/*
**
** Copyright 2015, 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.
*/

#ifndef ANDROID_MEDIA_RESOURCEMANAGERSERVICE_H
#define ANDROID_MEDIA_RESOURCEMANAGERSERVICE_H

#include <map>
#include <set>
#include <mutex>
#include <string>
#include <vector>

#include <aidl/android/media/BnResourceManagerService.h>
#include <media/MediaResource.h>
#include <utils/Errors.h>
#include <utils/String8.h>
#include <utils/threads.h>

#include "ResourceManagerServiceUtils.h"

namespace android {

class ResourceObserverService;
class ServiceLog;
struct ProcessInfoInterface;
class ResourceManagerMetrics;

using Status = ::ndk::ScopedAStatus;
using ::aidl::android::media::IResourceManagerClient;
using ::aidl::android::media::BnResourceManagerService;
using ::aidl::android::media::MediaResourceParcel;
using ::aidl::android::media::MediaResourcePolicyParcel;
using ::aidl::android::media::ClientInfoParcel;
using ::aidl::android::media::ClientConfigParcel;

class ResourceManagerService : public BnResourceManagerService {
public:
    struct SystemCallbackInterface : public RefBase {
        virtual void noteStartVideo(int uid) = 0;
        virtual void noteStopVideo(int uid) = 0;
        virtual void noteResetVideo() = 0;
        virtual bool requestCpusetBoost(bool enable) = 0;
    };

    static char const *getServiceName() { return "media.resource_manager"; }
    static void instantiate();

        // Static creation methods.
    static std::shared_ptr<ResourceManagerService> Create();
    static std::shared_ptr<ResourceManagerService> Create(
        const sp<ProcessInfoInterface>& processInfo,
        const sp<SystemCallbackInterface>& systemResource);

    virtual binder_status_t dump(
            int /*fd*/, const char** /*args*/, uint32_t /*numArgs*/);

    ResourceManagerService();
    explicit ResourceManagerService(const sp<ProcessInfoInterface> &processInfo,
            const sp<SystemCallbackInterface> &systemResource);
    virtual ~ResourceManagerService();

    virtual void setObserverService(
            const std::shared_ptr<ResourceObserverService>& observerService);

    // IResourceManagerService interface
    Status config(const std::vector<MediaResourcePolicyParcel>& policies) override;

    Status addResource(const ClientInfoParcel& clientInfo,
                       const std::shared_ptr<IResourceManagerClient>& client,
                       const std::vector<MediaResourceParcel>& resources) override;

    Status removeResource(const ClientInfoParcel& clientInfo,
                          const std::vector<MediaResourceParcel>& resources) override;

    Status removeClient(const ClientInfoParcel& clientInfo) override;

    // Tries to reclaim resource from processes with lower priority than the calling process
    // according to the requested resources.
    // Returns true if any resource has been reclaimed, otherwise returns false.
    Status reclaimResource(const ClientInfoParcel& clientInfo,
                           const std::vector<MediaResourceParcel>& resources,
                           bool* _aidl_return) override;

    Status overridePid(int32_t originalPid, int32_t newPid) override;

    Status overrideProcessInfo(const std::shared_ptr<IResourceManagerClient>& client,
                               int32_t pid, int32_t procState, int32_t oomScore) override;

    Status markClientForPendingRemoval(const ClientInfoParcel& clientInfo) override;

    Status reclaimResourcesFromClientsPendingRemoval(int32_t pid) override;

    Status notifyClientCreated(const ClientInfoParcel& clientInfo) override;

    Status notifyClientStarted(const ClientConfigParcel& clientConfig) override;

    Status notifyClientStopped(const ClientConfigParcel& clientConfig) override;

    Status notifyClientConfigChanged(const ClientConfigParcel& clientConfig) override;

protected:
    // To get notifications when a resource is added for the first time.
    void onFirstAdded(const MediaResourceParcel& res, uid_t uid);
    // To get notifications when a resource has been removed at last.
    void onLastRemoved(const MediaResourceParcel& res, uid_t uid);

    // Reclaims resources from |clients|. Returns true if reclaim succeeded
    // for all clients.
    bool reclaimUnconditionallyFrom(const std::vector<ClientInfo>& targetClients);

    // A helper function that returns true if the callingPid has higher priority than pid.
    // Returns false otherwise.
    bool isCallingPriorityHigher_l(int callingPid, int pid);

    // To notify the metrics about client being released.
    void notifyClientReleased(const ClientInfoParcel& clientInfo);

    virtual Status removeResource(const ClientInfoParcel& clientInfo, bool checkValid);

private:
    friend class ResourceManagerServiceTest;
    friend class ResourceManagerServiceTestBase;
    friend class DeathNotifier;
    friend class OverrideProcessInfoDeathNotifier;

    // Gets the client who owns biggest piece of specified resource type from pid.
    // Returns false with no change to client if there are no clients holding resources of this
    // type.
    bool getBiggestClient_l(int pid, MediaResource::Type type,
                            MediaResource::SubType subType,
                            ClientInfo& clientsInfo,
                            bool pendingRemovalOnly = false);

    // A helper function that gets the biggest clients of the process pid that
    // is marked to be (pending) removed and has the needed resources.
    bool getBiggestClientPendingRemoval_l(int pid, MediaResource::Type type,
                                          MediaResource::SubType subType,
                                          ClientInfo& clientsInfo);

    // From the list of clients, pick/select client(s) based on the reclaim policy.
    void getClientForResource_l(const ResourceRequestInfo& resourceRequestInfo,
                                std::vector<ClientInfo>& clientsInfo);
    // A helper function that pushes Reclaim Atom (for metric collection).
    void pushReclaimAtom(const ClientInfoParcel& clientInfo,
                         const std::vector<ClientInfo>& targetClients,
                         bool reclaimed);

    // Remove the override info for the given process
    void removeProcessInfoOverride_l(int pid);

    // Eventually we want to phase out this implementation of IResourceManagerService
    // (ResourceManagerService) and replace that with the newer implementation
    // (ResourceManagerServiceNew).
    // So, marking the following methods as private virtual and for the newer implementation
    // to override is the easiest way to maintain both implementation.

    // Initializes the internal state of the ResourceManagerService
    virtual void init();

    // Gets the list of all the clients who own the list of specified resource type
    // and satisfy the resource model and the reclaim policy.
    virtual bool getTargetClients(
        const ClientInfoParcel& clientInfo,
        const std::vector<MediaResourceParcel>& resources,
        std::vector<ClientInfo>& targetClients);

    // Gets the list of all the clients who own the specified resource type.
    // Returns false if any client belongs to a process with higher priority than the
    // calling process. The clients will remain unchanged if returns false.
    virtual bool getAllClients_l(const ResourceRequestInfo& resourceRequestInfo,
                                 std::vector<ClientInfo>& clientsInfo);

    // Gets the client who owns specified resource type from lowest possible priority process.
    // Returns false if the calling process priority is not higher than the lowest process
    // priority. The client will remain unchanged if returns false.
    virtual bool getLowestPriorityBiggestClient_l(
        const ResourceRequestInfo& resourceRequestInfo,
        ClientInfo& clientInfo);

    // override the pid of given process
    virtual bool overridePid_l(int32_t originalPid, int32_t newPid);

    // override the process info of given process
    virtual bool overrideProcessInfo_l(const std::shared_ptr<IResourceManagerClient>& client,
                                       int pid, int procState, int oomScore);

    // Get priority from process's pid
    virtual bool getPriority_l(int pid, int* priority) const;

    // Gets lowest priority process that has the specified resource type.
    // Returns false if failed. The output parameters will remain unchanged if failed.
    virtual bool getLowestPriorityPid_l(MediaResource::Type type, MediaResource::SubType subType,
                                        int* lowestPriorityPid, int* lowestPriority);

    // Removes the pid from the override map.
    virtual void removeProcessInfoOverride(int pid);

    // Get the client for given pid and the clientId from the map
    virtual std::shared_ptr<IResourceManagerClient> getClient_l(
        int pid, const int64_t& clientId) const;

    // Remove the client for given pid and the clientId from the map
    virtual bool removeClient_l(int pid, const int64_t& clientId);

    // Get all the resource status for dump
    virtual void getResourceDump(std::string& resourceLog) const;

    // The following utility functions are used only for testing by ResourceManagerServiceTest
    // START: TEST only functions
    // Get the peak concurrent pixel count (associated with the video codecs) for the process.
    long getPeakConcurrentPixelCount(int pid) const;
    // Get the current concurrent pixel count (associated with the video codecs) for the process.
    long getCurrentConcurrentPixelCount(int pid) const;
    // To create object of type ResourceManagerServiceNew
    static std::shared_ptr<ResourceManagerService> CreateNew(
        const sp<ProcessInfoInterface>& processInfo,
        const sp<SystemCallbackInterface>& systemResource);
    // Returns a unmodifiable reference to the internal resource state as a map
    virtual const std::map<int, ResourceInfos>& getResourceMap() const {
        return mMap;
    }
    // enable/disable process priority based reclaim and client importance based reclaim
    virtual void setReclaimPolicy(bool processPriority, bool clientImportance) {
        // Implemented by the refactored/new RMService
        (void)processPriority;
        (void)clientImportance;
    }
    // END: TEST only functions

protected:
    mutable std::mutex mLock;
    sp<ProcessInfoInterface> mProcessInfo;
    sp<SystemCallbackInterface> mSystemCB;
    sp<ServiceLog> mServiceLog;
    bool mSupportsMultipleSecureCodecs;
    bool mSupportsSecureWithNonSecureCodec;
    int32_t mCpuBoostCount;

private:
    PidResourceInfosMap mMap;
    struct ProcessInfoOverride {
        std::shared_ptr<DeathNotifier> deathNotifier = nullptr;
        std::shared_ptr<IResourceManagerClient> client;
    };
    std::map<int, int> mOverridePidMap;
    std::map<pid_t, ProcessInfoOverride> mProcessInfoOverrideMap;
    std::shared_ptr<ResourceObserverService> mObserverService;
    std::unique_ptr<ResourceManagerMetrics> mResourceManagerMetrics;
};

// ----------------------------------------------------------------------------
} // namespace android

#endif // ANDROID_MEDIA_RESOURCEMANAGERSERVICE_H