// C-Side of the Idris network library
// (C) Simon Fowler, 2014
// MIT Licensed. Have fun!
#include "idris_net.h"
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "idris_util.h"

#ifndef _WIN32
#include <arpa/inet.h>
#include <netinet/in.h>
#else
static int socket_inited = 0;
static WSADATA wsa_data;

static void clean_sockets(void) { WSACleanup(); }

static int check_init(void) {
  if (!socket_inited) {
    int result = WSAStartup(MAKEWORD(2, 2), &wsa_data);
    if (result == NO_ERROR) {
      socket_inited = 1;
      atexit(clean_sockets);
    }
  }
  return socket_inited;
}
#endif

void buf_htonl(void *buf, int len) {
  int *buf_i = (int *)buf;
  int i;
  for (i = 0; i < (len / sizeof(int)) + 1; i++) {
    buf_i[i] = htonl(buf_i[i]);
  }
}

void buf_ntohl(void *buf, int len) {
  int *buf_i = (int *)buf;
  int i;
  for (i = 0; i < (len / sizeof(int)) + 1; i++) {
    buf_i[i] = ntohl(buf_i[i]);
  }
}

struct sockaddr_un get_sockaddr_unix(char *host) {
  struct sockaddr_un addr;
  memset(&addr, 0, sizeof(addr));
  addr.sun_family = AF_UNIX;
  strcpy(addr.sun_path, host);
  return addr;
}

unsigned int idrnet_peek(void *ptr, unsigned int offset) {
  unsigned char *buf_c = (unsigned char *)ptr;
  return (unsigned int)buf_c[offset];
}

void idrnet_poke(void *ptr, unsigned int offset, char val) {
  char *buf_c = (char *)ptr;
  buf_c[offset] = val;
}

int idrnet_socket(int domain, int type, int protocol) {
#ifdef _WIN32
  if (!check_init()) {
    return -1;
  }
#endif
  return socket(domain, type, protocol);
}

int idrnet_close(int fd) {
#ifdef _WIN32
  return _close(fd);
#else
  return close(fd);
#endif
}

// Get the address family constants out of C and into Idris
int idrnet_af_unspec() { return AF_UNSPEC; }

int idrnet_af_unix() { return AF_UNIX; }

int idrnet_af_inet() { return AF_INET; }

int idrnet_af_inet6() { return AF_INET6; }

// We call this from quite a few functions. Given a textual host and an int
// port, populates a struct addrinfo.
int idrnet_getaddrinfo(struct addrinfo **address_res, char *host, int port,
                       int family, int socket_type) {

  struct addrinfo hints;
  // Convert port into string
  char str_port[8];
  sprintf(str_port, "%d", port);

  // Set up hints structure
  memset(&hints, 0, sizeof(hints)); // zero out hints
  hints.ai_family = family;
  hints.ai_socktype = socket_type;

  // If the length of the hostname is 0 (i.e, it was set to Nothing in Idris)
  // then we want to instruct the C library to fill in the IP automatically
  if (strlen(host) == 0) {
    hints.ai_flags = AI_PASSIVE; // fill in IP automatically
    return getaddrinfo(NULL, str_port, &hints, address_res);
  }
  return getaddrinfo(host, str_port, &hints, address_res);
}

int idrnet_bind(int sockfd, int family, int socket_type, char *host, int port) {
  int bind_res;
  if (family == AF_UNIX) {
    struct sockaddr_un addr = get_sockaddr_unix(host);
    bind_res = bind(sockfd, (struct sockaddr *)&addr, sizeof(addr));
  } else {
    struct addrinfo *address_res;
    int addr_res =
        idrnet_getaddrinfo(&address_res, host, port, family, socket_type);
    if (addr_res != 0) {
      // printf("Lib err: bind getaddrinfo\n");
      return -1;
    }

    bind_res = bind(sockfd, address_res->ai_addr, address_res->ai_addrlen);
  }
  if (bind_res == -1) {
    // freeaddrinfo(address_res);
    // printf("Lib err: bind\n");
    return -1;
  }
  return 0;
}

// to retrieve information about a socket bound to port 0
int idrnet_getsockname(int sockfd, void *address, void *len) {
  int res = getsockname(sockfd, address, len);
  if (res != 0) {
    return -1;
  }

  return 0;
}

int idrnet_sockaddr_port(int sockfd) {
  struct sockaddr_storage address;
  socklen_t addrlen = sizeof(struct sockaddr_storage);
  int res = getsockname(sockfd, (struct sockaddr *)&address, &addrlen);
  if (res < 0) {
    return -1;
  }

  switch (address.ss_family) {
  case AF_INET:
    return ntohs(((struct sockaddr_in *)&address)->sin_port);
  case AF_INET6:
    return ntohs(((struct sockaddr_in6 *)&address)->sin6_port);
  default:
    return -1;
  }
}

int idrnet_connect(int sockfd, int family, int socket_type, char *host,
                   int port) {
  if (family == AF_UNIX) {
    struct sockaddr_un addr = get_sockaddr_unix(host);
    return connect(sockfd, (struct sockaddr *)&addr, sizeof(addr));
  }
  struct addrinfo *remote_host;
  int addr_res =
      idrnet_getaddrinfo(&remote_host, host, port, family, socket_type);
  if (addr_res != 0) {
    return -1;
  }

  int connect_res =
      connect(sockfd, remote_host->ai_addr, remote_host->ai_addrlen);
  if (connect_res == -1) {
    freeaddrinfo(remote_host);
    return -1;
  }
  freeaddrinfo(remote_host);
  return 0;
}

int idrnet_listen(int socket, int backlog) { return listen(socket, backlog); }

FILE *idrnet_fdopen(int fd, const char *mode) {
#ifdef _WIN32
  return _fdopen(fd, mode);
#else
  return fdopen(fd, mode);
#endif
}

int idrnet_sockaddr_family(void *sockaddr) {
  struct sockaddr *addr = (struct sockaddr *)sockaddr;
  return (int)addr->sa_family;
}

char *idrnet_sockaddr_ipv4(void *sockaddr) {
  struct sockaddr_in *addr = (struct sockaddr_in *)sockaddr;
  char *ip_addr = (char *)malloc(sizeof(char) * INET_ADDRSTRLEN);
  inet_ntop(AF_INET, &(addr->sin_addr), ip_addr, INET_ADDRSTRLEN);
  // printf("Lib: ip_addr: %s\n", ip_addr);
  return ip_addr;
}

int idrnet_sockaddr_ipv4_port(void *sockaddr) {
  struct sockaddr_in *addr = (struct sockaddr_in *)sockaddr;
  return ((int)ntohs(addr->sin_port));
}

char *idrnet_sockaddr_unix(void *sockaddr) {
  struct sockaddr_un *addr = (struct sockaddr_un *)sockaddr;
  return addr->sun_path;
}

void *idrnet_create_sockaddr() {
  return malloc(sizeof(struct sockaddr_storage));
}

int idrnet_accept(int sockfd, void *sockaddr) {
  struct sockaddr *addr = (struct sockaddr *)sockaddr;
  socklen_t addr_size = sizeof(struct sockaddr_storage);
  return accept(sockfd, addr, &addr_size);
}

int idrnet_send(int sockfd, char *data) {
  int len = strlen(data); // For now.
  return send(sockfd, (void *)data, len, 0);
}

int idrnet_send_bytes(int sockfd, void *data, int len) {
  return send(sockfd, (void *)data, len, 0);
}

int idrnet_send_buf(int sockfd, void *data, int len) {
  void *buf_cpy = malloc(len);
  memset(buf_cpy, 0, len);
  memcpy(buf_cpy, data, len);
  buf_htonl(buf_cpy, len);
  int res = send(sockfd, buf_cpy, len, 0);
  free(buf_cpy);
  return res;
}

void *idrnet_recv(int sockfd, int len) {
  idrnet_recv_result *res_struct =
      (idrnet_recv_result *)malloc(sizeof(idrnet_recv_result));
  char *buf = malloc(len + 1);
  memset(buf, 0, len + 1);
  int recv_res = recv(sockfd, buf, len, 0);
  res_struct->result = recv_res;

  if (recv_res > 0) {         // Data was received
    buf[recv_res + 1] = 0x00; // Null-term, so Idris can interpret it
  }
  res_struct->payload = buf;
  return (void *)res_struct;
}

int idrnet_recv_bytes(int sockfd, void *buf, int len, int flags) {
  return recv(sockfd, buf, len, flags);
}

int idrnet_recv_buf(int sockfd, void *buf, int len) {
  int recv_res = recv(sockfd, buf, len, 0);
  if (recv_res != -1) {
    buf_ntohl(buf, len);
  }
  return recv_res;
}

int idrnet_get_recv_res(void *res_struct) {
  return (((idrnet_recv_result *)res_struct)->result);
}

char *idrnet_get_recv_payload(void *res_struct) {
  return (((idrnet_recv_result *)res_struct)->payload);
}

void idrnet_free_recv_struct(void *res_struct) {
  idrnet_recv_result *i_res_struct = (idrnet_recv_result *)res_struct;
  if (i_res_struct->payload != NULL) {
    free(i_res_struct->payload);
  }
  free(res_struct);
}

int idrnet_errno() { return errno; }

int idrnet_sendto(int sockfd, char *data, char *host, int port, int family) {

  struct addrinfo *remote_host;
  int addr_res =
      idrnet_getaddrinfo(&remote_host, host, port, family, SOCK_DGRAM);
  if (addr_res != 0) {
    return -1;
  }

  int send_res = sendto(sockfd, data, strlen(data), 0, remote_host->ai_addr,
                        remote_host->ai_addrlen);
  freeaddrinfo(remote_host);
  return send_res;
}

int idrnet_sendto_buf(int sockfd, void *buf, int buf_len, char *host, int port,
                      int family) {

  struct addrinfo *remote_host;
  int addr_res =
      idrnet_getaddrinfo(&remote_host, host, port, family, SOCK_DGRAM);
  if (addr_res != 0) {
    // printf("lib err: sendto getaddrinfo \n");
    return -1;
  }

  buf_htonl(buf, buf_len);

  int send_res = sendto(sockfd, buf, buf_len, 0, remote_host->ai_addr,
                        remote_host->ai_addrlen);
  if (send_res == -1) {
    perror("lib err: sendto \n");
  }
  // freeaddrinfo(remote_host);
  return send_res;
}

void *idrnet_recvfrom(int sockfd, int len) {
  /*
   * int recvfrom(int sockfd, void *buf, int len, unsigned int flags,
               struct sockaddr *from, int *fromlen);
  */
  // Allocate the required structures, and nuke them
  struct sockaddr_storage *remote_addr =
      (struct sockaddr_storage *)malloc(sizeof(struct sockaddr_storage));
  char *buf = (char *)malloc(len + 1);
  idrnet_recvfrom_result *ret =
      (idrnet_recvfrom_result *)malloc(sizeof(idrnet_recvfrom_result));
  memset(remote_addr, 0, sizeof(struct sockaddr_storage));
  memset(buf, 0, len + 1);
  memset(ret, 0, sizeof(idrnet_recvfrom_result));
  socklen_t fromlen = sizeof(struct sockaddr_storage);

  int recv_res =
      recvfrom(sockfd, buf, len, 0, (struct sockaddr *)remote_addr, &fromlen);
  ret->result = recv_res;
  // Check for failure...
  if (recv_res == -1) {
    free(buf);
    free(remote_addr);
  } else {
    // If data was received, process and populate
    ret->result = recv_res;
    ret->remote_addr = remote_addr;
    // Ensure the last byte is NULL, since in this mode we're sending strings
    buf[len] = 0x00;
    ret->payload = (void *)buf;
  }

  return ret;
}

void *idrnet_recvfrom_buf(int sockfd, void *buf, int len) {
  // Allocate the required structures, and nuke them
  struct sockaddr_storage *remote_addr =
      (struct sockaddr_storage *)malloc(sizeof(struct sockaddr_storage));
  idrnet_recvfrom_result *ret =
      (idrnet_recvfrom_result *)malloc(sizeof(idrnet_recvfrom_result));
  memset(remote_addr, 0, sizeof(struct sockaddr_storage));
  memset(ret, 0, sizeof(idrnet_recvfrom_result));
  socklen_t fromlen = 0;

  int recv_res =
      recvfrom(sockfd, buf, len, 0, (struct sockaddr *)remote_addr, &fromlen);
  // Check for failure... But don't free the buffer! Not our job.
  ret->result = recv_res;
  if (recv_res == -1) {
    free(remote_addr);
  }
  // Payload will be NULL -- since it's been put into the user-specified buffer.
  // We still need the return struct to get our hands on the remote address,
  // though.
  if (recv_res > 0) {
    buf_ntohl(buf, len);
    ret->payload = NULL;
    ret->remote_addr = remote_addr;
  }
  return ret;
}

int idrnet_get_recvfrom_res(void *res_struct) {
  return (((idrnet_recvfrom_result *)res_struct)->result);
}

char *idrnet_get_recvfrom_payload(void *res_struct) {
  return (((idrnet_recvfrom_result *)res_struct)->payload);
}

void *idrnet_get_recvfrom_sockaddr(void *res_struct) {
  idrnet_recvfrom_result *recv_struct = (idrnet_recvfrom_result *)res_struct;
  return recv_struct->remote_addr;
}

int idrnet_get_recvfrom_port(void *res_struct) {
  idrnet_recvfrom_result *recv_struct = (idrnet_recvfrom_result *)res_struct;
  if (recv_struct->remote_addr != NULL) {
    struct sockaddr_in *remote_addr_in =
        (struct sockaddr_in *)recv_struct->remote_addr;
    return ((int)ntohs(remote_addr_in->sin_port));
  }
  return -1;
}

void idrnet_free_recvfrom_struct(void *res_struct) {
  idrnet_recvfrom_result *recv_struct = (idrnet_recvfrom_result *)res_struct;
  if (recv_struct != NULL) {
    if (recv_struct->payload != NULL) {
      free(recv_struct->payload);
    }
    if (recv_struct->remote_addr != NULL) {
      free(recv_struct->remote_addr);
    }
  }
}

int idrnet_geteagain() { return EAGAIN; }

int isNull(void *ptr) { return ptr == NULL; }