/* -*- C -*- */
/*
* Copyright (c) 2005, 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. Neither the name of the Institute nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 the Contiki operating system.
*
*/


#include <stdio.h>
#include <string.h>
#include "contiki.h"

#include "net/linkaddr.h"
#include "sys/ctimer.h"

#include "net/ip/uip.h"
#include "net/ipv4/uip-fw.h"
#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])

#include "dev/slip.h"

#include "../sicslow_ethernet.h"
#include <stdlib.h>
#include "dev/stm32w-radio.h"

#define SLIP_END     0300
#define SLIP_ESC     0333
#define SLIP_ESC_END 0334
#define SLIP_ESC_ESC 0335

PROCESS(slip_process, "SLIP driver");

uint8_t slip_active;

#if 1
#define SLIP_STATISTICS(statement)
#else
uint16_t slip_rubbish, slip_twopackets, slip_overflow, slip_ip_drop;
#define SLIP_STATISTICS(statement) statement
#endif

/* Must be at least one byte larger than UIP_BUFSIZE! */
#define RX_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN + 16)

enum {
	STATE_TWOPACKETS = 0,	/* We have 2 packets and drop incoming data. */
	STATE_OK = 1,
	STATE_ESC = 2,
	STATE_RUBBISH = 3,
};

/*
* Variables begin and end manage the buffer space in a cyclic
* fashion. The first used byte is at begin and end is one byte past
* the last. I.e. [begin, end) is the actively used space.
*
* If begin != pkt_end we have a packet at [begin, pkt_end),
* furthermore, if state == STATE_TWOPACKETS we have one more packet at
* [pkt_end, end). If more bytes arrive in state STATE_TWOPACKETS
* they are discarded.
*/

static uint8_t state = STATE_TWOPACKETS;
static uint16_t begin, end;
static uint8_t rxbuf[RX_BUFSIZE];
static uint16_t pkt_end;		/* SLIP_END tracker. */


struct uip_eth_addr slip_eth_addr = {{0}};
const struct uip_eth_addr eth_addr_null = {{0}};

static struct ctimer t;
static void request_mac(void *);

uint8_t mac_hextoi(struct uip_eth_addr *a, const char * mac);

//static void (* input_callback)(void) = NULL;
static void (* tcpip_input_callback)(void) = NULL;
/*---------------------------------------------------------------------------*/
//void
//slip_set_input_callback(void (*c)(void))
//{
//  input_callback = c;
//}
/*---------------------------------------------------------------------------*/
void
slip_set_tcpip_input_callback(void (*c)(void))
{
	tcpip_input_callback = c;
}
/*---------------------------------------------------------------------------*/
#if NETSTACK_CONF_WITH_IPV4
uint8_t
slip_send(void)
{
	uint16_t i;
	uint8_t *ptr;
	uint8_t c;

	slip_arch_writeb(SLIP_END);

	ptr = &uip_buf[UIP_LLH_LEN];
	for(i = 0; i < uip_len; ++i) {
		if(i == UIP_TCPIP_HLEN) {
			ptr = (uint8_t *)uip_appdata;
		}
		c = *ptr++;
		if(c == SLIP_END) {
			slip_arch_writeb(SLIP_ESC);
			c = SLIP_ESC_END;
		} else if(c == SLIP_ESC) {
			slip_arch_writeb(SLIP_ESC);
			c = SLIP_ESC_ESC;
		}
		slip_arch_writeb(c);
	}
	slip_arch_writeb(SLIP_END);

	return UIP_FW_OK;
}
#endif /* NETSTACK_CONF_WITH_IPV4 */
/*---------------------------------------------------------------------------*/
uint8_t
slip_write(const void *_ptr, int len)
{
	const uint8_t *ptr = _ptr;
	uint16_t i;
	uint8_t c;

	slip_arch_writeb(SLIP_END);

	for(i = 0; i < len; ++i) {
		c = *ptr++;
		if(c == SLIP_END) {
			slip_arch_writeb(SLIP_ESC);
			c = SLIP_ESC_END;
		} else if(c == SLIP_ESC) {
			slip_arch_writeb(SLIP_ESC);
			c = SLIP_ESC_ESC;
		}
		slip_arch_writeb(c);
	}
	slip_arch_writeb(SLIP_END);

	return len;
}
/*---------------------------------------------------------------------------*/
static void
rxbuf_init(void)
{
	begin = end = pkt_end = 0;
	state = STATE_OK;
}
/*---------------------------------------------------------------------------*/
int from_slipbuffer(uint8_t *outbuf, uint16_t blen)
{
    
	/*
	* Interrupt can not change begin but may change pkt_end.
	* If pkt_end != begin it will not change again.
	*/
	if(begin != pkt_end) {
		uint16_t len;

		if(begin < pkt_end) {
			len = pkt_end - begin;
			if(len > blen) {
				len = 0;
			} else {
				memcpy(outbuf, &rxbuf[begin], len);
			}
		} else {
			len = (RX_BUFSIZE - begin) + (pkt_end - 0);
			if(len > blen) {
				len = 0;
			} else {
				unsigned i;
				for(i = begin; i < RX_BUFSIZE; i++) {
					*outbuf++ = rxbuf[i];
				}
				for(i = 0; i < pkt_end; i++) {
					*outbuf++ = rxbuf[i];
				}
			}
		}

		/* Remove data from buffer together with the copied packet. */
		begin = pkt_end;
		if(state == STATE_TWOPACKETS) {
			pkt_end = end;
			state = STATE_OK;		/* Assume no bytes where lost! */

			/* One more packet is buffered, need to be polled again! */
			process_poll(&slip_process);
		}
		return len;
	}

	return 0;
}

/* Upper half does the polling. */
static uint16_t
slip_poll_handler(uint8_t *outbuf, uint16_t blen)
{
    
    /* This is a hack and won't work across buffer edge! */
#if 0
    if(rxbuf[begin] == 'C') {
		int i;
		if(begin < end && (end - begin) >= 6
		   && memcmp(&rxbuf[begin], "CLIENT", 6) == 0) {
			   state = STATE_TWOPACKETS;	/* Interrupts do nothing. */
			   memset(&rxbuf[begin], 0x0, 6);
			   
			   rxbuf_init();
               
			   for(i = 0; i < 13; i++) {
				   slip_arch_writeb("CLIENTSERVER\300"[i]);
			   }
			   return 0;
		   }
	}
#endif

	if(rxbuf[begin] == '?' || rxbuf[begin] == '!') { // Should this characters be escaped?
		
		uint8_t tmpbuf[14];
		
		from_slipbuffer(tmpbuf, 14);


		if(tmpbuf[0] == '?') {
			int j;
			char* hexchar = "0123456789abcdef";
			if(tmpbuf[1] == 'M') {				
				
				/* this is just a test so far... just to see if it works */
				slip_arch_writeb('!');
				slip_arch_writeb('M');
				for(j = 0; j < LINKADDR_SIZE; j++) {
					slip_arch_writeb(hexchar[linkaddr_node_addr.u8[j] >> 4]);
					slip_arch_writeb(hexchar[linkaddr_node_addr.u8[j] & 15]);
				}
				slip_arch_writeb(SLIP_END);
				return 0;
			}
		}
#if 1          
		else if(tmpbuf[0] == '!') {
			
			if(tmpbuf[1] == 'M') {
				char * mac = (char *)tmpbuf + 2;				
				
				if(mac_hextoi(&slip_eth_addr,mac)!=0){
					/* Error! */
					/*rxbuf_init();
					slip_arch_writeb('!');
					slip_arch_writeb('E');						
					slip_arch_writeb(SLIP_END);*/
					printf("Error! Incorrect MAC format.\n");
					
                }
				/*for(int i=0;i<6;i++)
				printf("%02X ",slip_eth_addr.addr[i]);
				printf("\n");		*/
				return 0;
			}
			else if(memcmp(&tmpbuf[1], "OS1", 3) == 0) {        
				
				
				enable_sniffer_mode(1);
				
				return 0;
			}
			else if(memcmp(&tmpbuf[1], "OS0",3) == 0) {
				
				enable_sniffer_mode(0);             
				
				return 0;
			}
			else if(memcmp(&tmpbuf[1], "OC", 2) == 0) {                
				
				short ch_num;
				
				tmpbuf[5]='\0';
				if(ch_num = atoi((char *)tmpbuf+3)){
					ST_RadioSetChannel(ch_num);
				}           
				return 0;
			}
		}
	}
    
#endif

	return from_slipbuffer(outbuf, blen);
}
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(slip_process, ev, data)
{
	PROCESS_BEGIN();

	rxbuf_init();
    
    ctimer_set(&t, 2*CLOCK_SECOND, request_mac, NULL);

	while(1) {
		PROCESS_YIELD_UNTIL(ev == PROCESS_EVENT_POLL);

		slip_active = 1;

		/* Move packet from rxbuf to buffer provided by uIP. */
		uip_len = slip_poll_handler(&uip_buf[UIP_LLH_LEN],
			UIP_BUFSIZE - UIP_LLH_LEN);
#if !NETSTACK_CONF_WITH_IPV6
		if(uip_len == 4 && strncmp((char*)&uip_buf[UIP_LLH_LEN], "?IPA", 4) == 0) {
			char buf[8];
			memcpy(&buf[0], "=IPA", 4);
			memcpy(&buf[4], &uip_hostaddr, 4);
			if(input_callback) {
				input_callback();
			}
			slip_write(buf, 8);
		} else if(uip_len > 0
			&& uip_len == (((uint16_t)(BUF->len[0]) << 8) + BUF->len[1])
			&& uip_ipchksum() == 0xffff) {
#define IP_DF   0x40
				if(BUF->ipid[0] == 0 && BUF->ipid[1] == 0 && BUF->ipoffset[0] & IP_DF) {
					static uint16_t ip_id;
					uint16_t nid = ip_id++;
					BUF->ipid[0] = nid >> 8;
					BUF->ipid[1] = nid;
					nid = htons(nid);
					nid = ~nid;		/* negate */
					BUF->ipchksum += nid;	/* add */
					if(BUF->ipchksum < nid) { /* 1-complement overflow? */
						BUF->ipchksum++;
					}
				}
				if(tcpip_input_callback) {
					tcpip_input_callback();
				} else {
					tcpip_input();
				}
		} else {
			uip_clear_buf();
			SLIP_STATISTICS(slip_ip_drop++);
		}
#else /* NETSTACK_CONF_WITH_IPV6 */
		if(uip_len > 0) {
			if(tcpip_input_callback) {
				tcpip_input_callback();
			} else {
				tcpip_input();
			}
		}
#endif /* NETSTACK_CONF_WITH_IPV6 */
	}

	PROCESS_END();
}
/*---------------------------------------------------------------------------*/
int
slip_input_byte(unsigned char c)
{
	switch(state) {
	  case STATE_RUBBISH:
		  if(c == SLIP_END) {
			  state = STATE_OK;
		  }
		  return 0;

	  case STATE_TWOPACKETS:       /* Two packets are already buffered! */
		  return 0;

	  case STATE_ESC:
		  if(c == SLIP_ESC_END) {
			  c = SLIP_END;
		  } else if(c == SLIP_ESC_ESC) {
			  c = SLIP_ESC;
		  } else {
			  state = STATE_RUBBISH;
			  SLIP_STATISTICS(slip_rubbish++);
			  end = pkt_end;		/* remove rubbish */
			  return 0;
		  }
		  state = STATE_OK;
		  break;

	  case STATE_OK:
		  if(c == SLIP_ESC) {
			  state = STATE_ESC;
			  return 0;
		  } else if(c == SLIP_END) {
			  /*
			  * We have a new packet, possibly of zero length.
			  *
			  * There may already be one packet buffered.
			  */
			  if(end != pkt_end) {	/* Non zero length. */
				  if(begin == pkt_end) {	/* None buffered. */
					  pkt_end = end;
				  } else {
					  state = STATE_TWOPACKETS;
					  SLIP_STATISTICS(slip_twopackets++);
				  }
				  process_poll(&slip_process);
				  return 1;
			  }
			  return 0;
		  }
		  break;
	}

	/* add_char: */
	{
		unsigned next;
		next = end + 1;
		if(next == RX_BUFSIZE) {
			next = 0;
		}
		if(next == begin) {		/* rxbuf is full */
			state = STATE_RUBBISH;
			SLIP_STATISTICS(slip_overflow++);
			end = pkt_end;		/* remove rubbish */
			return 0;
		}
		rxbuf[end] = c;
		end = next;
	}

	/* There could be a separate poll routine for this. */
	if(c == 'T' && rxbuf[begin] == 'C') {
		process_poll(&slip_process);
		return 1;
	}

	return 0;
}
/*---------------------------------------------------------------------------*/
uint8_t mac_hextoi(struct uip_eth_addr *a, const char * mac)
{
    int i,j;
    
    memset(a,0,sizeof(struct uip_eth_addr));
    
    for(i = 0, j = 0; j < 12; j++){
        
        if((mac[j] >= '0' && mac[j] <= '9')){
            a->addr[i] += (mac[j] - '0') * ((j & 1) ? 1 : 16);            
        }
        else if(mac[j] >= 'A' && mac[j] <= 'F'){
            a->addr[i] += (mac[j] - 'A' + 10) * ((j & 1) ? 1 : 16);
        }
        else {
            return 1;
        }
        if(j&1){
            i++;
        }
    }
    
    return 0;
}
/*---------------------------------------------------------------------------*/
static void request_mac(void * ptr)
{
    if(memcmp(&slip_eth_addr,&eth_addr_null,6)==0){
        slip_write("?M", 2);
        ctimer_set(&t, 6*CLOCK_SECOND, request_mac, NULL);
    }
}
/*---------------------------------------------------------------------------*/