/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of and a contribution to the lwIP TCP/IP stack.
 *
 * Credits go to Adam Dunkels (and the current maintainers) of this software.
 *
 * Christiaan Simons rewrote this file to get a more stable echo example.
 */

/**
 * @file
 * TCP echo server example using raw API.
 *
 * Echos all bytes sent by connecting client,
 * and passively closes when client is done.
 *
 */

 /** This file was modified by Geehy Semiconductor */

#include "lwip/opt.h"
#include "lwip/debug.h"
#include "lwip/stats.h"
#include "lwip/tcp.h"
#include "echo_c.h"
#include <stdlib.h>
#include <string.h>


#if LWIP_TCP

static struct tcp_pcb *tcpc_echo_pcb;

enum tcpc_echo_states
{
  ES_NONE = 0,
  ES_ACCEPTED,
  ES_RECEIVED,
  ES_CLOSING
};

struct tcpc_echo_state
{
  u8_t state;
  u8_t retries;
  struct tcp_pcb *pcb;
  /* pbuf (chain) to recycle */
  struct pbuf *p;
};

struct tcpc_echo_state * tcpc_echo_es;
uint8_t testdata[50] = "TCP Client to connect server";

err_t tcpc_echo_accept(void *arg, struct tcp_pcb *newpcb, err_t err);
err_t tcpc_echo_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err);
void tcpc_echo_error(void *arg, err_t err);
err_t tcpc_echo_poll(void *arg, struct tcp_pcb *tpcb);
err_t tcpc_echo_sent(void *arg, struct tcp_pcb *tpcb, u16_t len);
void tcpc_echo_send(struct tcp_pcb *tpcb, struct tcpc_echo_state *es);
void tcpc_echo_close(struct tcp_pcb *tpcb, struct tcpc_echo_state *es);
void PrintfRecData(struct pbuf *p);

/*!
 * @brief       tcp client init
 *
 * @param       tcpc_port£º client port
 *
 * @param       ipaddr£º point to the client ip address
 *
 * @retval      None
 */
void
tcpc_echo_init(ip_addr_t *ipaddr,uint16_t tcpc_port)
{
  tcpc_echo_pcb = tcp_new();
  if (tcpc_echo_pcb != NULL)
  {
    /* connect to server address£ºport */
    tcp_connect(tcpc_echo_pcb,ipaddr,tcpc_port,tcpc_echo_accept);
  }
  else
  {
    /* abort? output diagnostic? */
  }
}

/*!
 * @brief       closes tcp client
 *
 * @param       None
 *
 * @retval      None
 */
void tcpc_echo_disable(void)
{
    tcpc_echo_close(tcpc_echo_pcb,tcpc_echo_es);
}

/*!
 * @brief       Printf TCP Receive Data
 *
 * @param       p: pointer on the tcp pcb received pbuf
 *
 * @retval      None
 */
void PrintfRecData(struct pbuf *p)
{
    char recbuf[100] = {0};

    memcpy(recbuf,p->payload,p->len);
    printf("received message:%s\n",recbuf);
}

/*!
 * @brief       LwIP tcp_accept callback function
 *
 * @param       newpcb: point to the newly created tcp pcb
 *
 * @retval      None
 */
err_t
tcpc_echo_accept(void *arg, struct tcp_pcb *newpcb, err_t err)
{
  err_t ret_err;
  struct tcpc_echo_state *es;

  LWIP_UNUSED_ARG(arg);
  LWIP_UNUSED_ARG(err);

  /* Unless this pcb should have NORMAL priority, set its priority now.
     When running out of pcbs, low priority pcbs can be aborted to create
     new pcbs of higher priority. */
  tcp_setprio(newpcb, TCP_PRIO_MIN);

  es = (struct tcpc_echo_state *)mem_malloc(sizeof(struct tcpc_echo_state));
  tcpc_echo_es=es;

  if (es != NULL)
  {
    es->state = ES_ACCEPTED;
    es->pcb = newpcb;
    es->retries = 0;
    es->p = NULL;
    /* pass newly allocated es to our callbacks */
    tcp_arg(newpcb, es);
    tcp_recv(newpcb, tcpc_echo_recv);
    tcp_err(newpcb, tcpc_echo_error);
    tcp_poll(newpcb, tcpc_echo_poll, 0);

	/** Allocates the pbuf of the given type */
    es->p = pbuf_alloc(PBUF_TRANSPORT, strlen((char*)testdata) , PBUF_POOL);

    /** copy data to pbuf */
    pbuf_take(es->p, (char*)testdata, strlen((char*)testdata));

	/** send data */
    tcp_sent(newpcb, tcpc_echo_sent);
    tcpc_echo_send(newpcb,es);

    ret_err = ERR_OK;
  }
  else
  {
    /** close tcp connection */
    tcpc_echo_close(newpcb, es);
    ret_err = ERR_MEM;
  }
  return ret_err;
}

/*!
 * @brief       LwIP tcp_recv callback function
 *
 * @param       None
 *
 * @retval      None
 */
err_t
tcpc_echo_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
{
  struct tcpc_echo_state *es;
  err_t ret_err;

  LWIP_ASSERT("arg != NULL",arg != NULL);
  es = (struct tcpc_echo_state *)arg;
  if (p == NULL)
  {
    /* remote host closed connection */
    es->state = ES_CLOSING;
    if(es->p == NULL)
    {
       /* we're done sending, close it */
       tcpc_echo_close(tpcb, es);
    }
    else
    {
      /* we're not done yet */
      tcp_sent(tpcb, tcpc_echo_sent);
      tcpc_echo_send(tpcb, es);
    }
    ret_err = ERR_OK;
  }
  else if(err != ERR_OK)
  {
    /* cleanup, for unkown reason */
    if (p != NULL)
    {
      es->p = NULL;
      pbuf_free(p);
    }
    ret_err = err;
  }

  else if(es->state == ES_ACCEPTED)
  {
    tcp_recved(tpcb, p->tot_len);

    /** Printf TCP Receive Data */
    PrintfRecData(p);

    es->p = NULL;
    pbuf_free(p);
    ret_err = ERR_OK;
  }
  else
  {
    /* unkown es->state, trash data  */
    tcp_recved(tpcb, p->tot_len);
    es->p = NULL;
    pbuf_free(p);
    ret_err = ERR_OK;
  }
  return ret_err;
}

/*!
 * @brief       LwIP tcp_err callback function
 *
 * @param       None
 *
 * @retval      None
 */
void
tcpc_echo_error(void *arg, err_t err)
{
  struct tcpc_echo_state *es;

  LWIP_UNUSED_ARG(err);

  es = (struct tcpc_echo_state *)arg;
  if (es != NULL)
  {
    mem_free(es);
  }
}

/*!
 * @brief       LwIP tcp_poll callback function
 *
 * @param       None
 *
 * @retval      None
 */
err_t
tcpc_echo_poll(void *arg, struct tcp_pcb *tpcb)
{
  err_t ret_err;
  struct tcpc_echo_state *es;

  es = (struct tcpc_echo_state *)arg;
  if (es != NULL)
  {
    if (es->p != NULL)
    {
      /* there is a remaining pbuf (chain)  */
      tcp_sent(tpcb, tcpc_echo_sent);
      tcpc_echo_send(tpcb, es);
    }
    else
    {
      /* no remaining pbuf (chain)  */
      if(es->state == ES_CLOSING)
      {
        tcpc_echo_close(tpcb, es);
      }
    }
    ret_err = ERR_OK;
  }
  else
  {
    /* nothing to be done */
    tcp_abort(tpcb);
    ret_err = ERR_ABRT;
  }
  return ret_err;
}

/*!
 * @brief       LwIP tcp_sent callback function
 *
 * @param       None
 *
 * @retval      None
 */
err_t
tcpc_echo_sent(void *arg, struct tcp_pcb *tpcb, u16_t len)
{
  struct tcpc_echo_state *es;

  LWIP_UNUSED_ARG(len);

  es = (struct tcpc_echo_state *)arg;
  es->retries = 0;

  if(es->p != NULL)
  {
    /* still got pbufs to send */
    tcp_sent(tpcb, tcpc_echo_sent);
    tcpc_echo_send(tpcb, es);
  }
  else
  {
    /* no more pbufs to send */
    if(es->state == ES_CLOSING)
    {
      tcpc_echo_close(tpcb, es);
    }
  }
  return ERR_OK;
}

/*!
 * @brief       tcp send data function
 *
 * @param       tpcb: point to the tcp pcb
 *
 * @param       es: point to tcps_echo_state structure
 *
 * @retval      None
 */
void
tcpc_echo_send(struct tcp_pcb *tpcb, struct tcpc_echo_state *es)
{
  struct pbuf *ptr;
  err_t wr_err = ERR_OK;

  while ((wr_err == ERR_OK) &&
         (es->p != NULL) &&
         (es->p->len <= tcp_sndbuf(tpcb)))
  {
  ptr = es->p;

  /* enqueue data for transmission */
  wr_err = tcp_write(tpcb, ptr->payload, ptr->len, 1);
  if (wr_err == ERR_OK)
  {
     //u16_t plen;
      u8_t freed;

     //plen = ptr->len;
     /* continue with next pbuf in chain (if any) */
     es->p = ptr->next;
     if(es->p != NULL)
     {
       /* new reference! */
       pbuf_ref(es->p);
     }
     /* chop first pbuf from chain */
      do
      {
        /* try hard to free pbuf */
        freed = pbuf_free(ptr);
      }
      while(freed == 0);
      // /* we can read more data now */
      // tcp_recved(tpcb, plen);
   }
   else if(wr_err == ERR_MEM)
   {
      /* we are low on memory, try later / harder, defer to poll */
     es->p = ptr;
   }
   else
   {
     /* other problem ?? */
   }
  }
}

/*!
 * @brief       closes tcp pcb function
 *
 * @param       tpcb: point to the tcp pcb
 *
 * @param       es: point to tcps_echo_state structure
 *
 * @retval      None
 */
void
tcpc_echo_close(struct tcp_pcb *tpcb, struct tcpc_echo_state *es)
{
  tcp_arg(tpcb, NULL);
  tcp_sent(tpcb, NULL);
  tcp_recv(tpcb, NULL);
  tcp_err(tpcb, NULL);
  tcp_poll(tpcb, NULL, 0);

  if (es != NULL)
  {
    mem_free(es);
  }
  tcp_close(tpcb);
}

#endif /* LWIP_TCP */
