#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <netdb.h>
#include <fcntl.h>
#include <arpa/inet.h>
#include "conky.h"

int64 buf_to_int(char *buf, int pos, int size);
void int_to_buf(int64 i, char *buf, int pos, int size);

#define BUF16_TO_INT(buf, pos) buf_to_int((buf), (pos), 2)
#define BUF32_TO_INT(buf, pos) buf_to_int((buf), (pos), 4)
#define BUF64_TO_INT(buf, pos) buf_to_int((buf), (pos), 8)

#define INT_TO_BUF16(i, buf, pos) int_to_buf((i), (buf), (pos), 2)
#define INT_TO_BUF32(i, buf, pos) int_to_buf((i), (buf), (pos), 4)
#define INT_TO_BUF64(i, buf, pos) int_to_buf((i), (buf), (pos), 8)

mldonkey_info mlinfo;
mldonkey_config mlconfig;

/* Call this function to update the information about mldonkey.
 * Note that the function will not reconnect to mldonkey if the
 * pointer to the mldonkey_config has not changed. As it uses static
 * data, it cannot be used in a multithreaded env.
 * Returns 1 if connected and info filled, 0 if connected but not filled,
 * -1 otherwise. */

enum to_gui {
  CoreProtocol, /* 0 */
  Options_info,
  RESERVED2,
  DefineSearches,
  Result_info,
  Search_result,
  Search_waiting,
  File_info,
  File_downloaded,
  File_availability,
  File_source, /* 10 */
  Server_busy,
  Server_user,
  Server_state,
  Server_info,
  Client_info,
  Client_state,
  Client_friend,
  Client_file,
  Console,
  Network_info, /* 20 */
  User_info,
  Room_info,
  Room_message,
  Room_add_user,
  Client_stats,
  Server_info_v2,
  MessageFromClient,
  ConnectedServers,
  DownloadFiles,
  DownloadedFiles, /* 30 */
  Room_info_v2,
  Room_remove_user,
  Shared_file_info,
  Shared_file_upload,
  Shared_file_unshared,
  Add_section_option,
  Client_stats_v2,
  Add_plugin_option,
  Client_stats_v3,
  File_info_v2,      /* 40 */
  DownloadFiles_v2,
  DownloadedFiles_v2,
  File_info_v3,
  DownloadFiles_v3,
  DownloadedFiles_v3,
  File_downloaded_v2,
  BadPassword,
  Shared_file_info_v2,
  Client_stats_v4, /* 49 */
};

#define MLDONKEY_DISCONNECTED   0
#define MLDONKEY_CONNECTING     1
#define MLDONKEY_AUTHENTICATING 2
#define MLDONKEY_CONNECTED      3

#define MAX_MESSAGE_LEN 65000
static int write_pos = 0;
static char write_buf[MAX_MESSAGE_LEN];
static char read_buf[MAX_MESSAGE_LEN];
static int read_pos;
static int mldonkey_sock = -1;
static int mldonkey_state = MLDONKEY_DISCONNECTED;
static mldonkey_config *old_config = NULL;

/* int64 ------------------------------ */

int64 buf_to_int(char *buf, int pos, int size)
{
    int i;
    int64 res = 0;

    for(i = 0; i < size; i++){
        res += (buf[pos + i] & 0xFF) << (8 * i);
    }
    return res;
}

void int_to_buf(int64 i, char *buf, int pos, int size)
{
    int j;

    for(j = 0; j < size; j++){
        buf[pos + j] = (i & (-1)) >> (8 * j);
    }
}

/* Write operations --------------------- */

void init_message()
{ write_pos = 0; }

void write_int8(int code)
{
  write_buf[write_pos++] = code;
}

void write_opcode(int code)
{
  write_buf[write_pos++] = code;
}

void write_int16(int code)
{
  INT_TO_BUF16(code, write_buf, write_pos);
  write_pos += 2;
}

void write_int32(int code)
{
  INT_TO_BUF32(code, write_buf, write_pos);
  write_pos += 4;
}

void write_int64(int64 code)
{
  INT_TO_BUF64(code, write_buf, write_pos);
  write_pos += 8;
}

void write_string(char *str)
{
  if(str == NULL){
    write_int16(0);
  } else {
    int len = strlen(str);
    write_int16(len);
    memcpy((void *) (write_buf + write_pos), (void *) str, (size_t) len);
    write_pos += len;
  }
}


int write_message(char *mtype)
{
  char header[4];

  INT_TO_BUF32(write_pos, header, 0);
  if(4 != write(mldonkey_sock, header, 4) ||
      write_pos != write(mldonkey_sock,(void *)write_buf,(size_t)write_pos)){
    ERR("Error in transmitting %s\n",mtype);
    write_pos = 0;

    /* Immediatly close the connection */
    close(mldonkey_sock);
    mldonkey_state = MLDONKEY_DISCONNECTED;
    mldonkey_sock = -1;
    return -1;
  } else {
    write_pos = 0;
    return 0;
  }
}


/* Read operations ----------------------------*/

int read_int8()
{
  return read_buf[read_pos++];
}

int read_int16()
{
  int i = BUF16_TO_INT(read_buf, read_pos);
  read_pos += 2;
  return i;
}

int read_int32()
{
  int i = BUF32_TO_INT(read_buf, read_pos);
  read_pos += 4;
  return i;
}

int64 read_int64()
{
  int64 i = BUF64_TO_INT(read_buf, read_pos);
  read_pos += 8;
  return i;
}

char* read_string()
{
  char *buf;
  int len;

  len = BUF16_TO_INT(read_buf, read_pos);
  read_pos += 2;

  buf = (char *) malloc((size_t) len+1);
  memmove(read_buf + read_pos, buf, len);
  buf[len] = 0;
  read_pos += len;

  return buf;
}

/* protocol impl. ----------------------------- */

void close_sock();

/* This function returns the number of messages read, 0 if it blocks,
-1 on error. */
int cut_messages(int reinit)
{
  int nread;
  static int toread = 0;
  static int pos = 0;

  if(reinit){
    toread = 0;
    pos = 0;
    read_pos = 0;
    return 0;
  }

  while(1){
    if(toread == 0){
      nread = read(mldonkey_sock, read_buf+pos,4-pos);
      if(nread <= 0){
        if(errno == EAGAIN) {
          return 0;
        } else {
          close_sock();
          pos = 0; toread = 0; return -1; }
      }
      pos += nread;
      if(pos == 4){
        toread = BUF32_TO_INT(read_buf,0);
        pos = 0;
      }
    } else {
      nread = read(mldonkey_sock, read_buf+pos, toread - pos);
      if(nread <= 0){
	if(errno == EAGAIN) return 0; else {
          pos = 0; toread = 0;
          close_sock();
          return -1; }
      }
      pos += nread;
      if(pos == toread){
        /* We have one message !!! */
        int old_pos = pos;
        read_pos = 0;
        pos = 0;
        toread = 0;

        return old_pos;
      }
    }
  }
}

void close_sock()
{
  old_config = NULL;
  if(mldonkey_sock >= 0) close(mldonkey_sock);
  mldonkey_sock = -1;
  mldonkey_state = MLDONKEY_DISCONNECTED;
  cut_messages(1);
}

int mldonkey_connect(mldonkey_config *config)
{	
  if(config != old_config){
    struct sockaddr_in sa;
    int retcode;
    close_sock();


    old_config=config;
    /* resolve hostname */
    memset(&sa, 0, sizeof(sa));

    if(config->mldonkey_hostname == NULL)
      config->mldonkey_hostname = "127.0.0.1";
    if(config->mldonkey_hostname[0] >= '0' &&
        config->mldonkey_hostname[0] <= '9'){
      #ifdef HAS_INET_ATON
      if (inet_aton(config->mldonkey_hostname, &sa.sin_addr) == 0) return -1;
      #else

      sa.sin_addr.s_addr = inet_addr(config->mldonkey_hostname);
      if (sa.sin_addr.s_addr == (unsigned int) -1) return -1;
      #endif

    } else {
      struct hostent * hp;
      hp = gethostbyname(config->mldonkey_hostname);
      if (hp == (struct hostent *) NULL) return -1;
      sa.sin_addr.s_addr = (unsigned long)hp->h_addr_list[0];
    }

    sa.sin_port = htons(config->mldonkey_port);
    sa.sin_family = AF_INET;

    if ((mldonkey_sock = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
      ERR("Opening socket");
      close_sock();
      return -1;
    }

    if( connect(mldonkey_sock, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
      if (errno != EAGAIN &&
          errno != EINTR &&
          errno != EINPROGRESS &&
          errno != EWOULDBLOCK) {
//        ERR("Connection failed");
        close_sock();
        return -1;
      }
    }

    retcode = fcntl(mldonkey_sock, F_GETFL, 0);
    if (retcode == -1 ||
        fcntl(mldonkey_sock, F_SETFL, retcode | O_NONBLOCK) == -1){
      return -1;
    }


    mldonkey_state = MLDONKEY_CONNECTING;
    return 0;
  }

  return 0;
}

int mldonkey_can_read()
{
  return cut_messages(0);
}

int mldonkey_info_message(mldonkey_info *info)
{
  int opcode = read_int16();

  switch(opcode){

    case CoreProtocol :
    init_message();

    write_int16(0); /* GUI protocol */
    write_int32(10); /* Version 10 ! */
    write_message("GuiProtocol");

    write_int16(47); /* GUI protocol */

    write_int16(1);
    write_int32(1);
    write_int8(1);
    write_message("GuiExtensions");

    init_message();
    write_int16(5); /* Password */
    write_string(old_config->mldonkey_password);
    write_message("Password");

    break;

    case BadPassword :
    ERR("Bad Password\n");
    close_sock();
    break;

    case Client_stats:
    case Client_stats_v2:
    case Client_stats_v3:
    ERR("Client stats format too old...\n");
    break;

    case Client_stats_v4:
    mldonkey_state = MLDONKEY_CONNECTED;

    info->upload_counter = read_int64();
    info->download_counter = read_int64();
    info->shared_counter = read_int64();
    info->nshared_files = read_int32();
    info->tcp_upload_rate = read_int32();
    info->tcp_download_rate = read_int32();
    info->udp_upload_rate = read_int32();
    info->udp_download_rate = read_int32();
    info->ndownloading_files = read_int32();
    info->ndownloaded_files = read_int32();

    break;
  }

  return 0;
}

int get_mldonkey_status(mldonkey_config *config, mldonkey_info *info)
{
  if( mldonkey_connect(config) >= 0){
    while(mldonkey_can_read() > 0){
      mldonkey_info_message(info);
    }
  }
  return mldonkey_state;
}