# Get-RecentDocs.ps1
# Lists recently opened documents from OpenSavePidlMRU registry key

param(
    [int]$MaxPerType = 10,
    [switch]$ShowAll
)

Write-Host "=== Recently Opened Documents ===" -ForegroundColor Cyan
Write-Host "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32\OpenSavePidlMRU"

if ($ShowAll) {
    $MaxPerType = [int]::MaxValue
    Write-Host "Showing all entries`n" -ForegroundColor Yellow
} else {
    Write-Host "Showing top $MaxPerType per type (use -ShowAll or -MaxPerType N to see more)`n" -ForegroundColor Yellow
}

function Convert-PidlMRU {
    param([byte[]]$data)

    if (-not $data -or $data.Length -lt 10) {
        return ""
    }

    try {
        # Convert to Unicode string
        $unicodeText = [System.Text.Encoding]::Unicode.GetString($data)

        # Remove null characters
        $cleaned = $unicodeText -replace '\x00', ''

        # Try to extract valid file path (Windows path pattern)
        if ($cleaned -match '([A-Z]:\\(?:[^<>:"|?*\x00-\x1F]+\\)*[^<>:"|?*\x00-\x1F\\]+)') {
            return $matches[1]
        }

        # Extract filename - match only valid filename characters
        # This regex looks for a sequence that starts with alphanumeric and includes a file extension
        if ($cleaned -match '([a-zA-Z0-9][a-zA-Z0-9._\- ]{0,200}\.[a-zA-Z0-9]{1,10})') {
            return $matches[1]
        }

        # Fallback: filter to printable ASCII only and look for pattern
        $printable = -join ($cleaned.ToCharArray() | Where-Object {
            ($_ -ge 32 -and $_ -le 126)
        })

        # Try again with printable string
        if ($printable -match '([a-zA-Z0-9][a-zA-Z0-9._\- ]{0,200}\.[a-zA-Z0-9]{1,10})') {
            return $matches[1]
        }

        return ""
    } catch {
        return ""
    }
}

try {
    $mruPath = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32\OpenSavePidlMRU"

    if (Test-Path $mruPath) {
        # Get all extension subkeys
        $subKeys = Get-ChildItem -Path $mruPath -ErrorAction SilentlyContinue |
                   Sort-Object PSChildName

        if ($subKeys) {
            $totalFiles = 0
            $totalStored = 0

            foreach ($subKey in $subKeys) {
                $extension = $subKey.PSChildName

                $props = Get-ItemProperty -Path $subKey.PSPath -ErrorAction SilentlyContinue

                # Get MRUListEx for ordering
                if ($props.MRUListEx) {
                    $files = @()

                    for ($i = 0; $i -lt $props.MRUListEx.Length - 4; $i += 4) {
                        $index = [BitConverter]::ToInt32($props.MRUListEx, $i)
                        if ($index -eq -1) { break }

                        $propName = "$index"
                        if ($props.$propName) {
                            $fileName = Convert-PidlMRU -data $props.$propName
                            if ($fileName) {
                                $files += $fileName
                            }
                        }
                    }

                    $totalStored += $files.Count

                    # Only show if we found files
                    if ($files.Count -gt 0) {
                        if ($extension -eq "*") {
                            Write-Host "`n--- All File Types ($($files.Count) total) ---" -ForegroundColor Yellow
                        } else {
                            Write-Host "`n--- .$extension Files ($($files.Count) total) ---" -ForegroundColor Yellow
                        }

                        $count = 0
                        $displayFiles = $files | Select-Object -First $MaxPerType

                        foreach ($file in $displayFiles) {
                            $count++
                            $totalFiles++
                            Write-Host "  $count. $file" -ForegroundColor Green
                        }

                        if ($files.Count -gt $MaxPerType) {
                            $remaining = $files.Count - $MaxPerType
                            Write-Host "  ... and $remaining more" -ForegroundColor Gray
                        }
                    }
                }
            }

            Write-Host "`n=== Summary ===" -ForegroundColor Cyan
            Write-Host "Total stored: $totalStored files" -ForegroundColor Green
            Write-Host "Displayed: $totalFiles files" -ForegroundColor Green

            if ($totalFiles -eq 0) {
                Write-Host "`nNo readable file paths found in MRU data" -ForegroundColor Gray
                Write-Host "The PIDL binary format may require more advanced parsing" -ForegroundColor Gray
            }
        } else {
            Write-Host "`nNo recent file history found" -ForegroundColor Gray
        }

    } else {
        Write-Host "`nOpenSavePidlMRU registry key not found" -ForegroundColor Gray
    }

} catch {
    Write-Host "Error: $_" -ForegroundColor Red
}

Write-Host "`nNote: PIDL data parsing is limited. For complete analysis, use forensic tools like Registry Explorer" -ForegroundColor Cyan