/*
   Copyright (c) 2011, 2020, MariaDB Corporation.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */

/*
  Get Properties of an existing mysqld Windows service 
*/

#include <windows.h>
#include <winsvc.h>
#include "winservice.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <shellapi.h>

/*
  Get version from an executable file
*/
void get_file_version(const char *path, int *major, int *minor, int *patch)
{
  DWORD version_handle;
  char *ver= 0;
  VS_FIXEDFILEINFO info;
  UINT len;
  DWORD size;
  void *p;
  *major= *minor= *patch= 0;

  size= GetFileVersionInfoSize(path, &version_handle);
  if (size == 0)
    return;
  ver= (char *)malloc(size);
  if(!GetFileVersionInfo(path, version_handle, size, ver))
    goto end;

  if(!VerQueryValue(ver,"\\",&p,&len))
    goto end;
  memcpy(&info,p ,sizeof(VS_FIXEDFILEINFO));

  *major= (info.dwFileVersionMS & 0xFFFF0000) >> 16;
  *minor= (info.dwFileVersionMS & 0x0000FFFF);
  *patch= (info.dwFileVersionLS & 0xFFFF0000) >> 16;
end:
  free(ver);
}

void normalize_path(char *path, size_t size)
{
  char buf[MAX_PATH];
  if (*path== '"')
  {
    char *p;
    strcpy_s(buf, MAX_PATH, path+1);
    p= strchr(buf, '"');
    if (p)
      *p=0;
  }
  else
    strcpy_s(buf, MAX_PATH,  path);
  GetFullPathName(buf, MAX_PATH, buf, NULL);
  strcpy_s(path, size,  buf);
}

/*
  Exclusion rules.

  Some hardware manufacturers deliver systems with own preinstalled MySQL copy
  and services. We do not want to mess up with these installations. We will
  just ignore such services, pretending it is not MySQL.

  We also exclude MySQL5.7+ since we cannot upgrade it (and it is not an upgrade anyway)

  @return
    TRUE,  if this service should be excluded from UI lists etc
    FALSE otherwise.
*/
BOOL exclude_service(mysqld_service_properties *props)
{
  static const char* exclude_patterns[] =
  {
    "common files\\dell\\mysql\\bin\\", /* Dell's private installation */ 
    NULL
  };
  int i;
  char buf[MAX_PATH];

  /* Convert mysqld path to lower case, rules for paths are case-insensitive. */
  memcpy(buf, props->mysqld_exe, sizeof(props->mysqld_exe));
  _strlwr(buf);

  for(i= 0; exclude_patterns[i]; i++)
  {
    if (strstr(buf, exclude_patterns[i]))
      return TRUE;
  }
  if ((props->version_major == 0) ||
     (props->version_major > 5 && props->version_major < 10) ||
     (props->version_major == 5 && props->version_minor > 7))
  {
    return TRUE;
  }
  return FALSE;
}


static void get_datadir_from_ini(const char *ini, char *service_name, char *datadir, size_t sz)
{
  *datadir= 0;
  const char *sections[]= {service_name, "mysqld", "server", "mariadb",
                           "mariadbd"};
  for (int i= 0; i < sizeof(sections) / sizeof(sections[0]); i++)
  {
    if (sections[i])
    {
      GetPrivateProfileStringA(sections[i], "datadir", NULL, datadir,
                               (DWORD) sz, ini);
      if (*datadir)
        return;
    }
  }
}


static int fix_and_check_datadir(mysqld_service_properties *props)
{
  normalize_path(props->datadir, MAX_PATH);
  /* Check if datadir really exists */
  if (GetFileAttributes(props->datadir) != INVALID_FILE_ATTRIBUTES)
    return 0;
  /*
    It is possible, that datadir contains some unconvertable character.
    We just pretend not to know what's the data directory
  */
  props->datadir[0]= 0;
  return 0;
}

/*
  Retrieve some properties from windows mysqld service binary path.
  We're interested in ini file location and datadir, and also in version of
  the data. We tolerate missing mysqld.exe.

  Note that this function carefully avoids using mysql libraries (e.g dbug),
  since it is  used in unusual environments (windows installer, MFC), where we
  do not have much control over how threads are created and destroyed, so we
  cannot assume MySQL thread initilization here.
*/
int get_mysql_service_properties(const wchar_t *bin_path,
  mysqld_service_properties *props)
{
  int numargs;
  wchar_t mysqld_path[MAX_PATH + 4];
  wchar_t *file_part;
  wchar_t **args= NULL;
  int retval= 1;
  BOOL have_inifile;
  char service_name[MAX_PATH];

  props->datadir[0]= 0;
  props->inifile[0]= 0;
  props->mysqld_exe[0]= 0;
  props->version_major= 0;
  props->version_minor= 0;
  props->version_patch= 0;

  args= CommandLineToArgvW(bin_path, &numargs);
  if(numargs == 2)
  {
    /*
      There are rare cases where service config does not have
      --defaults-file in the binary path . There services were
      registered with plain mysqld --install, the data directory is
      next to "bin" in this case.
    */
    have_inifile= FALSE;
  }
  else if(numargs == 3)
  {
    have_inifile= TRUE;
  }
  else
  {
    goto end;
  }

  /* Last parameter is the service name*/
  wcstombs(service_name, args[numargs-1], MAX_PATH);

  if(have_inifile && wcsncmp(args[1], L"--defaults-file=", 16) != 0)
    goto end;

  GetFullPathNameW(args[0], MAX_PATH, mysqld_path, &file_part);

  if(wcsstr(mysqld_path, L".exe") == NULL)
    wcscat(mysqld_path, L".exe");

  if(wcsicmp(file_part, L"mysqld.exe") != 0 &&
    wcsicmp(file_part, L"mysqld-debug.exe") != 0 &&
    wcsicmp(file_part, L"mysqld-nt.exe") != 0 &&
    wcsicmp(file_part, L"mariadbd.exe") != 0)
  {
    /* The service executable is not mysqld. */
    goto end;
  }

  wcstombs(props->mysqld_exe, mysqld_path, MAX_PATH);
  /* If mysqld.exe exists, try to get its version from executable */
  if (GetFileAttributes(props->mysqld_exe) != INVALID_FILE_ATTRIBUTES)
  {
     get_file_version(props->mysqld_exe, &props->version_major,
      &props->version_minor, &props->version_patch);
  }

  if (have_inifile)
  {
    /* We have --defaults-file in service definition. */
    wcstombs(props->inifile, args[1]+16, MAX_PATH);
    normalize_path(props->inifile, MAX_PATH);
    if (GetFileAttributes(props->inifile) != INVALID_FILE_ATTRIBUTES)
    {
      get_datadir_from_ini(props->inifile, service_name, props->datadir,
                           sizeof(props->datadir));
    }
    else
    {
      /*
        Service will start even with invalid .ini file, using lookup for
        datadir relative to mysqld.exe. This is equivalent to the case no ini
        file used.
      */
      props->inifile[0]= 0;
      have_inifile= FALSE;
    }
  }

  if(!have_inifile || props->datadir[0] == 0)
  {
    /*
      Hard, although a rare case, we're guessing datadir and defaults-file.
      On Windows, defaults-file is traditionally install-root\my.ini
      and datadir is install-root\data
    */
    char install_root[MAX_PATH];
    int i;
    char *p;

    /*
      Get the  install root(parent of bin directory where mysqld.exe)
      is located.
    */
    strcpy_s(install_root, MAX_PATH, props->mysqld_exe);
    for (i=0; i< 2; i++)
    {
      p= strrchr(install_root, '\\');
      if(!p)
        goto end;
      *p= 0;
    }

    if (!have_inifile)
    {
      /* Look for my.ini, my.cnf in the install root */
      sprintf_s(props->inifile, MAX_PATH, "%s\\my.ini", install_root);
      if (GetFileAttributes(props->inifile) == INVALID_FILE_ATTRIBUTES)
      {
        sprintf_s(props->inifile, MAX_PATH, "%s\\my.cnf", install_root);
      }
      if (GetFileAttributes(props->inifile) != INVALID_FILE_ATTRIBUTES)
      {
        /* Ini file found, get datadir from there */
        get_datadir_from_ini(props->inifile, service_name, props->datadir,
                             sizeof(props->datadir));
      }
      else
      {
        /* No ini file */
        props->inifile[0]= 0;
      }
    }

    /* Try datadir in install directory.*/
    if (props->datadir[0] == 0)
    {
      sprintf_s(props->datadir, MAX_PATH, "%s\\data", install_root);
    }
  }

  if (props->datadir[0] == 0 || fix_and_check_datadir(props))
  {
    /* There is no datadir in ini file, or non-existing dir, bail out.*/
    goto end;
  }

  /*
    If version could not be determined so far, try mariadb_upgrade_info in
    database directory.
  */
  if(props->version_major == 0)
  {
    char buf[MAX_PATH];
    FILE *mariadb_upgrade_info;

    sprintf_s(buf, MAX_PATH, "%s\\mariadb_upgrade_info", props->datadir);
    mariadb_upgrade_info= fopen(buf, "r");
    if(mariadb_upgrade_info)
    {
      if (fgets(buf, MAX_PATH, mariadb_upgrade_info))
      {
        int major,minor,patch;
        if (sscanf(buf, "%d.%d.%d", &major, &minor, &patch) == 3)
        {
          props->version_major= major;
          props->version_minor= minor;
          props->version_patch= patch;
        }
      }
    }
  }

  if (!exclude_service(props))
    retval = 0;
end:
  LocalFree((HLOCAL)args);
  return retval;
}