More robust play-media action

CHANGELOG.md

@@ -21,6 +21,7 @@
 - Fix ending excursions with `ijkl` only when needed (#207)
 - Fixed video long-step handling (#207)
 - Removed confusing auto-generated IDs (#209)
+- Fix `play-media` behavior when facing errors (#210)
 
 ### Docs
 

src/engine/runtime/fast/fast.ml

@@ -12,6 +12,7 @@ let create () =
   let has_detonated = ref false in
   let wait, detonate = Fut.create () in
   let wait = Fut.map (fun () -> has_detonated := true) wait in
+  let detonate () = if !has_detonated then () else detonate () in
   { wait; has_detonated; detonate }
 
 type mode = Normal of hurry_bomb | Counting_for_toc | Fast | Slow

src/engine/runtime/step/actions_.ml

@@ -765,7 +765,7 @@ module Play_media = struct
   type args = Brr.El.t list
 
   let parse_args = Parse.parse_only_els
-  let log_error = function Ok x -> x | Error x -> Brr.Console.(log [ x ])
+  let log_error = function Ok x -> x | Error x -> Brr.Console.(error [ x ])
 
   let do_ ~mode _window elems =
     only_if_not_counting mode @@ fun _mode ->
@@ -791,6 +791,12 @@ module Play_media = struct
           let e = Brr_io.Media.El.of_el e in
           let () = if is_speaker_note then Brr_io.Media.El.set_muted e true in
           let current = Brr_io.Media.El.current_time_s e in
+          let () =
+            (* Strangely, without this, at least in my setup, firefox often
+               waits several seconds before showing the video, even in a very
+               simple html file just playing the file.  *)
+            Brr_io.Media.El.set_current_time_s e current
+          in
           let is_playing = not @@ Brr_io.Media.El.paused e in
           let undo () =
             let+ res =
@@ -805,22 +811,39 @@ module Play_media = struct
             let when_slow hurry_bomb =
               Brr.Console.(log [ "Playing" ]);
               let fut, activate = Fut.create () in
+              let activate =
+                let did = ref false in
+                fun () ->
+                  let old_did = !did in
+                  did := true;
+                  if not old_did then activate ()
+              in
               let _ =
                 let+ () = Fast.wait hurry_bomb in
-                set_current_time_s e (duration_s e);
+                let duration = duration_s e in
+                if not @@ Float.is_nan duration then
+                  set_current_time_s e duration;
                 activate ()
               in
               let _unlisten =
-                Brr.Ev.listen Brr.Ev.ended
+                let opts = Brr.Ev.listen_opts ~once:true () in
+                Brr.Ev.listen ~opts Brr.Ev.ended
                   (fun _ev -> activate ())
                   (e |> Brr_io.Media.El.to_el |> Brr.El.as_target)
               in
               let* err = Brr_io.Media.El.play e in
-              match err with Ok () -> fut | Error _e -> fut
+              match err with
+              | Ok () -> fut
+              | Error e ->
+                  Brr.Console.(error [ e ]);
+                  activate ();
+                  fut
             in
             let when_fast () =
               Brr.Console.(log [ "Just setting current time" ]);
-              Fut.return @@ set_current_time_s e (duration_s e)
+              let duration = duration_s e in
+              if Float.is_nan duration then Fut.return ()
+              else Fut.return @@ set_current_time_s e duration
             in
             match mode with
             | Fast.Normal hurry_bomb when not (Fast.has_detonated hurry_bomb) ->