(*

a computation console

- irmin store provides a tree of data objects
- the tree can be navigated in the default view
- the selected object can be edited <enter> or executed as an ocaml top level phrase <C-enter>
- each execution stores any edited modifications and the command to execute that phrase in the current irmin store context as a commit message
- while editing a data object <ctrl-enter> wille search for the previous and next `;;` or BOF/EOF and execute the enclosed text and the commit message includes the character offsets of the executed text.
- executions can modify the window system creating new windows and redirecting input focus. They define their own input handling however C-g,C-g,C-g will restore the window system to the default??


but how do we integrate this with the ocaml environment and name spaces??
some options:
- always wrap execution units from data objects in some sort of local namespace so opens are not global?
- dig into the toplevel environment and manipulate it, this will also help with things like completion and context help

*)

open Lwt.Infix
module F = Fmt

module Input = struct
  open CamomileLibrary

  (** Type of key code. *)
  type code =
    | UChar of UChar.t  (** A unicode character. *)
    | Enter
    | Escape
    | Tab
    | Up
    | Down
    | Left
    | Right
    | F1
    | F2
    | F3
    | F4
    | F5
    | F6
    | F7
    | F8
    | F9
    | F10
    | F11
    | F12
    | Next_page
    | Prev_page
    | Home
    | End
    | Insert
    | Delete
    | Backspace
    | Unknown
    | None

  type keystate =
    {ctrl: bool; meta: bool; shift: bool; super: bool; code: code}

  type mods = Ctrl | Meta | Super | Shift
  type key = Char of char | Code of code

  module Key = struct
    type t = keystate

    let compare = compare
  end

  module Bind = struct
    (* parts stolen from lambda-term/src/lTerm_{edit,key}.ml{,i} *)
    module S = Zed_input.Make (Key)

    type action =
      | Custom of (unit -> unit)
      | CustomLwt of (unit -> unit Lwt.t)
      | Zed of Zed_edit.action

    type t = action list S.t
    type resolver = action list S.resolver
    type result = action list S.result

    type state =
      { mutable bindings: t
      ; mutable state: result
      ; mutable last_keyseq: keystate list
      ; mutable last_actions: action list }

    let keystate_of_mods ks m =
      List.fold_left
        (fun ks m ->
          match m with
          | Meta -> {ks with meta= true}
          | Ctrl -> {ks with ctrl= true}
          | Super -> {ks with super= true}
          | Shift -> {ks with shift= true} )
        ks m

    let add events action bindings =
      let events =
        List.map
          (fun (m, k) ->
            keystate_of_mods
              { meta= false
              ; ctrl= false
              ; super= false
              ; shift= false
              ; code=
                  ( match k with
                  | Char c -> UChar (UChar.of_char c)
                  | Code c -> c ) }
              m )
          events in
      S.add events action bindings

    let default_resolver b = S.resolver [S.pack (fun x -> x) b]

    let get_resolver result default =
      match result with S.Continue r -> r | _ -> default

    let init bindings =
      {bindings; state= S.Rejected; last_keyseq= []; last_actions= []}

    let resolve = S.resolve
    let empty = S.empty

    let actions_of_events (state : state) events =
      List.flatten
        (List.filter_map
           (fun e ->
             (*F.epr "action_of_events: %s@." (to_string e) ;*)
             match e with
             | `Key_down (k : keystate) -> (
                 ( match state.state with
                 | Continue _ -> ()
                 | _ -> state.last_keyseq <- [] ) ;
                 state.state <-
                   resolve k
                     (get_resolver state.state
                        (default_resolver state.bindings) ) ;
                 state.last_keyseq <- k :: state.last_keyseq ;
                 match state.state with
                 | Accepted a ->
                     state.last_actions <- a ;
                     Some a
                 | Rejected ->
                     state.last_actions <- [] ;
                     None
                 | _ -> None )
             | _ -> None )
           events )

    let process bindstate events =
      Lwt_list.iter_s
        (function
          | Custom f -> Lwt.return (f ())
          | CustomLwt f -> f ()
          | Zed _ -> Lwt.return_unit )
        (actions_of_events bindstate events)
  end

  (* stolen from lambda-term/src/lTerm_{edit,key}.ml{,i} *)
  let string_of_code = function
    | UChar ch -> Printf.sprintf "Char 0x%02x" (UChar.code ch)
    | Enter -> "Enter"
    | Escape -> "Escape"
    | Tab -> "Tab"
    | Up -> "Up"
    | Down -> "Down"
    | Left -> "Left"
    | Right -> "Right"
    | F1 -> "F1"
    | F2 -> "F2"
    | F3 -> "F3"
    | F4 -> "F4"
    | F5 -> "F5"
    | F6 -> "F6"
    | F7 -> "F7"
    | F8 -> "F8"
    | F9 -> "F9"
    | F10 -> "F10"
    | F11 -> "F11"
    | F12 -> "F12"
    | Next_page -> "Next_page"
    | Prev_page -> "Prev_page"
    | Home -> "Home"
    | End -> "End"
    | Insert -> "Insert"
    | Delete -> "Delete"
    | Backspace -> "Backspace"
    | Unknown -> "Unknown"
    | None -> "None"

  let to_string key =
    Printf.sprintf
      "{ control = %B; meta = %B; shift = %B; super = %B; code = %s }"
      key.ctrl key.meta key.shift key.super
      (string_of_code key.code)

  let to_string_compact key =
    let buffer = Buffer.create 32 in
    if key.ctrl then Buffer.add_string buffer "Ctrl-" ;
    if key.meta then Buffer.add_string buffer "Meta-" ;
    if key.shift then Buffer.add_string buffer "Shift-" ;
    if key.super then Buffer.add_string buffer "Super-" ;
    ( match key.code with
    | UChar ch ->
        let code = UChar.code ch in
        if code <= 255 then
          match Char.chr code with
          | ( 'a' .. 'z'
            | 'A' .. 'Z'
            | '0' .. '9'
            | '_' | '(' | ')' | '[' | ']' | '{' | '}' | '#' | '~'
            | '&' | '$' | '*' | '%' | '!' | '?' | ',' | ';' | ':'
            | '/' | '\\' | '.' | '@' | '=' | '+' | '-' ) as ch ->
              Buffer.add_char buffer ch
          | ' ' -> Buffer.add_string buffer "space"
          | _ -> Printf.bprintf buffer "U+%02x" code
        else if code <= 0xffff then
          Printf.bprintf buffer "U+%04x" code
        else Printf.bprintf buffer "U+%06x" code
    | Next_page -> Buffer.add_string buffer "next"
    | Prev_page -> Buffer.add_string buffer "prev"
    | code ->
        Buffer.add_string buffer
          (String.lowercase_ascii (string_of_code code)) ) ;
    Buffer.contents buffer
end

module Event = struct
  open Tsdl
  open CamomileLibrary
  open Input

  type mouse = int * int

  type t =
    [ `Key_down of Input.keystate
    | `Key_up of Input.keystate
    | `Text_editing of string
    | `Text_input of string
    | `Mouse of mouse
    | `Quit
    | `Fullscreen of bool
    | `Unknown of string
    | `None ]

  type events = t list

  let string_of_event = function
    | `Key_down _ -> "`Key_down"
    | `Key_up _ -> "`Key_up"
    | `Text_editing _ -> "`Text_editing"
    | `Text_input _ -> "`Text_input"
    | `Mouse _ -> "`Mouse"
    | `Quit -> "`Quit"
    | `Fullscreen _ -> "`Fullscreen"
    | `Unknown _ -> "`Unknown"
    | `None -> "`None"

  let to_string ev =
    let p =
      match ev with
      | `Key_down k | `Key_up k -> Input.to_string k
      | `Text_editing s | `Text_input s -> s
      | `Mouse _ -> ""
      | `Fullscreen b -> Format.sprintf "%b" b
      | `Unknown s -> s
      | `Quit | `None -> "" in
    string_of_event ev ^ " " ^ p

  let event_of_sdlevent ev =
    let key_of_sdlkey ev =
      let (kc : Sdl.keycode) =
        Sdl.Event.get ev Sdl.Event.keyboard_keycode
        land lnot Sdl.K.scancode_mask in
      let open Sdl.K in
      let (c : Input.code) =
        match (kc : Sdl.keycode) with
        (* HACK WHENENENENENENENENEHWEHWEHNWEWHWEHWEN FUCK X WHEN X whatS>!!>!> *)
        | x when x = return -> Enter
        | x when x = escape -> Escape
        | x when x = backspace -> Backspace
        | x when x = tab -> Tab
        | x when x = f1 -> F1
        | x when x = f2 -> F2
        | x when x = f3 -> F3
        | x when x = f4 -> F4
        | x when x = f5 -> F5
        | x when x = f6 -> F6
        | x when x = f7 -> F7
        | x when x = f8 -> F8
        | x when x = f9 -> F9
        | x when x = f10 -> F10
        | x when x = f11 -> F11
        | x when x = f12 -> F12
        | x when x = insert -> Insert
        | x when x = delete -> Delete
        | x when x = home -> Home
        | x when x = kend -> End
        | x when x = pageup -> Prev_page
        | x when x = pagedown -> Next_page
        | x when x = right -> Right
        | x when x = left -> Left
        | x when x = down -> Down
        | x when x = up -> Up
        | k -> (
          match UChar.char_of (UChar.of_int k) with
          | 'a' .. 'z'
           |'A' .. 'Z'
           |'0' .. '9'
           |'_' | '(' | ')' | '[' | ']' | '{' | '}' | '#' | '~'
           |'&' | '$' | '*' | '%' | '!' | '?' | ',' | ';' | ':'
           |'/' | '\\' | '.' | '@' | '=' | '+' | '-' | ' ' | '"'
           |'\'' | '>' | '<' | '^' | '`' | '|' ->
              UChar (UChar.of_int k)
          | _ -> None ) in
      let km = Sdl.Event.get ev Sdl.Event.keyboard_keymod in
      { code= c
      ; ctrl= km land Sdl.Kmod.ctrl > 0
      ; meta= km land Sdl.Kmod.alt > 0
      ; super= km land Sdl.Kmod.gui > 0
      ; shift= km land Sdl.Kmod.shift > 0 } in
    let repeat = Sdl.Event.get ev Sdl.Event.keyboard_repeat in
    let r =
      match Sdl.Event.enum (Sdl.Event.get ev Sdl.Event.typ) with
      | `Text_editing ->
          `Unknown
            (Format.sprintf "`Text_editing %s"
               (Sdl.Event.get ev Sdl.Event.text_editing_text) )
      | `Text_input ->
          `Text_input (Sdl.Event.get ev Sdl.Event.text_input_text)
      | `Key_down ->
          if repeat < 1 then `Key_down (key_of_sdlkey ev) else `None
      | `Key_up ->
          if repeat < 1 then `Key_up (key_of_sdlkey ev) else `None
      | `Mouse_motion ->
          let _, mouse_xy = Tsdl.Sdl.get_mouse_state () in
          `Mouse mouse_xy
      | `Quit -> `Quit
      (* Unhandled events *)
      | `App_did_enter_background ->
          `Unknown "`App_did_enter_background"
      | `App_did_enter_foreground ->
          `Unknown "`App_did_enter_foreground "
      | `App_low_memory -> `Unknown "`App_low_memory "
      | `App_terminating -> `Unknown "`App_terminating "
      | `App_will_enter_background ->
          `Unknown "`App_will_enter_background "
      | `App_will_enter_foreground ->
          `Unknown "`App_will_enter_foreground "
      | `Clipboard_update -> `Unknown "`Clipboard_update "
      | `Controller_axis_motion -> `Unknown "`Controller_axis_motion "
      | `Controller_button_down -> `Unknown "`Controller_button_down "
      | `Controller_button_up -> `Unknown "`Controller_button_up "
      | `Controller_device_added ->
          `Unknown "`Controller_device_added "
      | `Controller_device_remapped ->
          `Unknown "`Controller_device_remapped "
      | `Controller_device_removed ->
          `Unknown "`Controller_device_removed "
      | `Dollar_gesture -> `Unknown "`Dollar_gesture "
      | `Dollar_record -> `Unknown "`Dollar_record "
      | `Drop_file -> `Unknown "`Drop_file "
      | `Finger_down -> `Unknown "`Finger_down"
      | `Finger_motion -> `Unknown "`Finger_motion "
      | `Finger_up -> `Unknown "`Finger_up "
      | `Joy_axis_motion -> `Unknown "`Joy_axis_motion "
      | `Joy_ball_motion -> `Unknown "`Joy_ball_motion "
      | `Joy_button_down -> `Unknown "`Joy_button_down "
      | `Joy_button_up -> `Unknown "`Joy_button_up "
      | `Joy_device_added -> `Unknown "`Joy_device_added "
      | `Joy_device_removed -> `Unknown "`Joy_device_removed "
      | `Joy_hat_motion -> `Unknown "`Joy_hat_motion "
      | `Mouse_button_down -> `Unknown "`Mouse_button_down "
      | `Mouse_button_up -> `Unknown "`Mouse_button_up"
      | `Mouse_wheel -> `Unknown "`Mouse_wheel "
      | `Multi_gesture -> `Unknown "`Multi_gesture"
      | `Sys_wm_event -> `Unknown "`Sys_wm_event "
      | `Unknown e -> `Unknown (Format.sprintf "`Unknown %d " e)
      | `User_event -> `Unknown "`User_event "
      | `Display_event -> `Unknown "`Display_event "
      | `Sensor_update -> `Unknown "`Sensor_update "
      | `Window_event -> `Unknown "`Window_event " in
    (*    F.epr "event_of_sdlevent: %s@." (to_string r) ;*)
    r

  let key_up : Sdl.keycode = 0x40000052
  let key_down : Sdl.keycode = 0x40000051
  let key_left : Sdl.keycode = 0x40000050
  let key_right : Sdl.keycode = 0x4000004f
  let handle_keyevents (el : events) f = List.iter f el
end

module Display = struct
  open Tgles2
  open Tsdl
  open Gg
  open Wall
  module I = Image
  module P = Path
  module Text = Wall_text

  let ( >>>= ) x f =
    match x with Ok a -> f a | Error _ as result -> result

  let get_result = function
    | Ok x -> x
    | Error (`Msg msg) -> failwith msg

  (* current window state to be passed to window renderer *)
  type state =
    { box: box2
          (* This is cannonically box within which the next element should draw *)
    ; time: float
    ; wall: Wall.renderer }

  (* the box2 here is cannonically the place the returner drew
     (the Wall.image extents) *)
  type image = box2 * Wall.image
  type pane = state -> state * image
  type actor = (Event.events -> pane Lwt.t) ref

  let pane_empty s =
    (s, (Box2.of_pts (Box2.o s.box) (Box2.o s.box), Image.empty))

  type frame =
    { sdl_win: Sdl.window
    ; gl: Sdl.gl_context
    ; wall: Wall.renderer
    ; mutable last_pane: pane
    ; mutable quit: bool
    ; mutable fullscreen: bool }

  let ticks () = Int32.to_float (Sdl.get_ticks ()) /. 1000.

  let on_failure ~cleanup result =
    (match result with Ok _ -> () | Error _ -> cleanup ()) ;
    result

  let video_initialized = lazy (Sdl.init Sdl.Init.video)

  let make_frame ?(title = "komm") ~w ~h () =
    Lazy.force video_initialized
    >>>= fun () ->
    Sdl.create_window ~w ~h title
      Sdl.Window.(
        opengl + allow_highdpi + resizable (*+ input_grabbed*))
    >>>= fun sdl_win ->
    Sdl.set_window_title sdl_win title ;
    ignore (Sdl.gl_set_swap_interval (-1)) ;
    ignore (Sdl.gl_set_attribute Sdl.Gl.stencil_size 1) ;
    on_failure
      ( Sdl.gl_create_context sdl_win
      >>>= fun gl ->
      let wall =
        Wall.Renderer.create ~antialias:true ~stencil_strokes:true ()
      in
      Ok
        { sdl_win
        ; gl
        ; wall
        ; quit= false
        ; fullscreen= false
        ; last_pane= pane_empty } )
      ~cleanup:(fun () -> Sdl.destroy_window sdl_win)

  let handle_frame_events frame events =
    List.iter
      (fun (e : Event.t) ->
        match e with
        | `Quit -> frame.quit <- true
        | `Fullscreen a ->
            frame.fullscreen <- a ;
            ignore (Sdl.show_cursor (not frame.fullscreen) : _ result) ;
            ignore
              ( Sdl.set_window_fullscreen frame.sdl_win
                  ( if frame.fullscreen then
                    Sdl.Window.fullscreen_desktop
                  else Sdl.Window.windowed )
                : _ result )
        | _ -> () )
      events

  let draw_pane frame pane =
    let width, height = Sdl.gl_get_drawable_size frame.sdl_win in
    let _, (_, image) =
      pane
        { box= Box2.v (P2.v 0. 0.) (P2.v (float width) (float height))
        ; time= ticks ()
        ; wall= frame.wall } in
    Sdl.gl_make_current frame.sdl_win frame.gl
    >>>= fun () ->
    Gl.viewport 0 0 width height ;
    Gl.clear_color 0.0 0.0 0.0 1.0 ;
    Gl.(
      clear
        (color_buffer_bit lor depth_buffer_bit lor stencil_buffer_bit)) ;
    Gl.enable Gl.blend ;
    Gl.blend_func_separate Gl.one Gl.src_alpha Gl.one
      Gl.one_minus_src_alpha ;
    Gl.enable Gl.cull_face_enum ;
    Gl.disable Gl.depth_test ;
    let width = float width and height = float height in
    Wall.Renderer.render frame.wall ~width ~height image ;
    Sdl.gl_swap_window frame.sdl_win ;
    Ok ()

  let rec get_events () : Event.t list =
    (* create and fill event list *)
    let ev = Sdl.Event.create () in
    if Sdl.poll_event (Some ev) then
      get_events () @ [Event.event_of_sdlevent ev]
    else []

  let display_frame frame (actor : actor) =
    let events = get_events () in
    handle_frame_events frame events ;
    if List.length events > 0 then (
      (* recompute the actor definition with the new events to return a new pane *)
      !actor events
      >>= fun p ->
      frame.last_pane <- p ;
      (* call draw_pane because we should redraw now that we have updated *)
      ignore (draw_pane frame frame.last_pane) ;
      Lwt.return_unit )
    else Lwt.return_unit

  let run frame actor () =
    let frame = get_result frame in
    Sdl.show_window frame.sdl_win ;
    let rec loop () =
      Lwt.pause () (* seems required for the irc connection to work *)
      >>= fun () ->
      Lwt_unix.sleep 0.030
      >>= fun () ->
      display_frame frame actor
      >>= fun () ->
      if not frame.quit then loop () else Lwt.return_unit in
    Lwt_main.run (loop ()) ;
    print_endline "quit" ;
    Sdl.hide_window frame.sdl_win ;
    Sdl.gl_delete_context frame.gl ;
    Sdl.destroy_window frame.sdl_win ;
    Sdl.quit () ;
    ()

  let gray ?(a = 1.0) v = Color.v v v v a

  let load_font name =
    let ic = open_in_bin name in
    let dim = in_channel_length ic in
    let fd = Unix.descr_of_in_channel ic in
    let buffer =
      Unix.map_file fd Bigarray.int8_unsigned Bigarray.c_layout false
        [|dim|]
      |> Bigarray.array1_of_genarray in
    let offset = List.hd (Stb_truetype.enum buffer) in
    match Stb_truetype.init buffer offset with
    | None -> assert false
    | Some font -> font

  let font_icons = lazy (load_font "fonts/entypo.ttf")
  let font_sans = lazy (load_font "fonts/Roboto-Regular.ttf")
  let font_sans_bold = lazy (load_font "fonts/Roboto-Bold.ttf")
  let font_sans_light = lazy (load_font "fonts/Roboto-Light.ttf")
  let font_sans_italic = lazy (load_font "fonts/Roboto-Italic.ttf")

  let font_sans_bold_italic =
    lazy (load_font "fonts/Roboto-BoldItalic.ttf")

  let font_serif =
    lazy (load_font "fonts/ScheherazadeNew-Regular.ttf")

  let font_serif_bold =
    lazy (load_font "fonts/ScheherazadeNew-Bold.ttf")

  let font_mono = lazy (load_font "fonts/static/RobotoMono-Regular")

  let font_mono_bold =
    lazy (load_font "fonts/static/RobotoMono-Regular")

  let font_mono_light =
    lazy (load_font "fonts/static/RobotoMono-Regular")

  let font_emoji = lazy (load_font "fonts/NotoEmoji-Regular.ttf")

  let str_of_box b =
    Printf.sprintf "(ox:%0.1f oy:%0.1f ex%0.1f ey%0.1f)" (Box2.ox b)
      (Box2.oy b) (Box2.maxx b) (Box2.maxy b)

  let draw_label text b =
    let f = Text.Font.make ~size:(Box2.h b) (Lazy.force font_sans) in
    ( Box2.v (Box2.o b) (P2.v (Text.Font.text_width f text) (Box2.h b))
    , I.paint
        (Paint.color (gray ~a:0.5 1.0))
        Text.(
          simple_text f ~valign:`BASELINE ~halign:`LEFT ~x:(Box2.ox b)
            ~y:(Box2.oy b +. (Box2.h b *. 0.75))
            text) )

  let fill_box c b =
    ( b
    , I.paint (Paint.color c)
        ( I.fill_path
        @@ fun t ->
        P.rect t ~x:(Box2.ox b) ~y:(Box2.oy b) ~w:(Box2.w b)
          ~h:(Box2.h b) ) )

  let draw_filled_box c (s : state) = (s, fill_box c s.box)

  let path_box c b (s : state) =
    ( s
    , ( b
      , I.paint (Paint.color c)
          ( I.stroke_path (Outline.make ())
          @@ fun t ->
          P.rect t ~x:(Box2.ox b) ~y:(Box2.oy b) ~w:(Box2.w b)
            ~h:(Box2.h b) ) ) )

  let path_circle c b (s : state) =
    ( s
    , ( b
      , I.paint (Paint.color c)
          ( I.stroke_path (Outline.make ())
          @@ fun t ->
          P.circle t ~cx:(Box2.midx b) ~cy:(Box2.midy b)
            ~r:(Box2.w b /. 2.) ) ) )

  (** Display.state.box as supplied to a widget defines the allowed drawing area for the widget.
    This way basic widgets will just expand to the full area of a box, while other widgets can have
    the express purpose of limiting the size of an object in a larger system of limitations. 

    Panes return a tuple: (state, (box, image))
    state is the updated state, where state.box is always 
      - the top left corner of the box the pane drew in, and
      - the bottom right corner of the state.box that was passed in
    box is the area the widget actually drew in (or wants to sort of "use")
    image is the Wall.image to compose with other panes and draw to the display
  *)

  let simple_text f text (s : state) =
    let fm = Text.Font.font_metrics f in
    let font_height = fm.ascent -. fm.descent +. fm.line_gap in
    let tm = Text.Font.text_measure f text in
    let br_pt =
      P2.v (Box2.ox s.box +. tm.width) (Box2.oy s.box +. font_height)
    in
    let bextent = Box2.of_pts (Box2.o s.box) br_pt in
    (*  let _, (_, redbox) = path_box Color.red bextent s in*)
    ( {s with box= Box2.of_pts (Box2.br_pt bextent) (Box2.max s.box)}
    , ( bextent
      , (* I.stack redbox *)
        I.paint
          (Paint.color (gray ~a:0.5 1.0))
          Text.(
            simple_text f ~valign:`BASELINE ~halign:`LEFT
              ~x:(Box2.ox s.box)
              ~y:(Box2.oy s.box +. fm.ascent)
              text) ) )

  let pane_box next_point_func (subpanes : pane list) (so : state) =
    let sr, (br, ir) =
      List.fold_left
        (fun (sp, (bp, ip)) (pane : pane) ->
          (* uses br to hold max extent of boxes *)
          let sr, (br, ir) = pane sp in
          (* draw the pane *)
          let _, (_, irb) = path_box Color.blue br sr in
          (* draw the box around the pane *)
          ( { sr with
              box= Box2.of_pts (next_point_func br) (Box2.max sp.box)
            }
          , ( Box2.of_pts (Box2.o bp)
                (P2.v
                   (max (Box2.maxx br) (Box2.maxx bp))
                   (max (Box2.maxy br) (Box2.maxy bp)) )
            , Image.seq [ip; irb; ir] ) ) )
        ( so
        , (Box2.of_pts (Box2.o so.box) (Box2.o so.box), Image.empty)
        )
        subpanes in
    let _, (_, redbox) = path_box Color.red br sr in
    (sr, (br, Image.stack redbox ir))
end

module Panel = struct
  open Display
  open Gg

  type t =
    { mutable act: t -> Event.events -> Display.pane Lwt.t
    ; mutable subpanels: t Lwt.t list
    ; mutable tag: string }

  let blank =
    { act= (fun _panel _events -> Lwt.return Display.pane_empty)
    ; subpanels= []
    ; tag= "blank pane" }

  let draw (pane : Display.pane) =
    Lwt.return
      { act= (fun _panel _events -> Lwt.return pane)
      ; subpanels= []
      ; tag= "draw-pane" }

  let actor (panel : t) : Event.events -> Display.pane Lwt.t =
   fun events ->
    panel.act panel events >>= fun pane -> Lwt.return pane

  let filter_events ef p =
    p
    >>= fun p' ->
    Lwt.return
      {p' with act= (fun panel events -> p'.act panel (ef events))}

  let resolve_panels events =
    Lwt_list.map_s (fun s ->
        s
        >>= fun subpanel ->
        subpanel.act subpanel events >>= fun pane -> Lwt.return pane )

  (* draws subsequent items below *)
  let vbox subpanels =
    Lwt.return
      { act=
          (fun panel events ->
            resolve_panels events panel.subpanels
            >|= fun pl -> pane_box Box2.tl_pt pl )
          (* tl_pt is actually bl_pt in the Wall coordinate system *)
      ; subpanels
      ; tag= "vertical-box" }

  (* draws subsequent item to the right *)
  let hbox subpanels =
    Lwt.return
      { act=
          (fun panel events ->
            resolve_panels events panel.subpanels
            >|= fun pl -> pane_box Box2.br_pt pl )
          (* br_pt is actually tr_pt in the Wall coordinate system *)
      ; subpanels
      ; tag= "horizontal-box" }

  (* draws subsequent panels overtop each other *)
  let obox (subpanels : t Lwt.t list) =
    { act=
        (fun panel events ->
          resolve_panels events panel.subpanels
          >|= fun pl -> pane_box Box2.o pl )
    ; subpanels
    ; tag= "origin-box" }

  let g_text_height = ref 25.

  type Format.stag += Color_bg of Wall.color
  type Format.stag += Color_fg of Wall.color
  type Format.stag += Cursor of Wall.color
  type Format.stag += None_tag

  let draw_pp height fpp (s : state) =
    let node, sc, box = (ref I.empty, ref s, ref Box2.zero) in
    let push (s, (b, i)) =
      node := I.stack !node i ;
      sc := s ;
      box := b in
    let font = Text.Font.make ~size:height (Lazy.force font_sans) in
    let fm = Text.Font.font_metrics font in
    let font_height = fm.ascent -. fm.descent +. fm.line_gap in
    let max_x = ref 0. in
    let out_string text o l =
      let sp = !sc in
      push @@ simple_text font (String.sub text o l) !sc ;
      max_x := max !max_x (Box2.maxx !box) ;
      sc :=
        { !sc with
          box=
            Box2.of_pts
              (P2.v (Box2.maxx !box) (Box2.oy sp.box))
              (Box2.max sp.box) } in
    let out_flush () = () in
    let out_newline () =
      sc :=
        { !sc with
          box=
            Box2.of_pts
              (P2.v (Box2.ox s.box) (Box2.oy !sc.box +. font_height))
              (Box2.max s.box) } in
    let out_spaces n =
      let wpx = Text.Font.text_width font " " in
      if Box2.ox !sc.box +. (float n *. wpx) > Box2.maxx !sc.box then
        (* WRAP *)
        out_newline () ;
      let so = !sc in
      (* let bsp = Box2.v (Box2.br_pt !box) (P2.v wpx height) in
         push @@ pane_hbox (List.init n (fun _ -> path_circle Color.green bsp)) !sc;*)
      box := Box2.v (Box2.o so.box) (P2.v (float n *. wpx) height) ;
      sc :=
        {!sc with box= Box2.of_pts (Box2.br_pt !box) (Box2.max so.box)}
    in
    let out_indent n =
      let p = min (Box2.w !sc.box -. 1.) (height *. 2.0 *. float n) in
      sc :=
        { !sc with
          box=
            Box2.of_pts
              (P2.v (Box2.ox !sc.box +. p) (Box2.oy !sc.box))
              (Box2.max !sc.box) } in
    let out_funs =
      Format.
        {out_string; out_flush; out_newline; out_spaces; out_indent}
    in
    let pp = Format.formatter_of_out_functions out_funs in
    Format.pp_set_formatter_stag_functions pp
      { mark_open_stag=
          (fun s ->
            ( match s with
            | Cursor c ->
                push
                @@ ( !sc
                   , fill_box c
                       (Box2.v (Box2.o !sc.box)
                          (P2.v (height *. 0.333) height) ) )
            | Color_bg c -> push @@ (!sc, fill_box c !box)
            | _ -> () ) ;
            "" )
      ; mark_close_stag= (function _ -> () ; "")
      ; print_open_stag= (fun _ -> (*"<open_stag>"*) ())
      ; (* TKTKTKTK XXX IT SHOULD BE USING THESE print ONES *)
        print_close_stag= (fun _ -> (*"<close_stag>"*) ()) } ;
    Format.pp_set_tags pp true ;
    let margin =
      int_of_float (Box2.w s.box /. Text.Font.text_width font " ")
    in
    let max_indent = margin - 1 in
    Format.pp_safe_set_geometry pp ~max_indent ~margin ;
    fpp pp ;
    Format.pp_force_newline pp () ;
    ( !sc
    , ( Box2.of_pts (Box2.o s.box) (P2.v !max_x (Box2.maxy !box))
      , !node ) )

  let format_symbolic_output_items (ppf : Format.formatter) buf =
    List.iter
      Format.(
        function
        | Output_flush -> F.pf ppf "@?"
        | Output_newline -> F.pf ppf "@."
        | Output_string s -> Format.pp_print_string ppf s
        | Output_spaces n | Output_indent n ->
            Format.pp_print_string ppf (String.make n ' '))
      buf

  let format_symbolic_output_buffer (ppf : Format.formatter) buf =
    format_symbolic_output_items ppf
      (Format.get_symbolic_output_buffer buf)

  let prettyprint ?(height = !g_text_height) ?(tag = "pretty-print")
      fpp =
    Lwt.return
      { act= (fun _panel _events -> Lwt.return (draw_pp height fpp))
      ; subpanels= []
      ; tag }

  module Textedit = struct
    type t =
      { mutable zed: unit Zed_edit.context
      ; mutable view: Zed_cursor.t
      ; mutable keybind: Input.Bind.state }

    let bindings te =
      let open Input.Bind in
      add [([], Code Left)] [Zed Prev_char]
      @@ add [([], Code Right)] [Zed Next_char]
      @@ add [([], Code Up)] [Zed Prev_line]
      @@ add [([], Code Down)] [Zed Next_line]
      @@ add [([], Code Home)] [Zed Goto_bol]
      @@ add [([], Code End)] [Zed Goto_eol]
      @@ add [([], Code Insert)] [Zed Switch_erase_mode]
      @@ add [([], Code Delete)] [Zed Delete_next_char]
      @@ add [([], Code Enter)] [Zed Newline]
      @@ add [([Ctrl], Char ' ')] [Zed Set_mark]
      @@ add [([Ctrl], Char 'a')] [Zed Goto_bol]
      @@ add [([Ctrl], Char 'e')] [Zed Goto_eol]
      @@ add [([Ctrl], Char 'd')] [Zed Delete_next_char]
      @@ add [([Ctrl], Char 'h')] [Zed Delete_prev_char]
      @@ add [([Ctrl], Char 'k')] [Zed Kill_next_line]
      @@ add [([Ctrl], Char 'u')] [Zed Kill_prev_line]
      @@ add [([Ctrl], Char 'n')] [Zed Next_line]
      @@ add [([Ctrl], Char 'p')] [Zed Prev_line]
      @@ add [([Ctrl], Char 'w')] [Zed Kill]
      @@ add [([Ctrl], Char 'y')] [Zed Yank]
      @@ add [([], Code Backspace)] [Zed Delete_prev_char]
      @@ add [([Meta], Char 'w')] [Zed Copy]
      @@ add [([Meta], Char 'c')] [Zed Capitalize_word]
      @@ add [([Meta], Char 'l')] [Zed Lowercase_word]
      @@ add [([Meta], Char 'u')] [Zed Uppercase_word]
      @@ add [([Meta], Char 'b')] [Zed Prev_word]
      @@ add [([Meta], Char 'f')] [Zed Next_word]
      @@ add [([Meta], Code Right)] [Zed Next_word]
      @@ add [([Meta], Code Left)] [Zed Prev_word]
      @@ add [([Ctrl], Code Right)] [Zed Next_word]
      @@ add [([Ctrl], Code Left)] [Zed Prev_word]
      @@ add [([Meta], Code Backspace)] [Zed Kill_prev_word]
      @@ add [([Meta], Code Delete)] [Zed Kill_prev_word]
      @@ add [([Ctrl], Code Delete)] [Zed Kill_next_word]
      @@ add [([Meta], Char 'd')] [Zed Kill_next_word]
      @@ add [([Ctrl], Char '/')] [Zed Undo]
      @@ add [([Ctrl], Char 'x'); ([], Char 'u')] [Zed Undo]
      @@ add
           [([Ctrl], Char 'v')]
           [ Custom
               (fun () ->
                 let r = Zed_edit.text (Zed_edit.edit te.zed) in
                 let l = Zed_lines.of_rope r in
                 let i = Zed_cursor.get_line te.view in
                 Zed_cursor.goto te.view
                   (Zed_lines.line_start l i + 10) ) ]
      @@ add
           [([Meta], Char 'v')]
           [ Custom
               (fun () ->
                 let r = Zed_edit.text (Zed_edit.edit te.zed) in
                 let l = Zed_lines.of_rope r in
                 let i = Zed_cursor.get_line te.view in
                 Zed_cursor.goto te.view
                   (Zed_lines.line_start l i - 10) ) ]
      @@ empty

    let clear te =
      let ze = Zed_edit.create () in
      te.zed <- Zed_edit.context ze (Zed_edit.new_cursor ze)

    let insert te text =
      Zed_edit.insert te.zed
        (Zed_rope.of_string (Zed_string.of_utf8 text))

    let contents (te : t) =
      Zed_string.to_utf8
        (Zed_rope.to_string (Zed_edit.text (Zed_edit.edit te.zed)))

    let make ?(keybinds = bindings) initialtext () =
      let ze = Zed_edit.create () in
      let te =
        { zed= Zed_edit.context ze (Zed_edit.new_cursor ze)
        ; view= Zed_edit.new_cursor ze
        ; keybind= Input.Bind.init Input.Bind.empty } in
      te.keybind.bindings <- keybinds te ;
      insert te initialtext ;
      te

    let panel ?(height = !g_text_height) te =
      Lwt.return
        { act=
            (fun _panel events ->
              (* collect events and update Zed context *)
              Lwt_list.iter_s
                (function
                  | `Key_down (k : Input.keystate) -> (
                      let open Input.Bind in
                      ( match te.keybind.state with
                      | Accepted _ | Rejected ->
                          te.keybind.last_keyseq <- [] ;
                          te.keybind.last_actions <- []
                      | Continue _ -> () ) ;
                      te.keybind.state <-
                        resolve k
                          (get_resolver te.keybind.state
                             (default_resolver te.keybind.bindings) ) ;
                      te.keybind.last_keyseq <-
                        k :: te.keybind.last_keyseq ;
                      match te.keybind.state with
                      | Accepted a ->
                          te.keybind.last_actions <- a ;
                          Lwt_list.iter_s
                            (function
                              | Input.Bind.Custom f ->
                                  Lwt.return (f ())
                              | Input.Bind.CustomLwt f -> f ()
                              | Zed za ->
                                  Lwt.return
                                    (Zed_edit.get_action za te.zed) )
                            a
                      | Continue _ | Rejected -> Lwt.return_unit )
                  | `Key_up _ -> Lwt.return_unit
                  | `Text_input s ->
                      Lwt.return
                        (Zed_edit.insert te.zed
                           (Zed_rope.of_string (Zed_string.of_utf8 s)) )
                  | _ -> Lwt.return_unit )
                events
              >>= fun () ->
              let draw_textedit =
                draw_pp height (fun pp ->
                    let _, view =
                      Zed_rope.break
                        (Zed_edit.text (Zed_edit.edit te.zed))
                        (Zed_cursor.get_position te.view) in
                    Format.pp_open_hvbox pp 0 ;
                    if
                      Zed_cursor.get_position te.view
                      > Zed_cursor.get_position
                          (Zed_edit.cursor te.zed)
                    then (
                      let zrb, zra =
                        Zed_rope.break
                          (Zed_edit.text (Zed_edit.edit te.zed))
                          (Zed_cursor.get_position
                             (Zed_edit.cursor te.zed) ) in
                      let before_cursor =
                        Zed_string.to_utf8 (Zed_rope.to_string zrb)
                      in
                      let after_cursor =
                        Zed_string.to_utf8 (Zed_rope.to_string zra)
                      in
                      F.text pp before_cursor ;
                      Format.pp_open_stag pp
                        (Cursor (Wall.Color.v 0.99 0.99 0.125 0.3)) ;
                      F.pf pp "" ;
                      Format.pp_close_stag pp () ;
                      F.text pp after_cursor )
                    else
                      F.text pp
                        (Zed_string.to_utf8 (Zed_rope.to_string view)) ;
                    F.pf pp "@." ;
                    Format.pp_close_box pp () ) in
              Lwt.return draw_textedit )
        ; subpanels= []
        ; tag= "textedit" }

    (* pane that displays last key binding match state *)
    let bindingstate ?(height = !g_text_height) (b : Input.Bind.state)
        =
      Lwt.return
        { act=
            (fun _panel _events ->
              Lwt.return
                (draw_pp height (fun pp ->
                     Format.pp_open_hbox pp () ;
                     F.text pp
                       (List.fold_left
                          (fun s x ->
                            Input.to_string_compact x ^ " " ^ s )
                          "" b.last_keyseq ) ;
                     F.text pp "-> " ;
                     F.text pp
                       ( match b.state with
                       | Accepted a ->
                           "Accepted "
                           ^ List.fold_right
                               (fun x s ->
                                 s
                                 ^ Input.Bind.(
                                     match x with
                                     | Zed a ->
                                         Zed_edit.name_of_action a
                                     | CustomLwt _ -> "CustomLwt"
                                     | Custom _ -> "Custom")
                                 ^ "; " )
                               a ""
                       | Rejected -> "Rejected"
                       | Continue _ -> "Continue" ) ;
                     Format.pp_close_box pp () ;
                     F.flush pp () ) ) )
        ; subpanels= []
        ; tag= "binding-state" }
  end

  module Modal = struct
    type t =
      { te: Textedit.t
      ; mutable input: string option
      ; mutable handle: string -> unit
      ; mutable prompt: string }

    let make () =
      { te= Textedit.make "" ()
      ; input= None
      ; handle= (fun _text -> ())
      ; prompt= "" }

    let panel ?(height = !g_text_height) me =
      let keybinds =
        let open Input.Bind in
        add [([], Code Enter)]
          [ Custom
              (fun () ->
                (* set input first so a modal can trigger another modal *)
                me.input <- None ;
                me.handle (Textedit.contents me.te) ) ]
          (Textedit.bindings me.te) in
      me.te.keybind.bindings <- keybinds ;
      Lwt.return
        { act=
            (fun panel events ->
              match me.input with
              | Some text ->
                  Textedit.insert me.te text ;
                  hbox panel.subpanels >>= fun p -> p.act panel events
              | None -> Lwt.return Display.pane_empty
              (* don't draw anything if modal isn't active *) )
        ; subpanels=
            [ prettyprint (fun pp -> F.text pp me.prompt)
            ; Textedit.panel ~height me.te ]
        ; tag= "modal-edit" }

    let start me ?(prompt = "> ") text handler =
      me.input <- Some text ;
      Textedit.clear me.te ;
      Textedit.insert me.te text ;
      me.handle <- handler ;
      me.prompt <- prompt

    let is_active me =
      match me.input with Some _ -> true | None -> false
  end

  module Nottui = struct
    open Nottui
    open Notty
    module P = Nottui_pretty

    let convert_events events : Nottui_lwt.event option list =
      let key_of_keystate
          (Input.{ctrl; meta; shift; super= _; code} as k) :
          Notty.Unescape.key option =
        F.epr "Nottui.convert_events: %s@."
          (Input.to_string_compact k) ;
        match code with
        | None | Unknown -> None
        | code ->
            Some
              ( ( match code with
                | UChar c ->
                    let d =
                      Uchar.of_int (CamomileLibrary.UChar.code c)
                    in
                    if Uchar.is_char d then `ASCII (Uchar.to_char d)
                    else `Uchar d
                | Enter -> `Enter
                | Escape -> `Escape
                | Tab -> `Tab
                | Up -> `Arrow `Up
                | Down -> `Arrow `Down
                | Left -> `Arrow `Left
                | Right -> `Arrow `Right
                | F1 -> `Function 1
                | F2 -> `Function 2
                | F3 -> `Function 3
                | F4 -> `Function 4
                | F5 -> `Function 5
                | F6 -> `Function 6
                | F7 -> `Function 7
                | F8 -> `Function 8
                | F9 -> `Function 9
                | F10 -> `Function 10
                | F11 -> `Function 11
                | F12 -> `Function 12
                | Next_page -> `Page `Down
                | Prev_page -> `Page `Up
                | Home -> `Home
                | End -> `End
                | Insert -> `Insert
                | Delete -> `Delete
                | Backspace -> `Backspace
                | _ -> `Uchar (Uchar.of_int 0) )
              , (if ctrl then [`Ctrl] else [])
                @ (if meta then [`Meta] else [])
                @ if shift then [`Shift] else [] ) in
      List.filter_map
        (function
          | `Key_down k -> (
            match key_of_keystate k with
            | None -> None
            | Some k -> Some (Some (`Key k)) )
          | _ -> None )
        events

    module Attr = struct
      type attr =
        { fg: Wall.color
        ; bg: Wall.color
        ; size: float
        ; font: [`Sans | `Serif | `Mono]
        ; weight: [`Bold | `Regular | `Light]
        ; italic: [`Italic | `None]
        ; underline: [`Underline | `None] }

      let empty =
        { fg= Color.void
        ; bg= Color.void
        ; size= 0.
        ; font= `Sans
        ; weight= `Regular
        ; italic= `None
        ; underline= `None }

      let equal = ( == )

      let ( ++ ) a1 a2 =
        if a1 == empty then a2
        else if a2 == empty then a1
        else
          { a1 with
            fg= Color.blend a1.fg a2.fg
          ; bg= Color.blend a1.bg a2.bg }

      let fg fg = {empty with fg}
      let bg bg = {empty with bg}

      let get_font a =
        Text.Font.make ~size:a.size
          (load_font
             ( match (a.font, a.weight, a.italic) with
             | `Sans, `Regular, `None -> "fonts/Roboto-Regular.ttf"
             | `Sans, `Bold, `None -> "fonts/Roboto-Bold.ttf"
             | `Sans, `Light, `None -> "fonts/Roboto-Light.ttf"
             | `Sans, `Regular, `Italic -> "fonts/Roboto-Italic.ttf"
             | `Sans, `Bold, `Italic -> "fonts/Roboto-BoldItalic.ttf"
             | `Sans, `Light, `Italic ->
                 "fonts/Roboto-LightItalic.ttf"
             | `Serif, `Bold, _ -> "fonts/ScheherazadeNew-Bold.ttf"
             | `Serif, _, _ -> "fonts/ScheherazadeNew-Regular.ttf"
             | `Mono, `Regular, `None ->
                 "fonts/static/RobotoMono-Regular.ttf"
             | _, _, _ -> "fonts/Roboto-Regular.ttf" ) )
    end

    open Notty

    let invalid_arg fmt = Format.kasprintf invalid_arg fmt
    let ( &. ) f g x = f (g x)
    let btw (x : int) a b = a <= x && x <= b
    let bit n b = b land (1 lsl n) > 0
    let max (a : int) b = if a > b then a else b
    let min (a : int) b = if a < b then a else b

    let is_C0 x = x < 0x20 || x = 0x7f
    and is_C1 x = 0x80 <= x && x < 0xa0

    let is_ctrl x = is_C0 x || is_C1 x and is_ascii x = x < 0x80

    let rec concatm z ( @ ) xs =
      let rec accum ( @ ) = function
        | ([] | [_]) as xs -> xs
        | a :: b :: xs -> (a @ b) :: accum ( @ ) xs in
      match xs with
      | [] -> z
      | [x] -> x
      | xs -> concatm z ( @ ) (accum ( @ ) xs)

    let rec linspcm z ( @ ) x n f =
      match n with
      | 0 -> z
      | 1 -> f x
      | _ ->
          let m = n / 2 in
          linspcm z ( @ ) x m f @ linspcm z ( @ ) (x + m) (n - m) f

    let memo (type a) ?(hash = Hashtbl.hash) ?(eq = ( = )) ~size f =
      let module H = Ephemeron.K1.Make (struct
        type t = a

        let hash, equal = (hash, eq)
      end) in
      let t = H.create size in
      fun x ->
        try H.find t x
        with Not_found ->
          let y = f x in
          H.add t x y ; y

    module List = struct
      include List

      let init n f =
        let rec go a n = if n < 0 then a else go (f n :: a) (n - 1) in
        go [] (n - 1)
    end

    module Buffer = struct
      include Buffer

      let buf = Buffer.create 1024

      let mkstring f =
        f buf ;
        let res = contents buf in
        reset buf ; res

      let add_decimal b = function
        | x when btw x 0 999 ->
            let d1 = x / 100
            and d2 = x mod 100 / 10
            and d3 = x mod 10 in
            if d1 > 0 then 0x30 + d1 |> Char.unsafe_chr |> add_char b ;
            if d1 + d2 > 0 then
              0x30 + d2 |> Char.unsafe_chr |> add_char b ;
            0x30 + d3 |> Char.unsafe_chr |> add_char b
        | x -> string_of_int x |> add_string b

      let add_chars b c n =
        for _ = 1 to n do
          add_char b c
        done
    end

    module Text = struct
      let err_ctrl u =
        invalid_arg "Notty: control char: U+%02X, %S" (Char.code u)

      let err_malformed = invalid_arg "Notty: malformed UTF-8: %s, %S"

      type t =
        | Ascii of string * int * int
        | Utf8 of string * int array * int * int

      let equal t1 t2 =
        match (t1, t2) with
        | Utf8 (s1, _, i1, n1), Utf8 (s2, _, i2, n2)
         |Ascii (s1, i1, n1), Ascii (s2, i2, n2) ->
            i1 = i2 && n1 = n2 && s1 = s2
        | _ -> false

      let width = function
        | Utf8 (_, _, _, w) -> w
        | Ascii (_, _, w) -> w

      let empty = Ascii ("", 0, 0)

      let graphemes str =
        let seg = Uuseg.create `Grapheme_cluster in
        let rec f ((is, w) as acc) i evt =
          match Uuseg.add seg evt with
          | `Await | `End -> acc
          | `Uchar u ->
              f (is, w + Uucp.Break.tty_width_hint u) i `Await
          | `Boundary ->
              let is =
                match w with
                | 0 -> is
                | 1 -> i :: is
                | _ -> i :: -1 :: is in
              f (is, 0) i `Await in
        let acc =
          Uutf.String.fold_utf_8
            (fun acc i -> function
              | `Malformed err -> err_malformed err str
              | `Uchar _ as u -> f acc i u )
            ([0], 0)
            str in
        f acc (String.length str) `End
        |> fst |> List.rev |> Array.of_list

      let dead = ' '

      let to_buffer buf = function
        | Ascii (s, off, w) -> Buffer.add_substring buf s off w
        | Utf8 (s, ix, off, w) ->
            let x1 =
              match ix.(off) with
              | -1 ->
                  Buffer.add_char buf dead ;
                  ix.(off + 1)
              | x -> x
            and x2 = ix.(off + w) in
            Buffer.add_substring buf s x1
            @@ ((if x2 = -1 then ix.(off + w - 1) else x2) - x1) ;
            if x2 = -1 then Buffer.add_char buf dead

      let sub t x w =
        let w1 = width t in
        if w = 0 || x >= w1 then empty
        else
          let w = min w (w1 - x) in
          if w = w1 then t
          else
            match t with
            | Ascii (s, off, _) -> Ascii (s, off + x, w)
            | Utf8 (s, ix, off, _) -> Utf8 (s, ix, off + x, w)

      let is_ascii_or_raise_ctrl s =
        let ( @! ) s i = String.unsafe_get s i |> Char.code in
        let rec go s acc i n =
          if n = 0 then acc
          else
            let x = s @! i in
            if is_C0 x then err_ctrl s.[i] s
            else if x = 0xc2 && n > 1 && is_C1 (s @! (i + 1)) then
              err_ctrl s.[i + 1] s
            else go s (acc && is_ascii x) (i + 1) (n - 1) in
        go s true 0 (String.length s)

      let of_ascii s = Ascii (s, 0, String.length s)

      and of_unicode s =
        let x = graphemes s in
        Utf8 (s, x, 0, Array.length x - 1)

      let of_unicode = memo ~eq:String.equal ~size:128 of_unicode

      let of_string = function
        | "" -> empty
        | s ->
            if is_ascii_or_raise_ctrl s then of_ascii s
            else of_unicode s

      let of_uchars ucs =
        of_string @@ Buffer.mkstring
        @@ fun buf -> Array.iter (Buffer.add_utf_8_uchar buf) ucs

      let replicateu w u =
        if is_ctrl (Uchar.to_int u) then
          err_ctrl (Uchar.unsafe_to_char u) "<repeated character>"
        else if w < 1 then empty
        else if is_ascii (Uchar.to_int u) then
          of_ascii (String.make w (Uchar.unsafe_to_char u))
        else
          of_unicode @@ Buffer.mkstring
          @@ fun buf ->
          for _ = 1 to w do
            Buffer.add_utf_8_uchar buf u
          done

      let replicatec w c = replicateu w (Uchar.of_char c)
    end

    module I = struct
      type dim = int * int

      type t =
        | Empty
        | Segment of Text.t
        | Attr of (t * Attr.attr) * dim
        | Hcompose of (t * t) * dim
        | Vcompose of (t * t) * dim
        | Zcompose of (t * t) * dim
        | Hcrop of (t * int * int) * dim
        | Vcrop of (t * int * int) * dim
        | Void of dim

      let width = function
        | Empty -> 0
        | Segment text -> Text.width text
        | Attr (_, (w, _)) -> w
        | Hcompose (_, (w, _)) -> w
        | Vcompose (_, (w, _)) -> w
        | Zcompose (_, (w, _)) -> w
        | Hcrop (_, (w, _)) -> w
        | Vcrop (_, (w, _)) -> w
        | Void (w, _) -> w
        [@@inline]

      let height = function
        | Empty -> 0
        | Segment _ -> 1
        | Attr (_, (_, h)) -> h
        | Hcompose (_, (_, h)) -> h
        | Vcompose (_, (_, h)) -> h
        | Zcompose (_, (_, h)) -> h
        | Hcrop (_, (_, h)) -> h
        | Vcrop (_, (_, h)) -> h
        | Void (_, h) -> h
        [@@inline]

      let equal t1 t2 =
        let rec eq t1 t2 =
          match (t1, t2) with
          | Empty, Empty -> true
          | Segment t1, Segment t2 -> Text.equal t1 t2
          | Attr ((a, a1), _), Attr ((b, a2), _) ->
              Attr.equal a1 a2 && eq a b
          | Hcompose ((a, b), _), Hcompose ((c, d), _)
           |Vcompose ((a, b), _), Vcompose ((c, d), _)
           |Zcompose ((a, b), _), Zcompose ((c, d), _) ->
              eq a c && eq b d
          | Hcrop ((a, i1, n1), _), Hcrop ((b, i2, n2), _)
           |Vcrop ((a, i1, n1), _), Vcrop ((b, i2, n2), _) ->
              i1 = i2 && n1 = n2 && eq a b
          | Void (a, b), Void (c, d) -> a = c && b = d
          | _ -> false in
        width t1 = width t2 && height t1 = height t2 && eq t1 t2

      let empty = Empty

      let void w h =
        if w < 1 && h < 1 then Empty else Void (max 0 w, max 0 h)

      let attr a = function
        | Attr ((t, a0), dim) -> Attr ((t, Attr.(a ++ a0)), dim)
        | t -> Attr ((t, a), (width t, height t))

      let ( <|> ) t1 t2 =
        match (t1, t2) with
        | _, Empty -> t1
        | Empty, _ -> t2
        | _ ->
            let w = width t1 + width t2
            and h = max (height t1) (height t2) in
            Hcompose ((t1, t2), (w, h))

      let ( <-> ) t1 t2 =
        match (t1, t2) with
        | _, Empty -> t1
        | Empty, _ -> t2
        | _ ->
            let w = max (width t1) (width t2)
            and h = height t1 + height t2 in
            Vcompose ((t1, t2), (w, h))

      let ( </> ) t1 t2 =
        match (t1, t2) with
        | _, Empty -> t1
        | Empty, _ -> t2
        | _ ->
            let w = max (width t1) (width t2)
            and h = max (height t1) (height t2) in
            Zcompose ((t1, t2), (w, h))

      let lincropinv crop void ( ++ ) init fini img =
        match (init >= 0, fini >= 0) with
        | true, true -> crop init fini img
        | true, _ -> crop init 0 img ++ void (-fini)
        | _, true -> void (-init) ++ crop 0 fini img
        | _ -> void (-init) ++ img ++ void (-fini)

      let hcrop =
        let ctor left right img =
          let h = height img and w = width img - left - right in
          if w > 0 then Hcrop ((img, left, right), (w, h))
          else void w h in
        lincropinv ctor (fun w -> void w 0) ( <|> )

      let vcrop =
        let ctor top bottom img =
          let w = width img and h = height img - top - bottom in
          if h > 0 then Vcrop ((img, top, bottom), (w, h))
          else void w h in
        lincropinv ctor (void 0) ( <-> )

      let crop ?(l = 0) ?(r = 0) ?(t = 0) ?(b = 0) img =
        let img = if l <> 0 || r <> 0 then hcrop l r img else img in
        if t <> 0 || b <> 0 then vcrop t b img else img

      let hpad left right img = hcrop (-left) (-right) img
      let vpad top bottom img = vcrop (-top) (-bottom) img

      let pad ?(l = 0) ?(r = 0) ?(t = 0) ?(b = 0) img =
        crop ~l:(-l) ~r:(-r) ~t:(-t) ~b:(-b) img

      let hcat = concatm empty ( <|> )
      let vcat = concatm empty ( <-> )
      let zcat xs = List.fold_right ( </> ) xs empty

      let text attr tx =
        match (Text.width tx, attr) with
        | 0, _ -> void 0 1
        | w, Some a -> Attr ((Segment tx, a), (w, 1))
        | _, _ -> Segment tx

      let string ?attr s = text attr (Text.of_string s)
      let uchars ?attr a = text attr (Text.of_uchars a)

      let tabulate m n f =
        let m = max m 0 and n = max n 0 in
        linspcm empty ( <-> ) 0 n (fun y ->
            linspcm empty ( <|> ) 0 m (fun x -> f x y) )

      let chars ctor ?attr c w h =
        let w = max 0 w and h = max 0 h in
        if w < 1 || h < 1 then void w h
        else
          let line = text attr (ctor w c) in
          tabulate 1 h (fun _ _ -> line)
    end

    (* let string ?(attr = Attr.empty) str =
       let control_character_index str i =
         let len = String.length str in
         let i = ref i in
         while
           let i = !i in
           i < len && str.[i] >= ' '
         do
           incr i
         done ;
         if !i = len then raise Not_found ;
         !i in
       let rec split str i =
         match control_character_index str i with
         | j ->
             let img = I.string ~attr (String.sub str i (j - i)) in
             img :: split str (j + 1)
         | exception Not_found ->
             [ I.string ~attr
                 ( if i = 0 then str
                 else String.sub str i (String.length str - i) ) ]
       in
       Ui.atom (I.vcat (split str 0))*)

    let attr_menu_main = Attr.(bg (Color.gray 0.7) ++ fg Color.black)
    let attr_menu_sub = Attr.(bg (Color.gray 0.5) ++ fg Color.black)
    let attr_clickable = Attr.(bg Color.blue)

    let sub' str p l =
      if p = 0 && l = String.length str then str
      else String.sub str p l

    (* let edit_field ?(focus = Focus.make ()) state ~on_change =
         let update focus_h focus (text, pos) =
           let pos = min (max 0 pos) (String.length text) in
           let content =
             Ui.atom @@ I.hcat
             @@
             if Focus.has_focus focus then
               let attr = attr_clickable in
               let len = String.length text in
               ( if pos >= len then [I.string attr text]
               else [I.string attr (sub' text 0 pos)] )
               @
               if pos < String.length text then
                 [ I.string Attr.(bg lightred) (sub' text pos 1)
                 ; I.string attr (sub' text (pos + 1) (len - pos - 1)) ]
               else [I.string Attr.(bg lightred) " "]
             else
               [ I.string
                   Attr.(st underline)
                   (if text = "" then " " else text) ] in
           let handler = function
             | `ASCII 'U', [`Ctrl] ->
                 on_change ("", 0) ;
                 `Handled (* clear *)
             | `ASCII 'k', [`Ctrl] ->
                 on_change (String.sub text 0 pos, pos) ;
                 `Handled (* clear *)
             | `Escape, [] | `ASCII 'n', [`Ctrl] ->
                 Focus.release focus_h ; `Handled
             | `ASCII k, [] ->
                 let text =
                   if pos < String.length text then
                     String.sub text 0 pos ^ String.make 1 k
                     ^ String.sub text pos (String.length text - pos)
                   else text ^ String.make 1 k in
                 on_change (text, pos + 1) ;
                 `Handled
             | `Backspace, _ ->
                 let text =
                   if pos > 0 then
                     if pos < String.length text then
                       String.sub text 0 (pos - 1)
                       ^ String.sub text pos (String.length text - pos)
                     else if String.length text > 0 then
                       String.sub text 0 (String.length text - 1)
                     else text
                   else text in
                 let pos = max 0 (pos - 1) in
                 on_change (text, pos) ;
                 `Handled
             | `Arrow `Left, [] | `ASCII 'b', [`Ctrl] ->
                 if pos > 0 && pos < String.length text then (
                   on_change (text, pos - 1) ;
                   `Handled )
                 else `Unhandled
             | `Arrow `Right, [] | `ASCII 'f', [`Ctrl] ->
                 let pos = pos + 1 in
                 if pos <= String.length text then (
                   on_change (text, pos) ;
                   `Handled )
                 else `Unhandled
             | `ASCII 'e', [`Ctrl] ->
                 on_change (text, String.length text) ;
                 `Handled
             | `ASCII 'a', [`Ctrl] ->
                 on_change (text, 0) ;
                 `Handled
             | _ -> `Unhandled in
           Ui.keyboard_area ~focus handler content in
         let node =
           Lwd.map2 ~f:(update focus) (Focus.status focus) state in
         let mouse_grab (text, pos) ~x ~y:_ = function
           | `Left ->
               if x <> pos then on_change (text, x) ;
               Nottui.Focus.request focus ;
               `Handled
           | _ -> `Unhandled in
         Lwd.map2 state node ~f:(fun state content ->
             Ui.mouse_area (mouse_grab state) content )

       let simple_edit s =
         let var = Lwd.var (s, 0) in
         edit_field (Lwd.get var) ~on_change:(Lwd.set var)
    *)
    (* let render (img : Notty.I.t) w h : Wall.Image.t =
       let module WI = Wall.Image in
       let open Operation in
       let simple_text ~x ~y s a : Wall.image =
         let font = get_font a in
         let fm = Text.Font.font_metrics font in
         let font_height = fm.ascent -. fm.descent +. fm.line_gap in
         (*  let _, (_, redbox) = path_box Color.red bextent s in*)
         WI.paint (Wall.Paint.color a.fg)
           Text.(simple_text font ~valign:`TOP ~halign:`LEFT ~x ~y s)
       in
       let a' = ref attr_default in
       let rec line (x, y) (op : Operation.t) : Wall.Image.t =
         match op with
         | End -> Image.empty
         | Skip (n, End) -> Image.empty
         | Text (a, x, End) -> erase cap buf ; text_op cap buf a x
         | Skip (n, ops) ->
             WI.stack
               (simple_text !a' (String.make n ' '))
               (line (x, y) 0)
         | Text (a, x, ops) ->
             a' := a ;
             WI.stack (simple_text a x) (line (x, y) ops) in
       let rec lines = function
         | [] -> ()
         | [ln] -> line cap buf ln ; cap.sgr Attr.empty buf
         | ln :: lns ->
             line cap buf ln ; cap.newline buf ; lines cap buf lns
       in
       simple_text
         Operation.of_image (0 0) (w h) img |> lines*)

    let scroll_area ?(offset = (0, 0)) ?(scroll_step = 1) t =
      let offset = Lwd.var offset in
      let scroll d_x d_y =
        let s_x, s_y = Lwd.peek offset in
        let s_x = max 0 (s_x + d_x) in
        let s_y = max 0 (s_y + d_y) in
        Lwd.set offset (s_x, s_y) ;
        `Handled in
      let focus_handler = function
        | `Arrow `Left, [] -> scroll (-scroll_step) 0
        | `Arrow `Right, [] -> scroll (+scroll_step) 0
        | `Arrow `Up, [] -> scroll 0 (-scroll_step)
        | `Arrow `Down, [] -> scroll 0 (+scroll_step)
        | `Page `Up, [] | `ASCII 'v', [`Ctrl] ->
            scroll 0 (-scroll_step * 8)
        | `Page `Down, [] | `ASCII 'v', [`Meta] ->
            scroll 0 (+scroll_step * 8)
        | _ -> `Unhandled in
      let scroll_handler ~x:_ ~y:_ = function
        | `Scroll `Up -> scroll 0 (-scroll_step)
        | `Scroll `Down -> scroll 0 (+scroll_step)
        | _ -> `Unhandled in
      Lwd.map2 t (Lwd.get offset) ~f:(fun t (s_x, s_y) ->
          t |> Ui.shift_area s_x s_y
          |> Ui.mouse_area scroll_handler
          |> Ui.keyboard_area focus_handler )

    (* let menu (items : 'a Lwd_table.t) : ui Lwd.t =
       Lwd_table.map_reduce
         (fun row r -> Ui.keyboard_area)
         Ui.pack_y items*)

    let panel wm () =
      let events, push_event = Lwt_stream.create () in
      let size = ref (200, 200) in
      let check_size ?(scale = 10.) {box; _} =
        let newsize =
          ( int_of_float (Box2.w box /. scale)
          , int_of_float (Box2.h box /. scale) ) in
        if newsize <> !size then size := newsize ;
        push_event (Some (`Resize !size)) in
      let pane = ref Display.pane_empty in
      let images = Nottui_lwt.render ~size:!size events wm in
      Lwt.return
        { act=
            (fun _panel ev ->
              List.iter push_event (convert_events ev) ;
              Lwt_stream.last_new images
              >>= fun img ->
              (pane :=
                 fun s ->
                   check_size s ;
                   draw_pp 20.0
                     (fun pp ->
                       (Notty.Render.pp Notty.Cap.dumb pp) img ;
                       F.flush pp () )
                     s ) ;
              Lwt.return !pane )
        ; subpanels= []
        ; tag= "binding-state" }
  end
end

module Toplevel = struct
  type t =
    {mutable eval: Topinf.evalenv; res: Format.symbolic_output_buffer}

  let init () =
    let sob = Format.make_symbolic_output_buffer () in
    Topinf.ppf := Format.formatter_of_symbolic_output_buffer sob ;
    {eval= !Topinf.eval; res= sob}

  let eval t str =
    let ppf = Format.formatter_of_symbolic_output_buffer t.res in
    Topinf.ppf := ppf ;
    ignore (Format.flush_symbolic_output_buffer t.res) ;
    try
      t.eval ppf (str ^ ";;") ;
      (*HACK to prevent getting stuck in parser*)
      let b = Buffer.create 69 in
      Panel.format_symbolic_output_buffer
        (Format.formatter_of_buffer b)
        t.res
    with e ->
      F.pf ppf "Exception in pane_top//eval@." ;
      Location.report_exception ppf e ;
      F.epr "Exception in pane_top//eval@."

  let result_sob t = t.res
end

module Store = struct
  module Istore = Irmin_unix.Git.FS.KV (Irmin.Contents.String)

  (* storeview shows items of the selected level *)

  type storeview =
    { store: Istore.t
    ; mutable view: Istore.key
    ; mutable selection: Istore.key
    ; mutable editmode: bool
    ; sob: Format.symbolic_output_buffer }

  let make_storeview ?(path = []) storepath branch =
    Istore.Repo.v (Irmin_git.config storepath)
    >>= fun repo ->
    Istore.of_branch repo branch
    >>= fun store ->
    let view = Istore.Key.v path in
    Istore.list store view
    >>= fun viewlist ->
    Lwt.return
      { store
      ; view
      ; selection= Istore.Key.v [fst (List.hd viewlist)]
      ; editmode= false
      ; sob= Format.make_symbolic_output_buffer () }

  let directives (top : Toplevel.t) sv =
    let dir_use_key key_lid =
      (* TODO: currently causes a segfault :( *)
      let key_obj =
        try
          match
            Env.find_value_by_name key_lid !Topinf.toplevel_env
          with
          | path, _desc ->
              Topinf.eval_value_path !Topinf.toplevel_env path
          | exception Not_found ->
              F.epr "Unbound value %a.@." Printtyp.longident key_lid ;
              raise Exit
        with Exit -> Obj.repr ["nofile"] in
      let key = Obj.obj key_obj in
      let contents =
        Lwt_main.run
          ( Istore.kind sv.store key
          >>= function
          | Some a -> (
            match a with
            | `Contents -> Istore.get sv.store key
            | `Node ->
                Lwt.return "\"use_key on Node not implemented yet\"" )
          | None -> Lwt.return "Invalid Selection..." ) in
      Toplevel.eval top contents in
    Topinf.add_directive "use_key" (Directive_ident dir_use_key)
      { section= "Console Store"
      ; doc=
          "Read, compile and execute source phrases from the given \
           store key." }

  let navigate sv action =
    let rec findi value = function
      | [] -> 0
      | a :: b -> (if a = value then -1 else findi value b) + 1 in
    fun () ->
      Istore.get_tree sv.store sv.view
      >>= fun top ->
      match Istore.Key.rdecons sv.selection with
      | Some (ppath, step) ->
          Istore.Tree.list top ppath
          >>= fun neighbors ->
          let steplist = fst (List.split neighbors) in
          let stepi = findi step steplist in
          Istore.Tree.list (snd (List.nth neighbors stepi)) []
          >>= fun subtreelist ->
          Lwt.return
            ( match action with
            | `Next ->
                let stepi = findi step steplist in
                if List.length steplist - 1 > stepi then
                  sv.selection <-
                    Istore.Key.rcons ppath
                      (List.nth steplist (stepi + 1))
            | `Prev ->
                if stepi > 0 then
                  sv.selection <-
                    Istore.Key.rcons ppath
                      (List.nth steplist (stepi - 1))
            | `Sub ->
                if List.length subtreelist > 0 then
                  sv.selection <-
                    sv.selection @ [fst (List.hd subtreelist)]
            | `Sup ->
                if List.length ppath > 0 then sv.selection <- ppath )
      | None -> Lwt.return_unit

  let editor ?(branch = "current") storepath : Panel.t Lwt.t =
    make_storeview storepath branch
    >>= fun sv ->
    let top = Toplevel.init () in
    let modalstate = Panel.Modal.make () in
    let te = Panel.Textedit.make "" () in
    let save store path content =
      Lwt.async (fun () ->
          Istore.set_exn store
            ~info:(Irmin_unix.info "editor-save")
            path content ) in
    let editbinds =
      let open Input.Bind in
      add
        [([Ctrl], Char 'c')]
        [ Custom
            (fun () ->
              sv.editmode <- not sv.editmode ;
              save sv.store
                (sv.view @ sv.selection)
                (Panel.Textedit.contents te) ) ]
      @@ add
           [([Ctrl], Char 's')]
           [ Custom
               (fun () ->
                 save sv.store
                   (sv.view @ sv.selection)
                   (Panel.Textedit.contents te) ) ]
      @@ add
           [([Ctrl], Char 'x'); ([], Char 'x')]
           [ Custom
               (fun () ->
                 Toplevel.eval top (Panel.Textedit.contents te) ) ]
           (Panel.Textedit.bindings te) in
    te.keybind.bindings <- editbinds ;
    let is_node path =
      Istore.get_tree sv.store sv.view
      >>= fun t ->
      Istore.Tree.kind t path
      >>= function
      | Some `Node -> Lwt.return_true | _ -> Lwt.return_false in
    let update_storeview () =
      ignore (Format.flush_symbolic_output_buffer sv.sob) ;
      let pp = Format.formatter_of_symbolic_output_buffer sv.sob in
      let rec draw_levels ?(indent = 0) (sel : Istore.key)
          (tree : Istore.tree) : unit Lwt.t =
        Istore.Tree.list tree []
        >>= Lwt_list.iteri_s (fun _i (step, node) ->
                Format.pp_open_box pp indent ;
                if sel = [step] then (
                  Format.pp_open_stag pp
                    (Panel.Cursor (Wall.Color.v 0.99 0.99 0.125 0.3)) ;
                  F.pf pp "@," ;
                  Format.pp_close_stag pp () ) ;
                Istore.Tree.kind node []
                >>= fun k ->
                ( match k with
                | Some `Contents ->
                    F.pf pp "- %s@." step ; Lwt.return_unit
                | Some `Node ->
                    F.pf pp "> %s@." step ;
                    let subsel =
                      match Istore.Key.decons sel with
                      | Some (_tstep, subkey) -> subkey
                      | None -> [] in
                    Format.pp_open_vbox pp 0 ;
                    draw_levels ~indent:(indent + 1) subsel node
                    >>= fun () ->
                    Format.pp_close_box pp () ;
                    Lwt.return_unit
                | None -> F.pf pp "ERROR: None" ; Lwt.return_unit )
                >>= fun () ->
                Format.pp_close_box pp () ;
                Lwt.return_unit ) in
      Istore.get_tree sv.store sv.view >>= draw_levels sv.selection
    in
    let update_textedit () =
      Panel.Textedit.clear te ;
      Istore.get_tree sv.store sv.view
      >>= fun t ->
      Istore.Tree.kind t sv.selection
      >>= function
      | Some `Contents ->
          Istore.Tree.get t sv.selection
          >>= fun content ->
          Panel.Textedit.insert te content ;
          Lwt.return_unit
      | Some `Node ->
          Panel.Textedit.insert te "Node..." ;
          Lwt.return_unit
      | None -> Lwt.return_unit in
    let navbinds =
      let open Input.Bind in
      let new_contents name content =
        Lwt.async (fun () ->
            let s =
              match Istore.Key.rdecons sv.selection with
              | Some (t, _) -> t
              | None -> Istore.Key.empty in
            Istore.get_tree sv.store (sv.view @ s)
            >>= fun tree ->
            Istore.Tree.add tree name content
            >>= fun newtree ->
            Istore.set_tree_exn
              ~info:(Irmin_unix.info "new Contents")
              sv.store sv.view newtree ) in
      add [([], Char 'n')] [CustomLwt (navigate sv `Next)]
      @@ add [([], Char 'p')] [CustomLwt (navigate sv `Prev)]
      @@ add [([], Char 'w')] [CustomLwt (navigate sv `Prev)]
      @@ add [([], Char 's')] [CustomLwt (navigate sv `Next)]
      @@ add [([], Char 'd')] [CustomLwt (navigate sv `Sub)]
      @@ add [([], Char 'a')] [CustomLwt (navigate sv `Sup)]
      @@ add
           [([], Char 'e')] (* enter edit mode *)
           [ Custom
               (fun () ->
                 Lwt.async (fun () ->
                     is_node sv.selection
                     >>= fun nb ->
                     if not nb then sv.editmode <- not sv.editmode ;
                     Lwt.return_unit ) ) ]
      @@ add
           [([], Char 'f')] (* find: enter path in modal *)
           [Custom (fun () -> ())]
      @@ add
           [([], Char 'c')] (* contents: create new contents node *)
           [ Custom
               (fun () ->
                 Panel.Modal.start ~prompt:"Contents name > "
                   modalstate "" (fun name ->
                     new_contents (Istore.Key.v [name]) "" ) ) ]
      @@ add
           [([], Char 't')] (* tree: create new subtree *)
           [ Custom
               (fun () ->
                 Panel.Modal.start ~prompt:"Node name > " modalstate
                   "" (fun nodename ->
                     Panel.Modal.start
                       ~prompt:"Initial Contents name > " modalstate
                       "" (fun contentsname ->
                         new_contents
                           (Istore.Key.v [nodename; contentsname])
                           "" ) ) ) ]
      @@ add
           [([], Char 'r')] (* remove contents/node *)
           [ CustomLwt
               (fun () ->
                 let selection = sv.selection in
                 navigate sv `Next ()
                 >>= fun () ->
                 Istore.get_tree sv.store sv.view
                 >>= fun tree ->
                 Istore.Tree.remove tree selection
                 >>= fun newtree ->
                 Istore.set_tree_exn
                   ~info:(Irmin_unix.info "remove Contents/Node")
                   sv.store sv.view newtree ) ]
      @@ add
           [([], Char 'x')] (* execute contents/node *)
           [ Custom
               (fun () ->
                 Toplevel.eval top (Panel.Textedit.contents te) ) ]
           empty in
    let bindstate = Input.Bind.init navbinds in
    Lwt.return
      Panel.
        { act=
            (fun panel events ->
              ( if
                (not sv.editmode)
                && not (Panel.Modal.is_active modalstate)
              then
                Input.Bind.process bindstate events
                >>= fun () ->
                Lwt.join [update_storeview (); update_textedit ()]
              else Lwt.return_unit )
              >>= fun () ->
              Panel.vbox panel.subpanels
              >>= fun p -> p.act panel events )
        ; subpanels=
            [ Panel.filter_events
                (fun ev ->
                  if Panel.Modal.is_active modalstate then ev else []
                  )
                (Panel.Modal.panel modalstate)
            ; Panel.hbox
                [ Panel.prettyprint (fun pp ->
                      Panel.format_symbolic_output_buffer pp sv.sob )
                ; Panel.vbox
                    [ Panel.filter_events
                        (fun ev -> if sv.editmode then ev else [])
                        (Panel.Textedit.panel te)
                    ; Panel.prettyprint (fun pp ->
                          Format.pp_open_hovbox pp 0 ;
                          Panel.format_symbolic_output_buffer pp
                            (Toplevel.result_sob top) ;
                          Format.pp_close_box pp () ;
                          F.flush pp () ) ] ]
            ; Panel.Textedit.bindingstate bindstate
            ; Panel.prettyprint (fun pp ->
                  Format.fprintf pp "sv.editmode = %b @." sv.editmode )
            ]
        ; tag= "store-editor" }
end

let std_actor (root_panel : Panel.t Lwt.t) =
  Panel.actor
    (Panel.obox
       [ Panel.draw (fun (s : Display.state) ->
             (s, Display.fill_box (Display.gray 0.125) s.box) )
       ; root_panel ] )

let root_actor = ref (std_actor (Store.editor "../rootstore"))

let start () =
  (* root_actor :=
     std_actor Panel.Nottui.(panel (simple_edit "hello edit") ()) ;*)
  Display.(
    run (make_frame ~title:"hi" ~w:1440 ~h:900 ()) root_actor ())

(* Implement the "window management" as just toplevel defined functions that manipulate the window tree *)

(* FUTURE: (thinking now this should be based on react for that sweet incremental compuation)

   type panetree
   type eventree
   type imagetree

   Display.run should be:
   Init: setup initial panetree and compute eventree and imagetree from it.last_actions
   New events trigger parsing the eventree, the results of which update the imagetree
      which is then parsed and displayed. *)