my.psm1

Function Get-HttpFile {
  param(
    [Parameter(Mandatory = $true)]
    [string]
    $Uri,
    
    [Parameter(Mandatory = $true)]
    [string]
    $OutFile,
    
    [switch]
    $Asynchronous = $False,
    
    [switch]
    $Force = $False
  )
  
  If (Test-Path $OutFile) {
    If ($Force) {
      Remove-Item $OutFile -Force | Out-Null
    }
    Else {
      Throw "${OutFile} already exists. If you want to remove it, use -Force."
    }
  }
  
  $Directory = Split-Path $OutFile
  If (-not (Test-Path $Directory)) {
    Write-Information 'Creating target directory' $Directory
    New-Item $Directory -Type Directory | Out-Null
  }
  
  $OutFile = Join-Path (Resolve-Path $Directory) (Split-Path $OutFile -Leaf)
  
  Function Get-HttpFileBits {
    Try {
      Write-Information 'Trying to use BITS Transfer'

      If ($Asynchronous) {
        Start-BitsTransfer -Source $Uri -Destination $OutFile -Asynchronous -ErrorAction SilentlyContinue | Out-Null
      }
      Else {
        Start-BitsTransfer -Source $Uri -Destination $OutFile -ErrorAction SilentlyContinue | Out-Null
      }
      
      $True
    }
    Catch {
      Write-Warning 'Failed to use BITS Transfer' $_
      $False
    }
  }
  
  Function Get-HttpFileWebClient {
    Write-Information 'Using System.Net.WebClient'

    If ($Asynchronous) {
      (New-Object System.Net.WebClient).DownloadFileAsync($Uri, $OutFile) | Out-Null
    }
    Else {
      (New-Object System.Net.WebClient).DownloadFile($Uri, $OutFile) | Out-Null
    }
  }

  If (-not (Get-HttpFileBits)) {
    Get-HttpFileWebClient | Out-Null
  }
}

Export-ModuleMember Get-HttpFile