/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/
// Original file Copyright Crytek GMBH or its affiliates, used under license.

// Description : Service network interface


#ifndef CRYINCLUDE_CRYCOMMON_IREMOTECOMMAND_H
#define CRYINCLUDE_CRYCOMMON_IREMOTECOMMAND_H
#pragma once


//-----------------------------------------------------------------------------
// Helpers for writing/reading command data stream from network message packets.
// Those interfaces automatically handle byteswapping for big endian systems.
// Tthe native format for data inside the messages is little endian.
//-----------------------------------------------------------------------------

/// Write stream interface
struct IDataWriteStream
{
public:
    virtual ~IDataWriteStream() {};

public:
    // Virtualized write method for general data buffer
    virtual void Write(const void* pData, const uint32 size) = 0;

    // Virtualized write method for types with size 8 (support byteswapping, a little bit faster than general case)
    virtual void Write8(const void* pData) = 0;

    // Virtualized write method for types with size 4 (support byteswapping, a little bit faster than general case)
    virtual void Write4(const void* pData) = 0;

    // Virtualized write method for types with size 2 (support byteswapping, a little bit faster than general case)
    virtual void Write2(const void* pData) = 0;

    // Virtualized write method for types with size 1 (a little bit faster than general case)
    virtual void Write1(const void* pData) = 0;

    // Get number of bytes written
    virtual const uint32 GetSize() const = 0;

    // Convert to service network message
    virtual struct IServiceNetworkMessage* BuildMessage() const = 0;

    // Save the data from this writer stream to the provided buffer
    virtual void CopyToBuffer(void* pData) const = 0;

    // Destroy object (if dynamically created)
    virtual void Delete() = 0;

public:
    ILINE IDataWriteStream& operator<<(const uint8& val)
    {
        Write1(&val);
        return *this;
    }

    ILINE IDataWriteStream& operator<<(const uint16& val)
    {
        Write2(&val);
        return *this;
    }

    ILINE IDataWriteStream& operator<<(const uint32& val)
    {
        Write4(&val);
        return *this;
    }

    ILINE IDataWriteStream& operator<<(const uint64& val)
    {
        Write8(&val);
        return *this;
    }

    ILINE IDataWriteStream& operator<<(const int8& val)
    {
        Write1(&val);
        return *this;
    }

    ILINE IDataWriteStream& operator<<(const int16& val)
    {
        Write2(&val);
        return *this;
    }

    ILINE IDataWriteStream& operator<<(const int32& val)
    {
        Write4(&val);
        return *this;
    }

    ILINE IDataWriteStream& operator<<(const int64& val)
    {
        Write8(&val);
        return *this;
    }

    ILINE IDataWriteStream& operator<<(const float& val)
    {
        Write4(&val);
        return *this;
    }

    // Bool is saved by writing an 8 bit value to make it portable
    ILINE IDataWriteStream& operator<<(const bool& val)
    {
        const uint8 uVal = val ? 1 : 0;
        Write1(&uVal);
        return *this;
    }

public:
    // Write C string to stream
    ILINE void WriteString(const char* str);

    // Write string to stream
    ILINE void WriteString(const string& str);

    // Write int8 value to stream
    ILINE void WriteInt8(const int8 val)
    {
        Write1(&val);
    }

    // Write int16 value to stream
    ILINE void WriteInt16(const int16 val)
    {
        Write2(&val);
    }

    // Write int32 value to stream
    ILINE void WriteInt32(const int32 val)
    {
        Write4(&val);
    }

    // Write int64 value to stream
    ILINE void WriteInt64(const int64 val)
    {
        Write8(&val);
    }

    // Write uint8 value to stream
    ILINE void WriteUint8(const uint8 val)
    {
        Write1(&val);
    }

    // Write uint16 value to stream
    ILINE void WriteUint16(const uint16 val)
    {
        Write2(&val);
    }

    // Write uint32 value to stream
    ILINE void WriteUint32(const uint32 val)
    {
        Write4(&val);
    }

    // Write uint64 value to stream
    ILINE void WriteUint64(const uint64 val)
    {
        Write8(&val);
    }

    // Write float value to stream
    ILINE void WriteFloat(const float val)
    {
        Write4(&val);
    }
};

//-----------------------------------------------------------------------------

/// Read stream interface
/// This interface should support endianess swapping
struct IDataReadStream
{
public:
    virtual ~IDataReadStream() {};

public:
    // Destroy object (if dynamically created)
    virtual void Delete() = 0;

    // Skip given amount of data without reading it
    virtual void Skip(const uint32 size) = 0;

    // Virtualized read method (for general buffers)
    virtual void Read(void* pData, const uint32 size) = 0;

    // Virtualized read method for types with size 8 (a little bit faster than general method, supports byte swapping for BE systems)
    virtual void Read8(void* pData) = 0;

    // Virtualized read method for types with size 4 (a little bit faster than general method, supports byte swapping for BE systems)
    virtual void Read4(void* pData) = 0;

    // Virtualized read method for types with size 2 (a little bit faster than general method, supports byte swapping for BE systems)
    virtual void Read2(void* pData) = 0;

    // Virtualized read method for types with size 1 (a little bit faster than general method, supports byte swapping for BE systems)
    virtual void Read1(void* pData) = 0;

    // Optimization case - get direct pointer to the underlying buffer
    virtual const void* GetPointer() = 0;

public:
    ILINE IDataReadStream& operator<<(uint8& val)
    {
        Read1(&val);
        return *this;
    }

    ILINE IDataReadStream& operator<<(uint16& val)
    {
        Read2(&val);
        return *this;
    }

    ILINE IDataReadStream& operator<<(uint32& val)
    {
        Read4(&val);
        return *this;
    }

    ILINE IDataReadStream& operator<<(uint64& val)
    {
        Read8(&val);
        return *this;
    }

    ILINE IDataReadStream& operator<<(int8& val)
    {
        Read1(&val);
        return *this;
    }

    ILINE IDataReadStream& operator<<(int16& val)
    {
        Read2(&val);
        return *this;
    }

    ILINE IDataReadStream& operator<<(int32& val)
    {
        Read4(&val);
        return *this;
    }

    ILINE IDataReadStream& operator<<(int64& val)
    {
        Read8(&val);
        return *this;
    }

    ILINE IDataReadStream& operator<<(float& val)
    {
        Read4(&val);
        return *this;
    }

    // Bool is saved by writing an 8 bit value to make it portable
    ILINE IDataReadStream& operator<<(bool& val)
    {
        uint8 uVal = 0;
        Read1(&uVal);
        val = (uVal != 0);
        return *this;
    }

public:
    // Read string from stream
    ILINE string ReadString();

    // Skip string data in a stream without loading the data
    ILINE void SkipString();

    // Read int8 from stream
    ILINE int8 ReadInt8()
    {
        int8 val = 0;
        Read1(&val);
        return val;
    }

    // Read int16 from stream
    ILINE int16 ReadInt16()
    {
        int16 val = 0;
        Read2(&val);
        return val;
    }

    // Read int32 from stream
    ILINE int32 ReadInt32()
    {
        int32 val = 0;
        Read4(&val);
        return val;
    }

    // Read int64 from stream
    ILINE int64 ReadInt64()
    {
        int64 val = 0;
        Read8(&val);
        return val;
    }

    // Read uint8 from stream
    ILINE uint8 ReadUint8()
    {
        uint8 val = 0;
        Read1(&val);
        return val;
    }

    // Read uint16 from stream
    ILINE uint16 ReadUint16()
    {
        uint16 val = 0;
        Read2(&val);
        return val;
    }

    // Read uint32 from stream
    ILINE uint32 ReadUint32()
    {
        uint32 val = 0;
        Read4(&val);
        return val;
    }

    // Read int64 from stream
    ILINE uint64 ReadUint64()
    {
        uint64 val = 0;
        Read8(&val);
        return val;
    }

    // Read float from stream
    ILINE float ReadFloat()
    {
        float val = 0.0f;
        Read4(&val);
        return val;
    }
};

//-----------------------------------------------------------------------------

/// Remote command class info (simple RTTI)
struct IRemoteCommandClass
{
public:
    virtual ~IRemoteCommandClass() {};

    // Get class name
    virtual const char* GetName() const = 0;

    // Create command instance
    virtual struct IRemoteCommand* CreateObject() = 0;
};

/// Remote command interface
struct IRemoteCommand
{
protected:
    virtual ~IRemoteCommand() {};

public:
    // Get command class
    virtual IRemoteCommandClass* GetClass() const = 0;

    // Save to data stream
    virtual void SaveToStream(struct IDataWriteStream& writeStream) const = 0;

    // Load from data stream
    virtual void LoadFromStream(struct IDataReadStream& readStream) = 0;

    // Execute (remote call) = 0;
    virtual void Execute() = 0;

    // Delete the command object (can be allocated from different heap)
    virtual void Delete() = 0;
};

//-----------------------------------------------------------------------------

// This is a implementation of a synchronous listener (limited to the engine tick rate)
// that processes and responds to the raw messages received from clients.
struct IRemoteCommandListenerSync
{
public:
    virtual ~IRemoteCommandListenerSync() {};

    // Process a raw message and optionally provide an answer to the request, return true if you have processed the message.
    // Messages is accessible via the data reader. Response can be written to a data writer.
    virtual bool OnRawMessageSync(const class ServiceNetworkAddress& remoteAddress, struct IDataReadStream& msg, struct IDataWriteStream& response) = 0;
};

//-----------------------------------------------------------------------------

// This is a implementation of a asynchronous listener (called from network thread)
// that processes and responds to the raw messages received from clients.
struct IRemoteCommandListenerAsync
{
public:
    virtual ~IRemoteCommandListenerAsync() {};

    // Process a raw message and optionally provide an answer to the request, return true if you have processed the message.
    // Messages is accessible via the data reader. Response can be written to a data writer.
    virtual bool OnRawMessageAsync(const class ServiceNetworkAddress& remoteAddress, struct IDataReadStream& msg, struct IDataWriteStream& response) = 0;
};

//-----------------------------------------------------------------------------

/// Remote command server
struct IRemoteCommandServer
{
protected:
    virtual ~IRemoteCommandServer() {};

public:
    // Execute all of the received pending commands
    // This should be called from a safe place (main thread)
    virtual void FlushCommandQueue() = 0;

    // Suppress command execution
    virtual void SuppressCommands() = 0;

    // Resume command execution
    virtual void ResumeCommands() = 0;

    // Register/Unregister synchronous message listener (limited to tick rate)
    virtual void RegisterSyncMessageListener(IRemoteCommandListenerSync* pListener) = 0;
    virtual void UnregisterSyncMessageListener(IRemoteCommandListenerSync* pListener) = 0;

    // Register/Unregister asynchronous message listener (called from network thread)
    virtual void RegisterAsyncMessageListener(IRemoteCommandListenerAsync* pListener) = 0;
    virtual void UnregisterAsyncMessageListener(IRemoteCommandListenerAsync* pListener) = 0;

    // Broadcast a message to all connected clients
    virtual void Broadcast(IServiceNetworkMessage* pMessage) = 0;

    // Do we have any clients connected ?
    virtual bool HasConnectedClients() const = 0;

    // Delete the client
    virtual void Delete() = 0;
};

//-----------------------------------------------------------------------------

/// Connection to remote command server
struct IRemoteCommandConnection
{
protected:
    virtual ~IRemoteCommandConnection() {};

public:
    // Are we connected ?
    // This returns false when the underlying network connection has failed (sockets error).
    // Also, this returns false if the remote connection was closed by remote peer.
    virtual bool IsAlive() const = 0;

    // Get address of remote command server
    // This returns the full address of the endpoint (with valid port)
    virtual const ServiceNetworkAddress& GetRemoteAddress() const = 0;

    // Send raw message to the other side of this connection.
    // Raw messages are not buffer and are sent right away,
    // they also have precedence over internal command traffic.
    // The idea is that you need some kind of bidirectional signaling
    // channel to extend  the rather one-directional nature of commands.
    // Returns true if message was added to the send queue.
    virtual bool SendRawMessage(IServiceNetworkMessage* pMessage) = 0;

    // See if there's a raw message waiting for us and if it is, get it
    // Be aware that messages are reference counted.
    virtual IServiceNetworkMessage* ReceiveRawMessage() = 0;

    // Close connection
    // - pending commands are not sent
    // - pending raw messages are sent or not (depending on the flag)
    virtual void Close(bool bFlushQueueBeforeClosing = false) = 0;

    // Add internal reference to object (Refcounting interface)
    virtual void AddRef() = 0;

    // Release internal reference to object (Refcounting interface)
    virtual void Release() = 0;
};

//-----------------------------------------------------------------------------

/// Remote command client
struct IRemoteCommandClient
{
protected:
    virtual ~IRemoteCommandClient() {};

public:
    // Connect to remote server, returns true on success, false on failure
    virtual IRemoteCommandConnection* ConnectToServer(const class ServiceNetworkAddress& serverAddress) = 0;

    // Schedule command to be executed on the all of the remote servers
    virtual bool Schedule(const IRemoteCommand& command) = 0;

    // Delete the client object
    virtual void Delete() = 0;
};

//-----------------------------------------------------------------------------

/// Remote command manager
struct IRemoteCommandManager
{
public:
    virtual ~IRemoteCommandManager() {};

    // Set debug message verbose level
    virtual void SetVerbosityLevel(const uint32 level) = 0;

    // Create local server for executing remote commands on given local port
    virtual IRemoteCommandServer* CreateServer(uint16 localPort) = 0;

    // Create client interface for executing remote commands on remote servers
    virtual IRemoteCommandClient* CreateClient() = 0;

    // Register command class (will be accessible by both clients and server)
    virtual void RegisterCommandClass(IRemoteCommandClass& commandClass) = 0;
};

//-----------------------------------------------------------------------------

/// Class RTTI wrapper for remote command classes
template< typename T >
class CRemoteCommandClass
    : public IRemoteCommandClass
{
private:
    const char*     m_szName;

public:
    ILINE CRemoteCommandClass(const char* szName)
        : m_szName(szName)
    {}

    virtual const char* GetName() const
    {
        return m_szName;
    }

    virtual struct IRemoteCommand* CreateObject()
    {
        return new T();
    }
};

#define DECLARE_REMOTE_COMMAND(x)                                                                                                           \
public: static IRemoteCommandClass& GetStaticClass() {                                                                                      \
        static IRemoteCommandClass* theClass = new CRemoteCommandClass<x>(#x); return *theClass; }                                          \
public: virtual IRemoteCommandClass* GetClass() const { return &GetStaticClass(); }                                                         \
public: virtual void Delete() { delete this; }                                                                                              \
public: virtual void SaveToStream(IDataWriteStream & writeStream) const { const_cast<x*>(this)->Serialize<IDataWriteStream>(writeStream); } \
public: virtual void LoadFromStream(IDataReadStream & readStream) { Serialize<IDataReadStream>(readStream); }

//-----------------------------------------------------------------------------

/// CryString serialization helper (read)
ILINE IDataReadStream& operator<<(IDataReadStream& stream, string& outString)
{
    const uint32 kMaxTempString = 256;

    // read length
    uint32 length = 0;
    stream << length;

    // load string
    if (length > 0)
    {
        if (length < kMaxTempString)
        {
            // load the string into temporary buffer
            char temp[kMaxTempString];
            stream.Read(&temp, length);
            temp[length] = 0;

            // set the string with new value
            outString = temp;
        }
        else
        {
            // allocate temporary memory and load the string
            std::vector<char> temp;
            temp.resize(length + 1, 0);
            stream.Read(&temp[0], length);

            // set the string with new value
            outString = &temp[0];
        }
    }
    else
    {
        // empty string
        outString.clear();
    }

    return stream;
}

/// CryString serialization helper (write)
ILINE IDataWriteStream& operator<<(IDataWriteStream& stream, const string& str)
{
    // write length
    const uint32 length = str.length();
    stream << length;

    // write string data
    if (length > 0)
    {
        stream.Write(str.c_str(), length);
    }

    return stream;
}

//------------------------------------------------------------------------

/// Vector serialization helper (reading)
template< class T >
ILINE IDataReadStream& operator<<(IDataReadStream& ar, std::vector<T>& outVector)
{
    // Load item count
    uint32 count = 0;
    ar << count;

    // Adapt the vector size (exact fit)
    outVector.resize(count);

    // Load items
    for (uint32 i = 0; i < count; ++i)
    {
        ar << outVector[i];
    }

    return ar;
}

/// Vector serialization helper (writing)
template< class T >
ILINE IDataWriteStream& operator<<(IDataWriteStream& ar, const std::vector<T>& vec)
{
    // Save item count
    const uint32 count = vec.size();
    ar << count;

    // Save items
    for (uint32 i = 0; i < count; ++i)
    {
        ar << const_cast<T&>(vec[i]);
    }

    return ar;
}

//------------------------------------------------------------------------

ILINE void IDataWriteStream::WriteString(const char* str)
{
    string tempString(str);
    *this << tempString;
}

ILINE void IDataWriteStream::WriteString(const string& str)
{
    *this << str;
}

ILINE string IDataReadStream::ReadString()
{
    string ret;
    *this << ret;
    return ret;
}

ILINE void IDataReadStream::SkipString()
{
    // read length
    uint32 length = 0;
    *this << length;
    Skip(length);
}


//------------------------------------------------------------------------

// Helper class for using the data reader and writer classes
// The only major differce betwen auto_ptr is that we call Delete() instead of operator delete
template<class T>
class TAutoDelete
{
public:
    T* m_ptr;

public:
    ILINE TAutoDelete(T* ptr)
        : m_ptr(ptr)
    {
    }

    ILINE ~TAutoDelete()
    {
        if (NULL != m_ptr)
        {
            m_ptr->Delete();
            m_ptr = NULL;
        }
    }

    ILINE operator bool()
    {
        return (NULL != m_ptr);
    }

    ILINE operator T& ()
    {
        return *m_ptr;
    }

    ILINE T* operator->()
    {
        return m_ptr;
    }

private:
    TAutoDelete(const TAutoDelete& other)
        : m_ptr(NULL){};
    TAutoDelete& operator=(const TAutoDelete& other) { return *this; }
};

//------------------------------------------------------------------------


#endif // CRYINCLUDE_CRYCOMMON_IREMOTECOMMAND_H