/*
 * 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.
 */

#include <mutex>
#include <unistd.h>

#include <android/app/IProcessObserver.h>
#include <android/app/RunningAppProcessInfo.h>
#include <android/permission_manager.h>
#include <binder/ActivityManager.h>
#include <binder/Binder.h>
#include <binder/IServiceManager.h>
#include <binder/ProcessState.h>

namespace android {

using namespace std::chrono_literals;

ActivityManager::ActivityManager()
{
}

sp<IActivityManager> ActivityManager::getService()
{
    std::lock_guard<Mutex> scoped_lock(mLock);
    sp<IActivityManager> service = mService;
    if (ProcessState::self()->isThreadPoolStarted()) {
        if (service == nullptr || !IInterface::asBinder(service)->isBinderAlive()) {
            sp<IBinder> binder = defaultServiceManager()->waitForService(String16("activity"));
            service = interface_cast<IActivityManager>(binder);
            mService = service;
        }
    } else {
        ALOGI("Thread pool not started. Polling for activity service.");
        auto startTime = std::chrono::steady_clock::now().min();
        while (service == nullptr || !IInterface::asBinder(service)->isBinderAlive()) {
            sp<IBinder> binder = defaultServiceManager()->checkService(String16("activity"));
            if (binder == nullptr) {
                // Wait for the activity service to come back...
                if (startTime == startTime.min()) {
                    startTime = std::chrono::steady_clock::now();
                    ALOGI("Waiting for activity service");
                } else if (std::chrono::steady_clock::now() - startTime > 1000s) {
                    // TODO(b/342453147): timeout of 1000s = 16min and 40s doesn't seem intended
                    ALOGW("Waiting too long for activity service, giving up");
                    service = nullptr;
                    break;
                }
                usleep(25000);
            } else {
                service = interface_cast<IActivityManager>(binder);
                mService = service;
            }
        }
    }
    return mService;
}

int ActivityManager::openContentUri(const String16& stringUri)
{
    sp<IActivityManager> service = getService();
    return service != nullptr ? service->openContentUri(stringUri) : -1;
}

status_t ActivityManager::registerUidObserver(const sp<IUidObserver>& observer,
                                          const int32_t event,
                                          const int32_t cutpoint,
                                          const String16& callingPackage)
{
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->registerUidObserver(observer, event, cutpoint, callingPackage);
    }
    // ActivityManagerService appears dead. Return usual error code for dead service.
    return DEAD_OBJECT;
}

status_t ActivityManager::registerUidObserverForUids(const sp<IUidObserver>& observer,
                                                     const int32_t event, const int32_t cutpoint,
                                                     const String16& callingPackage,
                                                     const int32_t uids[], size_t nUids,
                                                     /*out*/ sp<IBinder>& observerToken) {
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->registerUidObserverForUids(observer, event, cutpoint, callingPackage, uids,
                                                   nUids, observerToken);
    }
    // ActivityManagerService appears dead. Return usual error code for dead service.
    return DEAD_OBJECT;
}

status_t ActivityManager::unregisterUidObserver(const sp<IUidObserver>& observer)
{
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->unregisterUidObserver(observer);
    }
    // ActivityManagerService appears dead. Return usual error code for dead service.
    return DEAD_OBJECT;
}

status_t ActivityManager::addUidToObserver(const sp<IBinder>& observerToken,
                                           const String16& callingPackage, int32_t uid) {
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->addUidToObserver(observerToken, callingPackage, uid);
    }
    // ActivityManagerService appears dead. Return usual error code for dead service.
    return DEAD_OBJECT;
}

status_t ActivityManager::removeUidFromObserver(const sp<IBinder>& observerToken,
                                                const String16& callingPackage, int32_t uid) {
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->removeUidFromObserver(observerToken, callingPackage, uid);
    }
    // ActivityManagerService appears dead. Return usual error code for dead service.
    return DEAD_OBJECT;
}

bool ActivityManager::isUidActive(const uid_t uid, const String16& callingPackage)
{
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->isUidActive(uid, callingPackage);
    }
    return false;
}

int32_t ActivityManager::getUidProcessState(const uid_t uid, const String16& callingPackage)
{
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->getUidProcessState(uid, callingPackage);
    }
    return PROCESS_STATE_UNKNOWN;
}

status_t ActivityManager::checkPermission(const String16& permission,
                                     const pid_t pid,
                                     const uid_t uid,
                                     int32_t* outResult) {
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->checkPermission(permission, pid, uid, outResult);
    }
    // ActivityManagerService appears dead. Return usual error code for dead service.
    return DEAD_OBJECT;
}

status_t ActivityManager::registerProcessObserver(const sp<app::IProcessObserver> observer) {
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->registerProcessObserver(observer);
    }
    return INVALID_OPERATION;
}

status_t ActivityManager::unregisterProcessObserver(const sp<app::IProcessObserver> observer) {
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->unregisterProcessObserver(observer);
    }
    return INVALID_OPERATION;
}

status_t ActivityManager::getRunningAppProcesses(
        ::std::vector<app::RunningAppProcessInfo>* output) {
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return service->getRunningAppProcesses(output);
    }
    return INVALID_OPERATION;
}

status_t ActivityManager::linkToDeath(const sp<IBinder::DeathRecipient>& recipient) {
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return IInterface::asBinder(service)->linkToDeath(recipient);
    }
    return INVALID_OPERATION;
}

status_t ActivityManager::unlinkToDeath(const sp<IBinder::DeathRecipient>& recipient) {
    sp<IActivityManager> service = getService();
    if (service != nullptr) {
        return IInterface::asBinder(service)->unlinkToDeath(recipient);
    }
    return INVALID_OPERATION;
}

} // namespace android