#include "lwip_driver.h"
#include "efm32.h"
#include "em_cmu.h"
#include "ksz8851snl_driver.h"
#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include "lwip/sys.h"
#include <lwip/stats.h>
#include <lwip/snmp.h>
#include "netif/etharp.h"
#include "netif/ppp_oe.h"

/** Initialization function that should be passed to netif_add */
err_t  LWIP_driver_init(struct netif *netif)
{
  localNetif = netif;
  netif->name[0] = IFNAME0;
  netif->name[1] = IFNAME1;
  
  netif->output = etharp_output;
  netif->linkoutput = LWIP_driver_output;
  
  /** set the HW address length */
  netif->hwaddr_len = ETH_MAC_ADDR_LEN;
  
  /** set the HW address */
  KSZ8851SNL_getMACAddress(netif->hwaddr);

  /** set the maximum transfer unit */
  netif->mtu = 1500;

  /** Set the flags according to device capabilities */
  netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_LINK_UP | NETIF_FLAG_ETHARP ;

  /** initialize the timers */
  timestamp_ETH_ARP = *timestamp_current;
  timestamp_ETH_TCP = *timestamp_current;

  /** initialize the hardware */
  KSZ8851SNL_init();

  return ERR_OK;
}

u32_t sys_now(void)
{
  return *timestamp_current; 
}

/** Called when a raw packet is ready to be transmitted. */
err_t LWIP_driver_output(struct netif *netif, struct pbuf *p)
{
  struct pbuf *q;
//#if ETH_PAD_SIZE
//  pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
//#endif
  for(q = p; q != NULL; q = q->next) {
    KSZ8851SNL_send(p->tot_len, p->payload);
  }
//#if ETH_PAD_SIZE
//  pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
//#endif  
  
  LINK_STATS_INC(link.xmit);
  
  return ERR_OK;
}

///** Called when a packet is received */
//err_t LWIP_driver_input(struct pbuf *pbuf, struct netif *netif)
//{  	
//  uint16_t length;
//  //TODO improve this
//  uint8_t payload[1500];
//  KSZ8851SNL_receive(payload, &length);
//  struct pbuf *p = pbuf_alloc(PBUF_RAW, length, PBUF_POOL);
//  p->len=length;
//  p->tot_len+=length;
//  for (int i=0;i<length;i++)
//  {
//   (p->payload)[i] = (uint8_t)payload[i];
//  }
//    
//  ethernet_input(p, netif);
//  return ERR_OK;
//}

static void LWIP_driver_input(struct netif *netif)
{
  struct eth_hdr *ethhdr;
  struct pbuf *p;

 /* move received packet into a new pbuf */
  p = low_level_input(netif);
    
  /** no packet could be read, silently ignore this */
  if (p == NULL) return;
  /* points to packet payload, which starts with an Ethernet header */
  ethhdr = p->payload;

 switch (htons(ethhdr->type)) {
    /* IP or ARP packet? */
    case ETHTYPE_IP:
    case ETHTYPE_ARP:
//#if PPPOE_SUPPORT
//  /* PPPoE packet? */
//  case ETHTYPE_PPPOEDISC:
//  case ETHTYPE_PPPOE:
//#endif /* PPPOE_SUPPORT */
    /* full packet send to tcpip_thread to process */
      if (netif->input(p, netif)!=ERR_OK)
      { 
         LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
         pbuf_free(p);
         p = NULL;
      }
      break;

  default:
    pbuf_free(p);
    p = NULL;
    break;
  }
}

static struct pbuf *low_level_input(struct netif *netif)
{
  struct pbuf *p;
  u16_t len=100;
//#if ETH_PAD_SIZE
//  len += ETH_PAD_SIZE; /* allow room for Ethernet padding */
//#endif
  

  /* We allocate a pbuf chain of pbufs from the pool. */
  p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
  if (p != NULL) 
  {
    KSZ8851SNL_receive(p->payload, &(p->len));

   LINK_STATS_INC(link.recv);
  } else 
  {
    //TODO drop packet();
    LINK_STATS_INC(link.memerr);
    LINK_STATS_INC(link.drop);
  }

  return p;  
}

/** Timestamp capabilities */
void LWIP_driver_timestamp_engine(void)
{
  if (abs(timestamp_ETH_ARP - *timestamp_current) >= LWIP_ETH_ARP_INTERVAL) {
      etharp_tmr();
      timestamp_ETH_ARP = *timestamp_current;
  }
  if (abs(timestamp_ETH_TCP - *timestamp_current) >= LWIP_ETH_TCP_INTERVAL) {
      tcp_tmr();
      timestamp_ETH_TCP = *timestamp_current;
  }
}

/** LWIP main loop */
void LWIP_loop(struct netif *netif, uint32_t *global_timestamp)
{
  timestamp_current=global_timestamp;
  while(1)
  {
    LWIP_driver_timestamp_engine();
    LWIP_driver_input(localNetif);//blocking call for the moment
  }
}