# encoding: ascii
# api: powershell
# title: Get-WebFile
# description: An upgrade to my wget script which can output the downloaded html to the pipeline. Get-WebFile can download text or binary files, automatically determine file names, and present a progress report for large files…
# version: 3.7
# type: script
# author: Joel Bennett
# license: CC0
# function: Get-WebFile
# x-poshcode-id: 3203
# x-derived-from-id: 3204
# x-archived: 2015-03-09T00:11:18
# x-published: 2012-02-06T13:07:00
#
#
## Get-WebFile (aka wget for PowerShell)
##############################################################################################################
## Downloads a file or page from the web
## History:
## v3.7 - [int] to [long] to support files larger than 2.0 GB
## v3.6 - Add -Passthru switch to output TEXT files 
## v3.5 - Add -Quiet switch to turn off the progress reports ...
## v3.4 - Add progress report for files which don't report size
## v3.3 - Add progress report for files which report their size
## v3.2 - Use the pure Stream object because StreamWriter is based on TextWriter:
##        it was messing up binary files, and making mistakes with extended characters in text
## v3.1 - Unwrap the filename when it has quotes around it
## v3   - rewritten completely using HttpWebRequest + HttpWebResponse to figure out the file name, if possible
## v2   - adds a ton of parsing to make the output pretty
##        added measuring the scripts involved in the command, (uses Tokenizer)
##############################################################################################################
function Get-WebFile {
   param( 
      $url = (Read-Host "The URL to download"),
      $fileName = $null,
      [switch]$Passthru,
      [switch]$quiet
   )
   
   $req = [System.Net.HttpWebRequest]::Create($url);
   $res = $req.GetResponse();
 
   if($fileName -and !(Split-Path $fileName)) {
      $fileName = Join-Path (Get-Location -PSProvider "FileSystem") $fileName
   } 
   elseif((!$Passthru -and ($fileName -eq $null)) -or (($fileName -ne $null) -and (Test-Path -PathType "Container" $fileName)))
   {
      [string]$fileName = ([regex]'(?i)filename=(.*)$').Match( $res.Headers["Content-Disposition"] ).Groups[1].Value
      $fileName = $fileName.trim("\/""'")
      if(!$fileName) {
         $fileName = $res.ResponseUri.Segments[-1]
         $fileName = $fileName.trim("\/")
         if(!$fileName) { 
            $fileName = Read-Host "Please provide a file name"
         }
         $fileName = $fileName.trim("\/")
         if(!([IO.FileInfo]$fileName).Extension) {
            $fileName = $fileName + "." + $res.ContentType.Split(";")[0].Split("/")[1]
         }
      }
      $fileName = Join-Path (Get-Location -PSProvider "FileSystem") $fileName
   }
   if($Passthru) {
      $encoding = [System.Text.Encoding]::GetEncoding( $res.CharacterSet )
      [string]$output = ""
   }
 
   if($res.StatusCode -eq 200) {
      [long]$goal = $res.ContentLength
      $reader = $res.GetResponseStream()
      if($fileName) {
         $writer = new-object System.IO.FileStream $fileName, "Create"
      }
      [byte[]]$buffer = new-object byte[] 4096
      [long]$total = [long]$count = 0
      do
      {
         $count = $reader.Read($buffer, 0, $buffer.Length);
         if($fileName) {
            $writer.Write($buffer, 0, $count);
         } 
         if($Passthru){
            $output += $encoding.GetString($buffer,0,$count)
         } elseif(!$quiet) {
            $total += $count
            if($goal -gt 0) {
               Write-Progress "Downloading $url" "Saving $total of $goal" -id 0 -percentComplete (($total/$goal)*100)
            } else {
               Write-Progress "Downloading $url" "Saving $total bytes..." -id 0
            }
         }
      } while ($count -gt 0)
      
      $reader.Close()
      if($fileName) {
         $writer.Flush()
         $writer.Close()
      }
      if($Passthru){
         $output
      }
   }
   $res.Close(); 
   if($fileName) {
      ls $fileName
   }
}
