/// @file
/// @brief QS/C++ port to POSIX API
/// @cond
///***************************************************************************
/// Last updated for version 6.6.0
/// Last updated on  2019-11-04
///
///                    Q u a n t u m  L e a P s
///                    ------------------------
///                    Modern Embedded Software
///
/// Copyright (C) 2005-2019 Quantum Leaps. All rights reserved.
///
/// This program is open source software: you can redistribute it and/or
/// modify it under the terms of the GNU General Public License as published
/// by the Free Software Foundation, either version 3 of the License, or
/// (at your option) any later version.
///
/// Alternatively, this program may be distributed and modified under the
/// terms of Quantum Leaps commercial licenses, which expressly supersede
/// the GNU General Public License and are specifically designed for
/// licensees interested in retaining the proprietary status of their code.
///
/// This program is distributed in the hope that it will be useful,
/// but WITHOUT ANY WARRANTY; without even the implied warranty of
/// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
/// GNU General Public License for more details.
///
/// You should have received a copy of the GNU General Public License
/// along with this program. If not, see <www.gnu.org/licenses>.
///
/// Contact information:
/// <www.state-machine.com/licensing>
/// <info@state-machine.com>
///***************************************************************************
/// @endcond
///

// expose features from the 2008 POSIX standard (IEEE Standard 1003.1-2008)
#define _POSIX_C_SOURCE 200809L

#ifndef Q_SPY
    #error "Q_SPY must be defined to compile qs_port.cpp"
#endif // Q_SPY

#define QP_IMPL         // this is QP implementation
#include "qf_port.hpp"  // QF port
#include "qassert.h"    // QP embedded systems-friendly assertions
#include "qs_port.hpp"  // include QS port

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>

#define QS_TX_SIZE     (8*1024)
#define QS_RX_SIZE     (2*1024)
#define QS_TX_CHUNK    QS_TX_SIZE
#define QS_TIMEOUT_MS  10

#define INVALID_SOCKET -1
#define SOCKET_ERROR   -1

namespace QP {

//DEFINE_THIS_MODULE("qs_port")

// local variables ...........................................................
static int l_sock = INVALID_SOCKET;
static struct timespec const c_timeout = { 0, QS_TIMEOUT_MS*1000000L };

//............................................................................
bool QS::onStartup(void const *arg) {
    static uint8_t qsBuf[QS_TX_SIZE];   // buffer for QS-TX channel
    static uint8_t qsRxBuf[QS_RX_SIZE]; // buffer for QS-RX channel
    char hostName[128];
    char const *serviceName = "6601";   // default QSPY server port
    char const *src;
    char *dst;
    int status;

    struct addrinfo *result = NULL;
    struct addrinfo *rp = NULL;
    struct addrinfo hints;
    int sockopt_bool;

    // initialize the QS transmit and receive buffers
    initBuf(qsBuf, sizeof(qsBuf));
    rxInitBuf(qsRxBuf, sizeof(qsRxBuf));

    // extract hostName from 'arg' (hostName:port_remote)...
    src = (arg != nullptr)
          ? static_cast<char const *>(arg)
          : "localhost"; // default QSPY host
    dst = hostName;
    while ((*src != '\0')
           && (*src != ':')
           && (dst < &hostName[sizeof(hostName) - 1]))
    {
        *dst++ = *src++;
    }
    *dst = '\0'; // zero-terminate hostName

    // extract serviceName from 'arg' (hostName:serviceName)...
    if (*src == ':') {
        serviceName = src + 1;
    }
    //printf("<TARGET> Connecting to QSPY on Host=%s:%s...\n",
    //       hostName, serviceName);

    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;
    status = getaddrinfo(hostName, serviceName, &hints, &result);
    if (status != 0) {
        fprintf(stderr,
            "<TARGET> ERROR   cannot resolve host Name=%s:%s,Err=%d\n",
                    hostName, serviceName, status);
        goto error;
    }

    for (rp = result; rp != NULL; rp = rp->ai_next) {
        l_sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
        if (l_sock != INVALID_SOCKET) {
            if (connect(l_sock, rp->ai_addr, rp->ai_addrlen)
                == SOCKET_ERROR)
            {
                close(l_sock);
                l_sock = INVALID_SOCKET;
            }
            break;
        }
    }

    freeaddrinfo(result);

    // socket could not be opened & connected?
    if (l_sock == INVALID_SOCKET) {
        fprintf(stderr, "<TARGET> ERROR   cannot connect to QSPY at "
            "host=%s:%s\n",
            hostName, serviceName);
        goto error;
    }

    // set the socket to non-blocking mode
    status = fcntl(l_sock, F_GETFL, 0);
    if (status == -1) {
        fprintf(stderr,
            "<TARGET> ERROR   Socket configuration failed errno=%d\n",
            errno);
        QS_EXIT();
        goto error;
    }
    if (fcntl(l_sock, F_SETFL, status | O_NONBLOCK) != 0) {
        fprintf(stderr, "<TARGET> ERROR   Failed to set non-blocking socket "
            "errno=%d\n", errno);
        QS_EXIT();
        goto error;
    }

    // configure the socket to reuse the address and not to linger
    sockopt_bool = 1;
    setsockopt(l_sock, SOL_SOCKET, SO_REUSEADDR,
               &sockopt_bool, sizeof(sockopt_bool));
    sockopt_bool = 0; // negative option
    setsockopt(l_sock, SOL_SOCKET, SO_LINGER,
               &sockopt_bool, sizeof(sockopt_bool));

    //printf("<TARGET> Connected to QSPY at Host=%s:%d\n",
    //       hostName, port_remote);
    onFlush();

    return true;  // success

error:
    return false; // failure
}
//............................................................................
void QS::onCleanup(void) {
    if (l_sock != INVALID_SOCKET) {
        close(l_sock);
        l_sock = INVALID_SOCKET;
    }
    //printf("<TARGET> Disconnected from QSPY\n");
}
//............................................................................
void QS::onReset(void) {
    onCleanup();
    exit(0);
}
//............................................................................
void QS::onFlush(void) {
    uint16_t nBytes;
    uint8_t const *data;
    QS_CRIT_STAT_

    if (l_sock == INVALID_SOCKET) { // socket NOT initialized?
        fprintf(stderr, "<TARGET> ERROR   invalid TCP socket\n");
        return;
    }

    nBytes = QS_TX_CHUNK;
    QS_CRIT_ENTRY_();
    while ((data = getBlock(&nBytes)) != (uint8_t *)0) {
        QS_CRIT_EXIT_();
        for (;;) { // for-ever until break or return
            int nSent = send(l_sock, (char const *)data, (int)nBytes, 0);
            if (nSent == SOCKET_ERROR) { // sending failed?
                if ((errno == EWOULDBLOCK) || (errno == EAGAIN)) {
                    // sleep for the timeout and then loop back
                    // to send() the SAME data again
                    //
                    nanosleep(&c_timeout, NULL);
                }
                else { // some other socket error...
                    fprintf(stderr, "<TARGET> ERROR   sending data over TCP,"
                           "errno=%d\n", errno);
                    return;
                }
            }
            else if (nSent < (int)nBytes) { // sent fewer than requested?
                nanosleep(&c_timeout, NULL); // sleep for the timeout
                // adjust the data and loop back to send() the rest
                data   += nSent;
                nBytes -= (uint16_t)nSent;
            }
            else {
                break;
            }
        }
        // set nBytes for the next call to QS::getBlock()
        nBytes = QS_TX_CHUNK;
        QS_CRIT_ENTRY_();
    }
    QS_CRIT_EXIT_();
}
//............................................................................
QSTimeCtr QS::onGetTime(void) {
    struct timespec tspec;
    QSTimeCtr time;
    clock_gettime(CLOCK_MONOTONIC_RAW, &tspec);

    // convert to units of 0.1 microsecond
    time = (QSTimeCtr)(tspec.tv_sec * 10000000 + tspec.tv_nsec / 100);
    return time;
}

//............................................................................
void QS_output(void) {
    uint16_t nBytes;
    uint8_t const *data;

    if (l_sock == INVALID_SOCKET) { // socket NOT initialized?
        fprintf(stderr, "<TARGET> ERROR   invalid TCP socket\n");
        return;
    }

    nBytes = QS_TX_CHUNK;
    QS_CRIT_STAT_
    QS_CRIT_ENTRY_();
    if ((data = QS::getBlock(&nBytes)) != (uint8_t *)0) {
        QS_CRIT_EXIT_();
        for (;;) { // for-ever until break or return
            int nSent = send(l_sock, (char const *)data, (int)nBytes, 0);
            if (nSent == SOCKET_ERROR) { // sending failed?
                if ((errno == EWOULDBLOCK) || (errno == EAGAIN)) {
                    // sleep for timeout and then loop back
                    // to send() the SAME data again
                    //
                    nanosleep(&c_timeout, NULL);
                }
                else { // some other socket error...
                    fprintf(stderr, "<TARGET> ERROR   sending data over TCP,"
                           "errno=%d\n", errno);
                    return;
                }
            }
            else if (nSent < (int)nBytes) { // sent fewer than requested?
                nanosleep(&c_timeout, NULL); // sleep for the timeout
                // adjust the data and loop back to send() the rest
                data   += nSent;
                nBytes -= (uint16_t)nSent;
            }
            else {
                break;
            }
        }
        // set nBytes for the next call to QS::getBlock()
        nBytes = QS_TX_CHUNK;
    }
    else {
        QS_CRIT_EXIT_();
    }
}
//............................................................................
void QS_rx_input(void) {
    uint8_t buf[QS_RX_SIZE];
    int status = recv(l_sock, (char *)buf, (int)sizeof(buf), 0);
    if (status != SOCKET_ERROR) { // any data received?
        uint8_t *pb;
        int i = (int)QS::rxGetNfree();
        if (i > status) {
            i = status;
        }
        status -= i;
        // reorder the received bytes into QS-RX buffer
        for (pb = &buf[0]; i > 0; --i, ++pb) {
            QS::rxPut(*pb);
        }
        QS::rxParse(); // parse all n-bytes of data
    }
}

} // namespace QP