#include "seobeo/seobeo.h"


Seobeo_PHandle Seobeo_Stream_Handle_Server_Create(const char *host,  const char* port)
{
  Seobeo_PHandle p_handle;
  struct addrinfo hints, *server_infos, *free_server_info;
  int32 socket_fd, yes = 1;  // Need this for setsockopt 

  memset(&hints, 0, sizeof hints);
  hints.ai_family   = AF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_protocol = IPPROTO_TCP;
  hints.ai_flags    = AI_PASSIVE;

  if (getaddrinfo(host, port, &hints, &server_infos) != 0)
  { perror("getaddrinfo"); return NULL; }

  for
  (
    free_server_info = server_infos;
    free_server_info != NULL;
    free_server_info = free_server_info->ai_next
  )
  {
    if((socket_fd = socket(free_server_info->ai_family,
                        free_server_info->ai_socktype, free_server_info->ai_protocol)) == -1)
    { perror("socket"); continue; }

     if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) == -1)
     { perror("setsockopt"); continue; }

     if (bind(socket_fd, free_server_info->ai_addr, free_server_info->ai_addrlen) == -1)
     { perror("v_network: Couldn't make socket non-blocking\n"); continue; }

     break;
  }

  if (listen(socket_fd, 16) != 0)
  { 
    printf("Closing: %d", socket_fd);
    perror("listen"); close(socket_fd); return NULL; 
  }

  int flags = fcntl(socket_fd, F_GETFL, 0);
	if(fcntl(socket_fd, F_SETFL, flags | O_NONBLOCK) != 0) { perror("fcntl"); return NULL; }
  freeaddrinfo(server_infos);

  p_handle = malloc(sizeof(*p_handle));
  p_handle->socket = socket_fd;
  p_handle->type = SEOBEO_STREAM_TYPE_SERVER;
  p_handle->connected = FALSE;

  p_handle->host = host != NULL ? strdup(host) : "localhost";
  p_handle->port = strdup(port);

  p_handle->ssl_ctx              = NULL;
  p_handle->ssl                  = NULL;


  p_handle->read_buffer = malloc(sizeof(*p_handle->read_buffer) * INITIAL_BUFFER_CAPACITY);
  p_handle->read_buffer_capacity = INITIAL_BUFFER_CAPACITY;
  p_handle->read_buffer_len = 0;

  p_handle->write_buffer = malloc(sizeof(*p_handle->read_buffer) * INITIAL_BUFFER_CAPACITY);
  p_handle->write_buffer_capacity = INITIAL_BUFFER_CAPACITY;
  p_handle->write_buffer_len = 0;

  p_handle->destroyed = false;

  return p_handle;
}


Seobeo_PHandle Seobeo_Stream_Handle_Client_Create(const char *host,  const char* port, boolean use_tls)
{
  Seobeo_PHandle p_handle;
  p_handle = malloc(sizeof(*p_handle));

  struct addrinfo hints, *server_infos;
  int32 socket_fd;  // Need this for setsockopt 

  memset(&hints, 0, sizeof hints);
  hints.ai_family   = AF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;

  if (getaddrinfo(host, port, &hints, &server_infos) != 0)
  { perror("getaddrinfo"); return NULL; }


  if((socket_fd = socket(server_infos->ai_family,
                      server_infos->ai_socktype, server_infos->ai_protocol)) == -1)
  { perror("socket"); return NULL; }

  if (connect(socket_fd, server_infos->ai_addr, server_infos->ai_addrlen) != 0)
  { perror("connect"); return NULL; }
  freeaddrinfo(server_infos);

  p_handle->socket = socket_fd;
  p_handle->type = SEOBEO_STREAM_TYPE_CLIENT;
  if (use_tls)
  {
    printf("USE SSL\n\n");
    Seobeo_Web_SSL_Init();
    p_handle->ssl_ctx = SSL_CTX_new(TLS_client_method());
    SSL_CTX_set_default_verify_paths(p_handle->ssl_ctx);

    p_handle->ssl = SSL_new(p_handle->ssl_ctx);
    SSL_set_fd(p_handle->ssl, p_handle->socket);

    SSL_set_tlsext_host_name(p_handle->ssl, host);
    // Blocking for TSL handshake
  	fcntl(socket_fd, F_SETFL, 0);

    if (SSL_connect(p_handle->ssl) != 1)
    {
      fprintf(stderr, "SSL_connect failed\n");
      ERR_print_errors_fp(stderr);
      return NULL;
    }
  }else
  {
    p_handle->ssl_ctx = NULL;
    p_handle->ssl = NULL;
  }
  p_handle->connected = true;

  p_handle->host = host != NULL ? strdup(host) : "localhost";
  p_handle->port = strdup(port);

  p_handle->read_buffer = malloc(sizeof(*p_handle->read_buffer) * INITIAL_BUFFER_CAPACITY);
  p_handle->read_buffer_capacity = INITIAL_BUFFER_CAPACITY;
  p_handle->read_buffer_len = 0;

  p_handle->write_buffer = malloc(sizeof(*p_handle->read_buffer) * INITIAL_BUFFER_CAPACITY);
  p_handle->write_buffer_capacity = INITIAL_BUFFER_CAPACITY;
  p_handle->write_buffer_len = 0;

  p_handle->destroyed = false;

  return p_handle;
}

Seobeo_PHandle Seobeo_Stream_Handle_Server_Accept(Seobeo_PHandle p_server_handle)
{
  struct sockaddr_storage addr;
  socklen_t addrlen = sizeof addr;
  char client_inet_addr[INET6_ADDRSTRLEN];

  int client_fd = accept(p_server_handle->socket,
                         (struct sockaddr*)&addr,
                         &addrlen);
  inet_ntop(
      addr.ss_family,
      Seobeo_Get_IP4_Or_IP6((struct sockaddr *)&addr),
      client_inet_addr, sizeof client_inet_addr);
  if (client_fd == -1) return NULL;

  // Set non blocking...
  int flags = fcntl(client_fd, F_GETFL, 0);
  if (flags == -1) return NULL;
  fcntl(client_fd, F_SETFL, flags | O_NONBLOCK);

  Seobeo_PHandle p_client_handle        = malloc(sizeof *p_client_handle);

  p_client_handle->socket               = client_fd;
  p_client_handle->type                 = SEOBEO_STREAM_TYPE_CLIENT;
  p_client_handle->connected            = true;

  // TODO: support SSL in the future.
  p_client_handle->ssl_ctx              = NULL;
  p_client_handle->ssl                  = NULL;

  p_client_handle->host                 = strdup(client_inet_addr);
  p_client_handle->port                 = NULL;

  p_client_handle->read_buffer_capacity = p_server_handle->read_buffer_capacity;
  p_client_handle->read_buffer_len      = 0;
  p_client_handle->read_buffer          = malloc(p_client_handle->read_buffer_capacity);

  p_client_handle->write_buffer_capacity = p_server_handle->write_buffer_capacity;
  p_client_handle->write_buffer_len      = 0;
  p_client_handle->write_buffer          = malloc(p_client_handle->write_buffer_capacity);

  p_client_handle->destroyed = false;

  return p_client_handle;
}

void Seobeo_Handle_Destroy(Seobeo_PHandle p_handle)
{
  if (!p_handle) return;

  bool expected = false;
  // Need to check
  if (!atomic_compare_exchange_strong(&p_handle->destroyed, &expected, true))
  {
    return;
  }

  if (p_handle->host) Dowa_Free(p_handle->host);
  if (p_handle->port) Dowa_Free(p_handle->port);

  if (p_handle->ssl)
  {
    SSL_shutdown(p_handle->ssl);
    SSL_free(p_handle->ssl);
    p_handle->ssl = NULL;
  }

  if (p_handle->ssl_ctx)
  {
    SSL_CTX_free(p_handle->ssl_ctx);
    p_handle->ssl_ctx = NULL;
  }

  if (p_handle->socket) {
    printf("Closing: %d", p_handle->socket);
    close(p_handle->socket);
  }

  if (p_handle->read_buffer) Dowa_Free(p_handle->read_buffer);
  if (p_handle->write_buffer) Dowa_Free(p_handle->write_buffer);

  Dowa_Free(p_handle);
}


int32 Seobeo_Handle_Flush(Seobeo_PHandle p_handle)
{
  uint32 total = p_handle->write_buffer_len;
  uint32 sent  = 0;

  printf("Total: %d\n\n", p_handle->write_buffer_len);

  while (sent < total)
  {
    if (p_handle->ssl)
    {
      int n = SSL_write(p_handle->ssl, p_handle->write_buffer + sent, total - sent);
      if (n < 0)
      {
        int err = SSL_get_error(p_handle->ssl, n);
        if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE)
        {
          // caller must wait for socket readiness and retry
          return 0;
        }
        ERR_print_errors_fp(stderr);
        return -1;
      }
      sent += (uint32)n;
    }else
    {
      printf("socket: %d\n", p_handle->socket);
      ssize_t n = write(
        p_handle->socket,
        p_handle->write_buffer + sent,
        total - sent
      );
      if (n < 0) {
        if (errno == EINTR)  continue;
        if (errno == EAGAIN) return 1;
        return -1;
      }
      sent += (uint32)n;
    }
  }

  p_handle->write_buffer_len = 0;
  return 0;
}

int32 Seobeo_Handle_Queue(Seobeo_PHandle p_handle, const uint8 *data, uint32 data_size)
{
  if (p_handle->write_buffer_len + data_size > p_handle->write_buffer_capacity)
  {
    int32 rc = Seobeo_Handle_Flush(p_handle);
    if (rc < 0) return -1;
    if (rc > 0) return 1;
  }

  if (data_size > p_handle->write_buffer_capacity)
  {
    uint32 offset = 0;
    while (offset < data_size)
    {
      ssize_t n = write(p_handle->socket,
                data + offset,
                data_size - offset);
      if (n==0)
      {
        // DEBUG
        printf("NONE %d\n", offset);
        break;
      }
      if (n < 0)
      {
        if (errno == EINTR || errno == EAGAIN)
        {
          // DEBUG
          // printf("Partial write, returning early (offset=%d)\n", offset);
          continue;
        }
        if (errno == EAGAIN) return 1;
        return -1;
      }
      offset += (uint32)n;
      // DEBUG
      printf("\n\noffset: %d data_size: %d\n\n", offset, data_size);
    }
    // DEBUG
    printf("\n\nTotal: %d\n", offset);
    return 0;
  }

  if (!p_handle) {
    printf("[ERROR] p_handle is NULL before memcpy\n");
    return;
  }
  
  if (!p_handle->write_buffer) {
    printf("[ERROR] p_handle->write_buffer is NULL (len=%zu, size=%zu)\n",
            p_handle->write_buffer_len, data_size);
    return;
  }
  
  printf("[DEBUG] memcpy -> dest=%p (write_buffer=%p + offset=%zu), src=%p, size=%zu\n",
          p_handle->write_buffer + p_handle->write_buffer_len,
          p_handle->write_buffer,
          p_handle->write_buffer_len,
          data,
          data_size); 

  memcpy(p_handle->write_buffer + p_handle->write_buffer_len,
         data,
         data_size);
  p_handle->write_buffer_len += data_size;
  return 0;
}

int32 Seobeo_Handle_Read(Seobeo_PHandle p_handle)
{
  int32 read_size;
  if (!p_handle) return -1;

  // How many bytes we can still read into the buffer
  uint32 free_space = p_handle->read_buffer_capacity - p_handle->read_buffer_len;
  if (free_space == 0)
    return -1;

  if (p_handle->ssl)
  {
    read_size = (int32)SSL_read(p_handle->ssl, p_handle->read_buffer,
                                free_space);
    if (read_size <= 0)
    {
      int err = SSL_get_error(p_handle->ssl, read_size);
      switch (err)
      {
        case SSL_ERROR_WANT_READ:
        case SSL_ERROR_WANT_WRITE:
          return 0;
        case SSL_ERROR_ZERO_RETURN:
        default:
          // TODO: Handle these errors
          return -2;
      }
    }
  }else
  {
    read_size = (int32)read(p_handle->socket,
                            p_handle->read_buffer + p_handle->read_buffer_len,
                            free_space);
    if (read_size == 0) return -2; 
    if (read_size < 0)
    {
      if (errno == EAGAIN || errno == EWOULDBLOCK) return 0;
      return -1;
    }
  }

  p_handle->read_buffer_len += (uint32)read_size;
  return read_size;
}

void Seobeo_Handle_Consume(Seobeo_PHandle p_handle, uint32 consumed)
{
  if (consumed >= p_handle->read_buffer_len)
  {
    p_handle->read_buffer_len = 0;
    return;
  }

  // Slide remaining bytes to the front
  memmove(
    p_handle->read_buffer,
    p_handle->read_buffer + consumed,
    p_handle->read_buffer_len - consumed
  );
  p_handle->read_buffer_len -= consumed;
}

void *Seobeo_Get_IP4_Or_IP6(struct sockaddr *sa)
{
  if (sa->sa_family == AF_INET) 
  {
    return &(((struct sockaddr_in*)sa)->sin_addr);
  }

  return &(((struct sockaddr_in6*)sa)->sin6_addr);
}