/**
 * @file udpSockets.hpp
 * @author Gustice
 * @brief UDP-Socket wrapper for ESP-IDF socket implementation
 *
 * @copyright Copyright (c) 2024
 */
#pragma once

#include "Task.hpp"
#include "esp_log.h"
#include "etherCommon.hpp"
#include "utils.hpp"
#include <cstdarg>
#include <iostream>
#include <string>

constexpr bool UDP_WITH_TIMEOUT = false;

/**
 * @brief UDP-Socket wrapper for ESP-IDF socket implementation
 */
class UdpSocket : public ByteStream, public SocketBase {
  public:
    /// @brief Constructor for UDP-Socket-Server
    /// @note Socket not active until call of attach method
    /// @param addr Server/Client address
    UdpSocket(const IpAdr &addr)
        : Local(addr), _other(INADDR_ANY, 0) {
        _listenSockId = socket(addr.ProtocolFamily, SOCK_DGRAM, addr.IpProtocol);
        if (_listenSockId < 0) {
            ESP_LOGE("UDP", "Unable to create socket: errno %d", errno);
            throw CoreException("Unable to create socket");
        }
        ESP_LOGD("UDP", "Socket created");

        if constexpr (NETBUF_RECVINFO && !USE_IPV6) {
            int enable = 1;
            lwip_setsockopt(_listenSockId, IPPROTO_IP, IP_PKTINFO, &enable, sizeof(enable));
        }

        if constexpr (USE_IPV4 && USE_IPV6) {
            if (addr.ProtocolFamily == AF_INET6) {
                // Note that by default IPV6 binds to both protocols, it is must be disabled
                // if both protocols used at the same time (used in CI)
                int opt = 1;
                setsockopt(_listenSockId, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
                setsockopt(_listenSockId, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof(opt));
            }
        }

        if constexpr (UDP_WITH_TIMEOUT) { // Set timeout if desired
            struct timeval timeout {
                .tv_sec = 10,
                .tv_usec = 0,
            };
            setsockopt(_listenSockId, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout));
        }
    }

    /// @brief Destructor
    ~UdpSocket() {
        active = false;
        ESP_LOGD("UDP", "Shutting down socket and restarting...");
        shutdown(_listenSockId, 0);
        close(_listenSockId);
    }

    /// @brief Attach to configured socket
    /// @note Blocks until successful or failed
    /// @return true if successful
    bool bindTo() {
        active = false;
        int err = bind(_listenSockId, Local.asSockAddrPtr(), sizeof(sockaddr_storage));
        if (err < 0) {
            ESP_LOGE("UDP", "Socket unable to bind: errno %d", errno);
            throw CoreException("Socket unable to bind");
        }
        ESP_LOGI("UDP", "Socket bound, port %d", Local.getPort());

        if constexpr (NETBUF_RECVINFO && !USE_IPV6) {
            _iov.iov_base = _rxBuffer;
            _iov.iov_len = sizeof(_rxBuffer);
            _msg.msg_control = _cmsg_buf;
            _msg.msg_controllen = sizeof(_cmsg_buf);
            _msg.msg_flags = 0;
            _msg.msg_iov = &_iov;
            _msg.msg_iovlen = 1;
            _msg.msg_name = _other.asSockAddrPtr();
            _msg.msg_namelen = _other.Size;
        }

        active = true;
        return active;
    }

    /// @brief Read from socket
    /// @note This call blocks until data is received
    /// @return read bytes
    std::vector<uint8_t> read() override {
        char buffer[256];
        int len = 0;
        if constexpr (NETBUF_RECVINFO && !USE_IPV6) {
            len = recvmsg(_listenSockId, &_msg, 0);
        } else {
            socklen_t socklen = _other.Size;
            len = recvfrom(_listenSockId, buffer, sizeof(buffer) - 1, 0, _other.asSockAddrPtr(), &socklen);
        }
        if (len < 0) {
            ESP_LOGE("UDP", "recvfrom failed: errno %d", errno);
            return {};
        }

        std::string addrStr;
        // Get the sender's ip address as string
        if (Local.ProtocolFamily == PF_INET) {
            addrStr = _other.getIp();

            if constexpr (NETBUF_RECVINFO && !USE_IPV6) {
                struct cmsghdr *cmsgtmp;
                for (cmsgtmp = CMSG_FIRSTHDR(&_msg); cmsgtmp != NULL; cmsgtmp = CMSG_NXTHDR(&_msg, cmsgtmp)) {
                    if (cmsgtmp->cmsg_level == IPPROTO_IP && cmsgtmp->cmsg_type == IP_PKTINFO) {
                        struct in_pktinfo *pktinfo;
                        pktinfo = (struct in_pktinfo *)CMSG_DATA(cmsgtmp);
                        ESP_LOGI("UDP", "dest ip: %s", inet_ntoa(pktinfo->ipi_addr));
                    }
                }
            }
        } // else if (Local.ProtocolFamily == PF_INET6) {
        //     inet6_ntoa_r(((struct sockaddr_in6 *)&_other.addrStore)->sin6_addr, addrStr, sizeof(addrStr) - 1);
        // }

        ESP_LOGD("UDP", "Received %d bytes from %s:", len, addrStr.c_str());
        std::vector<uint8_t> ret(buffer, buffer + len);
        return ret;
    }

    /// @brief Write character to socket
    /// @param b character to write
    void write(uint8_t b) override {}

    /// @brief Write bytes to socket
    /// @param data payload as series of bytes
    void write(std::vector<uint8_t> data) override {
        write(&data[0], data.size());
    }

    /// @brief Write string to specific socket
    /// @param message payload
    /// @param dest Destination for message
    void write(std::string &message, IpAdr *dest = nullptr) {
        auto data = message.c_str();
        write((uint8_t *)data, message.size() + 1, dest);
    }

    /// @brief Write string to specific socket or to last source
    /// @param data payload
    /// @param size size of data
    /// @param addr Destination for message (if nullptr it will be send to last source)
    void write(uint8_t *data, uint size, IpAdr *dest = nullptr) {
        int err;
        if (dest == nullptr) {
            err = sendto(_listenSockId, data, size, 0, _other.asSockAddrPtr(), sizeof(sockaddr_storage));
        } else {
            struct sockaddr_in *ipV4 = (struct sockaddr_in *)dest->asSockAddrPtr();
            // ESP_LOGI("UDP", "EthIP: %s", inet_ntoa(ipV4->sin_addr.s_addr));
            // ESP_LOGI("UDP", "PORT: %i", ntohs(ipV4->sin_port));
            err = sendto(_listenSockId, data, size, 0, dest->asSockAddrPtr(), sizeof(sockaddr_storage));
        }

        if (err < 0) {
            ESP_LOGE("UDP", "Error occurred during sending: errno %d", errno);
            active = false;
        }
    }

    /// @brief Standard destination address
    const IpAdr &Local;

    /// @brief query if stream is still active
    /// @return true if active
    bool isValid() {
        return _listenSockId >= 0;
    }

    IpAdr getOther() {
        return _other;
    }

  private:
    int _listenSockId; // os handle for socket
    IpAdr _other;      // Remote Station
    char _rxBuffer[128];

    // Only used if NETBUF_RECVINFO is active
    iovec _iov;
    msghdr _msg;
    u8_t _cmsg_buf[CMSG_SPACE(sizeof(struct in_pktinfo))];
};

/**
 * @brief
 * @details according to RFC-5424
 * https://datatracker.ietf.org/doc/html/rfc5424
 */
class Syslog {
  public:
    static constexpr uint16_t SyslogPort = 514;
    static constexpr std::string_view NilValue = "-";

    enum class Severity {
        Emergency = 0,
        Alert = 1,
        Critical = 2,
        Error = 3,
        Warning = 4,
        Notice = 5,
        Informational = 6,
        Debug = 7,
    };
    static constexpr uint8_t SeverityMask = 0x000F;

    enum class Facility {
        kern = 0 << 3,
        User = 1 << 3,
        Mail = 2 << 3,
        Daemon = 3 << 3,
        Auth = 4 << 3,
        Syslog = 5 << 3,
        Lpr = 6 << 3,
        News = 7 << 3,
        Uucp = 8 << 3,
        Cron = 9 << 3,
        Authpriv = 10 << 3,
        Ftp = 11 << 3,
        Ntp = 12 << 3,
        LogAudit = 13 << 3,
        LogAlert = 14 << 3,
        Clock = 15 << 3,
        Local0 = 16 << 3,
        Local1 = 17 << 3,
        Local2 = 18 << 3,
        Local3 = 19 << 3,
        Local4 = 20 << 3,
        Local5 = 21 << 3,
        Local6 = 22 << 3,
        Local7 = 23 << 3,
    };

    static void log(Severity severity, std::string message) {
        if (_Socket == nullptr) {
            return;
        }

        char buffer[512];
        //                              V T  H  A P M D  Msg
        // alternatively with BOM flag UTF8 \xEF\xBB\xBF
        auto pos = sprintf(buffer, "<%i>1 - %s %s - - - %s",
                           static_cast<int>(_Facility) | static_cast<int>(severity),
                           _HostName.c_str(),
                           _AppName.c_str(),
                           message.c_str());
        _Socket->write((uint8_t *)buffer, pos, &_Target);
    }

    template <typename...Params>
    static void logv(Severity severity, const char *fmt, Params&&... args) {
        if (_Socket == nullptr) {
            return;
        }

        char buffer[512];
        //                              V T  H  A P M D  Msg
        // alternatively with BOM flag UTF8 \xEF\xBB\xBF
        auto pos = sprintf(buffer, "<%i>1 - %s %s - - - ",
                           static_cast<int>(_Facility) | static_cast<int>(severity),
                           _HostName.c_str(),
                           _AppName.c_str());
        pos += sprintf(&buffer[pos], fmt, std::forward<Params> (args)...);

        _Socket->write((uint8_t *)buffer, pos, &_Target);
    }

    static void setupTask(IpAdr target) {
        if (_Socket) {
            return;
        }
        _Facility = Facility::Syslog;
        _HostName = "ESP";
        _AppName = "App";
        _Target = IpAdr{target.getIp(), SyslogPort};

        static fos::Task syslogTask(SyslogTask, "SysLog", 4096);
    }

  private:
    static void SyslogTask();
    static Facility _Facility;
    static std::string _HostName;
    static std::string _AppName;
    static UdpSocket *_Socket;
    static IpAdr _Target;
};