// C STD lib
#include <assert.h>
#include <string.h>

// SDK
#include "esp_err.h"
#include "esp_eth.h"
#include "esp_eth_driver.h"
#include "esp_event.h"
#include "esp_log.h"
#include "esp_netif.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "ethernet_init.h"

// Project includes
#include "types.hpp"

// Forward declarations
internal esp_err_t get_ip_info(esp_netif_ip_info_t *ip_info);
internal void led_blink_number(int n, uint8_t r, uint8_t g, uint8_t b);
internal void blink_last_ip_octet();

// === Ethernet ===

internal constexpr char kLogEthernet[] = "ETH";
internal constexpr char kNetifDescEth[] = "eth0";

internal esp_eth_handle_t *s_eth_handles = nullptr;
internal uint8_t s_eth_count = 0;
internal esp_eth_netif_glue_handle_t s_eth_glue = nullptr;
internal esp_netif_t *s_eth_netif = nullptr;
internal SemaphoreHandle_t s_semph_get_ip_addrs = nullptr;
#ifndef NDEBUG
internal bool s_ethernet_connected = false;
#endif

void eth_on_got_ip(void *arg, esp_event_base_t event_base, int32_t event_id,
                   void *event_data) {
  ip_event_got_ip_t *event = (ip_event_got_ip_t *)event_data;
  bool isEthernetNetif =
      strncmp(kNetifDescEth, esp_netif_get_desc(event->esp_netif),
              strlen(kNetifDescEth) - 1) == 0;
  if (!isEthernetNetif) {
    return;
  }
  ESP_LOGI(kLogEthernet, "Got IPv4 event: Interface \"%s\" address: " IPSTR,
           esp_netif_get_desc(event->esp_netif), IP2STR(&event->ip_info.ip));

  xSemaphoreGive(s_semph_get_ip_addrs);
}

void teardown_ethernet() {
  if (s_semph_get_ip_addrs != nullptr) {
    vSemaphoreDelete(s_semph_get_ip_addrs);
    s_semph_get_ip_addrs = nullptr;
  }

  if (s_eth_netif) {

    ESP_ERROR_CHECK(esp_event_handler_unregister(IP_EVENT, IP_EVENT_ETH_GOT_IP,
                                                 &eth_on_got_ip));
    ESP_ERROR_CHECK(esp_eth_stop(s_eth_handles[0]));
    ESP_ERROR_CHECK(esp_eth_del_netif_glue(s_eth_glue));
    esp_netif_destroy(s_eth_netif);
    ethernet_deinit_all(s_eth_handles);
  }

  s_eth_glue = nullptr;
  s_eth_netif = nullptr;
  s_eth_handles = nullptr;
  s_eth_count = 0;

  esp_netif_deinit();
}

internal esp_err_t connect_ethernet(bool blockUntilIPAcquired) {
#ifndef NDEBUG
  assert(!s_ethernet_connected &&
         "Ethernet connect called but already connected!");
  s_ethernet_connected = true;
#endif

  s_semph_get_ip_addrs = xSemaphoreCreateBinary();
  if (s_semph_get_ip_addrs == NULL) {
    return ESP_ERR_NO_MEM;
  }
  // Connection is split in two steps. First we open the connection and ask for
  // an ip. Second a semaphor will block until the ip is acquired. If we dont
  // block then the user have to verify the semaphore before continuing.
  ESP_ERROR_CHECK(esp_netif_init());
  ESP_ERROR_CHECK(ethernet_init_all(&s_eth_handles, &s_eth_count));

  esp_netif_inherent_config_t esp_netif_config =
      ESP_NETIF_INHERENT_DEFAULT_ETH();
  // Warning: the interface desc is used in tests to capture actual connection
  // details (IP, gw, mask)
  esp_netif_config.if_desc = kNetifDescEth;
  esp_netif_config.route_prio = 64;
  esp_netif_config_t netif_config = {.base = &esp_netif_config,
                                     .driver = nullptr,
                                     .stack = ESP_NETIF_NETSTACK_DEFAULT_ETH};
  s_eth_netif = esp_netif_new(&netif_config);

  s_eth_glue = esp_eth_new_netif_glue(s_eth_handles[0]);
  esp_netif_attach(s_eth_netif, s_eth_glue);

  // Register user defined event handlers
  ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, IP_EVENT_ETH_GOT_IP,
                                             &eth_on_got_ip, NULL));

  ESP_ERROR_CHECK(esp_eth_start(s_eth_handles[0]));

  // Will teardown connection properly on shutdown
  ESP_ERROR_CHECK(esp_register_shutdown_handler(&teardown_ethernet));

  if (blockUntilIPAcquired) {
    ESP_LOGI(kLogEthernet, "Waiting for IP address.");
    xSemaphoreTake(s_semph_get_ip_addrs, portMAX_DELAY);
    blink_last_ip_octet();
  }

  return ESP_OK;
}

void disconnect_ethernet() {
#ifndef NDEBUG
  assert(s_ethernet_connected &&
         "Ethernet disconnect called but not connected!");
  s_ethernet_connected = false;
#endif

  teardown_ethernet();
  ESP_ERROR_CHECK(esp_unregister_shutdown_handler(&teardown_ethernet));
}

internal esp_err_t check_ethernet_connection(uint32_t timeoutSeconds) {
  ESP_LOGI(kLogEthernet, "Waiting for IP address for %d seconds.",
           timeoutSeconds);
  if (xSemaphoreTake(s_semph_get_ip_addrs,
                     pdMS_TO_TICKS(timeoutSeconds * 1000))) {
    blink_last_ip_octet();
    return ESP_OK;
  } else {
    return ESP_ERR_TIMEOUT;
  }
}

// === WiFi ===

internal constexpr char kLogWifi[] = "WIFI";
internal esp_netif_t *s_wifi_netif = nullptr;
internal SemaphoreHandle_t s_semph_get_wifi_ip_addrs = nullptr;
#ifndef NDEBUG
internal bool s_wifi_connected = false;
#endif

void wifi_event_handler(void *arg, esp_event_base_t event_base,
                        int32_t event_id, void *event_data) {
  if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
    ESP_LOGI(kLogWifi, "WiFi disconnected, retrying...");
    esp_wifi_connect();
  } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
    ip_event_got_ip_t *event = (ip_event_got_ip_t *)event_data;
    ESP_LOGI(kLogWifi, "Got IPv4 event: Interface \"%s\" address: " IPSTR,
             esp_netif_get_desc(event->esp_netif), IP2STR(&event->ip_info.ip));

    xSemaphoreGive(s_semph_get_wifi_ip_addrs);
  }
}

void teardown_wifi() {
  if (s_semph_get_wifi_ip_addrs != nullptr) {
    vSemaphoreDelete(s_semph_get_wifi_ip_addrs);
    s_semph_get_wifi_ip_addrs = nullptr;
  }

  esp_event_handler_unregister(WIFI_EVENT, WIFI_EVENT_STA_DISCONNECTED,
                               &wifi_event_handler);
  esp_event_handler_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP,
                               &wifi_event_handler);

  if (s_wifi_netif) {
    esp_wifi_disconnect();
    esp_wifi_stop();
    esp_wifi_deinit();
    esp_netif_destroy(s_wifi_netif);
    s_wifi_netif = nullptr;
  }
}

internal esp_err_t connect_wifi(const char *ssid, const char *password,
                                bool blockUntilIPAcquired) {
#ifndef NDEBUG
  assert(!s_wifi_connected && "WiFi connect called but already connected!");
  s_wifi_connected = true;
#endif

  s_semph_get_wifi_ip_addrs = xSemaphoreCreateBinary();
  if (s_semph_get_wifi_ip_addrs == NULL) {
    return ESP_ERR_NO_MEM;
  }

  // esp_netif_init() is already called by Ethernet, but safe to call multiple
  // times or we can assume it's initialized.
  s_wifi_netif = esp_netif_create_default_wifi_sta();

  wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
  ESP_ERROR_CHECK(esp_wifi_init(&cfg));

  ESP_ERROR_CHECK(esp_event_handler_register(
      WIFI_EVENT, WIFI_EVENT_STA_DISCONNECTED, &wifi_event_handler, NULL));
  ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP,
                                             &wifi_event_handler, NULL));

  wifi_config_t wifi_config = {};
  strncpy((char *)wifi_config.sta.ssid, ssid, sizeof(wifi_config.sta.ssid) - 1);
  strncpy((char *)wifi_config.sta.password, password,
          sizeof(wifi_config.sta.password) - 1);
  // Setting a default auth mode if password is provided
  wifi_config.sta.threshold.authmode =
      password[0] != '\0' ? WIFI_AUTH_WPA2_PSK : WIFI_AUTH_OPEN;

  ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
  ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config));
  ESP_ERROR_CHECK(esp_wifi_start());
  ESP_ERROR_CHECK(esp_wifi_connect());

  ESP_ERROR_CHECK(esp_register_shutdown_handler(&teardown_wifi));

  if (blockUntilIPAcquired) {
    ESP_LOGI(kLogWifi, "Waiting for IP address.");
    xSemaphoreTake(s_semph_get_wifi_ip_addrs, portMAX_DELAY);
    blink_last_ip_octet();
  }

  return ESP_OK;
}

void disconnect_wifi() {
#ifndef NDEBUG
  assert(s_wifi_connected && "WiFi disconnect called but not connected!");
  s_wifi_connected = false;
#endif

  teardown_wifi();
  ESP_ERROR_CHECK(esp_unregister_shutdown_handler(&teardown_wifi));
}

internal esp_err_t check_wifi_connection(uint32_t timeoutSeconds) {
  ESP_LOGI(kLogWifi, "Waiting for IP address for %d seconds.", timeoutSeconds);
  if (xSemaphoreTake(s_semph_get_wifi_ip_addrs,
                     pdMS_TO_TICKS(timeoutSeconds * 1000))) {
    blink_last_ip_octet();
    return ESP_OK;
  } else {
    return ESP_ERR_TIMEOUT;
  }
}

internal esp_err_t get_ip_info(esp_netif_ip_info_t *ip_info) {
  if (s_eth_netif) {
    return esp_netif_get_ip_info(s_eth_netif, ip_info);
  } else if (s_wifi_netif) {
    return esp_netif_get_ip_info(s_wifi_netif, ip_info);
  }
  return ESP_FAIL;
}

internal void led_blink_number(int n, uint8_t r, uint8_t g, uint8_t b);

internal void blink_last_ip_octet() {
  esp_netif_ip_info_t ip_info;
  if (get_ip_info(&ip_info) == ESP_OK) {
    uint8_t last_octet = (ip_info.ip.addr >> 24) & 0xFF;
    printf("IP Address: " IPSTR "\n", IP2STR(&ip_info.ip));

    // Blink digits of last_octet
    int h = last_octet / 100;
    int t = (last_octet / 10) % 10;
    int u = last_octet % 10;

    led_blink_number(h, 255, 255, 255);
    led_blink_number(t, 255, 255, 255);
    led_blink_number(u, 255, 255, 255);
  }
}