    }

    int vndkVersion = base::GetIntProperty(BOARD_API_LEVEL_PROP, MAX_VENDOR_API_LEVEL);

    if (vndkVersion == MAX_VENDOR_API_LEVEL) {
        // Couldn't find property
        return defaultVersion;
    }

    if (vndkVersion < __ANDROID_API_V__) {
        // VNDK versions below V return the corresponding SDK version.
        return vndkVersion;
    }

    // VNDK for Android V and above are of the format YYYYMM starting with 202404 and is bumped
    // up once a year. So V would be 202404 and the next one would be 202504.
    // This is the same assumption as that made in system/core/init/property_service.cpp.
    vndkVersion = (vndkVersion - FIRST_VNDK_VERSION) / 100;
    return __ANDROID_API_V__ + vndkVersion;
}
}  // anonymous namespace

int getVNDKVersionFromProp(int defaultVersion) {
    if (!flags::use_system_api_for_vndk_version()) {
        return legacyGetVNDKVersionFromProp(defaultVersion);
    }

    int vendorApiLevel = AVendorSupport_getVendorApiLevel();
    if (vendorApiLevel == 0) {
        // Couldn't find vendor API level, return default
        return defaultVersion;
    }

    // Vendor API level for Android V and above are of the format YYYYMM starting with 202404.
    // AVendorSupport_getSdkApiLevelOf maps them back to SDK API levels while leaving older
    // values unchanged.
    return AVendorSupport_getSdkApiLevelOf(vendorApiLevel);
}

RunThreadWithRealtimePriority::RunThreadWithRealtimePriority(int tid)
    : mTid(tid), mPreviousPolicy(sched_getscheduler(tid)) {
    if (flags::realtime_priority_bump()) {
        auto res = sched_getparam(mTid, &mPreviousParams);
        if (res != OK) {
            ALOGE("Can't retrieve thread scheduler parameters: %s (%d)", strerror(-res), res);
            return;
        }

        struct sched_param param = {0};
        param.sched_priority = kRequestThreadPriority;

        res = sched_setscheduler(mTid, SCHED_FIFO, &param);
        if (res != OK) {
            ALOGW("Can't set realtime priority for thread: %s (%d)", strerror(-res), res);
        } else {
            ALOGD("Set real time priority for thread (tid %d)", mTid);
            mPolicyBumped = true;
        }
    }
}

RunThreadWithRealtimePriority::~RunThreadWithRealtimePriority() {
    if (mPolicyBumped && flags::realtime_priority_bump()) {
        auto res = sched_setscheduler(mTid, mPreviousPolicy, &mPreviousParams);
        if (res != OK) {
            ALOGE("Can't set regular priority for thread: %s (%d)", strerror(-res), res);
        } else {
            ALOGD("Set regular priority for thread (tid %d)", mTid);
        }
    }
}

}  // namespace android