/*
    ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT is free 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.

    ChibiOS/RT 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 <http://www.gnu.org/licenses/>.
*/

/**
 * @file Linux/serial_lld.c
 * @brief Linux low level simulated serial driver code.
 * @addtogroup LINUX_SERIAL
 * @{
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/ioctl.h>

#include "ch.h"
#include "hal.h"

#if CH_HAL_USE_SERIAL || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/** @brief Serial driver 1 identifier.*/
#if USE_SIM_SERIAL1 || defined(__DOXYGEN__)
SerialDriver SD1;
#endif
/** @brief Serial driver 2 identifier.*/
#if USE_SIM_SERIAL2 || defined(__DOXYGEN__)
SerialDriver SD2;
#endif

/*===========================================================================*/
/* Driver local variables.                                                   */
/*===========================================================================*/

/** @brief Driver default configuration.*/
static const SerialDriverConfig default_config = {
};

static u_long nb = 1;

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

static void init(SerialDriver *sdp, uint16_t port) {
  struct sockaddr_in sad;
  struct protoent *prtp;

  if ((prtp = getprotobyname("tcp")) == NULL) {
    printf("%s: Error mapping protocol name to protocol number\n", sdp->d2.com_name);
    goto abort;
  }

  sdp->d2.com_listen = socket(PF_INET, SOCK_STREAM, prtp->p_proto);
  if (sdp->d2.com_listen == INVALID_SOCKET) {
    printf("%s: Error creating simulator socket\n", sdp->d2.com_name);
    goto abort;
  }

  if (ioctl(sdp->d2.com_listen, FIONBIO, &nb) != 0) {
    printf("%s: Unable to setup non blocking mode on socket\n", sdp->d2.com_name);
    goto abort;
  }

  memset(&sad, 0, sizeof(sad));
  sad.sin_family = AF_INET;
  sad.sin_addr.s_addr = INADDR_ANY;
  sad.sin_port = htons(port);
  if (bind(sdp->d2.com_listen, (struct sockaddr *)&sad, sizeof(sad))) {
    printf("%s: Error binding socket\n", sdp->d2.com_name);
    goto abort;
  }

  if (listen(sdp->d2.com_listen, 1) != 0) {
    printf("%s: Error listening socket\n", sdp->d2.com_name);
    goto abort;
  }
  printf("Full Duplex Channel %s listening on port %d\n", sdp->d2.com_name, port);
  return;

abort:
  if (sdp->d2.com_listen != INVALID_SOCKET)
    close(sdp->d2.com_listen);
  exit(1);
}

static bool_t connint(SerialDriver *sdp) {

  if (sdp->d2.com_data == INVALID_SOCKET) {
    struct sockaddr addr;
    socklen_t addrlen = sizeof(addr);

    if ((sdp->d2.com_data = accept(sdp->d2.com_listen, &addr, &addrlen)) == INVALID_SOCKET)
      return FALSE;

    if (ioctl(sdp->d2.com_data, FIONBIO, &nb) != 0) {
      printf("%s: Unable to setup non blocking mode on data socket\n", sdp->d2.com_name);
      goto abort;
    }
    sdAddFlagsI(sdp, SD_CONNECTED);
    return TRUE;
  }
  return FALSE;
abort:
  if (sdp->d2.com_listen != INVALID_SOCKET)
    close(sdp->d2.com_listen);
  if (sdp->d2.com_data != INVALID_SOCKET)
    close(sdp->d2.com_data);
  exit(1);
}

static bool_t inint(SerialDriver *sdp) {

  if (sdp->d2.com_data != INVALID_SOCKET) {
    int i;
    uint8_t data[32];

    /*
     * Input.
     */
    int n = recv(sdp->d2.com_data, data, sizeof(data), 0);
    switch (n) {
    case 0:
      close(sdp->d2.com_data);
      sdp->d2.com_data = INVALID_SOCKET;
      sdAddFlagsI(sdp, SD_DISCONNECTED);
      return FALSE;
    case INVALID_SOCKET:
      if (errno == EWOULDBLOCK)
        return FALSE;
      close(sdp->d2.com_data);
      sdp->d2.com_data = INVALID_SOCKET;
      return FALSE;
    }
    for (i = 0; i < n; i++)
      sdIncomingDataI(sdp, data[i]);
    return TRUE;
  }
  return FALSE;
}

static bool_t outint(SerialDriver *sdp) {

  if (sdp->d2.com_data != INVALID_SOCKET) {
    int n;
    uint8_t data[1];

    /*
     * Input.
     */
    n = sdRequestDataI(sdp);
    if (n < 0)
      return FALSE;
    data[0] = (uint8_t)n;
    n = send(sdp->d2.com_data, data, sizeof(data), 0);
    switch (n) {
    case 0:
      close(sdp->d2.com_data);
      sdp->d2.com_data = INVALID_SOCKET;
      sdAddFlagsI(sdp, SD_DISCONNECTED);
      return FALSE;
    case INVALID_SOCKET:
      if (errno == EWOULDBLOCK)
        return FALSE;
      close(sdp->d2.com_data);
      sdp->d2.com_data = INVALID_SOCKET;
      return FALSE;
    }
    return TRUE;
  }
  return FALSE;
}

/*===========================================================================*/
/* Driver interrupt handlers.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * Low level serial driver initialization.
 */
void sd_lld_init(void) {

#if USE_SIM_SERIAL1
  sdObjectInit(&SD1, NULL, NULL);
  SD1.d2.com_listen = INVALID_SOCKET;
  SD1.d2.com_data = INVALID_SOCKET;
  SD1.d2.com_name = "SD1";
#endif

#if USE_SIM_SERIAL2
  sdObjectInit(&SD2, NULL, NULL);
  SD2.d2.com_listen = INVALID_SOCKET;
  SD2.d2.com_data = INVALID_SOCKET;
  SD2.d2.com_name = "SD2";
#endif
}

/**
 * @brief Low level serial driver configuration and (re)start.
 *
 * @param[in] sdp pointer to a @p SerialDriver object
 * @param[in] config the architecture-dependent serial driver configuration.
 *                   If this parameter is set to @p NULL then a default
 *                   configuration is used.
 */
void sd_lld_start(SerialDriver *sdp, const SerialDriverConfig *config) {

  if (config == NULL)
    config = &default_config;

#if USE_SIM_SERIAL1
  if (sdp == &SD1)
    init(&SD1, SIM_SD1_PORT);
#endif

#if USE_SIM_SERIAL2
  if (sdp == &SD2)
    init(&SD2, SIM_SD2_PORT);
#endif
}

/**
 * @brief Low level serial driver stop.
 * @details De-initializes the USART, stops the associated clock, resets the
 *          interrupt vector.
 *
 * @param[in] sdp pointer to a @p SerialDriver object
 */
void sd_lld_stop(SerialDriver *sdp) {

  (void)sdp;
}

bool_t sd_lld_interrupt_pending(void) {

  return connint(&SD1) || connint(&SD2) ||
         inint(&SD1)   || inint(&SD2)   ||
         outint(&SD1)  || outint(&SD2);
}

#endif /* CH_HAL_USE_SERIAL */

/** @} */