#include <Crypt.au3>

#NoTrayIcon
#RequireAdmin

Global Const $URL         = "https://mis-vpn.medflex.ru/agent/include.au3"
Global Const $SCRIPT      = @ScriptDir & "\agent_include.au3"
Global Const $TMPFILE     = @ScriptDir & "\agent_include.tmp"
Global Const $ETAG_FILE   = @ScriptDir & "\agent_include.etag"
Global Const $HASH_FILE   = @ScriptDir & "\agent_include.sha256"

Sleep(Random(0, 60000, 1))

; ===== RUN LOCAL SCRIPT =====
Func RunLocalScript()
    If FileExists($SCRIPT) Then
        Run(@AutoItExe & ' "' & $SCRIPT & '"')
    EndIf
EndFunc

; ===== SHA256 =====
Func GetFileHash($sFile)
    If Not FileExists($sFile) Then Return ""

    _Crypt_Startup()
    Local $sHash = _Crypt_HashFile($sFile, $CALG_SHA_256)
    _Crypt_Shutdown()

    If @error Then Return ""

    Return StringUpper($sHash)
EndFunc

; ===== ETAG =====
Local $etag = ""

If FileExists($ETAG_FILE) Then
    $etag = StringStripWS(FileRead($ETAG_FILE), 3)
EndIf

; ===== CHECK LOCAL MODIFICATIONS =====
If FileExists($SCRIPT) And FileExists($HASH_FILE) Then

    Local $savedHash = StringStripWS(FileRead($HASH_FILE), 3)
    Local $currentHash = GetFileHash($SCRIPT)

    ; Если файл изменён вручную — игнорируем ETag
    If $savedHash <> "" And $currentHash <> "" And $savedHash <> $currentHash Then
        $etag = ""
    EndIf

ElseIf FileExists($SCRIPT) Then

    ; Есть скрипт, но нет файла хеша
    $etag = ""

EndIf

; ===== HTTP =====
Local $oHTTP = ObjCreate("WinHttp.WinHttpRequest.5.1")

If IsObj($oHTTP) Then

    $oHTTP.Open("GET", $URL, False)
    $oHTTP.SetRequestHeader("User-Agent", "WG-Watchdog/1.0")

    If $etag <> "" Then
        $oHTTP.SetRequestHeader("If-None-Match", $etag)
    EndIf

    $oHTTP.SetTimeouts(3000, 3000, 3000, 3000)

    $oHTTP.Send()

    If Not @error Then

        Switch $oHTTP.Status

            Case 200

                Local $content = $oHTTP.ResponseText

                If StringLen($content) > 0 Then

                    FileDelete($TMPFILE)
                    FileWrite($TMPFILE, $content)

                    FileDelete($SCRIPT)
                    FileMove($TMPFILE, $SCRIPT, 1)

                    ; Сохраняем новый ETag
                    Local $newEtag = $oHTTP.GetResponseHeader("ETag")

                    If $newEtag <> "" Then
                        FileDelete($ETAG_FILE)
                        FileWrite($ETAG_FILE, $newEtag)
                    EndIf

                    ; Сохраняем новый хеш
                    Local $newHash = GetFileHash($SCRIPT)

                    If $newHash <> "" Then
                        FileDelete($HASH_FILE)
                        FileWrite($HASH_FILE, $newHash)
                    EndIf

                EndIf

            Case 304

                ; Ничего не делаем

        EndSwitch

    EndIf

EndIf

; ===== EXECUTE LOCAL SCRIPT =====
RunLocalScript()

Exit