#define MG_ENABLE_SOCKET 0
#define MG_ENABLE_LINES 1
#define MG_ENABLE_MIP 1
#define MG_ENABLE_PACKED_FS 0

#include <assert.h>
#include <linux/if.h>
#include <linux/if_tun.h>
#include <sys/ioctl.h>
#include "mongoose.c"

   #include "driver_mock.c"

static int s_num_tests = 0;

#define ASSERT(expr)                                            \
  do {                                                          \
    s_num_tests++;                                              \
    if (!(expr)) {                                              \
      printf("FAILURE %s:%d: %s\n", __FILE__, __LINE__, #expr); \
      abort();                                                  \
    }                                                           \
  } while (0)



static void test_queue(void) {
  static uint8_t
      buf[sizeof(size_t) + sizeof(uint16_t) + 3];  // fit 1 element but not 2
  uint16_t val = 1234;
  static struct queue q = {buf, sizeof(buf), 0, 0};

  // Write to an empty queue, and read back
  assert(q_avail(&q) == 0);
  assert(q_write(&q, &val, sizeof(val)) == true);
  assert(q_avail(&q) == sizeof(val));
  assert(q.head > q.tail);
  // Only one element may fit
  assert(q_write(&q, &val, sizeof(val)) == false);
  val = 0;
  assert(q_read(&q, &val) == sizeof(val));
  assert(val == 1234);
  assert(q_avail(&q) == 0);

  // Second write - wrap over the buffer boundary
  assert(q_write(&q, &val, sizeof(val)) == true);
  assert(q_avail(&q) == sizeof(val));
  assert(q.head < q.tail);
  // Only one element may fit
  assert(q_write(&q, &val, sizeof(val)) == false);
  val = 0;
  assert(q_read(&q, &val) == sizeof(val));
  assert(val == 1234);
  assert(q_avail(&q) == 0);
}

static void test_statechange(void) {
  char tx[1540];
  struct mip_if iface;
  memset(&iface, 0, sizeof(iface));
  iface.ip = mg_htonl(0x01020304);
  iface.state = MIP_STATE_READY;
  iface.tx.ptr = tx, iface.tx.len = sizeof(tx);
  iface.driver = &mip_driver_mock;
  onstatechange(&iface);
}

// MIP TUNTAP driver
static size_t tap_rx(void *buf, size_t len, void *userdata) {
  ssize_t received = read(*(int *) userdata, buf, len);
  usleep(1);  // This is to avoid 100% CPU
  if (received < 0) return 0;
  return (size_t) received;
}

static size_t tap_tx(const void *buf, size_t len, void *userdata) {
  ssize_t res = write(*(int *) userdata, buf, len);
  if (res < 0) {
    MG_ERROR(("tap_tx failed: %d", errno));
    return 0;
  }
  return (size_t) res;
}

static bool tap_up(void *userdata) {
  return userdata ? true : false;
}

// HTTP fetches IOs
struct Post_reply {
  char* post;                           // HTTP POST data
  void* http_response;                  // Server response(s)
  unsigned int http_responses_received; // Number responses received
};

char *fetch(struct mg_mgr *mgr, const char *url, const char *post_data);
static void f_http_fetch_query(struct mg_connection *c, int ev, void *ev_data, void *fn_data);
int get_response_code(char *); // Returns HTTP status code from full char* msg

static void f_http_fetch_query(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
  static char* http_response = 0;
  static bool http_response_allocated = 0; // So that we will update out parameter
  unsigned int http_responses_received = 0;
  struct Post_reply *post_reply_l;
  post_reply_l = (struct Post_reply*)fn_data;

  if (ev == MG_EV_CONNECT) {
    mg_printf(c, post_reply_l->post);
  } else if (ev == MG_EV_HTTP_MSG) {
    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
    http_responses_received++;
    if (!http_response_allocated) {
      http_response = (char*)mg_strdup(hm->message).ptr;
      http_response_allocated = 1;
    }
    if (http_responses_received > 0) {
      post_reply_l->http_response = http_response;
      post_reply_l->http_responses_received = http_responses_received;
    }
  }
}

// Fetch utility returns message from fetch(..., URL, POST)
char *fetch(struct mg_mgr *mgr, const char *url, const char *fn_data) {
  struct Post_reply post_reply;
  {
    post_reply.post=(char*)fn_data;
    post_reply.http_response=0;
    post_reply.http_responses_received=0;
  }
  struct mg_connection *conn;
  conn = mg_http_connect(mgr, url, f_http_fetch_query, &post_reply);
  ASSERT(conn != NULL);		// Assertion on initialisation
  for (int i = 0; i < 500 && !post_reply.http_responses_received; i++) { 
    mg_mgr_poll(mgr, 100);
    usleep(10000); // 10 ms. Slow down poll loop to ensure packets transit
  }
  conn->is_closing = 1;
  mg_mgr_poll(mgr, 0);
  if (!post_reply.http_responses_received)
    return 0;
  else
    return (char*)post_reply.http_response;
}

// Returns server's HTTP response code
int get_response_code(char * http_msg_raw) {
  int http_status = 0;
  struct mg_http_message http_msg_parsed;
  if (mg_http_parse(http_msg_raw, strlen(http_msg_raw), &http_msg_parsed)) {
    http_status = mg_http_status(&http_msg_parsed);
  } else {
    printf("Error: mg_http_parse()\n");
    ASSERT(http_status != 0); // Couldn't parse.
  }
  return http_status;
}

static void test_http_fetch(void) {
  // Setup interface
  const char *iface = "tap0";             // Network iface
  const char *mac = "00:00:01:02:03:78";  // MAC address
  int fd = open("/dev/net/tun", O_RDWR);  // Open network interface

  struct ifreq ifr;
  memset(&ifr, 0, sizeof(ifr));
  strncpy(ifr.ifr_name, iface, IFNAMSIZ);
  ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
  if (ioctl(fd, TUNSETIFF, (void *) &ifr) < 0) {
    MG_ERROR(("Failed to setup TAP interface: %s", ifr.ifr_name));
    abort(); // return EXIT_FAILURE;
  }
  fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK);  // Non-blocking mode

  MG_INFO(("Opened TAP interface: %s", iface));

  // Events
  struct mg_mgr mgr;  // Event manager
  mg_mgr_init(&mgr);  // Initialise event manager

  // MIP driver

  // Zero init fields required (C/C++ style diverge)
  #ifndef __cplusplus
  struct mip_driver driver = {.tx = tap_tx, .up = tap_up, .rx = tap_rx};
  // DHCP
  // struct mip_if mif = {.use_dhcp = true, .driver = &driver, .driver_data = &fd};
  // Static
  // 192.168.32.2/24 gw 192.168.32.1
  struct mip_if mif = {.use_dhcp = false, \
  .ip=0x0220a8c0 , .mask=0x00ffffff, .gw=0x0120a8c0, \
  .driver = &driver, .driver_data = &fd};

  #else
  struct mip_driver driver {};
    driver.tx = tap_tx;
    driver.up = tap_up;
    driver.rx = tap_rx;
  struct mip_if mif {};
//  mif.use_dhcp = true;   // DHCP
    mif.use_dhcp = false;  // Static IP
    mif.ip = 0x0220a8c0;   // 192.168.32.2
    mif.mask = 0x00ffffff; // 255.255.255.0
    mif.gw = 0x0120a8c0;   // 192.168.32.1
    mif.driver = &driver;
    mif.driver_data = &fd;
  #endif

  sscanf(mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &mif.mac[0], &mif.mac[1], &mif.mac[2],
         &mif.mac[3], &mif.mac[4], &mif.mac[5]);

  mip_init(&mgr, &mif);
  MG_INFO(("Init done, starting main loop"));

  // Stack initialization, Network configuration (DHCP lease, ...)
  {
    if (mif.ip) MG_INFO(("MIF configuration: Static IP"));
    else MG_INFO(("MIF configuration: DHCP"));
    MG_INFO(("Opened TAP interface: %s", iface));
    // ASSERT(!mif.ip); // Check we are set for DHCP
    int pc = 500; // Timout on DHCP lease 500 ~ approx 5s (typical delay <1s)
    while (((pc--)>0) /*& !mif.ip*/) {
      mg_mgr_poll(&mgr, 100);
      usleep(10000); // 10 ms
    }
    if (!mif.ip) printf("No ip assigned (DHCP lease may have failed).\n");
    ASSERT(mif.ip); // We have an IP (lease or static)
  }

  // Simple HTTP fetch
  {
    char* http_feedback = (char*)"";
    const bool ipv6 = 0;
    if (ipv6) {
      http_feedback = fetch (&mgr, "ipv6.google.com",\
                                   "GET/ HTTP/1.0\r\nHost: ipv6.google.com\r\n\r\n");
    } else {
      http_feedback = fetch (&mgr, "http://cesanta.com",\
                                   "GET //robots.txt HTTP/1.0\r\nHost: cesanta.com\r\n\r\n");
    }

    ASSERT(*http_feedback != '\0'); // Received HTTP response ?

    int http_status = get_response_code(http_feedback);
    // printf("Server response HTTP status code: %d\n",http_status);
    ASSERT(http_status != 0);
    ASSERT(http_status == 301); // OK: Permanently moved (HTTP->HTTPS redirect)

    if (http_feedback) {
      free(http_feedback);
      http_feedback = 0;
    }
  }

  // Clear
  mip_free(&mif);
  mg_mgr_free(&mgr);
  ASSERT(mgr.conns == NULL); // Deconstruction OK
  close(fd);
}

int main(void) {
  test_queue();
  test_statechange();
  test_http_fetch();
  printf("SUCCESS. Total tests: %d\n", s_num_tests);
  return 0;
}