param(
  [string]$PdfRoot = 'C:\inetpub\wwwroot\pdf\2026',
  [string]$MapCsv = 'C:\inetpub\wwwroot\cmod\mapping acc to host.csv',
  [string]$LogCsv = 'C:\inetpub\wwwroot\cmod\pdf_rename_2026_log.csv'
)

$rows = Import-Csv $MapCsv -Delimiter "`t"
$map = @{}
foreach ($r in $rows) {
  $acc = ($r.SP_ACCESSNUMBER + '').Trim()
  $hostOrder = ($r.HOSTORDERNUMBER + '').Trim()
  if ($acc -and $hostOrder) { $map[$acc] = $hostOrder }
}

$files = Get-ChildItem -Path $PdfRoot -Recurse -File -Filter '*.pdf'
$latest = @{}
foreach ($f in $files) {
  if ($f.BaseName -notmatch '^(?<acc>.+?)(?<suffix>_eng)?$') { continue }
  $acc = $Matches.acc
  $suffix = $Matches.suffix
  if (-not $map.ContainsKey($acc)) { continue }
  $targetName = '{0}{1}.pdf' -f $map[$acc], $suffix
  $targetPath = Join-Path $f.DirectoryName $targetName
  if (-not $latest.ContainsKey($targetPath) -or $f.LastWriteTime -gt $latest[$targetPath].LastWriteTime) {
    $latest[$targetPath] = $f
  }
}

$log = foreach ($targetPath in $latest.Keys) {
  $src = $latest[$targetPath]
  if ($src.BaseName -notmatch '^(?<acc>.+?)(?<suffix>_eng)?$') { continue }
  $acc = $Matches.acc
  $suffix = $Matches.suffix
  $hostOrder = $map[$acc]
  $targetName = '{0}{1}.pdf' -f $hostOrder, $suffix
  $finalTarget = Join-Path $src.DirectoryName $targetName

  try {
    if (Test-Path $finalTarget) { Remove-Item -Path $finalTarget -Force }
    if ($src.FullName -ne $finalTarget) {
      Move-Item -Path $src.FullName -Destination $finalTarget -Force
      [pscustomobject]@{Status='RENAMED'; Source=$src.FullName; Target=$finalTarget; AccessNumber=$acc; HostOrderNumber=$hostOrder; Notes=''}
    } else {
      [pscustomobject]@{Status='UNCHANGED'; Source=$src.FullName; Target=$finalTarget; AccessNumber=$acc; HostOrderNumber=$hostOrder; Notes='Already correct name'}
    }
  } catch {
    [pscustomobject]@{Status='ERROR'; Source=$src.FullName; Target=$finalTarget; AccessNumber=$acc; HostOrderNumber=$hostOrder; Notes=$_.Exception.Message}
  }
}

$log | Export-Csv -Path $LogCsv -NoTypeInformation -Encoding UTF8
Write-Host "Done. Log: $LogCsv"