open Avutil

external init : unit -> unit = "ocaml_avdevice_init" [@@noalloc]

let init_done = ref false

let () =
  if not !init_done then init ();
  init_done := true

let hd = function [] -> raise Not_found | x :: _ -> x

external get_audio_input_formats : unit -> (input, audio) format array
  = "ocaml_avdevice_get_audio_input_formats"

let get_audio_input_formats () = Array.to_list (get_audio_input_formats ())
let get_default_audio_input_format () = hd (get_audio_input_formats ())

external get_video_input_formats : unit -> (input, video) format array
  = "ocaml_avdevice_get_video_input_formats"

let get_video_input_formats () = Array.to_list (get_video_input_formats ())
let get_default_video_input_format () = hd (get_video_input_formats ())

external get_audio_output_formats : unit -> (output, audio) format array
  = "ocaml_avdevice_get_audio_output_formats"

let get_audio_output_formats () = Array.to_list (get_audio_output_formats ())
let get_default_audio_output_format () = hd (get_audio_output_formats ())

external get_video_output_formats : unit -> (output, video) format array
  = "ocaml_avdevice_get_video_output_formats"

let get_video_output_formats () = Array.to_list (get_video_output_formats ())
let get_default_video_output_format () = hd (get_video_output_formats ())

let find_input name fmts =
  try List.find (fun d -> Av.Format.get_input_name d = name) fmts
  with Not_found ->
    raise (Error (`Failure ("Input device not found : " ^ name)))

let find_audio_input name = find_input name (get_audio_input_formats ())
let find_video_input name = find_input name (get_video_input_formats ())

let find_output name fmts =
  try List.find (fun d -> Av.Format.get_output_name d = name) fmts
  with Not_found ->
    raise (Error (`Failure ("Output device not found : " ^ name)))

let find_audio_output name = find_output name (get_audio_output_formats ())
let find_video_output name = find_output name (get_video_output_formats ())
let open_audio_input name = Av.open_input ~format:(find_audio_input name) ""

let open_default_audio_input () =
  Av.open_input ~format:(get_default_audio_input_format ()) ""

let open_video_input name = Av.open_input ~format:(find_video_input name) ""

let open_default_video_input () =
  Av.open_input ~format:(get_default_video_input_format ()) ""

external open_output_format :
  (output, _) format ->
  (string * string) array ->
  output container * string array = "ocaml_av_open_output_format"

let _opt_val = function
  | `String s -> s
  | `Int i -> string_of_int i
  | `Int64 i -> Int64.to_string i
  | `Float f -> string_of_float f

let mk_opts = function
  | None -> [||]
  | Some opts ->
      Array.of_list
        (Hashtbl.fold
           (fun opt_name opt_val cur -> (opt_name, _opt_val opt_val) :: cur)
           opts [])

let filter_opts unused = function
  | None -> ()
  | Some opts ->
      Hashtbl.filter_map_inplace
        (fun k v -> if Array.mem k unused then Some v else None)
        opts

let open_audio_output ?opts name =
  let ret, unused =
    open_output_format (find_audio_output name) (mk_opts opts)
  in
  filter_opts unused opts;
  ret

let open_default_audio_output ?opts () =
  let ret, unused =
    open_output_format (get_default_audio_output_format ()) (mk_opts opts)
  in
  filter_opts unused opts;
  ret

let open_video_output ?opts name =
  let ret, unused =
    open_output_format (find_video_output name) (mk_opts opts)
  in
  filter_opts unused opts;
  ret

let open_default_video_output ?opts () =
  let ret, unused =
    open_output_format (get_default_video_output_format ()) (mk_opts opts)
  in
  filter_opts unused opts;
  ret

module App_to_dev = struct
  type message =
    | None
    | Window_size of int * int * int * int
    | Window_repaint of int * int * int * int
    | Pause
    | Play
    | Toggle_pause
    | Set_volume of float
    | Mute
    | Unmute
    | Toggle_mute
    | Get_volume
    | Get_mute

  external control_message : message -> _ container -> unit
    = "ocaml_avdevice_app_to_dev_control_message"

  let control_messages messages av =
    List.iter (fun msg -> control_message msg av) messages
end

module Dev_to_app = struct
  type message =
    | None
    | Create_window_buffer of (int * int * int * int) option
    | Prepare_window_buffer
    | Display_window_buffer
    | Destroy_window_buffer
    | Buffer_overflow
    | Buffer_underflow
    | Buffer_readable of Int64.t option
    | Buffer_writable of Int64.t option
    | Mute_state_changed of bool
    | Volume_level_changed of float

  external set_control_message_callback :
    (message -> unit) -> _ container -> unit
    = "ocaml_avdevice_set_control_message_callback"
end
