package web

import(
  "fmt"
  "net/http"
  "os"
  "io"
  "io/ioutil"
  "strings"
  "strconv"
  "../arch"
)

func Download(url string, target string) bool {

  output, err := os.Create(target)
  if err != nil {
    fmt.Println("Error while creating", target, "-", err)
  }
  defer output.Close()

  response, err := http.Get(url)
  if err != nil {
    fmt.Println("Error while downloading", url, "-", err)
  }
  defer response.Body.Close()

  n, err := io.Copy(output, response.Body)
  n=n
  if err != nil {
    fmt.Println("Error while downloading", url, "-", err)
  }

  if response.Status[0:3] != "200" {
    fmt.Println("Download failed. Rolling Back.")
    err := os.Remove(target)
    if err != nil {
      fmt.Println("Rollback failed.",err)
    }
    return false
  }

  return true
}

func GetNodeJS(root string, v string, a string) bool {

  a = arch.Validate(a)

  url := ""
  if a == "32" {
    url = "http://nodejs.org/dist/v"+v+"/node.exe"
  } else {
    if !IsNode64bitAvailable(v) {
      fmt.Println("Node.js v"+v+" is only available in 32-bit.")
      return false
    }
    url = "http://nodejs.org/dist/v"+v+"/x64/node.exe"
  }
  fileName := root+"\\v"+v+"\\node"+a+".exe"

  fmt.Printf("Downloading node.js version "+v+" ("+a+"-bit)... ")

  if Download(url,fileName) {
    fmt.Printf("Complete\n")
    return true
  } else {
    return false
  }

}

func GetNpm(v string) bool {
  url := "https://github.com/npm/npm/archive/v"+v+".zip"
  fileName := os.TempDir()+"\\"+"npm-v"+v+".zip"

  fmt.Printf("Downloading npm version "+v+"... ")
  if Download(url,fileName) {
    fmt.Printf("Complete\n")
    return true
  } else {
    return false
  }
}

func GetRemoteTextFile(url string) string {
  response, httperr := http.Get(url)
  if httperr != nil {
    fmt.Println("\nCould not retrieve "+url+".\n\n")
    fmt.Printf("%s", httperr)
    os.Exit(1)
  } else {
    defer response.Body.Close()
    contents, readerr := ioutil.ReadAll(response.Body)
    if readerr != nil {
      fmt.Printf("%s", readerr)
      os.Exit(1)
    }
    return string(contents)
  }
  os.Exit(1)
  return ""
}

func IsNode64bitAvailable(v string) bool {
  if v == "latest" {
    return true
  }

  // Anything below version 8 doesn't have a 64 bit version
  vers := strings.Fields(strings.Replace(v,"."," ",-1))
  main, _ := strconv.ParseInt(vers[0],0,0)
  minor, _ := strconv.ParseInt(vers[1],0,0)
  if main == 0 && minor < 8 {
    return false
  }

  // Check online to see if a 64 bit version exists
  res, err := http.Head("http://nodejs.org/dist/v"+v+"/x64/node.exe")
  if err != nil {
    return false
  }
  return res.StatusCode == 200
}