/*
 * Copyright (C) 2012-2022 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "Connection.h"
#include "MessageReceiverMap.h"
#include "ProcessLauncher.h"
#include "ProcessThrottler.h"
#include "ResponsivenessTimer.h"
#include <WebCore/ProcessIdentifier.h>
#include <memory>
#include <wtf/CheckedRef.h>
#include <wtf/Forward.h>
#include <wtf/HashMap.h>
#include <wtf/ProcessID.h>
#include <wtf/Seconds.h>
#include <wtf/SystemTracing.h>
#include <wtf/TZoneMalloc.h>
#include <wtf/ThreadSafeRefCounted.h>
#include <wtf/UniqueRef.h>
#include <wtf/VectorHash.h>

namespace WebCore {
class SharedBuffer;
}

namespace WebKit {

class ExtensionCapabilityGrant;
class ProcessThrottler;
class ProcessAssertion;
class SandboxExtensionHandle;

struct AuxiliaryProcessCreationParameters;

enum class ProcessThrottleState : uint8_t;

enum class ShouldTakeUIBackgroundAssertion : bool { No, Yes };
enum class AlwaysRunsAtBackgroundPriority : bool { No, Yes };

using ExtensionCapabilityGrantMap = HashMap<String, ExtensionCapabilityGrant>;

class AuxiliaryProcessProxy
    : public ThreadSafeRefCounted<AuxiliaryProcessProxy, WTF::DestructionThread::MainRunLoop>
    , public ResponsivenessTimer::Client
    , private ProcessLauncher::Client
    , public IPC::Connection::Client {
    WTF_MAKE_NONCOPYABLE(AuxiliaryProcessProxy);
    WTF_MAKE_TZONE_ALLOCATED(AuxiliaryProcessProxy);
    WTF_OVERRIDE_DELETE_FOR_CHECKED_PTR(AuxiliaryProcessProxy);
protected:
    AuxiliaryProcessProxy(ShouldTakeUIBackgroundAssertion, AlwaysRunsAtBackgroundPriority = AlwaysRunsAtBackgroundPriority::No, Seconds responsivenessTimeout = ResponsivenessTimer::defaultResponsivenessTimeout);

public:
    USING_CAN_MAKE_WEAKPTR(ResponsivenessTimer::Client);

    // ProcessLauncher::Client
    uint32_t checkedPtrCount() const final { return IPC::Connection::Client::checkedPtrCount(); }
    uint32_t checkedPtrCountWithoutThreadCheck() const final { return IPC::Connection::Client::checkedPtrCountWithoutThreadCheck(); }
    void incrementCheckedPtrCount() const final { IPC::Connection::Client::incrementCheckedPtrCount(); }
    void decrementCheckedPtrCount() const final { IPC::Connection::Client::decrementCheckedPtrCount(); }

    virtual ~AuxiliaryProcessProxy();

    static AuxiliaryProcessCreationParameters auxiliaryProcessParameters();

    enum class Type : uint8_t {
        GraphicsProcessing,
        Network,
#if ENABLE(MODEL_PROCESS)
        Model,
#endif
        WebContent,
    };
    virtual Type type() const = 0;

    void connect();
    virtual void terminate();

    ProcessThrottler& throttler() { return m_throttler; }
    const ProcessThrottler& throttler() const { return m_throttler; }
    Ref<ProcessThrottler> protectedThrottler() { return m_throttler; }
    Ref<const ProcessThrottler> protectedThrottler() const { return m_throttler; }

    template<typename T> bool send(T&& message, uint64_t destinationID, OptionSet<IPC::SendOption> sendOptions = { });

    template<typename T> using SendSyncResult = IPC::Connection::SendSyncResult<T>;
    template<typename T> SendSyncResult<T> sendSync(T&& message, uint64_t destinationID, IPC::Timeout = 1_s, OptionSet<IPC::SendSyncOption> sendSyncOptions = { });

    enum class ShouldStartProcessThrottlerActivity : bool { No, Yes };
    using AsyncReplyID = IPC::Connection::AsyncReplyID;
    template<typename T, typename C> std::optional<AsyncReplyID> sendWithAsyncReply(T&&, C&&, uint64_t destinationID = 0, OptionSet<IPC::SendOption> = { }, ShouldStartProcessThrottlerActivity = ShouldStartProcessThrottlerActivity::Yes);

    template<typename T, typename C, typename RawValue>
    std::optional<AsyncReplyID> sendWithAsyncReply(T&& message, C&& completionHandler, const ObjectIdentifierGenericBase<RawValue>& destinationID, OptionSet<IPC::SendOption> sendOptions = { }, ShouldStartProcessThrottlerActivity shouldStartProcessThrottlerActivity = ShouldStartProcessThrottlerActivity::Yes)
    {
        return sendWithAsyncReply(std::forward<T>(message), std::forward<C>(completionHandler), destinationID.toUInt64(), sendOptions, shouldStartProcessThrottlerActivity);
    }

    template<typename T, typename RawValue>
    bool send(T&& message, const ObjectIdentifierGenericBase<RawValue>& destinationID, OptionSet<IPC::SendOption> sendOptions = { })
    {
        return send<T>(std::forward<T>(message), destinationID.toUInt64(), sendOptions);
    }

    template<typename T, typename RawValue>
    SendSyncResult<T> sendSync(T&& message, const ObjectIdentifierGenericBase<RawValue>& destinationID, IPC::Timeout timeout = 1_s, OptionSet<IPC::SendSyncOption> sendSyncOptions = { })
    {
        return sendSync<T>(std::forward<T>(message), destinationID.toUInt64(), timeout, sendSyncOptions);
    }

    IPC::Connection& connection() const
    {
        RELEASE_ASSERT(m_connection);
        return *m_connection;
    }

    Ref<IPC::Connection> protectedConnection() const { return connection(); }

    bool hasConnection() const
    {
        return !!m_connection;
    }
    
    bool hasConnection(const IPC::Connection& connection) const
    {
        return m_connection == &connection;
    }
    static AuxiliaryProcessProxy* fromConnection(const IPC::Connection&);

    void addMessageReceiver(IPC::ReceiverName, IPC::MessageReceiver&);
    void addMessageReceiver(IPC::ReceiverName, uint64_t destinationID, IPC::MessageReceiver&);
    void removeMessageReceiver(IPC::ReceiverName, uint64_t destinationID);
    void removeMessageReceiver(IPC::ReceiverName);
    
    template<typename RawValue>
    void addMessageReceiver(IPC::ReceiverName messageReceiverName, const ObjectIdentifierGenericBase<RawValue>& destinationID, IPC::MessageReceiver& receiver)
    {
        addMessageReceiver(messageReceiverName, destinationID.toUInt64(), receiver);
    }
    
    template<typename RawValue>
    void removeMessageReceiver(IPC::ReceiverName messageReceiverName, const ObjectIdentifierGenericBase<RawValue>& destinationID)
    {
        removeMessageReceiver(messageReceiverName, destinationID.toUInt64());
    }

    enum class State {
        Launching,
        Running,
        Terminated,
    };
    inline State state() const;

    String stateString() const;
    bool isLaunching() const { return state() == State::Launching; }
    bool wasTerminated() const;

    ProcessID processID() const { return m_processLauncher ? m_processLauncher->processID() : 0; }

    bool canSendMessage() const { return state() != State::Terminated;}
    bool sendMessage(UniqueRef<IPC::Encoder>&&, OptionSet<IPC::SendOption>, std::optional<IPC::Connection::AsyncReplyHandler> = std::nullopt, ShouldStartProcessThrottlerActivity = ShouldStartProcessThrottlerActivity::Yes);
    bool sendMessageAfterResuming(Vector<uint8_t>&& coalescingKey, UniqueRef<IPC::Encoder>&&);

    void replyToPendingMessages();

    void shutDownProcess();

    WebCore::ProcessIdentifier coreProcessIdentifier() const { return m_processIdentifier; }

    void setProcessSuppressionEnabled(bool);
    bool platformIsBeingDebugged() const;

#if PLATFORM(MAC) && USE(RUNNINGBOARD)
    bool runningBoardThrottlingEnabled();
    void setRunningBoardThrottlingEnabled();
#endif

    enum class UseLazyStop : bool { No, Yes };
    void startResponsivenessTimer(UseLazyStop = UseLazyStop::No);
    void stopResponsivenessTimer();

    void checkForResponsiveness(CompletionHandler<void()>&& = nullptr, UseLazyStop = UseLazyStop::No);

    ResponsivenessTimer& responsivenessTimer() const { return m_responsivenessTimer.get(); }
    Ref<ResponsivenessTimer> protectedResponsivenessTimer() const { return m_responsivenessTimer; }

    void ref() const final { ThreadSafeRefCounted::ref(); }
    void deref() const final { ThreadSafeRefCounted::deref(); }

    bool operator==(const AuxiliaryProcessProxy& other) const { return (this == &other); }

    std::optional<SandboxExtensionHandle> createMobileGestaltSandboxExtensionIfNeeded() const;

#if USE(RUNNINGBOARD)
    void wakeUpTemporarilyForIPC();
#endif

#if USE(EXTENSIONKIT)
    std::optional<ExtensionProcess> extensionProcess() const;
    LaunchGrant* launchGrant() const;
#endif

#if ENABLE(EXTENSION_CAPABILITIES)
    ExtensionCapabilityGrantMap& extensionCapabilityGrants() { return m_extensionCapabilityGrants; }
#endif

#if PLATFORM(COCOA)
    struct TaskInfo {
        ProcessID pid;
        ProcessThrottleState state;
        Seconds totalUserCPUTime;
        Seconds totalSystemCPUTime;
        size_t physicalFootprint;
    };

    std::optional<TaskInfo> taskInfo() const;
#endif

#if ENABLE(CFPREFS_DIRECT_MODE)
    void notifyPreferencesChanged(const String& domain, const String& key, const std::optional<String>& encodedValue);
#endif

    enum ResumeReason : bool { ForegroundActivity, BackgroundActivity };
    virtual void sendPrepareToSuspend(IsSuspensionImminent, double remainingRunTime, CompletionHandler<void()>&&) = 0;
    virtual void sendProcessDidResume(ResumeReason) = 0;
    virtual void didChangeThrottleState(ProcessThrottleState);
    virtual ASCIILiteral clientName() const = 0;
    virtual String environmentIdentifier() const { return emptyString(); }
    virtual void prepareToDropLastAssertion(CompletionHandler<void()>&& completionHandler) { completionHandler(); }
    virtual void didDropLastAssertion() { }

protected:
    // ProcessLauncher::Client
    void didFinishLaunching(ProcessLauncher*, IPC::Connection::Identifier&&) override;

    bool dispatchMessage(IPC::Connection&, IPC::Decoder&);
    bool dispatchSyncMessage(IPC::Connection&, IPC::Decoder&, UniqueRef<IPC::Encoder>&);

    void logInvalidMessage(IPC::Connection&, IPC::MessageName);
    virtual ASCIILiteral processName() const = 0;

    virtual void getLaunchOptions(ProcessLauncher::LaunchOptions&);
    virtual void platformGetLaunchOptions(ProcessLauncher::LaunchOptions&) { }

    struct PendingMessage {
        UniqueRef<IPC::Encoder> encoder;
        OptionSet<IPC::SendOption> sendOptions;
        std::optional<IPC::Connection::AsyncReplyHandler> asyncReplyHandler;
    };

    virtual bool shouldSendPendingMessage(const PendingMessage&) { return true; }

    void beginResponsivenessChecks();

    // ResponsivenessTimer::Client.
    void didBecomeUnresponsive() override;
    void didBecomeResponsive() override { }
    void willChangeIsResponsive() override { }
    void didChangeIsResponsive() override { }
    bool mayBecomeUnresponsive() override;

#if HAVE(AUDIO_COMPONENT_SERVER_REGISTRATIONS)
    static RefPtr<WebCore::SharedBuffer> fetchAudioComponentServerRegistrations();
#endif

    struct InitializationActivityAndGrant {
        Ref<ProcessThrottler::ForegroundActivity> foregroundActivity;
#if USE(EXTENSIONKIT)
        RefPtr<LaunchGrant> launchGrant;
#endif
    };

    InitializationActivityAndGrant initializationActivityAndGrant();

private:
    virtual void connectionWillOpen(IPC::Connection&);
    virtual void processWillShutDown(IPC::Connection&) = 0;
    void outgoingMessageQueueIsGrowingLarge();

    void populateOverrideLanguagesLaunchOptions(ProcessLauncher::LaunchOptions&) const;
    Vector<String> platformOverrideLanguages() const;
    void platformStartConnectionTerminationWatchdog();

    // Connection::Client
    void requestRemoteProcessTermination() final;

    const Ref<ResponsivenessTimer> m_responsivenessTimer;
    Vector<PendingMessage> m_pendingMessages;
    RefPtr<ProcessLauncher> m_processLauncher;
    RefPtr<IPC::Connection> m_connection;
    IPC::MessageReceiverMap m_messageReceiverMap;
    bool m_alwaysRunsAtBackgroundPriority { false };
    bool m_didBeginResponsivenessChecks { false };
    bool m_isSuspended { false };
    const WebCore::ProcessIdentifier m_processIdentifier { WebCore::ProcessIdentifier::generate() };
    std::optional<UseLazyStop> m_delayedResponsivenessCheck;
    MonotonicTime m_processStart;
    ProcessThrottler m_throttler;
#if USE(RUNNINGBOARD)
    bool m_startedTerminationWatchdog { false };
#if PLATFORM(MAC)
    RefPtr<ProcessThrottler::ForegroundActivity> m_lifetimeActivity;
    RefPtr<ProcessAssertion> m_boostedJetsamAssertion;
#endif
#endif
#if ENABLE(EXTENSION_CAPABILITIES)
    ExtensionCapabilityGrantMap m_extensionCapabilityGrants;
#endif
    HashMap<Vector<uint8_t>, std::pair<unsigned, std::unique_ptr<IPC::Encoder>>> m_messagesToSendOnResume;
    unsigned m_messagesToSendOnResumeIndex { 0 };
};

template<typename T>
bool AuxiliaryProcessProxy::send(T&& message, uint64_t destinationID, OptionSet<IPC::SendOption> sendOptions)
{
    static_assert(!T::isSync, "Async message expected");

    if constexpr (T::deferSendingIfSuspended) {
        if (UNLIKELY(m_isSuspended)) {
            // encodeCoalescingKey must be called before arguments() below since arguments() takes ownership of the message's args tuple.
            auto coalescingKeyEncoder = makeUniqueRef<IPC::Encoder>(T::name(), destinationID);
            message.encodeCoalescingKey(coalescingKeyEncoder.get());
            Vector<uint8_t> coalescingKey { coalescingKeyEncoder->mutableSpan() };

            auto encoder = makeUniqueRef<IPC::Encoder>(T::name(), destinationID);
            encoder.get() << message.arguments();
            return sendMessageAfterResuming(WTFMove(coalescingKey), WTFMove(encoder));
        }
    }

    auto encoder = makeUniqueRef<IPC::Encoder>(T::name(), destinationID);
    encoder.get() << message.arguments();
    return sendMessage(WTFMove(encoder), sendOptions);
}

template<typename T>
AuxiliaryProcessProxy::SendSyncResult<T> AuxiliaryProcessProxy::sendSync(T&& message, uint64_t destinationID, IPC::Timeout timeout, OptionSet<IPC::SendSyncOption> sendSyncOptions)
{
    static_assert(T::isSync, "Sync message expected");

    RefPtr connection = m_connection;
    if (!connection)
        return { IPC::Error::InvalidConnection };

    TraceScope scope(SyncMessageStart, SyncMessageEnd);

    return connection->sendSync(std::forward<T>(message), destinationID, timeout, sendSyncOptions);
}

template<typename T, typename C>
std::optional<AuxiliaryProcessProxy::AsyncReplyID> AuxiliaryProcessProxy::sendWithAsyncReply(T&& message, C&& completionHandler, uint64_t destinationID, OptionSet<IPC::SendOption> sendOptions, ShouldStartProcessThrottlerActivity shouldStartProcessThrottlerActivity)
{
    static_assert(!T::isSync, "Async message expected");

    auto encoder = makeUniqueRef<IPC::Encoder>(T::name(), destinationID);
    encoder.get() << message.arguments();
    auto handler = IPC::Connection::makeAsyncReplyHandler<T>(std::forward<C>(completionHandler));
    auto replyID = handler.replyID;
    if (sendMessage(WTFMove(encoder), sendOptions, WTFMove(handler), shouldStartProcessThrottlerActivity))
        return replyID;
    return std::nullopt;
}

inline AuxiliaryProcessProxy::State AuxiliaryProcessProxy::state() const
{
    if (m_processLauncher && m_processLauncher->isLaunching())
        return AuxiliaryProcessProxy::State::Launching;

    if (!m_connection)
        return AuxiliaryProcessProxy::State::Terminated;

    return AuxiliaryProcessProxy::State::Running;
}

} // namespace WebKit