ADC/net/adc_device_netserver.h

#pragma once

#include "adc_device_netmsg.h"
#include "adc_netserver.h"

#include "../device/adc_device_concepts.h"

namespace adc
{


class AdcDeviceNetServer : public AdcGenericNetServer
{
protected:
    typedef std::vector<char> serialized_t;

    class DeviceWrapper
    {
        std::function<serialized_t()> _get_id = []() -> serialized_t { throw std::system_error(); };
        std::function<serialized_t(std::span<const char>)> _get_attr = [](auto) -> serialized_t {
            throw std::system_error();
        };
        std::function<void(std::span<const char>, std::span<const char>)> _set_attr = [](auto, auto) {
            throw std::system_error();
        };
        std::function<void(std::span<const char>)> _exec_cmd = [](auto) { throw std::system_error(); };

    public:
        DeviceWrapper() {
            // null device
        };

        template <interfaces::adc_device_c DeviceT,
                  typename IdSerialT = traits::adc_char_identity<typename DeviceT::ident_t>,
                  typename AttrIdDeserialT = traits::adc_char_identity<typename DeviceT::attr_ident_t>,
                  typename CmdIdDeserialT = traits::adc_char_identity<typename DeviceT::cmd_ident_t>>
        DeviceWrapper(DeviceT* dev_ptr,
                      IdSerialT&& id_ser_func = {},  // serializer of device ID
                      AttrIdDeserialT&& attr_id_deser_func = {},
                      CmdIdDeserialT&& cmd_id_deser_func = {})
        {
            _get_id = [dev_ptr, wrapper = traits::adc_pf_wrapper(std::forward<IdSerialT>(id_ser_func))]() {
                auto id = std::get<0>(wrapper)(dev_ptr->ident());
                return serialized_t{id.begin(), id.end()};
            };

            _get_attr = [dev_ptr, wrapper = traits::adc_pf_wrapper(std::forward<AttrIdDeserialT>(attr_id_deser_func))](
                            std::span<const char> attr_name) mutable {
                auto attr_id = std::get<0>(wrapper)(attr_name);
                auto val = (*dev_ptr)[attr_id].serialize();
                using val_t = std::remove_cvref_t<decltype(val)>;

                if constexpr (std::same_as<serialized_t, val_t> || std::convertible_to<val_t, serialized_t>) {
                    return val;
                } else {
                    // !!!!!!!!  TODO: val_t maust be a char range
                    return serialized_t{val.begin(), val.end()};
                }
            };

            _set_attr = [dev_ptr, wrapper = traits::adc_pf_wrapper(std::forward<AttrIdDeserialT>(attr_id_deser_func))](
                            std::span<const char> attr_name, std::span<const char> val) mutable {
                auto attr_id = std::get<0>(wrapper)(attr_name);
                (*dev_ptr)[attr_id].deserialize(val);
            };

            _exec_cmd = [dev_ptr, wrapper = traits::adc_pf_wrapper<CmdIdDeserialT>(cmd_id_deser_func)](
                            std::span<const char> cmd_name) mutable {
                auto cmd_id = std::get<0>(wrapper)(cmd_name);
                (*dev_ptr)(cmd_id);
            };
        }


        serialized_t ident() const
        {
            return _get_id();
        }

        serialized_t getAttr(std::span<const char> attr_name)
        {
            return _get_attr(attr_name);
        }

        void setAttr(std::span<const char> attr_name, std::span<const char> val)
        {
            _set_attr(attr_name, val);
        }

        void exec(std::span<const char> cmd_name)
        {
            _exec_cmd(cmd_name);
        }
    };

    static DeviceWrapper nullDevice;

    std::unordered_map<void*, DeviceWrapper> _devices;

public:
    template <interfaces::adc_netservice_c NetServiceT>
    class Session : std::enable_shared_from_this<Session<NetServiceT>>
    {
    public:
        typedef std::string netsession_ident_t;
        typedef NetServiceT netservice_t;
        typedef AdcDeviceNetServer* netsession_ctx_t;

        typedef std::vector<char> message_t;

        template <traits::adc_input_char_range R>
        Session(R&& id, netservice_t srv, AdcDeviceNetServer* srv_ptr)
            : _ident(),
              _netService(std::move(srv)),
              _serverPtr(srv_ptr),
              _bindDevice(_serverPtr->_devices.size() ? _serverPtr->_devices[0] : AdcDeviceNetServer::nullDevice)
        {
            if constexpr (std::is_array_v<std::remove_cvref_t<R>>) {
                _ident = id;
            } else {
                _ident = netsession_ident_t(id.begin(), id.end());
            }
        }

        netsession_ident_t ident() const
        {
            return _ident;
        }

        void start()
        {
            _netService.asyncReceive(
                [this](std::error_code ec, message_t msg) {
                    if (ec) {
                        stop();
                    } else {
                        auto msg_sptr = std::make_shared<message_t>(std::move(msg));

                        AdcDeviceProtoMessage dev_msg(*msg_sptr);

                        handleMessage(dev_msg);

                        _netService.asyncSend(
                            *msg_sptr,
                            [msg_sptr, this](std::error_code ec) {
                                if (ec) {
                                    stop();
                                } else {
                                    start();
                                }
                            },
                            _sendTimeout);
                    }
                },
                _recvTimeout);
        }

        void stop()
        {
            _netService.close();
        }

    protected:
        netsession_ident_t _ident;
        netservice_t _netService;
        AdcDeviceNetServer* _serverPtr;
        AdcDeviceNetServer::DeviceWrapper& _bindDevice;

        std::chrono::duration<size_t> _recvTimeout = std::chrono::seconds(3600);
        std::chrono::duration<size_t> _sendTimeout = std::chrono::seconds(5);

        void handleMessage(auto& msg)
        {
            try {
                if (msg.isACK()) {
                    msg.ack();
                } else if (msg.isDEVICE()) {
                    auto dev_name = msg.attrs(1, 1);
                    if (dev_name.size()) {
                        bool found = false;
                        for (auto& [ptr, dev_wr] : _serverPtr->_devices) {
                            if (dev_wr.ident() == dev_name[0]) {
                                _bindDevice = dev_wr;
                                found = true;
                                break;
                            }
                        }
                        if (found) {
                            msg.ack();
                        } else {
                            msg.err(std::error_code{});
                        }
                    } else {
                        msg.err(std::error_code{});
                    }
                } else if (msg.isNAMES()) {
                } else if (msg.isHELLO()) {
                } else if (msg.isGET()) {
                } else if (msg.isSET()) {
                } else if (msg.isCMD()) {
                    msg.ack();
                } else {
                    msg.err(std::error_code{});  // !!!!!!!!!!!!
                }
            } catch (std::system_error ex) {
                msg.err(ex.code());
            }
        }
    };


    using AdcGenericNetServer::AdcGenericNetServer;

    template <interfaces::adc_device_c DeviceT,
              typename IdSerialT = traits::adc_char_identity<typename DeviceT::ident_t>,
              typename AttrIdDeserialT = traits::adc_char_identity<typename DeviceT::attr_ident_t>,
              typename CmdIdDeserialT = traits::adc_char_identity<typename DeviceT::cmd_ident_t>>
    AdcDeviceNetServer& addDevice(DeviceT* dev_ptr,
                                  IdSerialT&& id_ser_func = {},               // serializer of device ID
                                  AttrIdDeserialT&& attr_id_deser_func = {},  // deserializer of attribute ID
                                  CmdIdDeserialT&& cmd_id_deser_func = {})    // deserializer of command ID
    {
        auto id = std::forward<IdSerialT>(id_ser_func)(dev_ptr->ident());
        _devices.try_emplace(dev_ptr, dev_ptr, std::forward<IdSerialT>(id_ser_func),
                             std::forward<AttrIdDeserialT>(attr_id_deser_func),
                             std::forward<CmdIdDeserialT>(cmd_id_deser_func));
    }

    template <interfaces::adc_device_c DeviceT>
    AdcDeviceNetServer& delDevice(DeviceT* dev_ptr)
    {
        _devices.erase(dev_ptr);
    }
};

}  // namespace adc