(* Some random utils for debugging *)
open Eio.Std

let traced_sink tag
    (Eio.Resource.T (t, handler) : Eio_unix.sink_ty Eio.Flow.sink) :
    Eio_unix.sink_ty r =
  let module Sink = (val Eio.Resource.get handler Eio.Flow.Pi.Sink) in
  let close = Eio.Resource.get handler Eio.Resource.Close in
  let buf = Cstruct.create 4096 in
  let copy () ~src =
    try
      while true do
        match Eio.Flow.single_read src buf with
        | i ->
            Eio.traceln ">>>>> %s Single read: %s" tag (Cstruct.to_string buf);
            let bufs = [ Cstruct.sub buf 0 i ] in
            Sink.copy ~src:(Eio.Flow.cstruct_source bufs) t
      done
    with End_of_file -> Eio.traceln ">>>>>> EOF"
  in
  let single_write () x =
    Eio.traceln ">>>>> single write: %s" (Cstruct.concat x |> Cstruct.to_string);
    Sink.single_write t x
  in
  let module T = struct
    type t = unit

    let single_write = single_write
    let copy = copy
  end in
  let t =
    Eio.Resource.handler
      [
        H (Eio.Flow.Pi.Sink, (module T));
        H (Eio.Resource.Close, fun () -> close t);
      ]
  in
  Eio.Resource.T ((), t)

let traced_sink_flow tag
    (Eio.Resource.T (t, handler) : Eio.Flow.sink_ty Eio.Flow.sink) :
    Eio.Flow.sink_ty r =
  let module Sink = (val Eio.Resource.get handler Eio.Flow.Pi.Sink) in
  let buf = Cstruct.create 4096 in
  let copy () ~src =
    try
      while true do
        match Eio.Flow.single_read src buf with
        | i ->
            Eio.traceln ">>>>> %s Single read: %s" tag (Cstruct.to_string buf);
            let bufs = [ Cstruct.sub buf 0 i ] in
            Sink.copy ~src:(Eio.Flow.cstruct_source bufs) t
      done
    with End_of_file -> Eio.traceln ">>>>>> EOF"
  in
  let single_write () x =
    Eio.traceln ">>>>> single write: %s" (Cstruct.concat x |> Cstruct.to_string);
    Sink.single_write t x
  in
  let module T = struct
    type t = unit

    let single_write = single_write
    let copy = copy
  end in
  let t = Eio.Resource.handler [ H (Eio.Flow.Pi.Sink, (module T)) ] in
  Eio.Resource.T ((), t)