open Brr
open Note_brr
module Js = Js_of_ocaml.Js

let create :
       ?form:'a Note.signal * El.t
    -> ?valid_on:bool Note.signal
    -> title:Jstr.t
    -> unit
    -> 'a option Note.event =
 fun ?form ?valid_on ~title () ->
  (* Ensure we keep a track for the signal event.

     This looks a bit like the old memory magment in C, as it require to
     destroy the logger each time the popup is removed. *)
  let log_opt =
    Option.map (fun (values, _) -> Note.S.log values (fun _ -> ())) form
  in

  let close_btn =
    El.span ~at:At.[ class' (Jstr.v "modal-close") ] [ El.txt' "×" ]
  and submit_btn = El.input () ~at:At.[ type' (Jstr.v "submit") ] in

  (match valid_on with
  | None -> ()
  | Some s ->
      Elr.def_at (Jstr.v "disabled")
        (Note.S.map
           (fun value -> if not value then Some Jstr.empty else None)
           s)
        submit_btn);

  let container =
    match form with
    | None -> El.div
    | Some _ -> El.form
  and body =
    match form with
    | None -> El.div []
    | Some (_, content) -> content
  and footer =
    match form with
    | None -> El.txt Jstr.empty
    | Some _ -> El.div [ submit_btn ] ~at:At.[ class' (Jstr.v "row") ]
  in

  (* HTML Element creation *)
  let el =
    El.div
      ~at:At.[ class' (Jstr.v "modal") ]
      [
        container
          ~at:At.[ class' (Jstr.v "modal-content") ]
          [
            El.div
              ~at:At.[ class' (Jstr.v "modal-header") ]
              [ close_btn; El.h3 [ El.txt title ] ]
          ; El.div ~at:At.[ class' (Jstr.v "modal-body") ] [ body ]
          ; El.div ~at:At.[ class' (Jstr.v "modal-footer") ] [ footer ]
          ]
      ]
  in

  let () = El.append_children (Document.body G.document) [ el ] in

  (* Add the focus to the first input element inside the form *)
  let () =
    match form with
    | Some (_, el) when El.is_el el -> (
        match El.find_by_tag_name ~root:el (Jstr.v "input") with
        | [] -> ()
        | hd :: _ -> El.set_has_focus true hd)
    | _ -> ()
  in

  (* Event handler *)
  let close_event =
    Evr.on_el Ev.click
      (fun _ ->
        El.remove el;
        Option.iter Note.Logr.destroy log_opt;
        None)
      close_btn
  and submit_event =
    Evr.on_el Ev.click
      (fun _ ->
        El.remove el;
        Option.iter Note.Logr.destroy log_opt;
        Option.map (fun v -> Note.S.value (fst v)) form)
      submit_btn
  in

  Note.E.select [ close_event; submit_event ]