/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include <assert.h>
#include <direct.h>
#include <malloc.h>
#include <stdio.h>
#include <string.h>

#include "uv.h"
#include "internal.h"
#include "tlhelp32.h"
#include "psapi.h"
#include "iphlpapi.h"


/*
 * Max title length; the only thing MSDN tells us about the maximum length
 * of the console title is that it is smaller than 64K. However in practice
 * it is much smaller, and there is no way to figure out what the exact length
 * of the title is or can be, at least not on XP. To make it even more
 * annoying, GetConsoleTitle failes when the buffer to be read into is bigger
 * than the actual maximum length. So we make a conservative guess here;
 * just don't put the novel you're writing in the title, unless the plot
 * survives truncation.
 */
#define MAX_TITLE_LENGTH 8192


static char *process_title;


int uv_utf16_to_utf8(const wchar_t* utf16Buffer, size_t utf16Size,
    char* utf8Buffer, size_t utf8Size) {
  return WideCharToMultiByte(CP_UTF8,
                             0,
                             utf16Buffer,
                             utf16Size,
                             utf8Buffer,
                             utf8Size,
                             NULL,
                             NULL);
}


int uv_utf8_to_utf16(const char* utf8Buffer, wchar_t* utf16Buffer,
    size_t utf16Size) {
  return MultiByteToWideChar(CP_UTF8,
                             0,
                             utf8Buffer,
                             -1,
                             utf16Buffer,
                             utf16Size);
}


int uv_exepath(char* buffer, size_t* size) {
  int retVal;
  size_t utf16Size;
  wchar_t* utf16Buffer;

  if (!buffer || !size) {
    return -1;
  }

  utf16Buffer = (wchar_t*)malloc(sizeof(wchar_t) * *size);
  if (!utf16Buffer) {
    retVal = -1;
    goto done;
  }

  /* Get the path as UTF-16 */
  utf16Size = GetModuleFileNameW(NULL, utf16Buffer, *size - 1);
  if (utf16Size <= 0) {
    /* uv__set_sys_error(loop, GetLastError()); */
    retVal = -1;
    goto done;
  }

  utf16Buffer[utf16Size] = L'\0';

  /* Convert to UTF-8 */
  *size = uv_utf16_to_utf8(utf16Buffer, utf16Size, buffer, *size);
  if (!*size) {
    /* uv__set_sys_error(loop, GetLastError()); */
    retVal = -1;
    goto done;
  }

  buffer[*size] = '\0';
  retVal = 0;

done:
  if (utf16Buffer) {
    free(utf16Buffer);
  }

  return retVal;
}


uv_err_t uv_cwd(char* buffer, size_t size) {
  uv_err_t err;
  size_t utf8Size;
  wchar_t* utf16Buffer = NULL;

  if (!buffer || !size) {
    err.code = UV_EINVAL;
    goto done;
  }

  utf16Buffer = (wchar_t*)malloc(sizeof(wchar_t) * size);
  if (!utf16Buffer) {
    err.code = UV_ENOMEM;
    goto done;
  }

  if (!_wgetcwd(utf16Buffer, size - 1)) {
    err = uv__new_sys_error(_doserrno);
    goto done;
  }

  utf16Buffer[size - 1] = L'\0';

  /* Convert to UTF-8 */
  utf8Size = uv_utf16_to_utf8(utf16Buffer, -1, buffer, size);
  if (utf8Size == 0) {
    err = uv__new_sys_error(GetLastError());
    goto done;
  }

  buffer[utf8Size] = '\0';
  err = uv_ok_;

done:
  if (utf16Buffer) {
    free(utf16Buffer);
  }

  return err;
}


uv_err_t uv_chdir(const char* dir) {
  uv_err_t err;
  wchar_t* utf16Buffer = NULL;
  size_t utf16Size;

  if (!dir) {
    err.code = UV_EINVAL;
    goto done;
  }

  utf16Size = uv_utf8_to_utf16(dir, NULL, 0);
  if (!utf16Size) {
    err = uv__new_sys_error(GetLastError());
    goto done;
  }

  utf16Buffer = (wchar_t*)malloc(sizeof(wchar_t) * utf16Size);
  if (!utf16Buffer) {
    err.code = UV_ENOMEM;
    goto done;
  }

  if (!uv_utf8_to_utf16(dir, utf16Buffer, utf16Size)) {
    err = uv__new_sys_error(GetLastError());
    goto done;
  }

  if (_wchdir(utf16Buffer) == -1) {
    err = uv__new_sys_error(_doserrno);
    goto done;
  }

  err = uv_ok_;

done:
  if (utf16Buffer) {
    free(utf16Buffer);
  }

  return err;
}


void uv_loadavg(double avg[3]) {
  /* Can't be implemented */
  avg[0] = avg[1] = avg[2] = 0;
}


uint64_t uv_get_free_memory(void) {
  MEMORYSTATUSEX memory_status;
  memory_status.dwLength = sizeof(memory_status);

  if(!GlobalMemoryStatusEx(&memory_status))
  {
     return -1;
  }

  return (uint64_t)memory_status.ullAvailPhys;
}


uint64_t uv_get_total_memory(void) {
  MEMORYSTATUSEX memory_status;
  memory_status.dwLength = sizeof(memory_status);

  if(!GlobalMemoryStatusEx(&memory_status))
  {
    return -1;
  }

  return (uint64_t)memory_status.ullTotalPhys;
}


int uv_parent_pid() {
  int parent_pid = -1;
  HANDLE handle;
  PROCESSENTRY32 pe;
  int current_pid = GetCurrentProcessId();

  pe.dwSize = sizeof(PROCESSENTRY32);
  handle = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);

  if (Process32First(handle, &pe)) {
    do {
      if (pe.th32ProcessID == current_pid) {
        parent_pid = pe.th32ParentProcessID;
        break;
      }
    } while( Process32Next(handle, &pe));
  }

  CloseHandle(handle);
  return parent_pid;
}


char** uv_setup_args(int argc, char** argv) {
  return argv;
}


uv_err_t uv_set_process_title(const char* title) {
  uv_err_t err;
  int length;
  wchar_t* title_w = NULL;

  /* Find out how big the buffer for the wide-char title must be */
  length = uv_utf8_to_utf16(title, NULL, 0);
  if (!length) {
    err = uv__new_sys_error(GetLastError());
    goto done;
  }

  /* Convert to wide-char string */
  title_w = (wchar_t*)malloc(sizeof(wchar_t) * length);
  if (!title_w) {
    uv_fatal_error(ERROR_OUTOFMEMORY, "malloc");
  }

  length = uv_utf8_to_utf16(title, title_w, length);
  if (!length) {
    err = uv__new_sys_error(GetLastError());
    goto done;
  };

  /* If the title must be truncated insert a \0 terminator there */
  if (length > MAX_TITLE_LENGTH) {
    title_w[MAX_TITLE_LENGTH - 1] = L'\0';
  }

  if (!SetConsoleTitleW(title_w)) {
    err = uv__new_sys_error(GetLastError());
    goto done;
  }

  free(process_title);
  process_title = strdup(title);

  err = uv_ok_;

done:
  free(title_w);
  return err;
}


static int uv__get_process_title() {
  wchar_t title_w[MAX_TITLE_LENGTH];
  int length;

  if (!GetConsoleTitleW(title_w, sizeof(title_w) / sizeof(WCHAR))) {
    return -1;
  }

  /* Find out what the size of the buffer is that we need */
  length = uv_utf16_to_utf8(title_w, -1, NULL, 0);
  if (!length) {
    return -1;
  }

  assert(!process_title);
  process_title = (char*)malloc(length);
  if (!process_title) {
    uv_fatal_error(ERROR_OUTOFMEMORY, "malloc");
  }

  /* Do utf16 -> utf8 conversion here */
  if (!uv_utf16_to_utf8(title_w, -1, process_title, length)) {
    free(process_title);
    return -1;
  }

  return 0;
}


uv_err_t uv_get_process_title(char* buffer, size_t size) {
  /*
   * If the process_title was never read before nor explicitly set,
   * we must query it with getConsoleTitleW
   */
  if (!process_title && uv__get_process_title() == -1) {
    return uv__new_sys_error(GetLastError());
  }
  
  assert(process_title);
  strncpy(buffer, process_title, size);  

  return uv_ok_;
}


uv_err_t uv_resident_set_memory(size_t* rss) {
  HANDLE current_process;
  PROCESS_MEMORY_COUNTERS pmc;

  current_process = GetCurrentProcess();

  if (!GetProcessMemoryInfo(current_process, &pmc, sizeof(pmc))) {
    return uv__new_sys_error(GetLastError());
  }

  *rss = pmc.WorkingSetSize;

  return uv_ok_;
}


uv_err_t uv_uptime(double* uptime) {
  *uptime = (double)GetTickCount()/1000.0;
  return uv_ok_;
}


uv_err_t uv_cpu_info(uv_cpu_info_t** cpu_infos, int* count) {
  uv_err_t err;
  char key[128];
  HKEY processor_key = NULL;
  DWORD cpu_speed = 0;
  DWORD cpu_speed_length = sizeof(cpu_speed);
  char cpu_brand[256];
  DWORD cpu_brand_length = sizeof(cpu_brand);
  SYSTEM_INFO system_info;
  uv_cpu_info_t* cpu_info;
  unsigned int i;

  GetSystemInfo(&system_info);

  *cpu_infos = (uv_cpu_info_t*)malloc(system_info.dwNumberOfProcessors *
    sizeof(uv_cpu_info_t));
  if (!(*cpu_infos)) {
    uv_fatal_error(ERROR_OUTOFMEMORY, "malloc");
  }

  *count = 0;

  for (i = 0; i < system_info.dwNumberOfProcessors; i++) {    
    _snprintf(key, sizeof(key), "HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\%d", i);

    if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, key, 0, KEY_QUERY_VALUE,
        &processor_key) != ERROR_SUCCESS) {
      if (i == 0) {
        err = uv__new_sys_error(GetLastError());
        goto done;
      }

      continue;
    }

    if (RegQueryValueEx(processor_key, "~MHz", NULL, NULL,
                        (LPBYTE)&cpu_speed, &cpu_speed_length)
                        != ERROR_SUCCESS) {
      err = uv__new_sys_error(GetLastError());
      goto done;
    }

    if (RegQueryValueEx(processor_key, "ProcessorNameString", NULL, NULL,
                        (LPBYTE)&cpu_brand, &cpu_brand_length)
                        != ERROR_SUCCESS) {
      err = uv__new_sys_error(GetLastError());
      goto done;
    }

    RegCloseKey(processor_key);
    processor_key = NULL;
    
    cpu_info = &(*cpu_infos)[i];

    /* $TODO: find times on windows */
    cpu_info->cpu_times.user = 0;
    cpu_info->cpu_times.nice = 0;
    cpu_info->cpu_times.sys = 0;
    cpu_info->cpu_times.idle = 0;
    cpu_info->cpu_times.irq = 0;

    cpu_info->model = strdup(cpu_brand);
    cpu_info->speed = cpu_speed;

    (*count)++;
  }

  err = uv_ok_;

done:
  if (processor_key) {
    RegCloseKey(processor_key);
  }

  if (err.code != UV_OK) {
    free(*cpu_infos);
    *cpu_infos = NULL;
    *count = 0;
  }

  return err;
}


void uv_free_cpu_info(uv_cpu_info_t* cpu_infos, int count) {
  int i;

  for (i = 0; i < count; i++) {
    free(cpu_infos[i].model);
  }

  free(cpu_infos);
}


uv_err_t uv_interface_addresses(uv_interface_address_t** addresses,
    int* count) {
  unsigned long size = 0;
  IP_ADAPTER_ADDRESSES* adapter_addresses;
  IP_ADAPTER_ADDRESSES* adapter_address;
  uv_interface_address_t* address;
  struct sockaddr* sock_addr;
  int length;

  if (GetAdaptersAddresses(AF_UNSPEC, 0, NULL, NULL, &size)
      != ERROR_BUFFER_OVERFLOW) {
    return uv__new_sys_error(GetLastError());
  }

  adapter_addresses = (IP_ADAPTER_ADDRESSES*)malloc(size);
  if (!adapter_addresses) {
    uv_fatal_error(ERROR_OUTOFMEMORY, "malloc");
  }

  if (GetAdaptersAddresses(AF_UNSPEC, 0, NULL, adapter_addresses, &size)
      != ERROR_SUCCESS) {
    return uv__new_sys_error(GetLastError());
  }

  /* Count the number of interfaces */
  *count = 0;

  for (adapter_address = adapter_addresses;
       adapter_address != NULL;
       adapter_address = adapter_address->Next) {
    (*count)++;
  }

  *addresses = (uv_interface_address_t*)
    malloc(*count * sizeof(uv_interface_address_t));
  if (!(*addresses)) {
    uv_fatal_error(ERROR_OUTOFMEMORY, "malloc");
  }

  address = *addresses;

  for (adapter_address = adapter_addresses;
       adapter_address != NULL;
       adapter_address = adapter_address->Next,
       address++) {

    /* Convert FriendlyName to utf8 */
    length = uv_utf16_to_utf8(adapter_address->FriendlyName, -1, NULL, 0);
    if (!length) {
      address->name = NULL;
      address->address.address4 = uv_addr_ip4_any_;
      continue;
    }

    address->name = (char*)malloc(length);
    if (!address->name) {
      uv_fatal_error(ERROR_OUTOFMEMORY, "malloc");
    }

    if (!uv_utf16_to_utf8(adapter_address->FriendlyName, -1, address->name,
        length)) {
      free(address->name);
      address->name = NULL;
      address->address.address4 = uv_addr_ip4_any_;
      continue;
    }

    if (adapter_address->FirstUnicastAddress) {
      sock_addr = adapter_address->FirstUnicastAddress->Address.lpSockaddr;
      if (sock_addr->sa_family == AF_INET6) {
        address->address.address6 = *((struct sockaddr_in6 *)sock_addr);
      } else {
        address->address.address4 = *((struct sockaddr_in *)sock_addr);
      }
    }

    address->is_internal =
      adapter_address->IfType == IF_TYPE_SOFTWARE_LOOPBACK ? 1 : 0;
  }

  free(adapter_addresses);

  return uv_ok_;
}


void uv_free_interface_addresses(uv_interface_address_t* addresses,
    int count) {
  int i;

  for (i = 0; i < count; i++) {
    free(addresses[i].name);
  }

  free(addresses);
}