// Copyright (2019-2022) Paul Scherrer Institute
// SPDX-License-Identifier: GPL-3.0-or-later

#include "LinuxSocketDevice.h"

#include <sys/socket.h>
#include <arpa/inet.h>
#include <ifaddrs.h>
#include <linux/if_packet.h>

#include "../common/JFJochException.h"

#define MAX_MODULES 16

LinuxSocketDevice::LinuxSocketDevice(uint32_t in_ipv4_addr, uint16_t in_udp_port,
                                     uint16_t data_stream, size_t in_frame_buffer_size_modules,
                                     int32_t in_rcv_buf_size, int16_t in_numa_node) :
        AcquisitionDevice(data_stream), ipv4_addr(in_ipv4_addr), udp_port(in_udp_port),
        numa_node(in_numa_node), rcv_buf_size(in_rcv_buf_size) {
    max_modules = 16;
    MapBuffersStandard(in_frame_buffer_size_modules, 1, numa_node);
    mac_addr = 0;
    FindMACAddress();
}

void LinuxSocketDevice::MeasureThread(int fd) {
    jf_udp_payload jf{};

    uint64_t packet_count = 0;

    completion_queue.Put(Completion{
            .type = Completion::Type::Start
    });

    try {
        ProcessJFPacket process(completion_queue, wr_queue, max_modules);

        while (!cancel) {
            auto count = recv(fd, &jf, sizeof(jf_udp_payload), 0);

            if (count == sizeof(jf_udp_payload)) {
                process.ProcessPacket(&jf);
                packet_count++;
            } else if ((count == -1) && (errno != EAGAIN) && (errno != EWOULDBLOCK))
                throw JFJochException(JFJochExceptionCategory::UDPError, "Error in UDP receiving");
        }
    } catch (const JFJochException &e) {
        if (logger)
            logger->ErrorException(e);
    }
    // End message should be sent always
    completion_queue.Put(Completion{
            .type = Completion::Type::End,
            .frame_number = packet_count
    });
    close(fd);
    idle = true;
}

Completion LinuxSocketDevice::ReadCompletion() {
    return completion_queue.GetBlocking();
}

void LinuxSocketDevice::HW_WriteActionRegister(const ActionConfig *job) {
    memcpy(&cfg, job,  sizeof(ActionConfig));
}

void LinuxSocketDevice::HW_ReadActionRegister(ActionConfig *job) {
    memcpy(job, &cfg, sizeof(ActionConfig));
}

void LinuxSocketDevice::HW_StartAction() {
    if (cfg.mode & MODE_CONV)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid,
                              "Conversion on CPU flag has to be enabled for Raw Ethernet device");

    int fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd < 0)
        throw JFJochException(JFJochExceptionCategory::UDPError, "Cannot create UDP socket");

    sockaddr_in server_addr{
            .sin_family = AF_INET,
            .sin_port = htons(udp_port),
            .sin_addr = {.s_addr = ipv4_addr}
    };

    timeval timeout{
            .tv_sec = 0,
            .tv_usec = 10000 // 10 ms
    };

    if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout)) != 0)
        throw JFJochException(JFJochExceptionCategory::UDPError, "Cannot set socket timeout");

    if (rcv_buf_size > 0) {
        if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &rcv_buf_size, sizeof(rcv_buf_size)) != 0)
            throw JFJochException(JFJochExceptionCategory::UDPError, "Cannot set receive buffer size");
    }
    if (bind(fd, (struct sockaddr *) &server_addr, sizeof(server_addr)) != 0)
        throw JFJochException(JFJochExceptionCategory::UDPError, "Cannot bind to UDP port");

    cancel = false;
    idle = false;

    measure = std::async(std::launch::async, &LinuxSocketDevice::MeasureThread, this, fd);
}

bool LinuxSocketDevice::HW_IsIdle() const {
    return idle;
}

void LinuxSocketDevice::HW_SetCancelDataCollectionBit() {
    cancel = true;
}

bool LinuxSocketDevice::HW_SendWorkRequest(uint32_t handle) {
    if (handle == UINT32_MAX)
        HW_SetCancelDataCollectionBit();
    else
        wr_queue.Put(ProcessWorkRequest{
                .ptr = buffer_device.at(handle),
                .handle = handle
        });

    return true;
}

void LinuxSocketDevice::HW_GetStatus(ActionStatus *status) const {
    memset(status, 0, sizeof(ActionStatus));

    status->modules_internal_packet_generator = 1;
    status->max_modules = max_modules;
}

uint64_t LinuxSocketDevice::HW_GetMACAddress() const {
    return mac_addr;
}

uint32_t LinuxSocketDevice::HW_GetIPv4Address() const {
    return ipv4_addr;
}

void LinuxSocketDevice::HW_EndAction() {
    if (measure.valid())
        measure.get();
}

void LinuxSocketDevice::CopyInternalPacketGenFrameToDeviceBuffer() {
    // Do nothing
}

void LinuxSocketDevice::InitializeCalibration(const DiffractionExperiment &experiment, const JFCalibration &calib) {
    // Do nothing
}

int32_t LinuxSocketDevice::GetNUMANode() const {
    return numa_node;
}

uint16_t LinuxSocketDevice::GetUDPPort() const {
    return udp_port;
}

void LinuxSocketDevice::FindMACAddress() {
    std::string ifname;
    bool found = false;

    ifaddrs *ifaddr;
    if (getifaddrs(&ifaddr) == -1)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "getifaddrs error");

    for (ifaddrs *ifa = ifaddr; ifa != nullptr; ifa = ifa->ifa_next) {
        if (ifa->ifa_addr->sa_family == AF_INET) {
            if (((sockaddr_in *) ifa->ifa_addr)->sin_addr.s_addr == ipv4_addr) {
                ifname = std::string(ifa->ifa_name);
                found = true;
            }
        }
    }

    if (!found)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "IPv4 address not found");
    found = false;

    for (ifaddrs *ifa = ifaddr; ifa != nullptr; ifa = ifa->ifa_next) {
        if ((std::string(ifa->ifa_name) == ifname) && ((ifa->ifa_addr->sa_family == AF_PACKET))) {
            memcpy(&mac_addr, ((sockaddr_ll *) ifa->ifa_addr)->sll_addr, sizeof(uint64_t));
            found = true;
        }
    }

    if (!found)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "MAC address not found");

    freeifaddrs(ifaddr);
}