Param($CsvPath, $PackageDir, $LogDir)
if ($PSBoundParameters.Count -ne 3)  { Write-host "Error: -CsvPath <path> -PackageDir <path> -LogDir <Path>" ;exit 1}
If ( -not (Test-Path $CsvPath)) { Write-host "Error: -CsvPath <path> does not exist." ;exit 1}
If ( -not (Test-Path $packagedir)) { Write-host "Error: -PackageDir <path> does not exist." ;exit 1}
If ( -not (Test-Path $LogDir)) { Write-host "Error: -LogDir <path> does not exist." ;exit 1}

# Keywords that are not downloaded based on part of the file name. 'KB9999999' is dummy (you can delete it).
# 'KB5043080' is a checkpoint cumulative update for Windows 11 24H2 and Windows Server 2025 or later, and does not require installation.
# Detail: https://learn.microsoft.com/ja-jp/windows/deployment/update/catalog-checkpoint-cumulative-updates
$ExcludeLists = 'KB5043080','KB9999999'

function Write-Log {
  param (
      [string]$Message,
      [string]$LogPath = "$env:TEMP\onlinepatch.log"
    )
  #Output to Console
  Write-Host $Message
  $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
  $entry = "[$timestamp] $Message"
  Add-Content -Path $LogPath -Value $entry
}

# for .\get-updateids.ps1
# for .\get-downloadLinks {
Set-Location -Path $PSScriptRoot

function Start-Download {
  param (
      [string]$downloaduri,
      [string]$PackageDir
    )
  $filename = Split-Path $downloaduri -Leaf
  if (Test-Path (Join-Path $PackageDir $filename)) {
    Write-Log -Message "File $($filename) has already beed downloaded. Skip download." -LogPath $LogPath
  } else {
    Write-Log -Message "Downloading $($filename) ..." -LogPath $LogPath
    if (Test-Path "$env:WINDIR\System32\curl.exe") {
      & curl.exe -L --fail --retry 3 --retry-delay 2 -o (Join-Path $PackageDir $filename) $downloaduri
    } else {
      $ProgressPreference = 'SilentlyContinue'
      Invoke-WebRequest -Uri $downloaduri -OutFile (Join-Path $PackageDir $filename)
      $ProgressPreference = 'Continue'
    }
    if (Test-Path (Join-Path $PackageDir $filename)) {
      Write-Log -Message "Download completed." -LogPath $LogPath
    } else {
      Write-Log -Message "Download failed." -LogPath $LogPath
    }
  }
}

$LogPath = "$LogDir\downloadupdates.log"
if (Test-Path $logPath) {
  $logTime = (get-item $logPath).LastWriteTime
} else {
  $logTime = get-Date("1900/1/1")
}

Write-Log -Message "Start download-updates.ps1" -LogPath $LogPath
Write-Log -Message "Import CSV from $($CsvPath)" -LogPath $LogPath
$csvrows = Import-Csv -Path $CsvPath
Write-Log -Message "Found $($csvrows.Count) udpates." -LogPath $LogPath

foreach ($csvrow in $csvrows) {
  $KBID = $csvrow.KBId
  $TITLE = $csvrow.TITLE
  $HINTID = $csvrow.UpdateId
  $HINT = "NOTMATCHTITLE"
  if ($TITLE -match "Server") {
    $HINT = "Server"
  } elseif ($TITLE -match "x64-based") {
    $HINT = "x64-based"
  } elseif ($TITLE -match "arm64-based") {
    $HINT = "arm64-based"
  }
  $UpdateIds = .\Get-UpdateIds.ps1 -KB $KBID
  if ($UpdateIds.Count -eq 0) {
    Write-Log -Message "UpdateID corresponding to $($KBID) not found." -LogPath $LogPath
  } else {
    foreach ($UpdateId in $UpdateIds) {
      $DownloadID = ""
      if($UpdateId.UpdateId -eq $HINTID) {
        $DownloadId = $UpdateId.UpdateId
      } elseif($UpdateId.TITLE -match $HINT) {
        $DownloadId = $UpdateId.UpdateId
      }
      if ($DownloadId -ne "") {
        $downloadlinks = .\Get-DownloadLinks.ps1 -UpdateId $DownloadId
        if ($downloadlinks.Count -eq 0) {
          Write-Log -Message "DownloadLinks corresponding to $($KBID) : $($UpdateId.UpdateId) not found." -LogPath $LogPath
        } else {
          foreach ($downloadlink in $downloadLinks) {
            if ($downloadlink.FileName | Select-String -Pattern $ExcludeLists -SimpleMatch -Quiet) {
              Write-Log -Message "Skip UpdateID: $($UpdateId.UpdateId) FileName $($downloadlink.FileName -replace '^(?s)(.{0,25}).*','$1') ... based on the ExcludeLists." -LogPath $LogPath
            } else {
              Start-Download -downloaduri $downloadlink.URL -PackageDir $PackageDir
            }
          }
        }
      } else {
          Write-Log -Message "Skip UpdateID: $($UpdateId.UpdateId) based on the hint (ID or Platform)." -LogPath $LogPath
      }
    }
  }
}