Add ability to listen (tap) the input

By doing something like
```
fn input_output_loop(input_output: Subject(List(String))) -> Nil {
  let output = process.receive_forever(input_output)

  echo output

  input_output_loop(input_output)
}
```

src/input/input.gleam

@@ -1,50 +0,0 @@
-import gleam/erlang/process.{type Name, type Subject}
-
-import input/key.{type Key}
-
-/// `new` accepts a list of listeners that are composed of two subjects;
-///   - one to get the final `Key` and
-///   - one to tap the input as it is read from i/o
-/// and
-///   - a subject name that is used to create a `Subject` that other processes
-///     know they can inject a `Key` into the input with
-pub fn new(
-  ui_input_keys_name: Name(Key),
-  ui_input_stream_name: Name(List(String)),
-  input_ui_inject_name: Name(Key),
-) -> Nil {
-  let _ =
-    process.spawn(fn() {
-      let ui_input_keys: Subject(Key) =
-        process.named_subject(ui_input_keys_name)
-      let ui_input_stream: Subject(List(String)) =
-        process.named_subject(ui_input_stream_name)
-
-      let input_ui_inject_input: Subject(Key) =
-        process.named_subject(input_ui_inject_name)
-      let assert Ok(_) = process.register(process.self(), input_ui_inject_name)
-
-      read_input(ui_input_keys, ui_input_stream, input_ui_inject_input)
-    })
-
-  echo "waiting for input"
-  key.start_raw_shell()
-
-  Nil
-}
-
-fn read_input(
-  ui_input_keys: Subject(Key),
-  ui_input_stream: Subject(List(String)),
-  input_ui_inject: Subject(Key),
-) -> Nil {
-  let buffer = case process.receive(input_ui_inject, 1) {
-    Ok(key.Continue(buffer)) -> buffer
-    Ok(_) | Error(_) -> []
-  }
-
-  key.read_input_until_key(buffer, ui_input_stream)
-  |> process.send(ui_input_keys, _)
-
-  read_input(ui_input_keys, ui_input_stream, input_ui_inject)
-}

src/input/key.gleam

@@ -62,7 +62,7 @@ pub fn start_raw_shell() {
 
 pub fn read_input_until_key(
   l: List(String),
-  ui_input_stream: Subject(List(String)),
+  tap_input: Subject(List(String)),
 ) -> Key {
   case
     internal_input.read_input()
@@ -71,8 +71,8 @@ pub fn read_input_until_key(
     |> from_list
   {
     Continue(l) -> {
-      process.send(ui_input_stream, l)
-      read_input_until_key(l, ui_input_stream)
+      process.send(tap_input, l)
+      read_input_until_key(l, tap_input)
     }
     k -> k
   }

src/mpv/control.gleam

@@ -2,7 +2,8 @@ import gleam/json
 import gleam/result
 import gleam/string
 
-import mpv/internal as internal_control
+import input/key.{type Key}
+import mpv/internal/control as internal_control
 import tcp/reason.{type Reason}
 import tcp/tcp.{type Socket}
 
@@ -16,6 +17,21 @@ pub type ControlError {
   ControlError(details: String)
 }
 
+pub fn from_key(key: Key) -> Result(Control, Nil) {
+  case key {
+    key.Char(char) -> char_control(char)
+    _ -> Error(Nil)
+  }
+}
+
+fn char_control(char: String) -> Result(Control, Nil) {
+  case char {
+    " " -> Ok(TogglePlayPause)
+    "q" -> Ok(Exit)
+    _ -> Error(Nil)
+  }
+}
+
 pub fn toggle_play_pause(socket: Socket) -> Result(Nil, ControlError) {
   let command =
     json.object([#("command", json.array(["cycle", "pause"], of: json.string))])

src/mpv/mpv.gleam

@@ -1,46 +1,55 @@
-import gleam/erlang/process.{type Name, type Subject}
+import gleam/erlang/process.{type Subject}
 import gleam/float
 import gleam/otp/actor
 import gleam/result
 import gleam/string
 
-import mpv/control as mpv_control
+import input/key.{type Key}
+import mpv/control.{type Control}
 import tcp/reason
 import tcp/tcp.{type Socket}
-import ui/control as ui_control
 
-type State(socket, mpv_ui, ui_mpv) {
+type State(socket, inject_input, tap_input, exit) {
   State(
     socket: Socket,
-    mpv_ui: Subject(ui_control.Control),
-    ui_mpv: Subject(mpv_control.Control),
+    inject_input: Subject(Key),
+    tap_input: Subject(List(String)),
+    exit: Subject(Nil),
   )
 }
 
-pub fn new(
-  mpv_ui_name: Name(ui_control.Control),
-  ui_mpv_name: Name(mpv_control.Control),
-) -> Result(Nil, String) {
+pub fn new(exit: Subject(Nil)) -> Result(Nil, String) {
   // TODO start up mvp here, currently hi-jacking `naviterm`s socket
   let socket_path = "/tmp/naviterm_mpv"
 
-  let mpv_ui: Subject(ui_control.Control) = process.named_subject(mpv_ui_name)
-  let ui_mpv: Subject(mpv_control.Control) = process.named_subject(ui_mpv_name)
-
   case tcp.connect(socket_path) {
     Error(r) -> Error("Could not connect to mpv: " <> reason.to_string(r))
     Ok(socket) -> {
+      // `inject_input` is created by name to allow the process that
+      // owns `read_input` to be able to register it, while the agent
+      // also have a reference to it to be able to inject input
+      let inject_input_name = process.new_name("inject_input")
+      let inject_input = process.named_subject(inject_input_name)
+
+      let tap_input_name = process.new_name("tap_input")
+      let tap_input = process.named_subject(tap_input_name)
+
       case
-        actor.new(State(socket, mpv_ui, ui_mpv))
+        actor.new(State(socket, inject_input, tap_input, exit))
         |> actor.on_message(handle_message)
         |> actor.start
       {
         Error(start_error) ->
           Error("Could not start actor: " <> string.inspect(start_error))
-        Ok(actor.Started(data: mpv, ..)) -> {
+        Ok(actor.Started(data:, ..)) -> {
+          echo "waiting for input"
+          key.start_raw_shell()
+
           process.spawn(fn() {
-            let assert Ok(_) = process.register(process.self(), ui_mpv_name)
-            handle_ui_control(mpv, ui_mpv)
+            let assert Ok(_) =
+              process.register(process.self(), inject_input_name)
+
+            read_input(data, inject_input, tap_input)
           })
 
           Ok(Nil)
@@ -51,41 +60,51 @@ pub fn new(
 }
 
 fn handle_message(
-  state: State(socket, mpv_ui, ui_mpv),
-  control: mpv_control.Control,
-) -> actor.Next(State(socket, mpv_ui, ui_mpv), mpv_control.Control) {
+  state: State(socket, inject, input_output, exit),
+  control: Control,
+) -> actor.Next(State(socket, inject, input_output, exit), Control) {
   case control {
-    mpv_control.TogglePlayPause -> {
+    control.TogglePlayPause -> {
       echo "toggling play/pause"
 
       let _ =
-        result.map_error(mpv_control.toggle_play_pause(state.socket), fn(err) {
+        result.map_error(control.toggle_play_pause(state.socket), fn(err) {
           echo "Could not toggle play/pause: " <> err.details
         })
 
       let _ =
-        result.map(mpv_control.get_playback_time(state.socket), fn(playback) {
+        result.map(control.get_playback_time(state.socket), fn(playback) {
           echo "playback: " <> float.to_string(playback.data)
         })
 
-      process.send(state.mpv_ui, ui_control.Ack)
-
       actor.continue(state)
     }
-    mpv_control.Exit -> {
-      // TODO close sockets
+    control.Exit -> {
+      process.send(state.exit, Nil)
       actor.stop()
     }
   }
 }
 
-fn handle_ui_control(
-  mpv: Subject(mpv_control.Control),
-  ui_mpv: Subject(mpv_control.Control),
-) {
-  let control = process.receive_forever(ui_mpv)
-  echo "handle_ui_control: " <> string.inspect(control)
-  process.send(mpv, control)
+/// `read_input` operates by reading from input until a `Key` can be created.
+/// It is possible to create a `Key` without the users input by sending
+/// messages to `inject_input` which will initialize the "input to key" sequence.
+/// This is useful to ultimately create a `Control` without the user having to
+/// input all of the character(s) needed.
+fn read_input(
+  subject: Subject(Control),
+  inject_input: Subject(Key),
+  tap_input: Subject(List(String)),
+) -> Nil {
+  let buffer = case process.receive(inject_input, 1) {
+    Ok(key.Continue(buffer)) -> buffer
+    Ok(_) | Error(_) -> []
+  }
 
-  handle_ui_control(mpv, ui_mpv)
+  let _ =
+    key.read_input_until_key(buffer, tap_input)
+    |> control.from_key
+    |> result.map(process.send(subject, _))
+
+  read_input(subject, inject_input, tap_input)
 }

src/musicplayer.gleam

@@ -1,45 +1,8 @@
-import gleam/erlang/process.{type Name}
-
-import input/input
-import input/key.{type Key}
-import mpv/control as mpv_control
+import gleam/erlang/process
 import mpv/mpv
-import ui/control as ui_control
-import ui/ui
 
 pub fn main() -> Nil {
   let exit = process.new_subject()
-
-  // `ui_input_keys` is owned by `ui`, this is where input sends keys
-  let ui_input_keys_name: Name(Key) = process.new_name("ui_input_keys")
-  // `ui_input_stream` is owned by `ui`, thi sis where input is streamed
-  let ui_input_stream_name: Name(List(String)) =
-    process.new_name("ui_input_stream")
-
-  // `inject_input` is created by name to allow the `input` process that
-  // owns `read_input` to be able to register and receive from it,
-  //  while the any other processes can use the name reference to
-  // inject input
-
-  // `input_ui_inject`  is owned by `input`, this is where `ui` injects `Key`
-  let input_ui_inject_name: Name(Key) = process.new_name("input_ui_inject_keys")
-
-  // `ui_mpv` is owned by `ui`, this is where `ui` asks `mpv` for things
-  let ui_mpv_name: Name(mpv_control.Control) = process.new_name("ui_mpv")
-  //   `mpv_ui` is owned by mpv and this is where mpv responds to ui
-  let mpv_ui_name: Name(ui_control.Control) = process.new_name("mpv_ui")
-
-  let assert Ok(_) =
-    ui.new(
-      ui_mpv_name,
-      mpv_ui_name,
-      ui_input_keys_name,
-      ui_input_stream_name,
-      exit,
-    )
-
-  let assert Ok(_) = mpv.new(mpv_ui_name, ui_mpv_name)
-  input.new(ui_input_keys_name, ui_input_stream_name, input_ui_inject_name)
-
+  let assert Ok(_) = mpv.new(exit)
   process.receive_forever(exit)
 }

src/ui/control.gleam

@@ -1,24 +0,0 @@
-import input/key.{type Key}
-
-pub type Control {
-  Ack
-
-  TogglePlayPause
-
-  Exit
-}
-
-pub fn from_key(key: Key) -> Result(Control, Nil) {
-  case key {
-    key.Char(char) -> char_control(char)
-    _ -> Error(Nil)
-  }
-}
-
-fn char_control(char: String) -> Result(Control, Nil) {
-  case char {
-    " " -> Ok(TogglePlayPause)
-    "q" -> Ok(Exit)
-    _ -> Error(Nil)
-  }
-}

src/ui/ui.gleam

@@ -1,122 +0,0 @@
-import gleam/erlang/process.{type Name, type Subject}
-import gleam/otp/actor
-import gleam/result
-import gleam/string
-
-import input/key.{type Key}
-import mpv/control as mpv_control
-import ui/control as ui_control
-
-pub type State(ui_mpv, mpv_ui, ui_input_keys, ui_input_stream, exit) {
-  State(
-    ui_mpv: Subject(mpv_control.Control),
-    mpv_ui: Subject(ui_control.Control),
-    ui_input_keys: Subject(Key),
-    ui_input_stream: Subject(List(String)),
-    exit: Subject(Nil),
-  )
-}
-
-pub fn new(
-  ui_mpv_name: Name(mpv_control.Control),
-  mpv_ui_name: Name(ui_control.Control),
-  ui_input_keys_name: Name(Key),
-  ui_input_stream_name: Name(List(String)),
-  exit: Subject(Nil),
-) -> Result(Nil, String) {
-  let ui_mpv: Subject(mpv_control.Control) = process.named_subject(ui_mpv_name)
-  let mpv_ui: Subject(ui_control.Control) = process.named_subject(mpv_ui_name)
-
-  let ui_input_keys: Subject(Key) = process.named_subject(ui_input_keys_name)
-  let ui_input_stream: Subject(List(String)) =
-    process.named_subject(ui_input_stream_name)
-
-  case
-    actor.new(State(ui_mpv, mpv_ui, ui_input_keys, ui_input_stream, exit))
-    |> actor.on_message(handle_message)
-    |> actor.start
-  {
-    Error(start_error) ->
-      Error("Could not start ui: " <> string.inspect(start_error))
-    Ok(actor.Started(data: ui, ..)) -> {
-      echo "ui started"
-
-      process.spawn(fn() {
-        let assert Ok(_) = process.register(process.self(), ui_input_keys_name)
-        handle_key(ui, ui_input_keys)
-      })
-
-      process.spawn(fn() {
-        let assert Ok(_) = process.register(process.self(), mpv_ui_name)
-        handle_mpv_control(ui, mpv_ui)
-      })
-
-      process.spawn(fn() {
-        let assert Ok(_) =
-          process.register(process.self(), ui_input_stream_name)
-        temp_input_stream(ui_input_stream)
-      })
-
-      Ok(Nil)
-    }
-  }
-}
-
-fn handle_message(
-  state: State(ui_mpv, mpv_ui, ui_input_keys, ui_input_stream, exit),
-  control: ui_control.Control,
-) -> actor.Next(
-  State(ui_mpv, mpv_ui, ui_input_keys, ui_input_stream, exit),
-  ui_control.Control,
-) {
-  case control {
-    ui_control.Ack -> {
-      echo "ack! use this to re-render?"
-      actor.continue(state)
-    }
-    ui_control.TogglePlayPause -> {
-      process.send(state.mpv_ui, ui_control.TogglePlayPause)
-      case process.receive(state.mpv_ui, 5000) {
-        Error(_) -> echo "mpv not responding: could not toggle pause :("
-        Ok(_) -> echo "toggled pause"
-      }
-
-      actor.continue(state)
-    }
-    ui_control.Exit -> {
-      // TODO call `mpv` to exit, wait for response
-      process.send(state.exit, Nil)
-      actor.stop()
-    }
-  }
-}
-
-/// `handle_key` listens to a subject onto which `input` will send messages with
-/// parsed `Key`s which will be mapped to `Control`s (if possible)
-fn handle_key(
-  ui: Subject(ui_control.Control),
-  ui_input_keys: Subject(Key),
-) -> Nil {
-  let _ =
-    process.receive_forever(ui_input_keys)
-    |> ui_control.from_key
-    |> result.map(process.send(ui, _))
-
-  handle_key(ui, ui_input_keys)
-}
-
-fn handle_mpv_control(
-  ui: Subject(ui_control.Control),
-  mpv_ui: Subject(ui_control.Control),
-) {
-  let control = process.receive_forever(mpv_ui)
-  process.send(ui, control)
-
-  handle_mpv_control(ui, mpv_ui)
-}
-
-fn temp_input_stream(ui_input_stream: Subject(List(String))) -> Nil {
-  let stream = process.receive_forever(ui_input_stream)
-  echo "input stream: " <> string.inspect(stream)
-  temp_input_stream(ui_input_stream)
-}

test/mpv/control_test.gleam

@@ -1,11 +1,29 @@
+import gleam/list
 import gleeunit
 
-import mpv/internal as control_internal
+import input/key.{type Key, Char}
+import mpv/control.{type Control}
+import mpv/internal/control as control_internal
 
 pub fn main() -> Nil {
   gleeunit.main()
 }
 
+type TestCase {
+  TestCase(key: Key, expected: Result(Control, Nil))
+}
+
+pub fn control_from_key_test() {
+  let test_cases = [
+    TestCase(Char(" "), Ok(control.TogglePlayPause)),
+    TestCase(Char("q"), Ok(control.Exit)),
+  ]
+
+  list.each(test_cases, fn(tc) {
+    assert tc.expected == control.from_key(tc.key)
+  })
+}
+
 pub fn parse_playback_time_test() {
   let json_string =
     "{\"data\":\"123.456789\",\"request_id\":0,\"error\":\"success\"}\n"

test/ui/ui_test.gleam

@@ -1,24 +0,0 @@
-import gleam/list
-import gleeunit
-
-import input/key.{type Key, Char}
-import ui/control.{type Control}
-
-pub fn main() -> Nil {
-  gleeunit.main()
-}
-
-type TestCase {
-  TestCase(key: Key, expected: Result(Control, Nil))
-}
-
-pub fn control_from_key_test() {
-  let test_cases = [
-    TestCase(Char(" "), Ok(control.TogglePlayPause)),
-    TestCase(Char("q"), Ok(control.Exit)),
-  ]
-
-  list.each(test_cases, fn(tc) {
-    assert tc.expected == control.from_key(tc.key)
-  })
-}