namespace Java

open System

open System.IO

open System.Reflection

open System.Reflection.Emit

open System.Collections.Generic

open System.Diagnostics

open Microsoft.FSharp.Core.CompilerServices

open Samples.FSharp.ProvidedTypes

open Microsoft.FSharp.Quotations

type Cache private () =

static let mutable instance = Dictionary<_, _>()

static member Instance = instance

module Helpers =

let memoize f =

fun n ->

match Cache.Instance.TryGetValue(n) with

| (true, v) -> v

| _ ->

let temp = f(n)

Cache.Instance.Add(n, temp)

temp

let fullPath (config :TypeProviderConfig) path =

if Path.IsPathRooted(path)

then path

else Path.Combine(config.ResolutionFolder, path)

let watchForChanges invalidate (fileName:string) =

let w = new FileSystemWatcher(Filter = Path.GetFileName(fileName), Path = Path.GetDirectoryName(fileName))

w.Changed.Add(fun _ -> invalidate())

w.EnableRaisingEvents <- true

[<TypeProvider>]

type public JavaTypeProvider(config: TypeProviderConfig) as this =

inherit TypeProviderForNamespaces()

let thisAssembly = Assembly.GetExecutingAssembly()

let rootNamespace = "Java"

let dir = IO.Path.GetDirectoryName(config.RuntimeAssembly)

let baseType = typeof<obj>

let staticParams =

[

ProvidedStaticParameter("JarFile", typeof<string>)

ProvidedStaticParameter("IKVMPath", typeof<string>, Path.Combine(config.ResolutionFolder, "IKVM"))

]

let containerType = ProvidedTypeDefinition(thisAssembly, rootNamespace, "JavaProvider", Some(baseType), IsErased = false)

let invalidate key = (fun () ->

if Cache.Instance.Remove(key)

then

GlobalProvidedAssemblyElementsTable.theTable.Clear()

this.Invalidate()

)

let loader (typeName, jarFile, ikvmPath) =

this.RegisterProbingFolder(ikvmPath)

this.RegisterProbingFolder(Path.GetDirectoryName(jarFile))

let assemblyBytes = IKVMCompiler.compile ikvmPath config.TemporaryFolder jarFile

let assembly = Assembly.Load(assemblyBytes)

GlobalProvidedAssemblyElementsTable.theTable.[assembly] <- assemblyBytes

let t = ProvidedTypeDefinition(thisAssembly, rootNamespace, typeName, Some(baseType), IsErased = false)

t.AddAssemblyTypesAsNestedTypesDelayed (fun _ -> assembly) false

t

do containerType.DefineStaticParameters(

staticParams,

(fun typeName [| :? string as jarFile ; :? string as ikvmPath|] ->

let jar, ikvm = Helpers.fullPath config jarFile, Helpers.fullPath config ikvmPath

Helpers.watchForChanges (invalidate (typeName, jar, ikvm)) jar

Helpers.memoize loader (typeName, jar, ikvm)

))

do

this.AddNamespace(rootNamespace, [containerType])

[<TypeProviderAssembly>]

do()