namespace Models

open System

open System.IO

open Microsoft.FSharp.Compiler.Interactive.Shell

open Tensor.Utils

module Config =

type private FsiEvaluator () =

// Build command line arguments & start FSI session

let inStream = new StringReader("")

let argv = [| "C:\\fsi.exe" |]

let allArgs = Array.append argv [|"--noninteractive"

"--quiet"

"--lib:" + Util.assemblyDirectory

"--reference:MLModels.dll"

"--reference:SymTensor.dll"

"--define:CONFIG"

|]

let fsiConfig = FsiEvaluationSession.GetDefaultConfiguration()

let fsiSession = FsiEvaluationSession.Create(fsiConfig, allArgs, inStream, Console.Out, Console.Error, true)

/// Evaluate F# expression and return the result, strongly typed.

member this.EvalExpression (text) : 'T =

match fsiSession.EvalExpression(text) with

| Some value ->

if value.ReflectionType <> typeof<'T> then

failwithf "evaluated expression is of type %A but type %A was expected"

value.ReflectionType typeof<'T>

value.ReflectionValue |> unbox

| None -> failwith "evaluated expression provided no result"

// Evaluate F# script.

member this.EvalScript path =

fsiSession.EvalInteraction (File.ReadAllText path)

/// Directory of the currently loading configuration file.

let mutable cfgDir = ""

/// First ancessor directory of configuration file directory that contains a "Cfg" subdirectory.

let mutable baseDir = ""

/// Load configuration F# script (.fsx file) and returns the variable named "cfg".

let load path =

if not (File.Exists path) then

failwithf "configuration file %s does not exist" (Path.GetFullPath path)

printfn "Using configuration file %s" (Path.GetFullPath path)

// set paths for configuration file consumption

cfgDir <- path |> Path.GetFullPath |> Path.GetDirectoryName

let rec findBaseDir dir iters =

if iters > 100 then

printfn "Cannot find base directory. Using current directory as base directory."

Directory.GetCurrentDirectory()

else

if Directory.Exists (Path.Combine (dir, "Cfg")) ||

Directory.Exists (Path.Combine (dir, "Cfgs")) then Path.GetFullPath dir

else findBaseDir (Path.Combine (dir, "..")) (iters+1)

baseDir <- findBaseDir cfgDir 0

// evaluate configuration script

try

let eval = FsiEvaluator()

eval.EvalScript path

eval.EvalExpression "cfg"

with

| _ ->

fprintfn Console.Error "Loading configuration file %s failed." (Path.GetFullPath path)

exit 1

/// Loads configuration script and changes current directory to output directory for that configuration.

let loadAndChdir path =

if not (File.Exists path) then

failwithf "configuration file %s does not exist" (Path.GetFullPath path)

Directory.SetCurrentDirectory (Path.GetDirectoryName path)

load (Path.GetFileName path)