#include <APIDlgConstants.au3>
#include <FontConstants.au3>
#include <GUIConstantsEx.au3>
#include <GuiRichEdit.au3>
#include <MsgBoxConstants.au3>
#include <SendMessage.au3>
#include <WinAPIDlg.au3>
#include <WinAPIGdi.au3>
#include <WinAPIMisc.au3>
#include <WinAPISysWin.au3>
#include <WindowsConstants.au3>

Local Const $sTxt = 'AutoIt v3 is a freeware BASIC-like scripting language designed for automating the Windows GUI and general scripting. It uses a combination of simulated keystrokes, mouse movement and window/control manipulation in order to automate tasks in a way not possible or reliable with other languages (e.g. VBScript and SendKeys). AutoIt is also very small, self-contained and will run on all versions of Windows out-of-the-box with no annoying "runtimes" required!' & @CRLF & @CRLF & _
        'AutoIt was initially designed for PC "roll out" situations to reliably automate and configure thousands of PCs. Over time it has become a powerful language that supports complex expressions, user functions, loops and everything else that veteran scripters would expect.'

; Create GUI
Local $hForm = GUICreate('Test ' & StringReplace(@ScriptName, '.au3', '()'), 800, 600)

; Create main menu
Local $idMenu = GUICtrlCreateMenu('&File')
Local $idExitItem = GUICtrlCreateMenuItem('E&xit...', $idMenu)
$idMenu = GUICtrlCreateMenu('&Edit')
Local $idFindItem = GUICtrlCreateMenuItem('&Find...', $idMenu)
Local $idReplaceItem = GUICtrlCreateMenuItem('R&eplace...', $idMenu)

; Create Rich Edit control with always visible text selection, and set "Courier New" font to the control
Local $hRichEdit = _GUICtrlRichEdit_Create($hForm, $sTxt, 0, 0, 800, 600, BitOR($ES_AUTOVSCROLL, $ES_NOHIDESEL, $ES_MULTILINE, $WS_VSCROLL), 0)
Local $hFont = _WinAPI_CreateFont(17, 0, 0, 0, $FW_NORMAL, 0, 0, 0, $DEFAULT_CHARSET, $OUT_DEFAULT_PRECIS, $CLIP_DEFAULT_PRECIS, $ANTIALIASED_QUALITY, $DEFAULT_PITCH, 'Courier New')
_SendMessage($hRichEdit, $WM_SETFONT, $hFont, 1)
_SendMessage($hRichEdit, $EM_SETSEL)

; Register FINDMSGSTRING message to receive the messages from the dialog box
GUIRegisterMsg(_WinAPI_RegisterWindowMessage('commdlg_FindReplace'), 'WM_FINDMSGSTRING')

; Show GUI
GUISetState(@SW_SHOW)

Global $g_hDlg
Local $iMsg, $sText
While 1
    $iMsg = GUIGetMsg()
    Switch $iMsg
        Case $GUI_EVENT_CLOSE, $idExitItem
            ExitLoop
        Case $idFindItem, $idReplaceItem
            $sText = _GUICtrlRichEdit_GetSelText($hRichEdit)
            If @error Then
                $sText = ''
            EndIf
            ; Disable "Find..." and "Replace..." menu items, otherwise, the script maay crash
            GUICtrlSetState($idFindItem, $GUI_DISABLE)
            GUICtrlSetState($idReplaceItem, $GUI_DISABLE)
            Switch $iMsg
                Case $idFindItem
                    $g_hDlg = _WinAPI_FindTextDlg($hForm, $sText, $FR_DOWN, 0, $hRichEdit)
                Case $idReplaceItem
                    $g_hDlg = _WinAPI_ReplaceTextDlg($hForm, $sText, '', 0, 0, $hRichEdit)
            EndSwitch
        Case $idReplaceItem
    EndSwitch
WEnd

GUIDelete()

Func _IsMatchSelection($hWnd, $sText, $iBehavior)
    Local $aPos = _GUICtrlRichEdit_GetSel($hWnd)
    If @error Then Return 0

    $aPos = _GUICtrlRichEdit_FindTextInRange($hWnd, $sText, $aPos[0], $aPos[1], BitAND($iBehavior, $FR_MATCHCASE) = $FR_MATCHCASE, BitAND($iBehavior, $FR_WHOLEWORD) = $FR_WHOLEWORD, BitAND($iBehavior, BitOR($FR_MATCHALEFHAMZA, $FR_MATCHDIAC, $FR_MATCHKASHIDA)))
    If @error Or ($aPos[0] = -1) Or ($aPos[1] = -1) Then
        Return 0
    Else
        Return 1
    EndIf
EndFunc   ;==>_IsMatchSelection

Func WM_FINDMSGSTRING($hWnd, $iMsg, $wParam, $lParam)
    #forceref $hWnd, $iMsg, $wParam

    Local $tFINDREPLACE = DllStructCreate($tagFINDREPLACE, $lParam)
    Local $sReplace = _WinAPI_GetString(DllStructGetData($tFINDREPLACE, 'ReplaceWith'))
    Local $sFind = _WinAPI_GetString(DllStructGetData($tFINDREPLACE, 'FindWhat'))
    Local $hRichEdit = Ptr(DllStructGetData($tFINDREPLACE, 'lParam'))
    Local $iFlags = DllStructGetData($tFINDREPLACE, 'Flags')
    Local $aPos, $iCur = -1

    Select
        ; The user clicked the "Replace" button in a Replace dialog box
        Case BitAND($iFlags, $FR_REPLACE)
            If _IsMatchSelection($hRichEdit, $sFind, $iFlags) Then
                _GUICtrlRichEdit_ReplaceText($hRichEdit, $sReplace)
            EndIf
            ContinueCase
            ; The user clicked the "Find Next" button in a Find or Replace dialog box
        Case BitAND($iFlags, $FR_FINDNEXT)
            $aPos = _GUICtrlRichEdit_GetSel($hRichEdit)
            If @error Then Return

            If BitAND($iFlags, $FR_DOWN) Then
                $aPos = _GUICtrlRichEdit_FindTextInRange($hRichEdit, $sFind, $aPos[1], -1, BitAND($iFlags, $FR_MATCHCASE) = $FR_MATCHCASE, BitAND($iFlags, $FR_WHOLEWORD) = $FR_WHOLEWORD)
            Else
                $aPos = _GUICtrlRichEdit_FindTextInRange($hRichEdit, $sFind, $aPos[0], 0, BitAND($iFlags, $FR_MATCHCASE) = $FR_MATCHCASE, BitAND($iFlags, $FR_WHOLEWORD) = $FR_WHOLEWORD, BitAND($iFlags, $FR_DOWN))
            EndIf
            If @error Or ($aPos[0] = -1) Or ($aPos[1] = -1) Then
                Local $iError = @error
                MsgBox(($MB_ICONINFORMATION + $MB_SYSTEMMODAL), WinGetTitle($g_hDlg), 'Cannot find "' & $sFind & '" (' & $iError & ')', 0, $g_hDlg)
                Return
            EndIf
            ; Here and below used the EM_SETSEL message directly because _GUICtrlRichEdit_SetSel() sets a focus to the Rich Edit control
            _SendMessage($hRichEdit, $EM_SETSEL, $aPos[0], $aPos[1])
            ;           _GUICtrlRichEdit_ScrollToCaret($hRichEdit)
            ; The user clicked the "Replace All" button in a Replace dialog box
        Case BitAND($iFlags, $FR_REPLACEALL)
            Dim $aPos[2] = [0, -1]
            While 1
                $aPos = _GUICtrlRichEdit_FindTextInRange($hRichEdit, $sFind, $aPos[0], -1, BitAND($iFlags, $FR_MATCHCASE) = $FR_MATCHCASE, BitAND($iFlags, $FR_WHOLEWORD) = $FR_WHOLEWORD)
                If ($aPos[0] = -1) Or ($aPos[1] = -1) Then
                    If $iCur = -1 Then
                        MsgBox(($MB_ICONINFORMATION + $MB_SYSTEMMODAL), WinGetTitle($g_hDlg), 'Cannot find "' & $sFind & '"', 0, $g_hDlg)
                        Return
                    EndIf
                    ExitLoop
                EndIf
                If $iCur = -1 Then
                    _GUICtrlRichEdit_PauseRedraw($hRichEdit)
                EndIf
                _SendMessage($hRichEdit, $EM_SETSEL, $aPos[0], $aPos[1])
                If _GUICtrlRichEdit_ReplaceText($hRichEdit, $sReplace) Then
                    $iCur = $aPos[0] + StringLen($sReplace)
                Else
                    ExitLoop
                EndIf
            WEnd
            _SendMessage($hRichEdit, $EM_SETSEL, $iCur, $iCur)
            ;           _GUICtrlRichEdit_ScrollToCaret($hRichEdit)
            _GUICtrlRichEdit_ResumeRedraw($hRichEdit)
            ; The dialog box is closing
        Case BitAND($iFlags, $FR_DIALOGTERM)
            ; Destroy internal buffer, and free allocated memory
            _WinAPI_FlushFRBuffer()
            ; Enable "Find..." and "Replace..." menu items
            GUICtrlSetState($idReplaceItem, $GUI_ENABLE)
            GUICtrlSetState($idFindItem, $GUI_ENABLE)
    EndSelect
EndFunc   ;==>WM_FINDMSGSTRING