/*
 *	AutoComplete interfaces implementation.
 *
 *	Copyright 2004	Maxime Bellengé <maxime.bellenge@laposte.net>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

/*
  Implemented:
  - ACO_AUTOAPPEND style
  - ACO_AUTOSUGGEST style
  - ACO_UPDOWNKEYDROPSLIST style

  - Handle pwzsRegKeyPath and pwszQuickComplete in Init

  TODO:
  - implement ACO_SEARCH style
  - implement ACO_FILTERPREFIXES style
  - implement ACO_USETAB style
  - implement ACO_RTLREADING style
  - implement ResetEnumerator
  - string compares should be case-insensitive, the content of the list should be sorted
  
 */
#include "config.h"

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

#define COBJMACROS

#include "wine/debug.h"
#include "windef.h"
#include "winbase.h"
#include "winreg.h"
#include "undocshell.h"
#include "shlwapi.h"
#include "winerror.h"
#include "objbase.h"

#include "pidl.h"
#include "shlobj.h"
#include "shldisp.h"
#include "debughlp.h"
#include "shell32_main.h"

#include "wine/unicode.h"

WINE_DEFAULT_DEBUG_CHANNEL(shell);

typedef struct
{
    IAutoComplete2 IAutoComplete2_iface;
    IAutoCompleteDropDown IAutoCompleteDropDown_iface;
    LONG ref;
    BOOL initialized;
    BOOL enabled;
    HWND hwndEdit;
    HWND hwndListBox;
    WNDPROC wpOrigEditProc;
    WNDPROC wpOrigLBoxProc;
    WCHAR *txtbackup;
    WCHAR *quickComplete;
    IEnumString *enumstr;
    AUTOCOMPLETEOPTIONS options;
} IAutoCompleteImpl;

static const WCHAR autocomplete_propertyW[] = {'W','i','n','e',' ','A','u','t','o',
                                               'c','o','m','p','l','e','t','e',' ',
                                               'c','o','n','t','r','o','l',0};

static inline IAutoCompleteImpl *impl_from_IAutoComplete2(IAutoComplete2 *iface)
{
    return CONTAINING_RECORD(iface, IAutoCompleteImpl, IAutoComplete2_iface);
}

static inline IAutoCompleteImpl *impl_from_IAutoCompleteDropDown(IAutoCompleteDropDown *iface)
{
    return CONTAINING_RECORD(iface, IAutoCompleteImpl, IAutoCompleteDropDown_iface);
}

/*
  Window procedure for autocompletion
 */
static LRESULT APIENTRY ACEditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    IAutoCompleteImpl *This = GetPropW(hwnd, autocomplete_propertyW);
    LPOLESTR strs;
    HRESULT hr;
    WCHAR hwndText[255];
    WCHAR *hwndQCText;
    RECT r;
    BOOL control, filled, displayall = FALSE;
    int cpt, height, sel;

    if (!This->enabled) return CallWindowProcW(This->wpOrigEditProc, hwnd, uMsg, wParam, lParam);

    switch (uMsg)
    {
        case CB_SHOWDROPDOWN:
            ShowWindow(This->hwndListBox, SW_HIDE);
            break;
        case WM_KILLFOCUS:
            if ((This->options & ACO_AUTOSUGGEST) && ((HWND)wParam != This->hwndListBox))
            {
                ShowWindow(This->hwndListBox, SW_HIDE);
            }
            return CallWindowProcW(This->wpOrigEditProc, hwnd, uMsg, wParam, lParam);
        case WM_KEYUP:
        {
            int len;

            GetWindowTextW( hwnd, hwndText, sizeof(hwndText)/sizeof(WCHAR));

            switch(wParam) {
                case VK_RETURN:
                    /* If quickComplete is set and control is pressed, replace the string */
                    control = GetKeyState(VK_CONTROL) & 0x8000;
                    if (control && This->quickComplete) {
                        hwndQCText = HeapAlloc(GetProcessHeap(), 0,
                                              (lstrlenW(This->quickComplete)+lstrlenW(hwndText))*sizeof(WCHAR));
                        sel = sprintfW(hwndQCText, This->quickComplete, hwndText);
                        SendMessageW(hwnd, WM_SETTEXT, 0, (LPARAM)hwndQCText);
                        SendMessageW(hwnd, EM_SETSEL, 0, sel);
                        HeapFree(GetProcessHeap(), 0, hwndQCText);
                    }

                    ShowWindow(This->hwndListBox, SW_HIDE);
                    return 0;
                case VK_LEFT:
                case VK_RIGHT:
                    return 0;
                case VK_UP:
                case VK_DOWN:
                    /* Two cases here :
                       - if the listbox is not visible, displays it
                       with all the entries if the style ACO_UPDOWNKEYDROPSLIST
                       is present but does not select anything.
                       - if the listbox is visible, change the selection
                    */
                    if ( (This->options & (ACO_AUTOSUGGEST | ACO_UPDOWNKEYDROPSLIST))
                         && (!IsWindowVisible(This->hwndListBox) && (! *hwndText)) )
                    {
                         /* We must display all the entries */
                         displayall = TRUE;
                    } else {
                        if (IsWindowVisible(This->hwndListBox)) {
                            int count;

                            count = SendMessageW(This->hwndListBox, LB_GETCOUNT, 0, 0);
                            /* Change the selection */
                            sel = SendMessageW(This->hwndListBox, LB_GETCURSEL, 0, 0);
                            if (wParam == VK_UP)
                                sel = ((sel-1) < 0) ? count-1 : sel-1;
                            else
                                sel = ((sel+1) >= count) ? -1 : sel+1;
                            SendMessageW(This->hwndListBox, LB_SETCURSEL, sel, 0);
                            if (sel != -1) {
                                WCHAR *msg;
                                int len;

                                len = SendMessageW(This->hwndListBox, LB_GETTEXTLEN, sel, 0);
                                msg = HeapAlloc(GetProcessHeap(), 0, (len+1)*sizeof(WCHAR));
                                SendMessageW(This->hwndListBox, LB_GETTEXT, sel, (LPARAM)msg);
                                SendMessageW(hwnd, WM_SETTEXT, 0, (LPARAM)msg);
                                SendMessageW(hwnd, EM_SETSEL, lstrlenW(msg), lstrlenW(msg));
                                HeapFree(GetProcessHeap(), 0, msg);
                            } else {
                                SendMessageW(hwnd, WM_SETTEXT, 0, (LPARAM)This->txtbackup);
                                SendMessageW(hwnd, EM_SETSEL, lstrlenW(This->txtbackup), lstrlenW(This->txtbackup));
                            }
                        }
                        return 0;
                    }
                    break;
                case VK_BACK:
                case VK_DELETE:
                    if ((! *hwndText) && (This->options & ACO_AUTOSUGGEST)) {
                        ShowWindow(This->hwndListBox, SW_HIDE);
                        return CallWindowProcW(This->wpOrigEditProc, hwnd, uMsg, wParam, lParam);
                    }
                    if (This->options & ACO_AUTOAPPEND) {
                        DWORD b;
                        SendMessageW(hwnd, EM_GETSEL, (WPARAM)&b, 0);
                        if (b>1) {
                            hwndText[b-1] = '\0';
                        } else {
                            hwndText[0] = '\0';
                            SetWindowTextW(hwnd, hwndText);
                        }
                    }
                    break;
                default:
                    ;
            }

            SendMessageW(This->hwndListBox, LB_RESETCONTENT, 0, 0);

            HeapFree(GetProcessHeap(), 0, This->txtbackup);
            len = strlenW(hwndText);
            This->txtbackup = HeapAlloc(GetProcessHeap(), 0, (len + 1)*sizeof(WCHAR));
            lstrcpyW(This->txtbackup, hwndText);

            /* Returns if there is no text to search and we doesn't want to display all the entries */
            if ((!displayall) && (! *hwndText) )
                break;

            IEnumString_Reset(This->enumstr);
            filled = FALSE;
            for(cpt = 0;;) {
                ULONG fetched;
                hr = IEnumString_Next(This->enumstr, 1, &strs, &fetched);
                if (hr != S_OK)
                    break;

                if (!strncmpiW(hwndText, strs, len)) {
                    if (!filled && (This->options & ACO_AUTOAPPEND)) {
                        WCHAR buffW[255];

                        strcpyW(buffW, hwndText);
                        strcatW(buffW, &strs[len]);
                        SetWindowTextW(hwnd, buffW);
                        SendMessageW(hwnd, EM_SETSEL, len, strlenW(strs));
                        if (!(This->options & ACO_AUTOSUGGEST))
                            break;
                    }

                    if (This->options & ACO_AUTOSUGGEST) {
                        SendMessageW(This->hwndListBox, LB_ADDSTRING, 0, (LPARAM)strs);
                        cpt++;
                    }

                    filled = TRUE;
                }
            }

            if (This->options & ACO_AUTOSUGGEST) {
                if (filled) {
                    height = SendMessageW(This->hwndListBox, LB_GETITEMHEIGHT, 0, 0);
                    SendMessageW(This->hwndListBox, LB_CARETOFF, 0, 0);
                    GetWindowRect(hwnd, &r);
                    SetParent(This->hwndListBox, HWND_DESKTOP);
                    /* It seems that Windows XP displays 7 lines at most
                       and otherwise displays a vertical scroll bar */
                    SetWindowPos(This->hwndListBox, HWND_TOP,
                                 r.left, r.bottom + 1, r.right - r.left, min(height * 7, height*(cpt+1)),
                                 SWP_SHOWWINDOW );
                } else {
                    ShowWindow(This->hwndListBox, SW_HIDE);
                }
            }

            break;
        }
        case WM_DESTROY:
        {
            WNDPROC proc = This->wpOrigEditProc;

            RemovePropW(hwnd, autocomplete_propertyW);
            SetWindowLongPtrW(hwnd, GWLP_WNDPROC, (LONG_PTR)proc);
            This->hwndEdit = NULL;
            if (This->hwndListBox)
                    DestroyWindow(This->hwndListBox);
            IAutoComplete2_Release(&This->IAutoComplete2_iface);
            return CallWindowProcW(proc, hwnd, uMsg, wParam, lParam);
        }
        default:
            return CallWindowProcW(This->wpOrigEditProc, hwnd, uMsg, wParam, lParam);

    }

    return 0;
}

static LRESULT APIENTRY ACLBoxSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    IAutoCompleteImpl *This = (IAutoCompleteImpl *)GetWindowLongPtrW(hwnd, GWLP_USERDATA);
    WCHAR *msg;
    int sel, len;

    switch (uMsg) {
        case WM_MOUSEMOVE:
            sel = SendMessageW(hwnd, LB_ITEMFROMPOINT, 0, lParam);
            SendMessageW(hwnd, LB_SETCURSEL, sel, 0);
            break;
        case WM_LBUTTONDOWN:
            sel = SendMessageW(hwnd, LB_GETCURSEL, 0, 0);
            if (sel < 0)
                break;
            len = SendMessageW(This->hwndListBox, LB_GETTEXTLEN, sel, 0);
            msg = HeapAlloc(GetProcessHeap(), 0, (len+1)*sizeof(WCHAR));
            SendMessageW(hwnd, LB_GETTEXT, sel, (LPARAM)msg);
            SendMessageW(This->hwndEdit, WM_SETTEXT, 0, (LPARAM)msg);
            SendMessageW(This->hwndEdit, EM_SETSEL, 0, lstrlenW(msg));
            ShowWindow(hwnd, SW_HIDE);
            HeapFree(GetProcessHeap(), 0, msg);
            break;
        default:
            return CallWindowProcW(This->wpOrigLBoxProc, hwnd, uMsg, wParam, lParam);
    }
    return 0;
}

static void create_listbox(IAutoCompleteImpl *This)
{
    HWND hwndParent;

    hwndParent = GetParent(This->hwndEdit);

    /* FIXME : The listbox should be resizable with the mouse. WS_THICKFRAME looks ugly */
    This->hwndListBox = CreateWindowExW(0, WC_LISTBOXW, NULL,
                                    WS_BORDER | WS_CHILD | WS_VSCROLL | LBS_HASSTRINGS | LBS_NOTIFY | LBS_NOINTEGRALHEIGHT,
                                    CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
                                    hwndParent, NULL, shell32_hInstance, NULL );

    if (This->hwndListBox) {
        This->wpOrigLBoxProc = (WNDPROC) SetWindowLongPtrW( This->hwndListBox, GWLP_WNDPROC, (LONG_PTR) ACLBoxSubclassProc);
        SetWindowLongPtrW( This->hwndListBox, GWLP_USERDATA, (LONG_PTR)This);
    }
}

/**************************************************************************
 *  AutoComplete_QueryInterface
 */
static HRESULT WINAPI IAutoComplete2_fnQueryInterface(
    IAutoComplete2 * iface,
    REFIID riid,
    LPVOID *ppvObj)
{
    IAutoCompleteImpl *This = impl_from_IAutoComplete2(iface);

    TRACE("(%p)->(IID:%s,%p)\n", This, shdebugstr_guid(riid), ppvObj);
    *ppvObj = NULL;

    if (IsEqualIID(riid, &IID_IUnknown) ||
        IsEqualIID(riid, &IID_IAutoComplete) ||
        IsEqualIID(riid, &IID_IAutoComplete2))
    {
        *ppvObj = &This->IAutoComplete2_iface;
    }
    else if (IsEqualIID(riid, &IID_IAutoCompleteDropDown))
    {
        *ppvObj = &This->IAutoCompleteDropDown_iface;
    }

    if (*ppvObj)
    {
	IUnknown_AddRef((IUnknown*)*ppvObj);
	TRACE("-- Interface: (%p)->(%p)\n", ppvObj, *ppvObj);
	return S_OK;
    }
    WARN("unsupported interface: %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

/******************************************************************************
 * IAutoComplete2_fnAddRef
 */
static ULONG WINAPI IAutoComplete2_fnAddRef(
	IAutoComplete2 * iface)
{
    IAutoCompleteImpl *This = impl_from_IAutoComplete2(iface);
    ULONG refCount = InterlockedIncrement(&This->ref);

    TRACE("(%p)->(%u)\n", This, refCount - 1);

    return refCount;
}

/******************************************************************************
 * IAutoComplete2_fnRelease
 */
static ULONG WINAPI IAutoComplete2_fnRelease(
	IAutoComplete2 * iface)
{
    IAutoCompleteImpl *This = impl_from_IAutoComplete2(iface);
    ULONG refCount = InterlockedDecrement(&This->ref);

    TRACE("(%p)->(%u)\n", This, refCount + 1);

    if (!refCount) {
        TRACE("destroying IAutoComplete(%p)\n", This);
        HeapFree(GetProcessHeap(), 0, This->quickComplete);
        HeapFree(GetProcessHeap(), 0, This->txtbackup);
        if (This->enumstr)
            IEnumString_Release(This->enumstr);
        HeapFree(GetProcessHeap(), 0, This);
    }
    return refCount;
}

/******************************************************************************
 * IAutoComplete2_fnEnable
 */
static HRESULT WINAPI IAutoComplete2_fnEnable(
    IAutoComplete2 * iface,
    BOOL fEnable)
{
    IAutoCompleteImpl *This = impl_from_IAutoComplete2(iface);
    HRESULT hr = S_OK;

    TRACE("(%p)->(%s)\n", This, (fEnable)?"true":"false");

    This->enabled = fEnable;

    return hr;
}

/******************************************************************************
 * IAutoComplete2_fnInit
 */
static HRESULT WINAPI IAutoComplete2_fnInit(
    IAutoComplete2 * iface,
    HWND hwndEdit,
    IUnknown *punkACL,
    LPCOLESTR pwzsRegKeyPath,
    LPCOLESTR pwszQuickComplete)
{
    IAutoCompleteImpl *This = impl_from_IAutoComplete2(iface);

    TRACE("(%p)->(%p, %p, %s, %s)\n",
	  This, hwndEdit, punkACL, debugstr_w(pwzsRegKeyPath), debugstr_w(pwszQuickComplete));

    if (This->options & ACO_SEARCH) FIXME(" ACO_SEARCH not supported\n");
    if (This->options & ACO_FILTERPREFIXES) FIXME(" ACO_FILTERPREFIXES not supported\n");
    if (This->options & ACO_USETAB) FIXME(" ACO_USETAB not supported\n");
    if (This->options & ACO_RTLREADING) FIXME(" ACO_RTLREADING not supported\n");

    if (!hwndEdit || !punkACL)
        return E_INVALIDARG;

    if (This->initialized)
    {
        WARN("Autocompletion object is already initialized\n");
        /* This->hwndEdit is set to NULL when the edit window is destroyed. */
        return This->hwndEdit ? E_FAIL : E_UNEXPECTED;
    }

    if (FAILED (IUnknown_QueryInterface (punkACL, &IID_IEnumString, (LPVOID*)&This->enumstr))) {
        WARN("No IEnumString interface\n");
        return E_NOINTERFACE;
    }

    This->initialized = TRUE;
    This->hwndEdit = hwndEdit;
    This->wpOrigEditProc = (WNDPROC) SetWindowLongPtrW( hwndEdit, GWLP_WNDPROC, (LONG_PTR) ACEditSubclassProc);
    /* Keep at least one reference to the object until the edit window is destroyed. */
    IAutoComplete2_AddRef(&This->IAutoComplete2_iface);
    SetPropW( hwndEdit, autocomplete_propertyW, This );

    if (This->options & ACO_AUTOSUGGEST)
        create_listbox(This);

    if (pwzsRegKeyPath) {
	WCHAR *key;
	WCHAR result[MAX_PATH];
	WCHAR *value;
	HKEY hKey = 0;
	LONG res;
	LONG len;

	/* pwszRegKeyPath contains the key as well as the value, so we split */
	key = HeapAlloc(GetProcessHeap(), 0, (lstrlenW(pwzsRegKeyPath)+1)*sizeof(WCHAR));
	strcpyW(key, pwzsRegKeyPath);
	value = strrchrW(key, '\\');
	*value = 0;
	value++;
	/* Now value contains the value and buffer the key */
	res = RegOpenKeyExW(HKEY_CURRENT_USER, key, 0, KEY_READ, &hKey);
	if (res != ERROR_SUCCESS) {
	    /* if the key is not found, MSDN states we must seek in HKEY_LOCAL_MACHINE */
	    res = RegOpenKeyExW(HKEY_LOCAL_MACHINE, key, 0, KEY_READ, &hKey);  
	}
	if (res == ERROR_SUCCESS) {
	    res = RegQueryValueW(hKey, value, result, &len);
	    if (res == ERROR_SUCCESS) {
		This->quickComplete = HeapAlloc(GetProcessHeap(), 0, len*sizeof(WCHAR));
		strcpyW(This->quickComplete, result);
	    }
	    RegCloseKey(hKey);
	}
	HeapFree(GetProcessHeap(), 0, key);
    }

    if ((pwszQuickComplete) && (!This->quickComplete)) {
	This->quickComplete = HeapAlloc(GetProcessHeap(), 0, (lstrlenW(pwszQuickComplete)+1)*sizeof(WCHAR));
	lstrcpyW(This->quickComplete, pwszQuickComplete);
    }

    return S_OK;
}

/**************************************************************************
 *  IAutoComplete2_fnGetOptions
 */
static HRESULT WINAPI IAutoComplete2_fnGetOptions(
    IAutoComplete2 * iface,
    DWORD *pdwFlag)
{
    IAutoCompleteImpl *This = impl_from_IAutoComplete2(iface);
    HRESULT hr = S_OK;

    TRACE("(%p) -> (%p)\n", This, pdwFlag);

    *pdwFlag = This->options;

    return hr;
}

/**************************************************************************
 *  IAutoComplete2_fnSetOptions
 */
static HRESULT WINAPI IAutoComplete2_fnSetOptions(
    IAutoComplete2 * iface,
    DWORD dwFlag)
{
    IAutoCompleteImpl *This = impl_from_IAutoComplete2(iface);
    HRESULT hr = S_OK;

    TRACE("(%p) -> (0x%x)\n", This, dwFlag);

    This->options = dwFlag;

    if ((This->options & ACO_AUTOSUGGEST) && This->hwndEdit && !This->hwndListBox)
        create_listbox(This);

    return hr;
}

/**************************************************************************
 *  IAutoComplete2 VTable
 */
static const IAutoComplete2Vtbl acvt =
{
    IAutoComplete2_fnQueryInterface,
    IAutoComplete2_fnAddRef,
    IAutoComplete2_fnRelease,
    IAutoComplete2_fnInit,
    IAutoComplete2_fnEnable,
    /* IAutoComplete2 */
    IAutoComplete2_fnSetOptions,
    IAutoComplete2_fnGetOptions,
};


static HRESULT WINAPI IAutoCompleteDropDown_fnQueryInterface(IAutoCompleteDropDown *iface,
            REFIID riid, LPVOID *ppvObj)
{
    IAutoCompleteImpl *This = impl_from_IAutoCompleteDropDown(iface);
    return IAutoComplete2_QueryInterface(&This->IAutoComplete2_iface, riid, ppvObj);
}

static ULONG WINAPI IAutoCompleteDropDown_fnAddRef(IAutoCompleteDropDown *iface)
{
    IAutoCompleteImpl *This = impl_from_IAutoCompleteDropDown(iface);
    return IAutoComplete2_AddRef(&This->IAutoComplete2_iface);
}

static ULONG WINAPI IAutoCompleteDropDown_fnRelease(IAutoCompleteDropDown *iface)
{
    IAutoCompleteImpl *This = impl_from_IAutoCompleteDropDown(iface);
    return IAutoComplete2_Release(&This->IAutoComplete2_iface);
}

/**************************************************************************
 *  IAutoCompleteDropDown_fnGetDropDownStatus
 */
static HRESULT WINAPI IAutoCompleteDropDown_fnGetDropDownStatus(
    IAutoCompleteDropDown *iface,
    DWORD *pdwFlags,
    LPWSTR *ppwszString)
{
    IAutoCompleteImpl *This = impl_from_IAutoCompleteDropDown(iface);
    BOOL dropped;

    TRACE("(%p) -> (%p, %p)\n", This, pdwFlags, ppwszString);

    dropped = IsWindowVisible(This->hwndListBox);

    if (pdwFlags)
        *pdwFlags = (dropped ? ACDD_VISIBLE : 0);

    if (ppwszString) {
        if (dropped) {
            int sel;

            sel = SendMessageW(This->hwndListBox, LB_GETCURSEL, 0, 0);
            if (sel >= 0)
            {
                DWORD len;

                len = SendMessageW(This->hwndListBox, LB_GETTEXTLEN, sel, 0);
                *ppwszString = CoTaskMemAlloc((len+1)*sizeof(WCHAR));
                SendMessageW(This->hwndListBox, LB_GETTEXT, sel, (LPARAM)*ppwszString);
            }
            else
                *ppwszString = NULL;
        }
        else
            *ppwszString = NULL;
    }

    return S_OK;
}

/**************************************************************************
 *  IAutoCompleteDropDown_fnResetEnumarator
 */
static HRESULT WINAPI IAutoCompleteDropDown_fnResetEnumerator(
    IAutoCompleteDropDown *iface)
{
    IAutoCompleteImpl *This = impl_from_IAutoCompleteDropDown(iface);

    FIXME("(%p): stub\n", This);

    return E_NOTIMPL;
}

/**************************************************************************
 *  IAutoCompleteDropDown VTable
 */
static const IAutoCompleteDropDownVtbl acdropdownvt =
{
    IAutoCompleteDropDown_fnQueryInterface,
    IAutoCompleteDropDown_fnAddRef,
    IAutoCompleteDropDown_fnRelease,
    IAutoCompleteDropDown_fnGetDropDownStatus,
    IAutoCompleteDropDown_fnResetEnumerator,
};

/**************************************************************************
 *  IAutoComplete_Constructor
 */
HRESULT WINAPI IAutoComplete_Constructor(IUnknown * pUnkOuter, REFIID riid, LPVOID * ppv)
{
    IAutoCompleteImpl *lpac;
    HRESULT hr;

    if (pUnkOuter && !IsEqualIID (riid, &IID_IUnknown))
        return CLASS_E_NOAGGREGATION;

    lpac = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(IAutoCompleteImpl));
    if (!lpac)
        return E_OUTOFMEMORY;

    lpac->ref = 1;
    lpac->IAutoComplete2_iface.lpVtbl = &acvt;
    lpac->IAutoCompleteDropDown_iface.lpVtbl = &acdropdownvt;
    lpac->enabled = TRUE;
    lpac->options = ACO_AUTOAPPEND;

    hr = IAutoComplete2_QueryInterface(&lpac->IAutoComplete2_iface, riid, ppv);
    IAutoComplete2_Release(&lpac->IAutoComplete2_iface);

    TRACE("-- (%p)->\n",lpac);

    return hr;
}