#include-once
#include <Crypt.au3>
#include <String.au3>
#include <File.au3>
#include <Date.au3>

; Configuration - Base Key for this specific version!
Global Const $APP_VERSION = "1.05"
Global Const $LICENSE_AES_BASE_KEY = "7C4A8D09CA3762AF61E59520943DC26494F8941B" ; 32 byte Hex key
Global Const $LICENSE_AES_IV  = "2B7E151628AED2A6ABF7158809CF4F3C" ; 16 byte Hex IV
Global Const $REGISTRY_PATH = "HKCU\Software\MyAutoItSaaS"

Global $g_iGlobalUnixTime = 0
Global $g_sGlobalDate = ""

;----------------------------------------------------------------------------------------
; Function Name: _License_TimeSync
; Description: Fetches global time, sets global variables, prevents local clock tampering.
;----------------------------------------------------------------------------------------
Func _License_TimeSync()
    Local $oHTTP = ObjCreate("WinHttp.WinHttpRequest.5.1")
    $oHTTP.Open("GET", "http://worldtimeapi.org/api/timezone/Etc/UTC", False)
    $oHTTP.Send()
    Local $sResponse = $oHTTP.ResponseText
    
    ; Parse unixtime
    Local $sUnixTime = StringRegExpReplace($sResponse, '.*"unixtime"\s*:\s*(\d+).*', "$1")
    If @extended = 0 Then Return SetError(1, 0, False)
    
    ; Parse datetime (e.g. "2026-07-06T00:00:00.000Z")
    Local $sDateTime = StringRegExpReplace($sResponse, '.*"datetime"\s*:\s*"([^"]+)".*', "$1")
    Local $sDate = StringLeft($sDateTime, 10) ; YYYY-MM-DD
    
    $g_iGlobalUnixTime = Int($sUnixTime)
    $g_sGlobalDate = $sDate
    
    ; Optional: Compare with local time to detect large discrepancies
    Local $sLocalTime = _Date_Time_GetSystemTime()
    ; ... implementation of check can be added ...

    Return True
EndFunc

;----------------------------------------------------------------------------------------
; Function Name: _CalculateMathMetric
; Description: Anti-Patching mathematical obfuscation to verify server response.
;----------------------------------------------------------------------------------------
Func _CalculateMathMetric($sPayload)
    Local $iResult = 0
    Local $aChars = StringSplit($sPayload, "")
    For $i = 1 To $aChars[0]
        Local $iCharVal = Asc($aChars[$i])
        ; Modulo 1000000
        $iResult = Mod($iResult + ($iCharVal * $i), 1000000)
        ; Bitwise XOR
        $iResult = BitXOR($iResult, $iCharVal)
    Next
    Return $iResult
EndFunc

;----------------------------------------------------------------------------------------
; Function Name: _License_GetHWID
; Description: Generates a unique hardware ID based on CPU, Baseboard, and Volume Serial.
;----------------------------------------------------------------------------------------
Func _License_GetHWID()
    Local $oWMIService = ObjGet("winmgmts:\\localhost\root\CIMV2")
    Local $sCPU = "", $sBaseboard = "", $sVolume = ""

    If IsObj($oWMIService) Then
        Local $colItems = $oWMIService.ExecQuery("SELECT ProcessorId FROM Win32_Processor", "WQL", 0x30)
        If IsObj($colItems) Then
            For $objItem In $colItems
                $sCPU = $objItem.ProcessorId
                ExitLoop
            Next
        EndIf

        $colItems = $oWMIService.ExecQuery("SELECT SerialNumber FROM Win32_BaseBoard", "WQL", 0x30)
        If IsObj($colItems) Then
            For $objItem In $colItems
                $sBaseboard = $objItem.SerialNumber
                ExitLoop
            Next
        EndIf

        $colItems = $oWMIService.ExecQuery("SELECT VolumeSerialNumber FROM Win32_LogicalDisk WHERE DeviceID='C:'", "WQL", 0x30)
        If IsObj($colItems) Then
            For $objItem In $colItems
                $sVolume = $objItem.VolumeSerialNumber
                ExitLoop
            Next
        EndIf
    EndIf

    _Crypt_Startup()
    Local $sRaw = $sCPU & "-" & $sBaseboard & "-" & $sVolume
    Local $bHash = _Crypt_HashData($sRaw, $CALG_SHA_256)
    _Crypt_Shutdown()
    
    Return StringUpper(StringTrimLeft($bHash, 2))
EndFunc

;----------------------------------------------------------------------------------------
; Internal Function: _License_PostRequest
; Description: Handles Dynamic Key generation, Encryption, Request, Decryption, Math Check.
;----------------------------------------------------------------------------------------
Func _License_PostRequest($sUrl, $sJsonPayload)
    If $g_iGlobalUnixTime = 0 Then 
        If Not _License_TimeSync() Then Return SetError(2, 0, False)
    EndIf
    
    ; 1. Generate Daily Mutated Dynamic Key: SHA256(BaseKey + YYYY-MM-DD)
    _Crypt_Startup()
    Local $bDynamicKeyRaw = _Crypt_HashData(Binary("0x" & $LICENSE_AES_BASE_KEY) & StringToBinary($g_sGlobalDate), $CALG_SHA_256)
    Local $bKey = $bDynamicKeyRaw
    Local $bIV = Binary("0x" & $LICENSE_AES_IV)
    
    ; Calculate our local math metric BEFORE encryption
    Local $iLocalMathResult = _CalculateMathMetric($sJsonPayload)
    
    ; 2. Encrypt Payload
    Local $bEncrypted = _Crypt_EncryptData($sJsonPayload, $bKey, $CALG_AES_256)
    Local $sBase64Payload = _Base64Encode($bEncrypted)
    _Crypt_Shutdown()

    ; 3. Prepare POST Request (Wrapping encrypted payload with plaintext version)
    Local $sRequest = '{"version":"' & $APP_VERSION & '","payload":"' & $sBase64Payload & '"}'
    
    Local $oHTTP = ObjCreate("WinHttp.WinHttpRequest.5.1")
    $oHTTP.Open("POST", $sUrl, False)
    $oHTTP.SetRequestHeader("Content-Type", "application/json")
    $oHTTP.Send($sRequest)
    
    Local $sResponse = $oHTTP.ResponseText
    
    ; Extract payload from response
    Local $sEncryptedResponse = StringRegExpReplace($sResponse, '.*"payload"\s*:\s*"([^"]+)".*', "$1")
    If @extended = 0 Then Return SetError(1, 0, False)
    
    ; 4. Decrypt Response
    Local $bDecoded = _Base64Decode($sEncryptedResponse)
    _Crypt_Startup()
    Local $bDecrypted = _Crypt_DecryptData($bDecoded, $bKey, $CALG_AES_256)
    _Crypt_Shutdown()
    Local $sDecryptedJson = BinaryToString($bDecrypted, 4)
    
    ; 5. Verify the Server Checksum (Anti-Spoofing & Anti-Patching)
    Local $iServerMathResult = Int(StringRegExpReplace($sDecryptedJson, '.*"math_result"\s*:\s*(\d+).*', "$1"))
    If $iServerMathResult <> $iLocalMathResult Then
        MsgBox(16, "Security Error", "Server Verification Failed (Code: Math Metric Mismatch).")
        Exit ; Instant kill if spoofed/patched
    EndIf
    
    ; 6. Verify Server Timestamp (Anti-Replay)
    Local $iServerTimestamp = Int(StringRegExpReplace($sDecryptedJson, '.*"timestamp"\s*:\s*(\d+).*', "$1"))
    If Abs($g_iGlobalUnixTime - $iServerTimestamp) > 120 Then
        MsgBox(16, "Security Error", "Server Verification Failed (Code: Replay Attack).")
        Exit
    EndIf
    
    Return $sDecryptedJson
EndFunc

;----------------------------------------------------------------------------------------
; Function Name: _License_Activate
;----------------------------------------------------------------------------------------
Func _License_Activate($sUrl, $sActivationKey)
    If Not _License_TimeSync() Then Return False
    
    Local $sHWID = _License_GetHWID()
    Local $sJson = '{"activation_key":"' & $sActivationKey & '","hwid":"' & $sHWID & '","os_version":"' & @OSVersion & '","timestamp":' & $g_iGlobalUnixTime & '}'
    
    Local $sResponse = _License_PostRequest($sUrl & "/api/activate.php", $sJson)
    If $sResponse = False Then Return False
    
    ; Check for business error
    If StringInStr($sResponse, '"error":true') Then
        Local $sError = StringRegExpReplace($sResponse, '.*"message"\s*:\s*"([^"]+)".*', "$1")
        MsgBox(16, "Activation Error", $sError)
        Return False
    EndIf
    
    ; Extract auth_token
    Local $sToken = StringRegExpReplace($sResponse, '.*"auth_token"\s*:\s*"([^"]+)".*', "$1")
    
    ; Encrypt and save token locally
    _Crypt_Startup()
    Local $bEncryptedToken = _Crypt_EncryptData($sToken, "LocalSecurePassword123!", $CALG_AES_256)
    _Crypt_Shutdown()
    
    Local $sTokenFile = @AppDataDir & "\MyApp_License.dat"
    FileDelete($sTokenFile)
    FileWrite($sTokenFile, $bEncryptedToken)
    
    ; Write to Registry
    RegWrite($REGISTRY_PATH, "InstallPath", "REG_SZ", @ScriptDir)
    RegWrite($REGISTRY_PATH, "Version", "REG_SZ", $APP_VERSION)
    RegWrite($REGISTRY_PATH, "TokenPath", "REG_SZ", $sTokenFile)
    
    Return True
EndFunc

;----------------------------------------------------------------------------------------
; Function Name: _License_Verify
;----------------------------------------------------------------------------------------
Func _License_Verify($sUrl)
    If Not _License_TimeSync() Then Return False
    
    Local $sTokenFile = RegRead($REGISTRY_PATH, "TokenPath")
    If Not FileExists($sTokenFile) Then Return False
    
    Local $bEncryptedToken = FileRead($sTokenFile)
    _Crypt_Startup()
    Local $bToken = _Crypt_DecryptData($bEncryptedToken, "LocalSecurePassword123!", $CALG_AES_256)
    _Crypt_Shutdown()
    Local $sToken = BinaryToString($bToken)
    
    Local $sHWID = _License_GetHWID()
    Local $sJson = '{"auth_token":"' & $sToken & '","hwid":"' & $sHWID & '","timestamp":' & $g_iGlobalUnixTime & '}'
    
    Local $sResponse = _License_PostRequest($sUrl & "/api/verify.php", $sJson)
    If $sResponse = False Then Return False
    
    If StringInStr($sResponse, '"error":true') Then
        Local $sError = StringRegExpReplace($sResponse, '.*"message"\s*:\s*"([^"]+)".*', "$1")
        MsgBox(16, "License Error", $sError)
        Return False
    EndIf
    
    Return True
EndFunc

;----------------------------------------------------------------------------------------
; Function Name: _License_CheckUpdate
;----------------------------------------------------------------------------------------
Func _License_CheckUpdate($sUrl)
    If Not _License_TimeSync() Then Return False
    
    Local $sJson = '{"client_version":"' & $APP_VERSION & '","timestamp":' & $g_iGlobalUnixTime & '}'
    Local $sResponse = _License_PostRequest($sUrl & "/api/update_check.php", $sJson)
    If $sResponse = False Then Return False
    
    If StringInStr($sResponse, '"update_available":true') Then
        Local $sNewUrl = StringRegExpReplace($sResponse, '.*"download_url"\s*:\s*"([^"]+)".*', "$1")
        Local $sHash = StringRegExpReplace($sResponse, '.*"file_hash"\s*:\s*"([^"]+)".*', "$1")
        MsgBox(64, "Update Available", "A new version is available. Setup auto-updater to download: " & $sNewUrl & " and verify SHA256: " & $sHash)
        ; Implementation of download & hash check & batch script restart goes here
        Return True
    EndIf
    Return False
EndFunc

; Basic Base64 Helper Functions
Func _Base64Encode($bData)
    Local $oXml = ObjCreate("Msxml2.DOMDocument")
    Local $oEl = $oXml.createElement("b64")
    $oEl.dataType = "bin.base64"
    $oEl.nodeTypedValue = $bData
    Return StringReplace($oEl.text, @CRLF, "")
EndFunc

Func _Base64Decode($sB64)
    Local $oXml = ObjCreate("Msxml2.DOMDocument")
    Local $oEl = $oXml.createElement("b64")
    $oEl.dataType = "bin.base64"
    $oEl.text = $sB64
    Return $oEl.nodeTypedValue
EndFunc