/*
 * SPDX-FileCopyrightText: 2001-2004 Swedish Institute of Computer Science
 *
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * SPDX-FileContributor: 2015-2022 Espressif Systems (Shanghai) CO LTD
 */
/**
 * @file
 * Ethernet Interface Skeleton used for WiFi
 *
 */

#include "lwip/opt.h"

#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include "lwip/stats.h"
#include "lwip/snmp.h"
#include "lwip/ethip6.h"
#include "netif/etharp.h"
#include "netif/wlanif.h"
#include "esp_private/wifi.h"

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

#include "esp_netif.h"
#include "esp_netif_net_stack.h"
#include "esp_compiler.h"
#include "netif/esp_pbuf_ref.h"


typedef struct wifi_custom_pbuf
{
    struct pbuf_custom p;
    void* l2_buf;
} wifi_custom_pbuf_t;

static struct netif *s_wifi_netifs[2] = { NULL };


/**
 * In this function, the hardware should be initialized.
 * Called from wlanif_input().
 *
 * @param netif the already initialized lwip network interface structure
 *        for this wlanif
 */
static void
low_level_init(struct netif *netif)
{
  /* set MAC hardware address length */
  netif->hwaddr_len = ETHARP_HWADDR_LEN;

  /* set MAC hardware address */

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

  /* device capabilities */
  /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
  netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;

#if ESP_LWIP
#if LWIP_IGMP
  netif->flags |= NETIF_FLAG_IGMP;
#endif
#endif

#if ESP_IPV6
#if LWIP_IPV6 && LWIP_IPV6_MLD
  netif->flags |= NETIF_FLAG_MLD6;
#endif
#endif

}

err_t set_wifi_netif(int wifi_inx, void* netif)
{
  if (wifi_inx < 2) {
    s_wifi_netifs[wifi_inx] = netif;
    return ERR_OK;
  }
  return ERR_ARG;
}


static void wifi_pbuf_free(struct pbuf *p)
{
  wifi_custom_pbuf_t* wifi_pbuf = (wifi_custom_pbuf_t*)p;
  if (wifi_pbuf) {
    esp_wifi_internal_free_rx_buffer(wifi_pbuf->l2_buf);
  }
  mem_free(wifi_pbuf);
}

static inline struct pbuf* wifi_pbuf_allocate(struct netif *netif, void *buffer, size_t len, void *l2_buff)
{
  struct pbuf *p;

  wifi_custom_pbuf_t* esp_pbuf = mem_malloc(sizeof(wifi_custom_pbuf_t));

  if (esp_pbuf == NULL) {
    return NULL;
  }
  esp_pbuf->p.custom_free_function = wifi_pbuf_free;
  esp_pbuf->l2_buf = l2_buff;
  p = pbuf_alloced_custom(PBUF_RAW, len, PBUF_REF, &esp_pbuf->p, buffer, len);
  if (p == NULL) {
    mem_free(esp_pbuf);
    return NULL;
  }
  return p;
}

esp_err_t wifi_rxcb_sta(void *buffer, uint16_t len, void *l2_buff)
{
  struct netif * netif = s_wifi_netifs[0];
  struct pbuf *p;

  if(unlikely(!buffer || !netif_is_up(netif))) {
    if (l2_buff) {
      esp_wifi_internal_free_rx_buffer(l2_buff);
    }
    return ESP_FAIL;
  }

  p = wifi_pbuf_allocate(netif, buffer, len, l2_buff);
  if (p == NULL) {
    esp_wifi_internal_free_rx_buffer(l2_buff);
    return ESP_FAIL;
  }

  /* full packet send to tcpip_thread to process */
  if (unlikely(netif->input(p, netif) != ERR_OK)) {
    LWIP_DEBUGF(NETIF_DEBUG, ("wlanif_input: IP input error\n"));
    pbuf_free(p);
  }
  return ESP_OK;
}

esp_err_t wifi_rxcb_ap(void *buffer, uint16_t len, void *l2_buff)
{
  struct netif * netif = s_wifi_netifs[1];
  struct pbuf *p;

  if(unlikely(!buffer || !netif_is_up(netif))) {
    if (l2_buff) {
        esp_wifi_internal_free_rx_buffer(l2_buff);
    }
    return ESP_FAIL;
  }

  p = wifi_pbuf_allocate(netif, buffer, len, l2_buff);
  if (p == NULL) {
    esp_wifi_internal_free_rx_buffer(l2_buff);
    return ESP_FAIL;
  }

  /* full packet send to tcpip_thread to process */
  if (unlikely(netif->input(p, netif) != ERR_OK)) {
    LWIP_DEBUGF(NETIF_DEBUG, ("wlanif_input: IP input error\n"));
    pbuf_free(p);
  }
  return ESP_OK;
}
/**
 * This function should be called when a packet is ready to be read
 * from the interface. It uses the function low_level_input() that
 * should handle the actual reception of bytes from the network
 * interface. Then the type of the received packet is determined and
 * the appropriate input function is called.
 *
 * @param h lwip network interface structure (struct netif) for this ethernetif
 * @param buffer wlan buffer
 * @param len length of buffer
 * @param l2_buff wlan's L2 buffer pointer
 */
void
wlanif_input(void *h, void *buffer, size_t len, void* l2_buff)
{
  struct netif * netif = h;
  esp_netif_t *esp_netif = esp_netif_get_handle_from_netif_impl(netif);
  struct pbuf *p;

  if(unlikely(!buffer || !netif_is_up(netif))) {
    if (l2_buff) {
      esp_netif_free_rx_buffer(esp_netif, l2_buff);
    }
    return;
  }

#ifdef CONFIG_LWIP_L2_TO_L3_COPY
  p = pbuf_alloc(PBUF_RAW, len, PBUF_RAM);
  if (p == NULL) {
    esp_netif_free_rx_buffer(esp_netif, l2_buff);
    return;
  }
  memcpy(p->payload, buffer, len);
  esp_netif_free_rx_buffer(esp_netif, l2_buff);
#else
  p = esp_pbuf_allocate(esp_netif, buffer, len, l2_buff);
  if (p == NULL) {
    esp_netif_free_rx_buffer(esp_netif, l2_buff);
    return;
  }

#endif

  /* full packet send to tcpip_thread to process */
  if (unlikely(netif->input(p, netif) != ERR_OK)) {
    LWIP_DEBUGF(NETIF_DEBUG, ("wlanif_input: IP input error\n"));
    pbuf_free(p);
  }
}

/**
 * This function should do the actual transmission of the packet. The packet is
 * contained in the pbuf that is passed to the function. This pbuf
 * might be chained.
 *
 * @param netif the lwip network interface structure for this wlanif
 * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
 * @return ERR_OK if the packet could be sent
 *         an err_t value if the packet couldn't be sent
 *
 * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
 *       strange results. You might consider waiting for space in the DMA queue
 *       to become available since the stack doesn't retry to send a packet
 *       dropped because of memory failure (except for the TCP timers).
 */
static err_t
sta_output(struct netif *netif, struct pbuf *p)
{
  struct pbuf *q = p;
  esp_err_t ret;

  if(q->next == NULL) {
    ret = esp_wifi_internal_tx(WIFI_IF_STA, q->payload, q->len);

  } else {
    LWIP_DEBUGF(PBUF_DEBUG, ("low_level_output: pbuf is a list, application may has bug"));
    q = pbuf_alloc(PBUF_RAW_TX, p->tot_len, PBUF_RAM);
    if (q != NULL) {
      pbuf_copy(q, p);
    } else {
      return ERR_MEM;
    }
    ret = esp_wifi_internal_tx(WIFI_IF_STA, q->payload, q->len);
    pbuf_free(q);
  }

  if (ret == ESP_OK) {
    return ERR_OK;
  } else if (ret == ESP_ERR_NO_MEM) {
    return ERR_MEM;
  } else if (ret == ESP_ERR_INVALID_ARG) {
    return ERR_ARG;
  } else {
    return ERR_IF;
  }
}

static err_t
ap_output(struct netif *netif, struct pbuf *p)
{
  struct pbuf *q = p;
  esp_err_t ret;

  if(q->next == NULL) {
    ret = esp_wifi_internal_tx(WIFI_IF_AP, q->payload, q->len);

  } else {
    LWIP_DEBUGF(PBUF_DEBUG, ("low_level_output: pbuf is a list, application may has bug"));
    q = pbuf_alloc(PBUF_RAW_TX, p->tot_len, PBUF_RAM);
    if (q != NULL) {
      pbuf_copy(q, p);
    } else {
      return ERR_MEM;
    }
    ret = esp_wifi_internal_tx(WIFI_IF_AP, q->payload, q->len);
    pbuf_free(q);
  }

  if (ret == ESP_OK) {
    return ERR_OK;
  } else if (ret == ESP_ERR_NO_MEM) {
    return ERR_MEM;
  } else if (ret == ESP_ERR_INVALID_ARG) {
    return ERR_ARG;
  } else {
    return ERR_IF;
  }
}

/**
 * Should be called at the beginning of the program to set up the
 * network interface. It calls the function low_level_init() to do the
 * actual setup of the hardware.
 *
 * This function should be passed as a parameter to netif_add().
 *
 * @param netif the lwip network interface structure for this wlanif
 * @return ERR_OK if the loopif is initialized
 *         ERR_MEM if private data couldn't be allocated
 *         any other err_t on error
 */
err_t
wlanif_init(struct netif *netif)
{
  LWIP_ASSERT("netif != NULL", (netif != NULL));

#if LWIP_NETIF_HOSTNAME
  /* Initialize interface hostname */

#if ESP_LWIP
  if (esp_netif_get_hostname(esp_netif_get_handle_from_netif_impl(netif), &netif->hostname) != ESP_OK) {
    netif->hostname = CONFIG_LWIP_LOCAL_HOSTNAME;
  }
#else
  netif->hostname = "lwip";
#endif

#endif /* LWIP_NETIF_HOSTNAME */

  /*
   * Initialize the snmp variables and counters inside the struct netif.
   * The last argument should be replaced with your link speed, in units
   * of bits per second.
   */
  NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, 100);

  /* We directly use etharp_output() here to save a function call.
   * You can instead declare your own function an call etharp_output()
   * from it if you have to do some checks before sending (e.g. if link
   * is available...) */
  netif->output = etharp_output;
#if LWIP_IPV6
  netif->output_ip6 = ethip6_output;
#endif /* LWIP_IPV6 */

  /* initialize the hardware */
  low_level_init(netif);

  return ERR_OK;
}

err_t wlanif_init_sta(struct netif *netif) {
  netif->name[0] = 's';
  netif->name[1] = 't';
  netif->linkoutput = sta_output;
  return wlanif_init(netif);
}

err_t wlanif_init_ap(struct netif *netif) {
  netif->name[0] = 'a';
  netif->name[1] = 'p';
  netif->linkoutput = ap_output;
  return wlanif_init(netif);
}