module Colab.Core.OS

open System
open System.Diagnostics

type Version =
 | Windows
 | Unix
 | OSX
 | Unknown

let isDarwin = ref None

let queryUname() =
    try
        let proc = new Process()
        let info = new ProcessStartInfo("uname", "-a")
        info.RedirectStandardOutput <- true
        info.WindowStyle <- ProcessWindowStyle.Hidden
        info.UseShellExecute <- false
        info.CreateNoWindow <- true
        proc.StartInfo <- info
        proc.Start() |> ignore
        let output = proc.StandardOutput.ReadToEnd()
        proc.WaitForExit()
        isDarwin := Some(output.Contains("Darwin Kernel"))
    with
     | _ ->
        ()

let isWindows() =
    Environment.OSVersion.Platform = PlatformID.Win32S ||
    Environment.OSVersion.Platform = PlatformID.Win32NT ||
    Environment.OSVersion.Platform = PlatformID.Win32Windows ||
    Environment.OSVersion.Platform = PlatformID.WinCE ||
    Environment.OSVersion.Platform = PlatformID.Xbox

let version =
    if isWindows() then Windows
    else
        queryUname()
        match !isDarwin with
         | Some(darwin) -> if darwin then OSX else Unix
         | None -> Unknown

let isPosix = match version with | Unix -> true | OSX -> true | _ -> false