open Lwt.Infix
module F = Fmt
open Tgles2
module Gv = Graphv_gles2_native
open Ogui

module GLFWExtras = struct
  open Ctypes
  open Foreign

  let glfwSetErrorCallback :
      (int -> string -> unit) -> int -> string -> unit =
    let errorfun = int @-> string @-> returning void in
    foreign "glfwSetErrorCallback"
      (funptr errorfun @-> returning (funptr errorfun))
end

let errorcb error desc =
  Printf.printf "GLFW error %d: %s\n%!" error desc

let load_data vg =
  let _ = Gv.Text.create vg ~name:"mono" ~file:"./assets/mono.ttf" in
  let _ =
    Gv.Text.create vg ~name:"icons" ~file:"./assets/entypo.ttf"
  in
  let _ =
    Gv.Text.create vg ~name:"sans" ~file:"./assets/Roboto-Regular.ttf"
  in
  let _ =
    Gv.Text.create vg ~name:"sans-bold"
      ~file:"./assets/Roboto-Bold.ttf"
  in
  let _ =
    Gv.Text.create vg ~name:"emoji"
      ~file:"./assets/NotoEmoji-Regular.ttf"
  in
  Gv.Text.add_fallback vg ~name:"sans" ~fallback:"emoji";
  Gv.Text.add_fallback vg ~name:"sans-bold" ~fallback:"emoji";
  Gv.Text.set_font_face vg ~name:"mono"

let () =
  GLFW.init ();
  at_exit GLFW.terminate;
  let _res = GLFWExtras.glfwSetErrorCallback errorcb in
  GLFW.windowHint ~hint:GLFW.ClientApi ~value:GLFW.OpenGLESApi;
  GLFW.windowHint ~hint:GLFW.ContextVersionMajor ~value:2;
  GLFW.windowHint ~hint:GLFW.ContextVersionMinor ~value:0;

  let window =
    GLFW.createWindow ~width:1000 ~height:600 ~title:"window" ()
  in
  (* Make the window's context current *)
  GLFW.makeContextCurrent ~window:(Some window);
  GLFW.swapInterval ~interval:0;

  Gl.clear_color 0.1 0.2 0.2 1.;

  Memtrace.trace_if_requested ();

  let ctx =
    Gv.create ~flags:Gv.CreateFlags.(antialias lor stencil_strokes) ()
  in

  let graph = Perfgraph.init Perfgraph.FPS "Frame Time" in
  let _odata = load_data ctx in
  let continue = ref true in
  let min_fps = ref Float.max_float in
  let max_fps = ref Float.min_float in

  (* Thread which is woken up when the main window is closed. *)
  let _waiter, _wakener = Lwt.wait () in

  F.pr "oplevel.ml: Toploop.initialize_toplevel_env@.";
  Toploop.initialize_toplevel_env ();
  let rootrepo =
    Store.init_default
      (F.str "%s/console/rootstore.git" Secrets.giturl)
  in

  let ui =
    Ogui.Ui.window ctx ~window Gg.(Box2.v P2.o (P2.v 500. 500.))
  in

  GLFW.setKeyCallback ~window
    ~f:
      (Some
         (fun _window key _int state mods ->
           Lwt.async (fun () ->
               Ogui.Ui.keycallback ui state key mods >>= fun _ ->
               Lwt.return_unit)))
  |> ignore;

  GLFW.setCharCallback ~window
    ~f:
      (Some
         (fun _window ch ->
           Lwt.async (fun () ->
               Ogui.Ui.chrcallback ui ch >>= fun _ -> Lwt.return_unit)))
  |> ignore;

  F.pr "oplevel.ml: building initial page@.";
  let page =
    ref
      Layout.(
        vbox
          [
            textedit
              (TextEdit.multiline ui
                 (TextBuffer.of_repo ~path:[ "README" ] ~repo:rootrepo));
            textedit
              (TextEdit.multiline ui
                 (TextBuffer.of_repo
                    ~path:[ ".config"; "init.ml" ]
                    ~repo:rootrepo));
          ])
  in

  (let open GLFW in
   let open Event in
   let open Ui in
   Ui.update_bindings ui
     (adds
        [
          [ Key (Press, X, [ Control ]); Key (Press, E, [ Control ]) ];
        ]
        [ Custom (fun () -> Lwt.return ()) ]));
  F.pr "oplevel.ml: entering drawing loop@.";
  let period_min = 1.0 /. 30. in
  let t = GLFW.getTime () |> ref in
  while (not GLFW.(windowShouldClose ~window)) && !continue do
    Lwt_main.run
      ((fun () ->
         let now = GLFW.getTime () in
         let dt = now -. !t in
         t := now;

         Perfgraph.update graph dt;

         if now > 2. then (
           let avg = 1. /. Perfgraph.average graph in
           min_fps := Float.min avg !min_fps;
           max_fps := Float.max avg !max_fps);

         let _mx, _my = GLFW.getCursorPos ~window in
         let win_w, win_h = GLFW.getWindowSize ~window in

         Gl.viewport 0 0 win_w win_h;
         Gl.clear
           (Gl.color_buffer_bit lor Gl.depth_buffer_bit
          lor Gl.stencil_buffer_bit);
         Gl.enable Gl.blend;
         Gl.blend_func Gl.src_alpha Gl.one_minus_src_alpha;
         Gl.enable Gl.cull_face_enum;
         Gl.disable Gl.depth_test;

         let width, height = (float win_w, float win_h) in
         let box = Gg.(Box2.v V2.zero Size2.(v width height)) in
         Gv.begin_frame ctx ~width ~height ~device_ratio:1.;
         Perfgraph.render graph ctx (width -. 205.) 5.;
         (* F.epr "box=%a@." Gg.Box2.pp box;
            F.epr "Painter.layout=%a@." Gg.Box2.pp *)
         Painter.layout box ui !page >>= fun _ ->
         (* Demo.render_demo ctx mx my win_w win_h now !blowup data; *)
         Gv.end_frame ctx;

         Gc.major_slice 0 |> ignore;
         GLFW.swapBuffers ~window;
         GLFW.pollEvents ();
         Unix.sleepf
           Float.(max 0. (period_min -. GLFW.getTime () +. !t));
         Lwt.return_unit)
         ())
  done;

  Printf.printf "MIN %.2f\n" !min_fps;
  Printf.printf "MAX %.2f\n%!" !max_fps;

  if Array.length Sys.argv = 1 then
    while not GLFW.(windowShouldClose ~window) do
      GLFW.pollEvents ();
      Unix.sleepf 0.25
    done

(* let out_ppf =
     Format.formatter_of_out_functions
       Format.
         {
           out_string = (fun s _ _ -> output_buffer#insert s);
           out_flush = (fun () -> ());
           out_indent =
             (fun n ->
               for _ = 0 to n do
                 output_buffer#insert "  "
               done);
           out_newline = (fun () -> output_buffer#insert "\n");
           out_spaces =
             (fun n -> output_buffer#insert (String.make n ' '));
         }
   in *)

(* ignore
   (Toploop.use_input out_ppf
      (String "#use \"topfind\";;\n#list;;")); *)
(* ignore (Toploop.use_input Format.std_formatter (String text)); *)
(* Wait for it to be closed. *)