# GPOFolderRedirection.ps1
# Folder Redirection management via GPO.
# Writes fdeploy1.ini to SYSVOL and registers the CSE extension GUIDs.
# Depends on: GPOCore.ps1 (Get-GPOSysvolPath, Add-GPOExtensionGuids)

$Script:FolderRedirectionCseGuid  = '{25537BA6-77A8-11D2-9B6C-0000F8080861}'
$Script:FolderRedirectionToolGuid = '{88E729D6-BDC1-11D1-BD2A-00C04FB9603F}'

# Maps settings.ps1 key names to fdeploy1.ini section names
$Script:FolderSectionMap = @{
    Desktop        = '.Desktop'
    Documents      = '.Documents'
    Pictures       = '.Pictures'
    Music          = '.Music'
    Videos         = '.Videos'
    Favorites      = '.Favorites'
    AppDataRoaming = '.AppData'
    Contacts       = '.Contacts'
    Downloads      = '.Downloads'
    Links          = '.Links'
    Searches       = '.Searches'
    StartMenu      = '.StartMenu'
}

function ConvertTo-FolderRedirectionIni {
    <#
    .SYNOPSIS
        Converts a FolderRedirection hashtable into fdeploy1.ini content.
    #>
    param(
        [Parameter(Mandatory)]
        [hashtable]$FolderRedirection
    )

    $sections = foreach ($folderName in $FolderRedirection.Keys) {
        $folder = $FolderRedirection[$folderName]
        $sectionName = $Script:FolderSectionMap[$folderName]
        if (-not $sectionName) {
            Write-Host "  [WARN] Unknown folder: $folderName" -ForegroundColor Yellow
            continue
        }

        $destPath = $folder.Path
        $grantExclusive = if ($folder.GrantExclusive) { '0x00000001' } else { '0x00000000' }
        $moveContents   = if ($folder.MoveContents)   { '0x00000001' } else { '0x00000000' }

        # Status=0x0001 = basic redirection (follow this folder)
        @"
[$sectionName]
Status=0x0001
DestPath=$destPath
GrantExclusive=$grantExclusive
MoveContents=$moveContents
"@
    }

    return ($sections -join "`r`n`r`n") + "`r`n"
}

function Set-GPOFolderRedirection {
    <#
    .SYNOPSIS
        Writes fdeploy1.ini to SYSVOL for folder redirection.
        Full overwrite semantics. User scope only.
    #>
    param(
        [Parameter(Mandatory)]
        [string]$GPOName,

        [Parameter(Mandatory)]
        [hashtable]$FolderRedirection,

        [string]$Domain = (Get-ADDomain).DNSRoot
    )

    Write-Host "  Applying folder redirection..." -ForegroundColor Yellow

    $ini = ConvertTo-FolderRedirectionIni -FolderRedirection $FolderRedirection

    $sysvolPath = Get-GPOSysvolPath -GPOName $GPOName -Domain $Domain
    $deployDir = Join-Path $sysvolPath 'User\Documents & Settings'

    if (-not (Test-Path $deployDir)) {
        New-Item -ItemType Directory -Path $deployDir -Force | Out-Null
    }

    $iniPath = Join-Path $deployDir 'fdeploy1.ini'

    # Write as UTF-16LE (same encoding as other INI files in SYSVOL)
    $utf16le = [System.Text.UnicodeEncoding]::new($false, $true)
    [System.IO.File]::WriteAllText($iniPath, $ini, $utf16le)

    Write-Host "  Written: User\Documents & Settings\fdeploy1.ini" -ForegroundColor Green

    # Register CSE extension GUIDs
    Add-GPOExtensionGuids -GPOName $GPOName `
        -CseGuid $Script:FolderRedirectionCseGuid `
        -ToolGuid $Script:FolderRedirectionToolGuid `
        -Scope User -Domain $Domain

    # Report what was configured
    foreach ($folderName in $FolderRedirection.Keys) {
        Write-Host "    $folderName -> $($FolderRedirection[$folderName].Path)" -ForegroundColor Green
    }
}

function Compare-GPOFolderRedirection {
    <#
    .SYNOPSIS
        Compares desired folder redirection against current fdeploy1.ini in SYSVOL.
    #>
    param(
        [Parameter(Mandatory)]
        [string]$GPOName,

        [Parameter(Mandatory)]
        [hashtable]$FolderRedirection,

        [string]$Domain = (Get-ADDomain).DNSRoot
    )

    $diffs = @()

    Write-Host "  Comparing folder redirection..." -ForegroundColor Yellow

    $sysvolPath = Get-GPOSysvolPath -GPOName $GPOName -Domain $Domain
    $iniPath = Join-Path $sysvolPath 'User\Documents & Settings\fdeploy1.ini'

    if (-not (Test-Path $iniPath)) {
        Write-Host "    [DRIFT] Missing: fdeploy1.ini" -ForegroundColor Red
        $diffs += [PSCustomObject]@{
            Type    = 'FolderRedirection'
            Folder  = '(all)'
            Status  = 'File missing'
        }
        return $diffs
    }

    # Parse existing INI
    $currentContent = Get-Content $iniPath -Raw
    $currentSections = @{}
    $currentSection = $null

    foreach ($line in ($currentContent -split "`r?`n")) {
        $trimmed = $line.Trim()
        if ($trimmed -match '^\[(.+)\]$') {
            $currentSection = $Matches[1]
            $currentSections[$currentSection] = @{}
        } elseif ($currentSection -and $trimmed -match '^(.+?)=(.*)$') {
            $currentSections[$currentSection][$Matches[1]] = $Matches[2]
        }
    }

    foreach ($folderName in $FolderRedirection.Keys) {
        $desired = $FolderRedirection[$folderName]
        $sectionName = $Script:FolderSectionMap[$folderName]
        if (-not $sectionName) { continue }

        if (-not $currentSections.ContainsKey($sectionName)) {
            Write-Host "    [DRIFT] Missing section: $sectionName ($folderName)" -ForegroundColor Red
            $diffs += [PSCustomObject]@{
                Type    = 'FolderRedirection'
                Folder  = $folderName
                Status  = 'Missing section'
            }
            continue
        }

        $section = $currentSections[$sectionName]

        # Check DestPath
        $currentPath = $section['DestPath']
        if ($currentPath -ne $desired.Path) {
            $pathDisplay = if ($currentPath) { $currentPath } else { '(not set)' }
            Write-Host "    [DRIFT] $folderName DestPath: $pathDisplay -> $($desired.Path)" -ForegroundColor Red
            $diffs += [PSCustomObject]@{
                Type    = 'FolderRedirection'
                Folder  = $folderName
                Status  = "DestPath: $pathDisplay -> $($desired.Path)"
            }
        } else {
            Write-Host "    [OK] $folderName -> $currentPath" -ForegroundColor Green
        }

        # Check GrantExclusive
        $desiredGrant = if ($desired.GrantExclusive) { '0x00000001' } else { '0x00000000' }
        if ($section['GrantExclusive'] -ne $desiredGrant) {
            Write-Host "    [DRIFT] $folderName GrantExclusive: $($section['GrantExclusive']) -> $desiredGrant" -ForegroundColor Red
            $diffs += [PSCustomObject]@{
                Type    = 'FolderRedirection'
                Folder  = $folderName
                Status  = "GrantExclusive mismatch"
            }
        }

        # Check MoveContents
        $desiredMove = if ($desired.MoveContents) { '0x00000001' } else { '0x00000000' }
        if ($section['MoveContents'] -ne $desiredMove) {
            Write-Host "    [DRIFT] $folderName MoveContents: $($section['MoveContents']) -> $desiredMove" -ForegroundColor Red
            $diffs += [PSCustomObject]@{
                Type    = 'FolderRedirection'
                Folder  = $folderName
                Status  = "MoveContents mismatch"
            }
        }
    }

    if ($diffs.Count -eq 0) {
        Write-Host "  [OK] Folder redirection matches desired state" -ForegroundColor Green
    } else {
        Write-Host "  [DRIFT] $($diffs.Count) folder redirection difference(s) found" -ForegroundColor Red
    }

    return $diffs
}