module Js = Js_of_ocaml.Js
module App = Editor_app

let uncheck_import =
  fun ~previous ~update ->
  let _ = previous
  and _ = update in
  true

let check_import =
  fun ~previous ~update ->
  Js.Opt.case previous##.date
    (fun () -> true)
    (fun previous_date ->
       Js.Opt.case update##.date
         (fun () -> true)
         (fun update_date ->
            update_date >= previous_date ))

module M = struct

  type t = Forms.Selector.t

  let process
    : t -> State.t -> State.t
    = fun t state ->
      match t.Forms.Selector.file with
      | None -> state
      | Some file ->
        let content = file.Elements.Input.content in
        let check =
          if t.Forms.Selector.preserve_newest then
            check_import
          else
            uncheck_import
        in
        match
          State.Storage.of_json
            ~check
            content with
        | Error _ -> state
        | Ok _obj ->
          State.load_page state.State.page_id state
end

let create () =
  let title = Jstr.v "Importer des notes" in
  let form = Forms.Selector.create () in
  let ev = Elements.Popup.create
      ~title
      ~form
      ~valid_on:(Note.S.map (fun form -> form.Forms.Selector.file != None) (fst form))
      ()
  in

  Note.E.map
    (fun v -> App.dispatch (module M) v)
    (Note.E.Option.on_some ev)