type mode =
  | Edit
  | Selection of Selection.t
  | Out

type worker_event = Worker_messages.from_worker

(*
 The state cant hold functionnal values, and thus cannot be used to store
 elements like timer
 *)
type state =
  { mode : mode
  ; paths : Outline.t list
  ; current : Path.Path_Builder.t
  ; width : float
  ; angle : float
  ; rendering : Layer.Paths.printer
  ; mouse_down_position : Gg.v2
  }

include Application.Make(struct type t = state end)

let post
  : Brr_webworkers.Worker.t -> Worker_messages.to_worker -> unit
  = Brr_webworkers.Worker.post

let insert_or_replace state ((x, y) as p) stamp path =
  let width = state.width
  and angle = state.angle in
  let point = Path.Point.create ~x ~y ~angle ~width ~stamp in
  match Path.Path_Builder.peek path with
  | None ->
    Path.Path_Builder.add_point
      point
      path
  | Some p1 ->
    let open Gg.V2 in

    let p1' = Path.Point.get_coord p1 in

    let dist = (norm (p1' - (of_tuple p))) in
    if dist < 5. then (
      path
    ) else (
      Path.Path_Builder.add_point
        point
        path
    )

(** Select the given segment, and modify angle and width accordingly *)
let select_segment _ (_, selected, p0, p1) state dist =

  let point' = Path.Point.mix dist (Path.Point.get_coord p0) p0 p1 in

  let angle = (Float.round @@ 10. *. Path.Point.get_angle point') /. 10.
  and width = (Float.round @@ 10. *. Path.Point.get_width point') /. 10. in

  let id = Selection.select_path selected in
  { state with
    mode = (Selection id)
  ; angle
  ; width }


let init =
  { paths = []
  ; current = Path.Path_Builder.empty
  ; mode = Out
  ; angle = 30.
  ; width = 10.
  ; rendering = `Fill
  ; mouse_down_position = Gg.V2.ox
  }