# Script Name:  Get-FileInventory.ps1
# Beschreibung: Erstellt eine Dateiliste mit Groesse, Erstellungsdatum und letzter Aenderung.
# Autor:        Patrick Asmus
# Web:          https://www.patrick-asmus.de
# Git-Reposit.: https://git.techniverse.net/scriptos/get-fileinventory.git
# Version:      1.0
# Datum:        16.06.2026
# Modifikation: Initial
#####################################################

param(
    [string]$Path,
    [string]$OutputDirectory = (Join-Path -Path $PSScriptRoot -ChildPath "exports"),
    [switch]$NoExcel
)

# Variablen:
$TargetFolder = "C:\Temp"

Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"

if (-not $PSBoundParameters.ContainsKey("Path") -or [string]::IsNullOrWhiteSpace($Path)) {
    $Path = $TargetFolder
}

function Convert-BytesToReadableSize {
    param(
        [Parameter(Mandatory = $true)]
        [long]$Bytes
    )

    if ($Bytes -ge 1GB) {
        return "{0:N2} GB" -f ($Bytes / 1GB)
    }

    if ($Bytes -ge 1MB) {
        return "{0:N2} MB" -f ($Bytes / 1MB)
    }

    if ($Bytes -ge 1KB) {
        return "{0:N2} KB" -f ($Bytes / 1KB)
    }

    return "$Bytes B"
}

if (-not (Test-Path -LiteralPath $Path -PathType Container)) {
    throw "Der angegebene Ordner wurde nicht gefunden: $Path"
}

$resolvedPath = (Resolve-Path -LiteralPath $Path).Path

if (-not (Test-Path -LiteralPath $OutputDirectory -PathType Container)) {
    New-Item -ItemType Directory -Path $OutputDirectory | Out-Null
}

$resolvedOutputDirectory = (Resolve-Path -LiteralPath $OutputDirectory).Path.TrimEnd("\")
$timestamp = Get-Date -Format "yyyyMMdd-HHmmss"
$safeFolderName = (Split-Path -Path $resolvedPath -Leaf)
if ([string]::IsNullOrWhiteSpace($safeFolderName)) {
    $safeFolderName = "Laufwerk"
}

$csvPath = Join-Path -Path $OutputDirectory -ChildPath "Dateiliste-$safeFolderName-$timestamp.csv"
$xlsxPath = Join-Path -Path $OutputDirectory -ChildPath "Dateiliste-$safeFolderName-$timestamp.xlsx"

Write-Host "Durchsuche Ordner inklusive Unterordner:" -ForegroundColor Cyan
Write-Host "  $resolvedPath"
Write-Host ""

$files = @(Get-ChildItem -LiteralPath $Path -File -Recurse -Force -ErrorAction SilentlyContinue |
    Where-Object {
        $filePath = $_.FullName
        -not (
            $filePath.Equals($resolvedOutputDirectory, [System.StringComparison]::InvariantCultureIgnoreCase) -or
            $filePath.StartsWith("$resolvedOutputDirectory\", [System.StringComparison]::InvariantCultureIgnoreCase)
        )
    } |
    Sort-Object FullName |
    Select-Object `
        @{Name = "Dateiname"; Expression = { $_.Name } },
        @{Name = "Ordner"; Expression = { $_.DirectoryName } },
        @{Name = "VollstaendigerPfad"; Expression = { $_.FullName } },
        @{Name = "Endung"; Expression = { $_.Extension } },
        @{Name = "GroesseBytes"; Expression = { $_.Length } },
        @{Name = "GroesseLesbar"; Expression = { Convert-BytesToReadableSize -Bytes $_.Length } },
        @{Name = "ErstelltAm"; Expression = { $_.CreationTime } },
        @{Name = "ZuletztGeaendertAm"; Expression = { $_.LastWriteTime } })

if ($files.Count -gt 0) {
    $files | Format-Table Dateiname, GroesseLesbar, ErstelltAm, ZuletztGeaendertAm -AutoSize
}
else {
    Write-Host "Keine Dateien gefunden." -ForegroundColor Yellow
}

$files | Export-Csv -Path $csvPath -Delimiter ";" -NoTypeInformation -Encoding UTF8
Write-Host ""
Write-Host "CSV exportiert nach:" -ForegroundColor Green
Write-Host "  $csvPath"

if (-not $NoExcel) {
    $importExcelModule = Get-Module -ListAvailable -Name ImportExcel | Select-Object -First 1

    if ($null -ne $importExcelModule) {
        $files | Export-Excel -Path $xlsxPath -WorksheetName "Dateiliste" -AutoSize -FreezeTopRow -BoldTopRow
        Write-Host "Excel-Datei exportiert nach:" -ForegroundColor Green
        Write-Host "  $xlsxPath"
    }
    else {
        Write-Host "Excel-XLSX wurde uebersprungen, weil das Modul 'ImportExcel' nicht installiert ist." -ForegroundColor Yellow
        Write-Host "Die CSV-Datei kann direkt mit Excel geoeffnet werden."
    }
}

Write-Host ""
Write-Host ("Gefundene Dateien: {0}" -f $files.Count) -ForegroundColor Cyan