/********************************************************************************
 * Copyright (C) 2021-2022 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH  *
 *                                                                              *
 *              This software is distributed under the terms of the             *
 *              GNU Lesser General Public Licence (LGPL) version 3,             *
 *                  copied verbatim in the file "LICENSE"                       *
 ********************************************************************************/

#ifndef FAIR_MQ_CHANNEL_H
#define FAIR_MQ_CHANNEL_H

#include <fairmq/Message.h>
#include <fairmq/Parts.h>
#include <fairmq/Properties.h>
#include <fairmq/Socket.h>
#include <fairmq/TransportFactory.h>
#include <fairmq/Transports.h>
#include <fairmq/UnmanagedRegion.h>

#include <cstdint>   // int64_t
#include <memory>   // unique_ptr, shared_ptr
#include <ostream>
#include <stdexcept>
#include <string>
#include <utility>   // std::move
#include <vector>

namespace fair::mq {

/**
 * @class Channel Channel.h <fairmq/Channel.h>
 * @brief Wrapper class for Socket and related methods
 *
 * The class is not thread-safe.
 */
class Channel
{
    friend class Device;

  public:
    /// Default constructor
    Channel();

    /// Constructor
    /// @param name Channel name
    Channel(const std::string& name);

    /// Constructor
    /// @param type Socket type (push/pull/pub/sub/spub/xsub/pair/req/rep/dealer/router/)
    /// @param method Socket method (bind/connect)
    /// @param address Network address to bind/connect to (e.g. "tcp://127.0.0.1:5555" or "ipc://abc")
    Channel(const std::string& type, const std::string& method, const std::string& address);

    /// Constructor
    /// @param name Channel name
    /// @param type Socket type (push/pull/pub/sub/spub/xsub/pair/req/rep/dealer/router/)
    /// @param factory TransportFactory
    Channel(const std::string& name, const std::string& type, std::shared_ptr<TransportFactory> factory);

    /// Constructor
    /// @param name Channel name
    /// @param type Socket type (push/pull/pub/sub/spub/xsub/pair/req/rep/dealer/router/)
    /// @param method Socket method (bind/connect)
    /// @param address Network address to bind/connect to (e.g. "tcp://127.0.0.1:5555" or "ipc://abc")
    /// @param factory TransportFactory
    Channel(std::string name, std::string type, std::string method, std::string address, std::shared_ptr<TransportFactory> factory);

    Channel(const std::string& name, int index, const Properties& properties);

    /// Copy Constructor
    Channel(const Channel&);

    /// Copy Constructor (with new name)
    Channel(const Channel&, std::string name);

    /// Move constructor
    Channel(Channel&&) = default;

    /// Assignment operator
    Channel& operator=(const Channel&);

    /// Move assignment operator
    Channel& operator=(Channel&&) = default;

    /// Destructor
    ~Channel() = default;
    // { LOG(warn) << "Destroying channel '" << fName << "'"; }

    struct ChannelConfigurationError : std::runtime_error { using std::runtime_error::runtime_error; };

    Socket& GetSocket() const
    {
        assert(fSocket); // NOLINT(cppcoreguidelines-pro-bounds-array-to-pointer-decay)
        return *fSocket;
    }

    bool Bind(const std::string& address)
    {
        fMethod = "bind";
        fAddress = address;
        return fSocket->Bind(address);
    }

    bool Connect(const std::string& address)
    {
        fMethod = "connect";
        fAddress = address;
        return fSocket->Connect(address);
    }

    /// Get channel name
    /// @return Returns full channel name (e.g. "data[0]")
    std::string GetName() const { return fName; }

    /// Get channel prefix
    /// @return Returns channel prefix (e.g. "data" in "data[0]")
    std::string GetPrefix() const
    {
        std::string prefix = fName;
        prefix = prefix.erase(fName.rfind('['));
        return prefix;
    }

    /// Get channel index
    /// @return Returns channel index (e.g. 0 in "data[0]")
    std::string GetIndex() const
    {
        std::string indexStr = fName;
        indexStr.erase(indexStr.rfind(']'));
        indexStr.erase(0, indexStr.rfind('[') + 1);
        return indexStr;
    }

    /// Get socket type
    /// @return Returns socket type (push/pull/pub/sub/spub/xsub/pair/req/rep/dealer/router/)
    std::string GetType() const { return fType; }

    /// Get socket method
    /// @return Returns socket method (bind/connect)
    std::string GetMethod() const { return fMethod; }

    /// Get socket address (e.g. "tcp://127.0.0.1:5555" or "ipc://abc")
    /// @return Returns socket address (e.g. "tcp://127.0.0.1:5555" or "ipc://abc")
    std::string GetAddress() const { return fAddress; }

    /// Get channel transport name ("default", "zeromq" or "shmem")
    /// @return Returns channel transport name (e.g. "default", "zeromq" or "shmem")
    std::string GetTransportName() const { return TransportName(fTransportType); }

    /// Get channel transport type
    /// @return Returns channel transport type
    mq::Transport GetTransportType() const { return fTransportType; }

    /// Get socket send buffer size (in number of messages)
    /// @return Returns socket send buffer size (in number of messages)
    int GetSndBufSize() const { return fSndBufSize; }

    /// Get socket receive buffer size (in number of messages)
    /// @return Returns socket receive buffer size (in number of messages)
    int GetRcvBufSize() const { return fRcvBufSize; }

    /// Get socket kernel transmit send buffer size (in bytes)
    /// @return Returns socket kernel transmit send buffer size (in bytes)
    int GetSndKernelSize() const { return fSndKernelSize; }

    /// Get socket kernel transmit receive buffer size (in bytes)
    /// @return Returns socket kernel transmit receive buffer size (in bytes)
    int GetRcvKernelSize() const { return fRcvKernelSize; }

    /// Get socket default send timeout (in ms)
    /// @return Returns socket default send timeout (in ms)
    int GetSndTimeout() const { return fSndTimeoutMs; }

    /// Get socket default receive timeout (in ms)
    /// @return Returns socket default receive timeout (in ms)
    int GetRcvTimeout() const { return fRcvTimeoutMs; }

    /// Get linger duration (in milliseconds)
    /// @return Returns linger duration (in milliseconds)
    int GetLinger() const { return fLinger; }

    /// Get socket rate logging interval (in seconds)
    /// @return Returns socket rate logging interval (in seconds)
    int GetRateLogging() const { return fRateLogging; }

    /// Get start of the port range for automatic binding
    /// @return start of the port range
    int GetPortRangeMin() const { return fPortRangeMin; }

    /// Get end of the port range for automatic binding
    /// @return end of the port range
    int GetPortRangeMax() const { return fPortRangeMax; }

    /// Set automatic binding (pick random port if bind fails)
    /// @return true/false, true if automatic binding is enabled
    bool GetAutoBind() const { return fAutoBind; }

    /// @par Thread Safety
    /// * @e Distinct @e objects: Safe.@n
    /// * @e Shared @e objects: Unsafe.
    auto GetNumberOfConnectedPeers() const
    {
        return fSocket ? fSocket->GetNumberOfConnectedPeers() : 0;
    }

    /// Set channel name
    /// @param name Arbitrary channel name
    void UpdateName(const std::string& name) { fName = name; Invalidate(); }

    /// Set socket type
    /// @param type Socket type (push/pull/pub/sub/spub/xsub/pair/req/rep/dealer/router/)
    void UpdateType(const std::string& type) { fType = type; Invalidate(); }

    /// Set socket method
    /// @param method Socket method (bind/connect)
    void UpdateMethod(const std::string& method) { fMethod = method; Invalidate(); }

    /// Set socket address
    /// @param Socket address (e.g. "tcp://127.0.0.1:5555" or "ipc://abc")
    void UpdateAddress(const std::string& address) { fAddress = address; Invalidate(); }

    /// Set channel transport
    /// @param transport transport string ("default", "zeromq" or "shmem")
    void UpdateTransport(const std::string& transport) { fTransportType = TransportType(transport); Invalidate(); }

    /// Set socket send buffer size
    /// @param sndBufSize Socket send buffer size (in number of messages)
    void UpdateSndBufSize(int sndBufSize) { fSndBufSize = sndBufSize; Invalidate(); }

    /// Set socket receive buffer size
    /// @param rcvBufSize Socket receive buffer size (in number of messages)
    void UpdateRcvBufSize(int rcvBufSize) { fRcvBufSize = rcvBufSize; Invalidate(); }

    /// Set socket kernel transmit send buffer size (in bytes)
    /// @param sndKernelSize Socket send buffer size (in bytes)
    void UpdateSndKernelSize(int sndKernelSize) { fSndKernelSize = sndKernelSize; Invalidate(); }

    /// Set socket kernel transmit receive buffer size (in bytes)
    /// @param rcvKernelSize Socket receive buffer size (in bytes)
    void UpdateRcvKernelSize(int rcvKernelSize) { fRcvKernelSize = rcvKernelSize; Invalidate(); }

    /// Set socket default send timeout (in ms)
    /// @param sndTimeoutMs Socket default send timeout (in ms)
    void UpdateSndTimeout(int sndTimeoutMs) { fSndTimeoutMs = sndTimeoutMs; Invalidate(); }

    /// Set socket default receive timeout (in ms)
    /// @param rcvTimeoutMs Socket default receive timeout (in ms)
    void UpdateRcvTimeout(int rcvTimeoutMs) { fRcvTimeoutMs = rcvTimeoutMs; Invalidate(); }

    /// Set linger duration (in milliseconds)
    /// @param duration linger duration (in milliseconds)
    void UpdateLinger(int duration) { fLinger = duration; Invalidate(); }

    /// Set socket rate logging interval (in seconds)
    /// @param rateLogging Socket rate logging interval (in seconds)
    void UpdateRateLogging(int rateLogging) { fRateLogging = rateLogging; Invalidate(); }

    /// Set start of the port range for automatic binding
    /// @param minPort start of the port range
    void UpdatePortRangeMin(int minPort) { fPortRangeMin = minPort; Invalidate(); }

    /// Set end of the port range for automatic binding
    /// @param maxPort end of the port range
    void UpdatePortRangeMax(int maxPort) { fPortRangeMax = maxPort; Invalidate(); }

    /// Set automatic binding (pick random port if bind fails)
    /// @param autobind true/false, true to enable automatic binding
    void UpdateAutoBind(bool autobind) { fAutoBind = autobind; Invalidate(); }

    /// Checks if the configured channel settings are valid (checks the validity parameter, without running full validation (as oposed to ValidateChannel()))
    /// @return true if channel settings are valid, false otherwise.
    bool IsValid() const { return fValid; }

    /// Validates channel configuration
    /// @return true if channel settings are valid, false otherwise.
    bool Validate();

    void Init();

    bool ConnectEndpoint(const std::string& endpoint);

    bool BindEndpoint(std::string& endpoint);

    /// invalidates the channel (requires validation to be used again).
    void Invalidate() { fValid = false; }

    /// Send message(s) to the socket queue.
    /// @param m reference to MessagePtr/Parts/vector<MessagePtr>
    /// @param sndTimeoutMs send timeout in ms.
    /// -1 will wait forever (or until interrupt (e.g. via state change)),
    /// 0 will not wait (return immediately if cannot send).
    /// If not provided, default timeout will be taken.
    /// @return Number of bytes that have been queued,
    /// TransferCode::timeout if timed out,
    /// TransferCode::error if there was an error,
    /// TransferCode::interrupted if interrupted (e.g. by requested state change)
    template<typename M, typename... Timeout>
    std::enable_if_t<is_transferrable<M>::value, int64_t>
    Send(M& m, Timeout&&... sndTimeoutMs)
    {
        static_assert(sizeof...(sndTimeoutMs) <= 1, "Send called with too many arguments");

        CheckSendCompatibility(m);
        int t = fSndTimeoutMs;
        if constexpr (sizeof...(sndTimeoutMs) == 1) {
            t = {sndTimeoutMs...};
        }
        return fSocket->Send(m, t);
    }

    /// Receive message(s) from the socket queue.
    /// @param m reference to MessagePtr/Parts/vector<MessagePtr>
    /// @param rcvTimeoutMs receive timeout in ms.
    /// -1 will wait forever (or until interrupt (e.g. via state change)),
    /// 0 will not wait (return immediately if cannot receive).
    /// If not provided, default timeout will be taken.
    /// @return Number of bytes that have been received,
    /// TransferCode::timeout if timed out,
    /// TransferCode::error if there was an error,
    /// TransferCode::interrupted if interrupted (e.g. by requested state change)
    template<typename M, typename... Timeout>
    std::enable_if_t<is_transferrable<M>::value, int64_t>
    Receive(M& m, Timeout&&... rcvTimeoutMs)
    {
        static_assert(sizeof...(rcvTimeoutMs) <= 1, "Receive called with too many arguments");

        CheckReceiveCompatibility(m);
        int t = fRcvTimeoutMs;
        if constexpr (sizeof...(rcvTimeoutMs) == 1) {
            t = {rcvTimeoutMs...};
        }
        return fSocket->Receive(m, t);
    }

    unsigned long GetBytesTx() const { return fSocket->GetBytesTx(); }
    unsigned long GetBytesRx() const { return fSocket->GetBytesRx(); }
    unsigned long GetMessagesTx() const { return fSocket->GetMessagesTx(); }
    unsigned long GetMessagesRx() const { return fSocket->GetMessagesRx(); }

    auto Transport() -> TransportFactory* { return fTransportFactory.get(); };

    template<typename... Args>
    MessagePtr NewMessage(Args&&... args)
    {
        return Transport()->CreateMessage(std::forward<Args>(args)...);
    }

    template<typename T>
    MessagePtr NewSimpleMessage(const T& data)
    {
        return Transport()->NewSimpleMessage(data);
    }

    template<typename T>
    MessagePtr NewStaticMessage(const T& data)
    {
        return Transport()->NewStaticMessage(data);
    }

    template<typename... Args>
    UnmanagedRegionPtr NewUnmanagedRegion(Args&&... args)
    {
        return Transport()->CreateUnmanagedRegion(std::forward<Args>(args)...);
    }

    static constexpr mq::Transport DefaultTransportType = mq::Transport::DEFAULT;
    static constexpr const char* DefaultTransportName = "default";
    static constexpr const char* DefaultName = "";
    static constexpr const char* DefaultType = "unspecified";
    static constexpr const char* DefaultMethod = "unspecified";
    static constexpr const char* DefaultAddress = "unspecified";
    static constexpr int DefaultSndBufSize = 1000;
    static constexpr int DefaultRcvBufSize = 1000;
    static constexpr int DefaultSndKernelSize = 0;
    static constexpr int DefaultRcvKernelSize = 0;
    static constexpr int DefaultSndTimeoutMs = -1;
    static constexpr int DefaultRcvTimeoutMs = -1;
    static constexpr int DefaultLinger = 500;
    static constexpr int DefaultRateLogging = 1;
    static constexpr int DefaultPortRangeMin = 22000;
    static constexpr int DefaultPortRangeMax = 23000;
#ifdef FAIRMQ_CHANNEL_DEFAULT_AUTOBIND
    static constexpr bool DefaultAutoBind = FAIRMQ_CHANNEL_DEFAULT_AUTOBIND;
#else
    static constexpr bool DefaultAutoBind = true;
#endif

    friend std::ostream& operator<<(std::ostream& os, const Channel& ch)
    {
        return os << "name: " << ch.fName
                  << ", type: "  << ch.fType
                  << ", method: "  << ch.fMethod
                  << ", address: "  << ch.fAddress;
    }

  private:
    std::shared_ptr<TransportFactory> fTransportFactory;
    mq::Transport fTransportType;
    std::unique_ptr<Socket> fSocket;

    std::string fName;
    std::string fType;
    std::string fMethod;
    std::string fAddress;
    int fSndBufSize;
    int fRcvBufSize;
    int fSndKernelSize;
    int fRcvKernelSize;
    int fSndTimeoutMs;
    int fRcvTimeoutMs;
    int fLinger;
    int fRateLogging;
    int fPortRangeMin;
    int fPortRangeMax;
    bool fAutoBind;

    bool fValid;

    bool fMultipart;

    void CheckSendCompatibility(MessagePtr& msg)
    {
        if (fTransportType != msg->GetType()) {
            if (msg->GetSize() > 0) {
                MessagePtr msgWrapper(NewMessage(
                    msg->GetData(),
                    msg->GetSize(),
                    [](void* /*data*/, void* _msg) { delete static_cast<Message*>(_msg); },
                    msg.get()
                ));
                msg.release();
                msg = std::move(msgWrapper);
            } else {
                MessagePtr newMsg(NewMessage());
                msg = std::move(newMsg);
            }
        }
    }

    void CheckSendCompatibility(Parts& parts) { CheckSendCompatibility(parts.fParts); }
    void CheckSendCompatibility(std::vector<MessagePtr>& msgVec)
    {
        for (auto& msg : msgVec) {
            if (fTransportType != msg->GetType()) {
                if (msg->GetSize() > 0) {
                    MessagePtr msgWrapper(NewMessage(
                        msg->GetData(),
                        msg->GetSize(),
                        [](void* /*data*/, void* _msg) { delete static_cast<Message*>(_msg); },
                        msg.get()
                    ));
                    msg.release();
                    msg = std::move(msgWrapper);
                } else {
                    MessagePtr newMsg(NewMessage());
                    msg = std::move(newMsg);
                }
            }
        }
    }

    void CheckReceiveCompatibility(MessagePtr& msg)
    {
        if (fTransportType != msg->GetType()) {
            MessagePtr newMsg(NewMessage());
            msg = std::move(newMsg);
        }
    }

    void CheckReceiveCompatibility(Parts& parts) { CheckReceiveCompatibility(parts.fParts); }
    void CheckReceiveCompatibility(std::vector<MessagePtr>& msgVec)
    {
        for (auto& msg : msgVec) {
            if (fTransportType != msg->GetType()) {

                MessagePtr newMsg(NewMessage());
                msg = std::move(newMsg);
            }
        }
    }

    void InitTransport(std::shared_ptr<TransportFactory> factory)
    {
        fTransportFactory = factory;
        fTransportType = factory->GetType();
    }
};

} // namespace fair::mq

using FairMQChannel [[deprecated("Use fair::mq::Channel")]] = fair::mq::Channel;

#endif   // FAIR_MQ_CHANNEL_H