///////////////////////////////////////////////////////////////////////////////
// Name:        msw/registry.cpp
// Purpose:     implementation of registry classes and functions
// Author:      Vadim Zeitlin
// Modified by: 
// Created:     03.04.98
// RCS-ID:      $Id$
// Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
// Licence:     wxWindows license
// TODO:        - parsing of registry key names
//              - support of other (than REG_SZ/REG_DWORD) registry types
//              - add high level functions (RegisterOleServer, ...)
///////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

// for compilers that support precompilation, includes "wx.h".
#include  "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

// other wxWindows headers
#include  "wx/string.h"
#include  "wx/intl.h"
#include  "wx/log.h"

// Windows headers
#define   STRICT
#define   WIN32_LEAN_AND_MEAN
#include  <windows.h>

// other std headers
#include  <stdlib.h>      // for _MAX_PATH

#ifndef _MAX_PATH
#define _MAX_PATH 256
#endif

// our header
#define   HKEY_DEFINED    // already defined in windows.h
#include  "wx/msw/registry.h"

// some registry functions don't like signed chars
typedef unsigned char *RegString;

// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------

// the standard key names, short names and handles all bundled together for
// convenient access
static struct
{
  HKEY        hkey;
  const char *szName;
  const char *szShortName;
}
aStdKeys[] = 
{ 
  { HKEY_CLASSES_ROOT,      "HKEY_CLASSES_ROOT",      "HKCR" },
#ifdef  __WIN32__
  { HKEY_CURRENT_USER,      "HKEY_CURRENT_USER",      "HKCU" },
  { HKEY_LOCAL_MACHINE,     "HKEY_LOCAL_MACHINE",     "HKLM" },
  { HKEY_USERS,             "HKEY_USERS",             "HKU"  }, // short name?
  { HKEY_PERFORMANCE_DATA,  "HKEY_PERFORMANCE_DATA",  "HKPD" },
#if     WINVER >= 0x0400
  { HKEY_CURRENT_CONFIG,    "HKEY_CURRENT_CONFIG",    "HKCC" },
#ifndef __GNUWIN32__
  { HKEY_DYN_DATA,          "HKEY_DYN_DATA",          "HKDD" }, // short name?
#endif  //_GNUWIN32__
#endif  //WINVER >= 4.0
#endif  //WIN32
};

// the registry name separator (perhaps one day MS will change it to '/' ;-)
#define   REG_SEPARATOR     '\\'

// ----------------------------------------------------------------------------
// macros
// ----------------------------------------------------------------------------
// @ const_cast<> is not yet supported by all compilers
#define CONST_CAST    ((wxRegKey *)this)->

#if   !USE_MUTABLE
  #define m_dwLastError   CONST_CAST m_dwLastError
#endif

// ----------------------------------------------------------------------------
// non member functions
// ----------------------------------------------------------------------------

// returns TRUE if given registry key exists
static bool KeyExists(HKEY hRootKey, const char *szKey);

// combines value and key name (uses static buffer!)
static const char *GetFullName(const wxRegKey *pKey, 
                               const char *szValue = NULL);

// ============================================================================
// implementation of wxRegKey class
// ============================================================================

// ----------------------------------------------------------------------------
// static functions and variables
// ----------------------------------------------------------------------------

const size_t wxRegKey::nStdKeys = WXSIZEOF(aStdKeys);

// @@ should take a `StdKey key', but as it's often going to be used in loops
//    it would require casts in user code.  
const char *wxRegKey::GetStdKeyName(uint key)
{
  // return empty string if key is invalid
  wxCHECK_RET( key < nStdKeys, "" );

  return aStdKeys[key].szName;
}

const char *wxRegKey::GetStdKeyShortName(uint key)
{
  // return empty string if key is invalid
  wxCHECK_RET( key < nStdKeys, "" );

  return aStdKeys[key].szShortName;
}

wxRegKey::StdKey wxRegKey::ExtractKeyName(wxString& strKey)
{
  wxString strRoot = strKey.Left(REG_SEPARATOR);

  HKEY hRootKey;
  uint ui;
  for ( ui = 0; ui < nStdKeys; ui++ ) {
    if ( strRoot.CmpNoCase(aStdKeys[ui].szName) == 0 || 
         strRoot.CmpNoCase(aStdKeys[ui].szShortName) == 0 ) {
      hRootKey = aStdKeys[ui].hkey;
      break;
    }
  }

  if ( ui == nStdKeys ) {
    wxFAIL_MSG("invalid key prefix in wxRegKey::ExtractKeyName.");

    hRootKey = HKEY_CLASSES_ROOT;
  }
  else {
    strKey = strKey.After(REG_SEPARATOR);
    if ( !strKey.IsEmpty() && strKey.Last() == REG_SEPARATOR )
      strKey.Truncate(strKey.Len() - 1);
  }

  return (wxRegKey::StdKey)(int)hRootKey;
}

wxRegKey::StdKey wxRegKey::GetStdKeyFromHkey(HKEY hkey)
{
  for ( uint ui = 0; ui < nStdKeys; ui++ ) {
    if ( aStdKeys[ui].hkey == hkey )
      return (StdKey)ui;
  }
  
  wxFAIL_MSG("non root hkey passed to wxRegKey::GetStdKeyFromHkey.");

  return HKCR;
}

// ----------------------------------------------------------------------------
// ctors and dtor
// ----------------------------------------------------------------------------

wxRegKey::wxRegKey()
{
  m_hKey = 0;
  m_hRootKey = aStdKeys[HKCR].hkey;
  m_dwLastError = 0;
}

wxRegKey::wxRegKey(const wxString& strKey) : m_strKey(strKey)
{
  m_hRootKey  = aStdKeys[ExtractKeyName(m_strKey)].hkey;
  m_hKey      = NULL;
  m_dwLastError = 0;
}

// parent is a predefined (and preopened) key
wxRegKey::wxRegKey(StdKey keyParent, const wxString& strKey) : m_strKey(strKey)
{
  if ( !m_strKey.IsEmpty() && m_strKey.Last() == REG_SEPARATOR )
    m_strKey.Truncate(m_strKey.Len() - 1);

  m_hRootKey  = aStdKeys[keyParent].hkey;
  m_hKey      = NULL;
  m_dwLastError = 0;
}

// parent is a normal regkey
wxRegKey::wxRegKey(const wxRegKey& keyParent, const wxString& strKey)
        : m_strKey(keyParent.m_strKey)
{
  // combine our name with parent's to get the full name
  if ( !m_strKey.IsEmpty() )
      m_strKey  += REG_SEPARATOR;

  m_strKey += strKey;
  if ( !m_strKey.IsEmpty() && m_strKey.Last() == REG_SEPARATOR )
    m_strKey.Truncate(m_strKey.Len() - 1);

  m_hRootKey  = keyParent.m_hRootKey;
  m_hKey      = NULL;
  m_dwLastError = 0;
}

// dtor closes the key releasing system resource
wxRegKey::~wxRegKey()
{
  Close();
}

// ----------------------------------------------------------------------------
// info about the key
// ----------------------------------------------------------------------------

// returns TRUE if the key exists
bool wxRegKey::Exists() const
{
  // opened key has to exist, try to open it if not done yet
  return IsOpened() ? TRUE : KeyExists(m_hRootKey, m_strKey);
}

// returns the full name of the key (prefix is abbreviated if bShortPrefix)
wxString wxRegKey::GetName(bool bShortPrefix) const
{
  StdKey key = GetStdKeyFromHkey(m_hRootKey);
  wxString str = bShortPrefix ? aStdKeys[key].szShortName 
                              : aStdKeys[key].szName;
  if ( !m_strKey.IsEmpty() )
    str << "\\" << m_strKey;

  return str;
}

// ----------------------------------------------------------------------------
// operations
// ----------------------------------------------------------------------------

// opens key (it's not an error to call Open() on an already opened key)
bool wxRegKey::Open()
{
  if ( IsOpened() )
    return TRUE;

  m_dwLastError = RegOpenKey(m_hRootKey, m_strKey, &m_hKey);
  if ( m_dwLastError != ERROR_SUCCESS ) {
    wxLogSysError(m_dwLastError, "can't open registry key '%s'", 
                  GetName().c_str());
    return FALSE;
  }
  else
    return TRUE;
}

// creates key, failing if it exists and !bOkIfExists
bool wxRegKey::Create(bool bOkIfExists)
{
  // check for existence only if asked (i.e. order is important!)
  if ( !bOkIfExists && Exists() ) {
    return FALSE;
  }

  if ( IsOpened() )
    return TRUE;

  m_dwLastError = RegCreateKey(m_hRootKey, m_strKey, &m_hKey);
  if ( m_dwLastError != ERROR_SUCCESS ) {
    wxLogSysError(m_dwLastError, "can't create registry key '%s'", 
                  GetName().c_str());
    return FALSE;
  }
  else
    return TRUE;
}

bool wxRegKey::DeleteSelf()
{
  if ( !Open() )
    return FALSE;

  wxString strKey;
  long lIndex;
  bool bCont = GetFirstKey(strKey, lIndex);
  while ( bCont ) {
    wxRegKey key(*this, strKey);
    if ( !key.DeleteSelf() )
      return FALSE;

    bCont = GetNextKey(strKey, lIndex);
  }

  Close();

  m_dwLastError = RegDeleteKey(m_hRootKey, m_strKey);
  if ( m_dwLastError != ERROR_SUCCESS ) {
    wxLogSysError(m_dwLastError, "can't delete key '%s'", GetName().c_str());
    return FALSE;
  }

  return TRUE;
}

bool wxRegKey::DeleteKey(const char *szKey)
{
  if ( !Open() )
    return FALSE;

  wxRegKey key(*this, szKey);
  return key.DeleteSelf();
}

bool wxRegKey::DeleteValue(const char *szValue)
{
  if ( !Open() )
    return FALSE;

  #ifdef  __WIN32__
    m_dwLastError = RegDeleteValue(m_hKey, szValue);
    if ( m_dwLastError != ERROR_SUCCESS ) {
      wxLogSysError(m_dwLastError, "can't delete value '%s' from key '%s'",
                    szValue, GetName().c_str());
      return FALSE;
    }
  #else   //WIN16
    // named registry values don't exist in Win16 world
    wxASSERT( IsEmpty(szValue) );

    // just set the (default and unique) value of the key to ""
    m_dwLastError = RegSetValue(m_hKey, NULL, REG_SZ, "", RESERVED);
    if ( m_dwLastError != ERROR_SUCCESS ) {
      wxLogSysError(m_dwLastError, "can't delete value of key '%s'", 
                    GetName().c_str());
      return FALSE;
    }
  #endif  //WIN16/32

  return TRUE;
}

// close the key, it's not an error to call it when not opened
bool wxRegKey::Close()
{
  if ( IsOpened() ) {
    m_dwLastError = RegCloseKey(m_hKey);
    if ( m_dwLastError != ERROR_SUCCESS ) {
      wxLogSysError(m_dwLastError, "can't close registry key '%s'", 
                    GetName().c_str());

      m_hKey = 0;
      return FALSE;
    }
    else {
      m_hKey = 0;
    }
  }

  return TRUE;
}

// ----------------------------------------------------------------------------
// access to values and subkeys
// ----------------------------------------------------------------------------

// returns TRUE if this key has any subkeys
bool wxRegKey::HasSubkeys() const
{
  // just call GetFirstKey with dummy parameters
  wxString str;
  long     l;
  return CONST_CAST GetFirstKey(str, l);
}

// returns TRUE if given subkey exists
bool wxRegKey::HasSubKey(const char *szKey) const
{
  if ( CONST_CAST Open() )
    return KeyExists(m_hKey, szKey);
  else
    return FALSE;
}

wxRegKey::ValueType wxRegKey::GetValueType(const char *szValue)
{
  #ifdef  __WIN32__
    if ( !Open() )
      return Type_None;

    DWORD dwType;
    m_dwLastError = RegQueryValueEx(m_hKey, szValue, RESERVED,
                                    &dwType, NULL, NULL);
    if ( m_dwLastError != ERROR_SUCCESS ) {
      wxLogSysError(m_dwLastError, "can't read value of key '%s'", 
                    GetName().c_str());
      return Type_None;
    }

    return (ValueType)dwType;
  #else   //WIN16
    return IsEmpty(szValue) ? Type_String : Type_None;
  #endif  //WIN16/32
}

#ifdef  __WIN32__
bool wxRegKey::SetValue(const char *szValue, long lValue)
{
  if ( CONST_CAST Open() ) {
    m_dwLastError = RegSetValueEx(m_hKey, szValue, RESERVED, REG_DWORD, 
                                  (RegString)&lValue, sizeof(lValue));
    if ( m_dwLastError == ERROR_SUCCESS )
      return TRUE;
  }

  wxLogSysError(m_dwLastError, "can't set value of '%s'", 
                GetFullName(this, szValue));
  return FALSE;
}

bool wxRegKey::QueryValue(const char *szValue, long *plValue) const
{
  if ( CONST_CAST Open() ) {
    DWORD dwType, dwSize = sizeof(DWORD);
    RegString pBuf = (RegString)plValue;
    m_dwLastError = RegQueryValueEx(m_hKey, szValue, RESERVED, 
                                    &dwType, pBuf, &dwSize);
    if ( m_dwLastError != ERROR_SUCCESS ) {
      wxLogSysError(m_dwLastError, "can't read value of key '%s'", 
                    GetName().c_str());
      return FALSE;
    }
    else {
      // check that we read the value of right type
      wxASSERT_MSG( dwType == REG_DWORD, 
                    "Type mismatch in wxRegKey::QueryValue()."  );

      return TRUE;
    }
  }
  else
    return FALSE;
}

#endif  //Win32

bool wxRegKey::QueryValue(const char *szValue, wxString& strValue) const
{
  if ( CONST_CAST Open() ) {
    #ifdef  __WIN32__
      // first get the type and size of the data
      DWORD dwType, dwSize;
      m_dwLastError = RegQueryValueEx(m_hKey, szValue, RESERVED, 
                                      &dwType, NULL, &dwSize);
      if ( m_dwLastError == ERROR_SUCCESS ) {
        RegString pBuf = (RegString)strValue.GetWriteBuf(dwSize);
        m_dwLastError = RegQueryValueEx(m_hKey, szValue, RESERVED, 
                                        &dwType, pBuf, &dwSize);
        if ( m_dwLastError == ERROR_SUCCESS ) {
          // check that it was the right type
          wxASSERT_MSG( dwType == REG_SZ, 
                        "Type mismatch in wxRegKey::QueryValue()." );

          return TRUE;
        }
      }
    #else   //WIN16
      // named registry values don't exist in Win16
      wxASSERT( IsEmpty(szValue) );

      m_dwLastError = RegQueryValue(m_hKey, 0, strValue.GetWriteBuf(256), &l);
      if ( m_dwLastError == ERROR_SUCCESS )
        return TRUE;
    #endif  //WIN16/32
  }

  wxLogSysError(m_dwLastError, "can't read value of '%s'", 
                GetFullName(this, szValue));
  return FALSE;
}

bool wxRegKey::SetValue(const char *szValue, const wxString& strValue)
{
  if ( CONST_CAST Open() ) {
    #ifdef  __WIN32__
      m_dwLastError = RegSetValueEx(m_hKey, szValue, RESERVED, REG_SZ, 
                                    (RegString)strValue.c_str(), 
                                    strValue.Len() + 1);
      if ( m_dwLastError == ERROR_SUCCESS )
        return TRUE;
    #else   //WIN16
      // named registry values don't exist in Win16
      wxASSERT( IsEmpty(szValue) );

      m_dwLastError = RegSetValue(m_hKey, NULL, REG_SZ, strValue, NULL);
      if ( m_dwLastError == ERROR_SUCCESS )
        return TRUE;
    #endif  //WIN16/32
  }

  wxLogSysError(m_dwLastError, "can't set value of '%s'", 
                GetFullName(this, szValue));
  return FALSE;
}

wxRegKey::operator wxString() const
{
  wxString str;
  QueryValue(NULL, str);
  return str;
}

// ----------------------------------------------------------------------------
// enumeration
// NB: all these functions require an index variable which allows to have
//     several concurrently running indexations on the same key
// ----------------------------------------------------------------------------

#ifdef  __WIN32__
bool wxRegKey::GetFirstValue(wxString& strValueName, long& lIndex)
{
  if ( !Open() )
    return FALSE;

  char  szValueName[1024];                  // @@ use RegQueryInfoKey...
  DWORD dwValueLen = WXSIZEOF(szValueName);

  lIndex = 0;
  m_dwLastError = RegEnumValue(m_hKey, lIndex, 
                               szValueName, &dwValueLen,
                               RESERVED, 
                               NULL,            // [out] type 
                               NULL,            // [out] buffer for value
                               NULL);           // [i/o]  it's length

  if ( m_dwLastError != ERROR_SUCCESS ) {
    if ( m_dwLastError == ERROR_NO_MORE_ITEMS )
      lIndex = -1;
    else {
      wxLogSysError(m_dwLastError, "can't enumerate values of key '%s'", 
                    GetName().c_str());
    }

    return FALSE;
  }

  strValueName = szValueName;
  return TRUE;
}

bool wxRegKey::GetNextValue(wxString& strValueName, long& lIndex) const
{
  wxASSERT( IsOpened() );
  wxASSERT( lIndex != -1 );

  char  szValueName[1024];                  // @@ use RegQueryInfoKey...
  DWORD dwValueLen = WXSIZEOF(szValueName);

  lIndex++;
  m_dwLastError = RegEnumValue(m_hKey, lIndex, 
                               szValueName, &dwValueLen,
                               RESERVED, 
                               NULL,           // buffer for type 
                               NULL, NULL);    // buffer for value and length

  if ( m_dwLastError != ERROR_SUCCESS ) {
    if ( m_dwLastError == ERROR_NO_MORE_ITEMS ) {
      m_dwLastError = ERROR_SUCCESS;
      lIndex = -1;
    }
    else {
      wxLogSysError(m_dwLastError, "can't enumerate values of key '%s'", 
                    GetName().c_str());
    }

    return FALSE;
  }

  strValueName = szValueName;
  return TRUE;
}
#endif  //Win32

bool wxRegKey::GetFirstKey(wxString& strKeyName, long& lIndex)
{
  if ( !Open() )
    return FALSE;

  char szKeyName[_MAX_PATH + 1];
  lIndex = 0;
  m_dwLastError = RegEnumKey(m_hKey, lIndex, szKeyName, WXSIZEOF(szKeyName));

  if ( m_dwLastError != ERROR_SUCCESS ) {
    if ( m_dwLastError == ERROR_NO_MORE_ITEMS ) {
      m_dwLastError = ERROR_SUCCESS;
      lIndex = -1;
    }
    else {
      wxLogSysError(m_dwLastError, "can't enumerate subkeys of key '%s'", 
                    GetName().c_str());
    }

    return FALSE;
  }

  strKeyName = szKeyName;
  return TRUE;
}

bool wxRegKey::GetNextKey(wxString& strKeyName, long& lIndex) const
{
  wxASSERT( IsOpened() );
  wxASSERT( lIndex != -1 );

  char szKeyName[_MAX_PATH + 1];
  lIndex++;
  m_dwLastError = RegEnumKey(m_hKey, lIndex, szKeyName, WXSIZEOF(szKeyName));

  if ( m_dwLastError != ERROR_SUCCESS ) {
    if ( m_dwLastError == ERROR_NO_MORE_ITEMS ) {
      m_dwLastError = ERROR_SUCCESS;
      lIndex = -1;
    }
    else {
      wxLogSysError(m_dwLastError, "can't enumerate subkeys of key '%s'", 
                    GetName().c_str());
    }

    return FALSE;
  }

  strKeyName = szKeyName;
  return TRUE;
}

// ============================================================================
// implementation of global functions
// ============================================================================
bool KeyExists(HKEY hRootKey, const char *szKey)
{
  HKEY hkeyDummy;
  if ( RegOpenKey(hRootKey, szKey, &hkeyDummy) == ERROR_SUCCESS ) {
    RegCloseKey(hkeyDummy);
    return TRUE;
  }
  else
    return FALSE;
}

const char *GetFullName(const wxRegKey *pKey, const char *szValue)
{
  static wxString s_str;
  s_str = pKey->GetName();
  if ( !IsEmpty(szValue) )
    s_str << "\\" << szValue;

  return s_str.c_str();
}