#Requires -RunAsAdministrator
<#
.SYNOPSIS
    Interactive Windows Registry Settings Manager
.DESCRIPTION
    Displays Windows registry settings in a navigable TUI menu.
    Use UP/DOWN arrows to move between settings, LEFT/RIGHT to toggle values.
    Changes are applied immediately to the registry.
    Some system-level settings require Administrator privileges.
.NOTES
    Based on registry paths from WinSetup.ps1
#>

# ─────────────────────────────────────────────────────────────────────────────
# REGION: Data model – each setting is a hashtable describing its registry
#         location, value name, the two toggle states, and display metadata.
# ─────────────────────────────────────────────────────────────────────────────

$Settings = @(
    # ── Explorer Advanced ─────────────────────────────────────────────────────
    @{
        Group       = "Explorer Advanced [User]"
        Label       = "Explorer window opens to"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced"
        ValueName   = "LaunchTo"
        States      = @("This PC", "Quick Access")
        StateValues = @(1, 2)
        OnValue     = 1   # value that matches States[0]
        Type        = "DWORD"
    },
    @{
        Group       = "Explorer Advanced [User]"
        Label       = "File extensions"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced"
        ValueName   = "HideFileExt"
        States      = @("Show", "Hide")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Explorer Advanced [User]"
        Label       = "Taskbar Chat icon"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced"
        ValueName   = "TaskbarMn"
        States      = @("Hide", "Show")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Explorer Advanced [User]"
        Label       = "Taskbar Widgets"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced"
        ValueName   = "TaskbarDa"
        States      = @("Hide", "Show")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Explorer Advanced [User]"
        Label       = "Taskbar Copilot icon"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced"
        ValueName   = "ShowCopilotButton"
        States      = @("Hide", "Show")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Explorer Advanced [User]"
        Label       = "Telemetry (Start_TrackProgs)"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced"
        ValueName   = "Start_TrackProgs"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Explorer Advanced [User]"
        Label       = "Tips & Suggestions (IrisRecommendations)"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced"
        ValueName   = "Start_IrisRecommendations"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Explorer Advanced [User]"
        Label       = "Sync Provider Notifications"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced"
        ValueName   = "ShowSyncProviderNotifications"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── Windows Search ────────────────────────────────────────────────────────
    @{
        Group       = "Windows Search [User]"
        Label       = "Bing Search in Start"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Search"
        ValueName   = "BingSearchEnabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Windows Search [User]"
        Label       = "Search Box Taskbar Mode"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Search"
        ValueName   = "SearchboxTaskbarMode"
        States      = @("Hidden", "Visible")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── Explorer Policy ───────────────────────────────────────────────────────
    @{
        Group             = "Explorer Policy [User]"
        Label             = "Disable Search Box Suggestions"
        Path              = "HKCU:\Software\Policies\Microsoft\Windows\Explorer"
        ValueName         = "DisableSearchBoxSuggestions"
        States            = @("Disabled (suggestions off)", "Enabled (suggestions on)")
        StateValues       = @(1, 0)
        OnValue           = 1
        Type              = "DWORD"
        CreatePathIfAbsent = $true
    },

    # ── Personalisation ───────────────────────────────────────────────────────
    @{
        Group       = "Personalisation [User]"
        Label       = "Apps Theme"
        Path        = "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Themes\Personalize"
        ValueName   = "AppsUseLightTheme"
        States      = @("Dark", "Light")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Personalisation [User]"
        Label       = "System Theme"
        Path        = "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Themes\Personalize"
        ValueName   = "SystemUsesLightTheme"
        States      = @("Dark", "Light")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Personalisation Settings [User]"
        Label       = "Accepted Privacy Policy"
        Path        = "HKCU:\Software\Microsoft\Personalization\Settings"
        ValueName   = "AcceptedPrivacyPolicy"
        States      = @("No", "Yes")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── Advertising ───────────────────────────────────────────────────────────
    @{
        Group       = "Advertising Info [User]"
        Label       = "Advertising ID"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\AdvertisingInfo"
        ValueName   = "Enabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── Privacy ───────────────────────────────────────────────────────────────
    @{
        Group       = "Privacy [User]"
        Label       = "Tailored Experiences with Diagnostic Data"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Privacy"
        ValueName   = "TailoredExperiencesWithDiagnosticDataEnabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── Content Delivery Manager ──────────────────────────────────────────────
    @{
        Group       = "Content Delivery [User]"
        Label       = "Suggested Apps (338388)"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager"
        ValueName   = "SubscribedContent-338388Enabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Content Delivery [User]"
        Label       = "Suggested Apps (338389)"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager"
        ValueName   = "SubscribedContent-338389Enabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Content Delivery [User]"
        Label       = "Start Menu Suggestions (338393)"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager"
        ValueName   = "SubscribedContent-338393Enabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Content Delivery [User]"
        Label       = "Tips & Tricks (353694)"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager"
        ValueName   = "SubscribedContent-353694Enabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Content Delivery [User]"
        Label       = "Tips & Tricks (353696)"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager"
        ValueName   = "SubscribedContent-353696Enabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Content Delivery [User]"
        Label       = "System Pane Suggestions"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager"
        ValueName   = "SystemPaneSuggestionsEnabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Content Delivery [User]"
        Label       = "Soft Landing (Feature Highlights)"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager"
        ValueName   = "SoftLandingEnabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },
    @{
        Group       = "Content Delivery [User]"
        Label       = "Silent App Installs"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager"
        ValueName   = "SilentInstalledAppsEnabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── Mobility ──────────────────────────────────────────────────────────────
    @{
        Group       = "Mobility [User]"
        Label       = "Mobile Plans Opt-In"
        Path        = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Mobility"
        ValueName   = "OptedIn"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── Notifications ─────────────────────────────────────────────────────────
    @{
        Group             = "Notifications [User]"
        Label             = "Suggested App Toasts"
        Path              = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Notifications\Settings\Windows.SystemToast.Suggested"
        ValueName         = "Enabled"
        States            = @("Disabled", "Enabled")
        StateValues       = @(0, 1)
        OnValue           = 0
        Type              = "DWORD"
        CreatePathIfAbsent = $true
    },

    # ── Engagement ────────────────────────────────────────────────────────────
    @{
        Group       = "Engagement [User]"
        Label       = "Scoobe System Setting (OOBE prompts)"
        Path        = "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\UserProfileEngagement"
        ValueName   = "ScoobeSystemSettingEnabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── Speech ────────────────────────────────────────────────────────────────
    @{
        Group             = "Speech [User]"
        Label             = "Online Speech Recognition"
        Path              = "HKCU:\Software\Microsoft\Speech_OneCore\Settings\OnlineSpeechPrivacy"
        ValueName         = "HasAccepted"
        States            = @("No", "Yes")
        StateValues       = @(0, 1)
        OnValue           = 0
        Type              = "DWORD"
        CreatePathIfAbsent = $true
    },

    # ── Input TIPC ────────────────────────────────────────────────────────────
    @{
        Group       = "Input TIPC [User]"
        Label       = "Typing Insights"
        Path        = "HKCU:\Software\Microsoft\Input\TIPC"
        ValueName   = "Enabled"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── Input Personalisation ─────────────────────────────────────────────────
    @{
        Group       = "Input Personalisation [User]"
        Label       = "Implicit Ink Collection"
        Path        = "HKCU:\Software\Microsoft\InputPersonalization"
        ValueName   = "RestrictImplicitInkCollection"
        States      = @("Restricted", "Unrestricted")
        StateValues = @(1, 0)
        OnValue     = 1
        Type        = "DWORD"
    },
    @{
        Group       = "Input Personalisation [User]"
        Label       = "Implicit Text Collection"
        Path        = "HKCU:\Software\Microsoft\InputPersonalization"
        ValueName   = "RestrictImplicitTextCollection"
        States      = @("Restricted", "Unrestricted")
        StateValues = @(1, 0)
        OnValue     = 1
        Type        = "DWORD"
    },
    @{
        Group       = "Input Trained Data [User]"
        Label       = "Harvest Contacts"
        Path        = "HKCU:\Software\Microsoft\InputPersonalization\TrainedDataStore"
        ValueName   = "HarvestContacts"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
    },

    # ── App Launch Tracking ───────────────────────────────────────────────────
    @{
        Group             = "App Launch Tracking [User]"
        Label             = "MFU Tracking"
        Path              = "HKCU:\Software\Policies\Microsoft\Windows\EdgeUI"
        ValueName         = "DisableMFUTracking"
        States            = @("Disabled (tracking off)", "Enabled (tracking on)")
        StateValues       = @(1, 0)
        OnValue           = 1
        Type              = "DWORD"
        CreatePathIfAbsent = $true
    },

    # ── Copilot User ──────────────────────────────────────────────────────────
    @{
        Group             = "Copilot [User]"
        Label             = "Windows Copilot"
        Path              = "HKCU:\Software\Policies\Microsoft\Windows\WindowsCopilot"
        ValueName         = "TurnOffWindowsCopilot"
        States            = @("Off", "On")
        StateValues       = @(1, 0)
        OnValue           = 1
        Type              = "DWORD"
        CreatePathIfAbsent = $true
    },

    # ── System: Data Collection ───────────────────────────────────────────────
    @{
        Group       = "Data Collection [System]"
        Label       = "Telemetry (AllowTelemetry)"
        Path        = "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\DataCollection"
        ValueName   = "AllowTelemetry"
        States      = @("Disabled", "Enabled")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
        RequiresAdmin = $true
    },

    # ── System: Copilot ───────────────────────────────────────────────────────
    @{
        Group             = "Copilot [System]"
        Label             = "Windows Copilot"
        Path              = "HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsCopilot"
        ValueName         = "TurnOffWindowsCopilot"
        States            = @("Off", "On")
        StateValues       = @(1, 0)
        OnValue           = 1
        Type              = "DWORD"
        RequiresAdmin     = $true
        CreatePathIfAbsent = $true
    },

    # ── System: App Launch Tracking ───────────────────────────────────────────
    @{
        Group             = "App Launch Tracking [System]"
        Label             = "MFU Tracking"
        Path              = "HKLM:\Software\Policies\Microsoft\Windows\EdgeUI"
        ValueName         = "DisableMFUTracking"
        States            = @("Disabled (tracking off)", "Enabled (tracking on)")
        StateValues       = @(1, 0)
        OnValue           = 1
        Type              = "DWORD"
        RequiresAdmin     = $true
        CreatePathIfAbsent = $true
    },

    # ── System: Windows Search ────────────────────────────────────────────────
    @{
        Group       = "Windows Search [System]"
        Label       = "Allow Cortana"
        Path        = "HKLM:\SOFTWARE\Policies\Microsoft\Windows\Windows Search"
        ValueName   = "AllowCortana"
        States      = @("No", "Yes")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
        RequiresAdmin = $true
    },
    @{
        Group       = "Windows Search [System]"
        Label       = "Cortana Consent"
        Path        = "HKLM:\SOFTWARE\Policies\Microsoft\Windows\Windows Search"
        ValueName   = "CortanaConsent"
        States      = @("No", "Yes")
        StateValues = @(0, 1)
        OnValue     = 0
        Type        = "DWORD"
        RequiresAdmin = $true
    }
)


# ─────────────────────────────────────────────────────────────────────────────
# REGION: Registry helpers
# ─────────────────────────────────────────────────────────────────────────────

function Test-RegistryPath {
    param([string]$Path)
    return (Test-Path -LiteralPath $Path)
}

function Get-SettingCurrentStateIndex {
    param($Setting)

    if (-not (Test-RegistryPath $Setting.Path)) {
        return -1   # path missing
    }

    try {
        $val = (Get-ItemProperty -LiteralPath $Setting.Path -Name $Setting.ValueName -ErrorAction Stop).$($Setting.ValueName)
        $idx = [Array]::IndexOf($Setting.StateValues, $val)
        if ($idx -lt 0) { return -1 }
        return $idx
    } catch {
        return -1   # value missing
    }
}

function Set-RegistrySetting {
    param($Setting, [int]$StateIndex)

    # Create the registry key if needed and allowed
    if (-not (Test-RegistryPath $Setting.Path)) {
        if ($Setting.CreatePathIfAbsent) {
            try {
                New-Item -Path $Setting.Path -Force | Out-Null
            } catch {
                return $false
            }
        } else {
            return $false
        }
    }

    try {
        Set-ItemProperty -LiteralPath $Setting.Path `
                         -Name $Setting.ValueName `
                         -Value $Setting.StateValues[$StateIndex] `
                         -Type $Setting.Type `
                         -ErrorAction Stop
        return $true
    } catch {
        return $false
    }
}


# ─────────────────────────────────────────────────────────────────────────────
# REGION: TUI rendering
# ─────────────────────────────────────────────────────────────────────────────

$ColLabel      = 0
$ColValue      = 52
$ColStatus     = 75
$TotalWidth    = 90

function Write-Header {
    $title = " Windows Registry Settings Manager "
    $pad   = [math]::Max(0, $TotalWidth - $title.Length)
    $left  = [math]::Floor($pad / 2)
    $right = $pad - $left

    [Console]::SetCursorPosition(0, 0)
    Write-Host ("═" * $TotalWidth) -ForegroundColor DarkCyan
    Write-Host (("═" * $left) + $title + ("═" * $right)) -ForegroundColor Cyan
    Write-Host ("═" * $TotalWidth) -ForegroundColor DarkCyan
    Write-Host " ↑/↓ Navigate   ←/→ Change value   Q Quit   R Reload" `
               -ForegroundColor DarkGray
    Write-Host ("─" * $TotalWidth) -ForegroundColor DarkGray
}

function Write-Row {
    param(
        [int]$RowY,
        $Setting,
        [int]$StateIndex,
        [bool]$Selected,
        [string]$StatusMsg = ""
    )

    [Console]::SetCursorPosition(0, $RowY)

    # Background for selected row
    $bgSel   = if ($Selected) { [ConsoleColor]::DarkBlue }  else { [ConsoleColor]::Black }
    $fgLabel = if ($Selected) { [ConsoleColor]::White }     else { [ConsoleColor]::Gray }

    # Group badge colour cycling
    $groupColors = @([ConsoleColor]::DarkMagenta, [ConsoleColor]::DarkCyan,
                     [ConsoleColor]::DarkYellow,  [ConsoleColor]::DarkGreen,
                     [ConsoleColor]::DarkRed,     [ConsoleColor]::Blue)
    $groupHash   = [Math]::Abs($Setting.Group.GetHashCode()) % $groupColors.Count
    $fgGroup     = $groupColors[$groupHash]

    # Prefix
    $prefix = if ($Selected) { "▶ " } else { "  " }

    # Build the label column (truncated to ColValue)
    $label = $prefix + $Setting.Label
    if ($label.Length -gt ($ColValue - 2)) { $label = $label.Substring(0, $ColValue - 5) + "..." }
    $label = $label.PadRight($ColValue - 2)

    # Value display
    if ($StateIndex -lt 0) {
        $valueStr = "(missing)".PadRight($ColStatus - $ColValue - 1)
        $fgValue  = [ConsoleColor]::DarkRed
    } else {
        $v        = $Setting.States[$StateIndex]
        $valueStr = $v.PadRight($ColStatus - $ColValue - 1)
        # Colour logic: index 0 is typically the "good/disabled/off" state
        $fgValue  = if ($StateIndex -eq 0) { [ConsoleColor]::Green } else { [ConsoleColor]::Yellow }
    }

    # Status message (applied / error / admin etc.)
    $statusStr = $StatusMsg.PadRight($TotalWidth - $ColStatus)

    # Write the row
    Write-Host $label         -NoNewline -ForegroundColor $fgLabel       -BackgroundColor $bgSel
    Write-Host " "            -NoNewline -BackgroundColor $bgSel
    Write-Host $valueStr      -NoNewline -ForegroundColor $fgValue        -BackgroundColor $bgSel
    Write-Host $statusStr     -ForegroundColor DarkGray                   -BackgroundColor Black
}

function Write-GroupHeader {
    param([int]$RowY, [string]$GroupName)
    [Console]::SetCursorPosition(0, $RowY)
    $line = "  ── $GroupName " + ("─" * [math]::Max(0, $TotalWidth - $GroupName.Length - 6))
    Write-Host $line -ForegroundColor DarkCyan
}

function Write-Footer {
    param([int]$Y, [string]$Message = "")
    [Console]::SetCursorPosition(0, $Y)
    $line = (" " * $TotalWidth)
    Write-Host $line -NoNewline
    [Console]::SetCursorPosition(0, $Y)
    Write-Host "  $Message" -ForegroundColor DarkGray
}


# ─────────────────────────────────────────────────────────────────────────────
# REGION: Build the display list (interleave group headers + setting rows)
# ─────────────────────────────────────────────────────────────────────────────

# Assign state indices and build a flat list of "rows" for rendering
# Each row is either type=Header or type=Setting
$DisplayRows = [System.Collections.Generic.List[hashtable]]::new()
$StatusMessages = @{}   # index → message string

$lastGroup = ""
$settingIdx = 0
foreach ($s in $Settings) {
    if ($s.Group -ne $lastGroup) {
        $DisplayRows.Add(@{ RowType = "Header"; Group = $s.Group })
        $lastGroup = $s.Group
    }
    $stateIdx = Get-SettingCurrentStateIndex $s
    $DisplayRows.Add(@{
        RowType    = "Setting"
        Setting    = $s
        StateIndex = $stateIdx
        DataIndex  = $settingIdx   # index back into $Settings
    })
    $settingIdx++
}

# Build a parallel list of only the "Setting" rows for navigation
$NavRows = $DisplayRows | Where-Object { $_.RowType -eq "Setting" }
$navCount = @($NavRows).Count


# ─────────────────────────────────────────────────────────────────────────────
# REGION: Scrolling / viewport
# ─────────────────────────────────────────────────────────────────────────────

$HeaderLines   = 5                    # lines used by Write-Header
$FooterLines   = 4                    # lines at bottom for status + path (path may wrap)
$ViewportH     = [Console]::WindowHeight - $HeaderLines - $FooterLines - 1
$ViewportH     = [math]::Max(5, $ViewportH)

$selectedNav   = 0   # index in $NavRows
$scrollOffset  = 0   # first display-row index that is visible

function Get-DisplayIndexForNav {
    param([int]$NavIdx)
    $target = $NavRows[$NavIdx]
    for ($i = 0; $i -lt $DisplayRows.Count; $i++) {
        if ($DisplayRows[$i] -eq $target) { return $i }
    }
    return 0
}

function Ensure-Selected-Visible {
    $dispIdx = Get-DisplayIndexForNav $selectedNav
    if ($dispIdx -lt $scrollOffset) {
        $script:scrollOffset = $dispIdx
    } elseif ($dispIdx -ge ($scrollOffset + $ViewportH)) {
        $script:scrollOffset = $dispIdx - $ViewportH + 1
    }
}


# ─────────────────────────────────────────────────────────────────────────────
# REGION: Full redraw
# ─────────────────────────────────────────────────────────────────────────────

function Draw-Screen {
    param([string]$FooterMsg = "")

    [Console]::CursorVisible = $false
    Write-Header

    $screenY = $HeaderLines

    # Render visible display rows
    $visibleEnd = [math]::Min($DisplayRows.Count, $scrollOffset + $ViewportH)
    for ($di = $scrollOffset; $di -lt $visibleEnd; $di++) {
        $row = $DisplayRows[$di]
        if ($row.RowType -eq "Header") {
            Write-GroupHeader -RowY $screenY -GroupName $row.Group
        } else {
            $isSelected = ($row -eq $NavRows[$selectedNav])
            $msg = if ($StatusMessages.ContainsKey($di)) { $StatusMessages[$di] } else { "" }
            Write-Row -RowY $screenY `
                      -Setting $row.Setting `
                      -StateIndex $row.StateIndex `
                      -Selected $isSelected `
                      -StatusMsg $msg
        }
        $screenY++
    }

    # Clear any leftover lines below the rendered rows
    $blankLine = " " * $TotalWidth
    while ($screenY -lt ($HeaderLines + $ViewportH)) {
        [Console]::SetCursorPosition(0, $screenY)
        Write-Host $blankLine
        $screenY++
    }

    # Scroll indicator
    [Console]::SetCursorPosition(0, $HeaderLines + $ViewportH)
    $scrollInfo = "  Showing rows $($scrollOffset + 1)–$visibleEnd of $($DisplayRows.Count)   ($navCount settings total)"
    Write-Host $scrollInfo.PadRight($TotalWidth) -ForegroundColor DarkGray

    # Registry path for the currently selected setting (wraps if too long)
    $selSetting   = $NavRows[$selectedNav].Setting
    $pathFull     = "  📂 " + $selSetting.Path + "  ›  " + $selSetting.ValueName
    $pathContinue = "     "
    $pathLines    = [System.Collections.Generic.List[string]]::new()
    $remaining    = $pathFull
    while ($remaining.Length -gt 0) {
        if ($remaining.Length -le $TotalWidth) {
            $pathLines.Add($remaining.PadRight($TotalWidth))
            $remaining = ""
        } else {
            $breakAt = $TotalWidth
            for ($ci = $TotalWidth - 1; $ci -gt 20; $ci--) {
                if ($remaining[$ci] -eq '\' -or $remaining[$ci] -eq ' ') {
                    $breakAt = $ci + 1
                    break
                }
            }
            $pathLines.Add($remaining.Substring(0, $breakAt).PadRight($TotalWidth))
            $remaining = $pathContinue + $remaining.Substring($breakAt).TrimStart('\')
        }
    }
    # Render up to 2 path lines
    $pathRender = @($pathLines | Select-Object -First 2)
    for ($pi = 0; $pi -lt $pathRender.Count; $pi++) {
        [Console]::SetCursorPosition(0, $HeaderLines + $ViewportH + 1 + $pi)
        Write-Host $pathRender[$pi] -ForegroundColor DarkGray
    }
    # Clear unused second line so no stale text lingers
    if ($pathRender.Count -lt 2) {
        [Console]::SetCursorPosition(0, $HeaderLines + $ViewportH + 2)
        Write-Host (" " * $TotalWidth)
    }

    # Footer message (always on the last reserved line)
    [Console]::SetCursorPosition(0, $HeaderLines + $ViewportH + 3)
    Write-Host ("  " + $FooterMsg).PadRight($TotalWidth) -ForegroundColor DarkYellow
}


# ─────────────────────────────────────────────────────────────────────────────
# REGION: Apply a change
# ─────────────────────────────────────────────────────────────────────────────

function Apply-Change {
    param([int]$NavIdx, [int]$Direction)   # Direction: +1 or -1

    $row = $NavRows[$NavIdx]
    $s   = $row.Setting

    # Find display index for status message storage
    $dispIdx = Get-DisplayIndexForNav $NavIdx

    # Current state index
    $cur = $row.StateIndex
    if ($cur -lt 0) { $cur = 0 }   # if missing, start from 0

    $count    = $s.States.Count
    $newIdx   = (($cur + $Direction) % $count + $count) % $count

    $ok = Set-RegistrySetting -Setting $s -StateIndex $newIdx
    if ($ok) {
        $row.StateIndex = $newIdx
        $StatusMessages[$dispIdx] = "✔ Applied"
        return "✔ Applied: $($s.Label) → $($s.States[$newIdx])"
    } else {
        $hint = if ($s.RequiresAdmin) { " (needs admin)" } else { "" }
        $StatusMessages[$dispIdx] = "✘ Failed$hint"
        return "✘ Failed to apply: $($s.Label)$hint"
    }
}


# ─────────────────────────────────────────────────────────────────────────────
# REGION: Main loop
# ─────────────────────────────────────────────────────────────────────────────

# Set up console
$origTitle = [Console]::Title
[Console]::Title = "Windows Registry Settings Manager"
[Console]::CursorVisible = $false
[Console]::TreatControlCAsInput = $true
Clear-Host

$footerMsg = "Ready. Use arrow keys to navigate and change settings."

Ensure-Selected-Visible
Draw-Screen -FooterMsg $footerMsg

try {
    while ($true) {
        if ([Console]::KeyAvailable) {
            $key = [Console]::ReadKey($true)

            switch ($key.Key) {
                "UpArrow" {
                    if ($selectedNav -gt 0) {
                        $selectedNav--
                        Ensure-Selected-Visible
                        Draw-Screen -FooterMsg $footerMsg
                    }
                }
                "DownArrow" {
                    if ($selectedNav -lt ($navCount - 1)) {
                        $selectedNav++
                        Ensure-Selected-Visible
                        Draw-Screen -FooterMsg $footerMsg
                    }
                }
                "LeftArrow" {
                    $footerMsg = Apply-Change -NavIdx $selectedNav -Direction -1
                    Draw-Screen -FooterMsg $footerMsg
                }
                "RightArrow" {
                    $footerMsg = Apply-Change -NavIdx $selectedNav -Direction 1
                    Draw-Screen -FooterMsg $footerMsg
                }
                "PageUp" {
                    $selectedNav = [math]::Max(0, $selectedNav - 10)
                    Ensure-Selected-Visible
                    Draw-Screen -FooterMsg $footerMsg
                }
                "PageDown" {
                    $selectedNav = [math]::Min($navCount - 1, $selectedNav + 10)
                    Ensure-Selected-Visible
                    Draw-Screen -FooterMsg $footerMsg
                }
                "Home" {
                    $selectedNav = 0
                    Ensure-Selected-Visible
                    Draw-Screen -FooterMsg $footerMsg
                }
                "End" {
                    $selectedNav = $navCount - 1
                    Ensure-Selected-Visible
                    Draw-Screen -FooterMsg $footerMsg
                }
                "R" {
                    # Reload all values from registry
                    $StatusMessages.Clear()
                    $settingIdx2 = 0
                    foreach ($dr in $DisplayRows) {
                        if ($dr.RowType -eq "Setting") {
                            $dr.StateIndex = Get-SettingCurrentStateIndex $dr.Setting
                            $settingIdx2++
                        }
                    }
                    $footerMsg = "All values reloaded from registry."
                    Draw-Screen -FooterMsg $footerMsg
                }
                "Q" {
                    break
                }
                { $key.KeyChar -eq 'q' -or $key.KeyChar -eq 'Q' } {
                    break
                }
            }

            if ($key.Key -eq "Q" -or $key.KeyChar -eq 'q' -or $key.KeyChar -eq 'Q') {
                break
            }

            # Ctrl+C
            if ($key.Key -eq "C" -and ($key.Modifiers -band [ConsoleModifiers]::Control)) {
                break
            }
        }
        Start-Sleep -Milliseconds 30
    }
} finally {
    [Console]::CursorVisible = $true
    [Console]::TreatControlCAsInput = $false
    [Console]::Title = $origTitle
    Clear-Host
    Write-Host "Windows Registry Settings Manager closed." -ForegroundColor Cyan
}