param(
    [object]$Config,
    [string]$LogFile
)

$ErrorActionPreference = "Continue"

function Write-Log {
    param([string]$Message, [string]$Level = "INFO")
    $line = "[$(Get-Date -Format 'HH:mm:ss')] [$Level] $Message"
    Add-Content -Path $LogFile -Value $line -Encoding UTF8
}

function Grant-RegWriteAccess {
    param([string]$Path)
    # Grants Administrators FullControl on a registry key that has restricted ACL.
    # Required for keys owned by TrustedInstaller or with locked-down ACL.
    try {
        $hive    = $Path -replace '^(HKLM|HKCU|HKU|HKCR|HKCC):\\.*', '$1'
        $subkey  = $Path -replace '^(HKLM|HKCU|HKU|HKCR|HKCC):\\', ''
        $rootKey = switch ($hive) {
            "HKLM" { [Microsoft.Win32.Registry]::LocalMachine }
            "HKCU" { [Microsoft.Win32.Registry]::CurrentUser }
            "HKCR" { [Microsoft.Win32.Registry]::ClassesRoot }
        }
        $rights  = [Microsoft.Win32.RegistryKeyPermissionCheck]::ReadWriteSubTree
        $regRights = [System.Security.AccessControl.RegistryRights]::TakeOwnership
        $key = $rootKey.OpenSubKey($subkey, $rights, $regRights)
        if ($key) {
            $acl = $key.GetAccessControl([System.Security.AccessControl.AccessControlSections]::None)
            $acl.SetOwner([System.Security.Principal.NTAccount]"BUILTIN\Administrators")
            $key.SetAccessControl($acl)
            $key.Close()
        }
        # Re-open with ChangePermissions to grant full control
        $key = $rootKey.OpenSubKey($subkey, $rights, [System.Security.AccessControl.RegistryRights]::ChangePermissions)
        if ($key) {
            $acl  = $key.GetAccessControl()
            $rule = New-Object System.Security.AccessControl.RegistryAccessRule(
                "BUILTIN\Administrators",
                [System.Security.AccessControl.RegistryRights]::FullControl,
                [System.Security.AccessControl.InheritanceFlags]"ContainerInherit,ObjectInherit",
                [System.Security.AccessControl.PropagationFlags]::None,
                [System.Security.AccessControl.AccessControlType]::Allow
            )
            $acl.SetAccessRule($rule)
            $key.SetAccessControl($acl)
            $key.Close()
        }
    }
    catch {
        Write-Log "  Grant-RegWriteAccess failed for $Path - $_" -Level WARN
    }
}

function Set-Reg {
    param(
        [string]$Path,
        [string]$Name,
        $Value,
        [string]$Type = "DWord"
    )
    try {
        if (-not (Test-Path $Path)) {
            New-Item -Path $Path -Force -ErrorAction Stop | Out-Null
        }
        Set-ItemProperty -Path $Path -Name $Name -Value $Value -Type $Type -Force -ErrorAction Stop
        Write-Log "  SET $Path\$Name = $Value" -Level OK
    }
    catch {
        # Retry 1: grant write access via ACL manipulation
        try {
            Grant-RegWriteAccess -Path $Path
            if (-not (Test-Path $Path)) {
                New-Item -Path $Path -Force -ErrorAction Stop | Out-Null
            }
            Set-ItemProperty -Path $Path -Name $Name -Value $Value -Type $Type -Force -ErrorAction Stop
            Write-Log "  SET $Path\$Name = $Value (after ACL fix)" -Level OK
            return
        }
        catch { }

        # Retry 2: write via scheduled task running as SYSTEM
        # SYSTEM has full registry access regardless of key ACL
        try {
            $regType = switch ($Type) {
                "DWord"       { "REG_DWORD" }
                "String"      { "REG_SZ" }
                "ExpandString"{ "REG_EXPAND_SZ" }
                "MultiString" { "REG_MULTI_SZ" }
                "QWord"       { "REG_QWORD" }
                default       { "REG_DWORD" }
            }
            # Convert registry PS path to reg.exe path
            $regPath = $Path -replace '^HKLM:\\', 'HKLM\' `
                             -replace '^HKCU:\\', 'HKCU\' `
                             -replace '^HKCR:\\', 'HKCR\'
            $tempScript = "$env:TEMP\set-reg-system-$([System.IO.Path]::GetRandomFileName()).ps1"
            "reg add `"$regPath`" /v `"$Name`" /t $regType /d $Value /f" |
                Set-Content -Path $tempScript -Encoding UTF8

            $taskName  = "TempRegFix-$([System.IO.Path]::GetRandomFileName())"
            $action    = New-ScheduledTaskAction -Execute "cmd.exe" `
                            -Argument "/c reg add `"$regPath`" /v `"$Name`" /t $regType /d $Value /f"
            $principal = New-ScheduledTaskPrincipal -UserId "SYSTEM" -RunLevel Highest
            $settings  = New-ScheduledTaskSettingsSet -ExecutionTimeLimit (New-TimeSpan -Seconds 30)
            $task      = New-ScheduledTask -Action $action -Principal $principal -Settings $settings

            Register-ScheduledTask -TaskName $taskName -InputObject $task -Force | Out-Null
            Start-ScheduledTask -TaskName $taskName
            Start-Sleep -Seconds 2
            Unregister-ScheduledTask -TaskName $taskName -Confirm:$false -ErrorAction SilentlyContinue
            Remove-Item $tempScript -Force -ErrorAction SilentlyContinue

            # Verify it was written
            $written = (Get-ItemProperty -Path $Path -Name $Name -ErrorAction SilentlyContinue).$Name
            if ($null -ne $written) {
                Write-Log "  SET $Path\$Name = $Value (via SYSTEM task)" -Level OK
            } else {
                Write-Log "  FAILED $Path\$Name - SYSTEM task ran but value not found" -Level ERROR
            }
        }
        catch {
            Write-Log "  FAILED $Path\$Name - $_" -Level ERROR
        }
    }
}

function Remove-Reg {
    param([string]$Path, [string]$Name)
    try {
        if (Test-Path $Path) {
            Remove-ItemProperty -Path $Path -Name $Name -Force -ErrorAction SilentlyContinue
            Write-Log "  REMOVED $Path\$Name" -Level OK
        }
    }
    catch {
        Write-Log "  FAILED removing $Path\$Name - $_" -Level ERROR
    }
}

Write-Log "3 - Applying HKLM system registry tweaks" -Level STEP

# -----------------------------------------------------------------------
# Bypass Network Requirement on OOBE (BypassNRO)
# -----------------------------------------------------------------------
Set-Reg -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\OOBE" `
        -Name "BypassNRO" -Value 1

# -----------------------------------------------------------------------
# Disable auto-install of Teams (Chat)
# -----------------------------------------------------------------------
Set-Reg -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Communications" `
        -Name "ConfigureChatAutoInstall" -Value 0

# -----------------------------------------------------------------------
# Disable Cloud Optimized Content (ads in Start menu etc.)
# -----------------------------------------------------------------------
Set-Reg -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\CloudContent" `
        -Name "DisableCloudOptimizedContent" -Value 1

Set-Reg -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\CloudContent" `
        -Name "DisableWindowsConsumerFeatures" -Value 1

# -----------------------------------------------------------------------
# Disable Widgets (News and Interests)
# -----------------------------------------------------------------------
Set-Reg -Path "HKLM:\SOFTWARE\Policies\Microsoft\Dsh" `
        -Name "AllowNewsAndInterests" -Value 0

# -----------------------------------------------------------------------
# Microsoft Edge - hide First Run Experience
# -----------------------------------------------------------------------
Set-Reg -Path "HKLM:\SOFTWARE\Policies\Microsoft\Edge" `
        -Name "HideFirstRunExperience" -Value 1

# Also disable Edge desktop shortcut creation after install
Set-Reg -Path "HKLM:\SOFTWARE\Policies\Microsoft\EdgeUpdate" `
        -Name "CreateDesktopShortcutDefault" -Value 0

# -----------------------------------------------------------------------
# Password - no expiration
# -----------------------------------------------------------------------
Write-Log "  Setting password max age to UNLIMITED" -Level INFO
$pwResult = & net accounts /maxpwage:UNLIMITED 2>&1
if ($LASTEXITCODE -eq 0) {
    Write-Log "  Password max age set to UNLIMITED" -Level OK
} else {
    Write-Log "  Failed to set password max age: $pwResult" -Level ERROR
}

# -----------------------------------------------------------------------
# Time zone
# -----------------------------------------------------------------------
$tz = "Central Europe Standard Time"
if ($Config -and $Config.deployment -and $Config.deployment.timezone) {
    $tz = $Config.deployment.timezone
}
Write-Log "  Setting time zone: $tz" -Level INFO
try {
    Set-TimeZone -Id $tz -ErrorAction Stop
    Write-Log "  Time zone set: $tz" -Level OK
}
catch {
    Write-Log "  Failed to set time zone: $_" -Level ERROR
}

# -----------------------------------------------------------------------
# OneDrive - prevent setup and remove shortcuts
# -----------------------------------------------------------------------
Write-Log "  Disabling OneDrive" -Level INFO

# Disable OneDrive via policy
Set-Reg -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\OneDrive" `
        -Name "DisableFileSyncNGSC" -Value 1

# Remove OneDriveSetup.exe if present
$oneDrivePaths = @(
    "$env:SystemRoot\System32\OneDriveSetup.exe"
    "$env:SystemRoot\SysWOW64\OneDriveSetup.exe"
)
foreach ($odPath in $oneDrivePaths) {
    if (Test-Path $odPath) {
        try {
            # Uninstall first
            & $odPath /uninstall 2>&1 | Out-Null
            Write-Log "  OneDrive uninstalled via $odPath" -Level OK
        }
        catch {
            Write-Log "  OneDrive uninstall failed: $_" -Level WARN
        }
    }
}

# Remove OneDrive Start Menu shortcut
$odLnk = "$env:ProgramData\Microsoft\Windows\Start Menu\Programs\OneDrive.lnk"
if (Test-Path $odLnk) {
    Remove-Item $odLnk -Force -ErrorAction SilentlyContinue
    Write-Log "  Removed OneDrive Start Menu shortcut" -Level OK
}

# -----------------------------------------------------------------------
# Outlook (new) - disable auto-install via UScheduler
# -----------------------------------------------------------------------
Write-Log "  Disabling Outlook (new) auto-install" -Level INFO

$uschedulerPaths = @(
    "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Orchestrator\UScheduler_Oobe\OutlookUpdate"
    "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Orchestrator\UScheduler\OutlookUpdate"
)
foreach ($uPath in $uschedulerPaths) {
    if (Test-Path $uPath) {
        try {
            Remove-Item -Path $uPath -Recurse -Force
            Write-Log "  Removed UScheduler key: $uPath" -Level OK
        }
        catch {
            Write-Log "  Failed to remove UScheduler key: $_" -Level WARN
        }
    }
}

# -----------------------------------------------------------------------
# Disable GameDVR
# -----------------------------------------------------------------------
Set-Reg -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\GameDVR" `
        -Name "AllowGameDVR" -Value 0

# -----------------------------------------------------------------------
# Disable Recall (Windows AI feature)
# -----------------------------------------------------------------------
Set-Reg -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsAI" `
        -Name "DisableAIDataAnalysis" -Value 1

Write-Log "Step 3 complete" -Level OK