// Learn more about F# at http://fsharp.net
// See the 'F# Tutorial' project for more help.

let CheckHost email =
    let addr = new System.Net.Mail.MailAddress(email)
    let res = ActiveUp.Net.Mail.Validator.GetMxRecords(addr.Host)
    if res <> null then Some(res) else None

[<EntryPoint>]
let main argv =
    let emailValidator = (new System.ComponentModel.DataAnnotations.EmailAddressAttribute()).IsValid
    let validEmails = System.IO.File.ReadAllLines(argv.[0]) |> Array.filter emailValidator
    System.IO.File.WriteAllLines(argv.[0] + "_out.txt", validEmails)
    let checkedEmails = validEmails |> Array.Parallel.choose (fun e-> let res = CheckHost e
                                                                      match res with | Some c -> Some((e,c.Count)) | None -> None)
    let badCount = validEmails.Length - checkedEmails.Length
    printfn "%d bad emails" badCount
    System.IO.File.WriteAllLines(argv.[0] + "_out2.txt", validEmails)
    printfn "%f bad emails" (float(badCount) / float(Seq.length checkedEmails))
    System.Console.ReadLine() |> ignore
    0 // return an integer exit codes