param(
  [string]$TargetPath = "basis14.py",
  [int]$Limit = 10
)

$ErrorActionPreference = 'Stop'

$base = Split-Path -Parent $MyInvocation.MyCommand.Path
$backupRoot = Join-Path $base "_auto_backups"

if (!(Test-Path $backupRoot)) {
  Write-Host "FEHLER: Backup-Ordner nicht gefunden: $backupRoot"
  exit 1
}

# Ziel vollqualifizieren (falls Datei nicht existiert, relativ zum Projekt)
try {
  $targetFull = (Resolve-Path $TargetPath).Path
} catch {
  $targetFull = (Join-Path $base $TargetPath)
}

# relativer Pfad (fuer exakten Match)
$rel = $targetFull
if ($targetFull.ToLower().StartsWith($base.ToLower())) {
  $rel = $targetFull.Substring($base.Length).TrimStart('\')
} else {
  $rel = Split-Path -Leaf $targetFull
}
$leaf = Split-Path -Leaf $rel

# Kandidaten sammeln
$exact = Get-ChildItem -Path $backupRoot -Recurse -File -ErrorAction SilentlyContinue |
  Where-Object { $_.FullName.ToLower().EndsWith(("\\" + $rel).ToLower()) }

$cands = @()
if ($exact -and $exact.Count -gt 0) {
  $cands = $exact
} else {
  $cands = Get-ChildItem -Path $backupRoot -Recurse -File -ErrorAction SilentlyContinue |
    Where-Object { $_.Name -ieq $leaf }
}

if (!$cands -or $cands.Count -eq 0) {
  Write-Host "FEHLER: Kein Backup gefunden fuer: $TargetPath"
  Write-Host "Gesucht nach rel=$rel bzw. Name=$leaf"
  exit 2
}

$latest = $cands | Sort-Object LastWriteTime -Descending | Select-Object -First $Limit

Write-Host ""
Write-Host "=========================================="
Write-Host " RESTORE PICK - Backups fuer: $TargetPath"
Write-Host "=========================================="
Write-Host ""

$idx = 1
foreach ($f in $latest) {
  $ts = $f.LastWriteTime.ToString("yyyy-MM-dd HH:mm:ss")
  Write-Host ("[{0}] {1}  {2}" -f $idx, $ts, $f.FullName)
  $idx++
}

Write-Host ""
$sel = Read-Host "Bitte Nummer (1-$($latest.Count)) eingeben"
if (-not $sel) { Write-Host "Abbruch."; exit 0 }

[int]$n = 0
if (-not [int]::TryParse($sel, [ref]$n)) { Write-Host "Ungueltige Eingabe."; exit 3 }
if ($n -lt 1 -or $n -gt $latest.Count) { Write-Host "Ungueltige Nummer."; exit 3 }

$chosen = $latest[$n-1]

Write-Host ""
Write-Host "GEWAEHLT:"
Write-Host "  $($chosen.FullName)"
Write-Host ""

# Vor Restore: Backup der aktuellen Datei falls existiert
if (Test-Path $targetFull) {
  try {
    & powershell -NoProfile -ExecutionPolicy Bypass -File (Join-Path $base "_make_backup.ps1") $targetFull | Out-Null
    Write-Host "OK: Aktuelle Datei vorher gesichert."
  } catch {
    Write-Host "WARNUNG: Konnte aktuelle Datei nicht backupen, fahre trotzdem fort."
  }
} else {
  $parent = Split-Path -Parent $targetFull
  if ($parent -and !(Test-Path $parent)) {
    New-Item -ItemType Directory -Force -Path $parent | Out-Null
  }
}

Copy-Item -Force $chosen.FullName $targetFull
Write-Host "OK: Wiederhergestellt -> $targetFull"