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/key.gleam

@@ -3,7 +3,7 @@ import gleam/erlang/process.{type Subject}
 import gleam/list
 import gleam/string
 
-import musicplayer/input/internal as internal_input
+import input/internal as internal_input
 
 pub type Key {
   Char(String)
@@ -38,9 +38,7 @@ pub fn from_list(l: List(String)) -> Key {
     [ci] | [ci, _] if ci == input_introducer -> Continue(l)
     [ii, cmd, tail] if ii == input_introducer -> {
       case tail {
-        // Return
         "\r" -> Input(cmd)
-        // Backspace
         "\u{007F}" -> Continue([ii, string.drop_end(cmd, 1)])
         _ -> Continue([ii, cmd <> tail])
       }
@@ -62,7 +60,7 @@ pub fn start_raw_shell() {
 
 pub fn read_input_until_key(
   l: List(String),
-  taps: List(Subject(List(String))),
+  tap_input: Subject(List(String)),
 ) -> Key {
   case
     internal_input.read_input()
@@ -71,8 +69,8 @@ pub fn read_input_until_key(
     |> from_list
   {
     Continue(l) -> {
-      list.each(taps, process.send(_, l))
-      read_input_until_key(l, taps)
+      process.send(tap_input, l)
+      read_input_until_key(l, tap_input)
     }
     k -> k
   }

src/mpv/control.gleam

@@ -2,14 +2,16 @@ import gleam/json
 import gleam/result
 import gleam/string
 
-import musicplayer/input/key.{type Key}
-import musicplayer/mpv/internal as internal_control
-import musicplayer/tcp/reason.{type Reason}
-import musicplayer/tcp/tcp.{type Socket}
+import input/key.{type Key}
+import mpv/internal/control as internal_control
+import tcp/reason.{type Reason}
+import tcp/tcp.{type Socket}
 
 pub type Control {
   TogglePlayPause
 
+  Search
+
   Exit
 }
 
@@ -17,7 +19,12 @@ pub type ControlError {
   ControlError(details: String)
 }
 
+// TODO this should also have a context:
+// `/` in "artist list" "context will should be`control.Search`
+// `<some char>` in "create new playlist" context should be `control.Input`
+// `q` in most contexts should be `Exit`, but in a popup it should be `Close`
 pub fn from_key(key: Key) -> Result(Control, Nil) {
+  echo key
   case key {
     key.Char(char) -> char_control(char)
     _ -> Error(Nil)
@@ -28,6 +35,7 @@ fn char_control(char: String) -> Result(Control, Nil) {
   case char {
     " " -> Ok(TogglePlayPause)
     "q" -> Ok(Exit)
+    "/" -> Ok(Search)
     _ -> Error(Nil)
   }
 }

src/mpv/mpv.gleam

@@ -0,0 +1,123 @@
+import gleam/erlang/process.{type Subject}
+import gleam/float
+import gleam/otp/actor
+import gleam/result
+import gleam/string
+
+import input/key.{type Key}
+import mpv/control.{type Control}
+import tcp/reason
+import tcp/tcp.{type Socket}
+
+type State(socket, inject_input, tap_input, exit) {
+  State(
+    socket: Socket,
+    inject_input: Subject(Key),
+    tap_input: Subject(List(String)),
+    exit: Subject(Nil),
+  )
+}
+
+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"
+
+  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, 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:, ..)) -> {
+          echo "waiting for input"
+          key.start_raw_shell()
+
+          process.spawn(fn() {
+            let assert Ok(_) =
+              process.register(process.self(), inject_input_name)
+
+            read_input(data, inject_input, tap_input)
+          })
+
+          process.spawn(fn() {
+            let assert Ok(_) = process.register(process.self(), tap_input_name)
+
+            input_output_loop(tap_input)
+          })
+
+          Ok(Nil)
+        }
+      }
+    }
+  }
+}
+
+fn handle_message(
+  state: State(socket, inject, input_output, exit),
+  control: Control,
+) -> actor.Next(State(socket, inject, input_output, exit), Control) {
+  case control {
+    control.Search -> {
+      process.send(state.inject_input, key.Continue([key.input_introducer]))
+      actor.continue(state)
+    }
+    control.TogglePlayPause -> {
+      echo "toggling play/pause"
+
+      let _ =
+        result.map_error(control.toggle_play_pause(state.socket), fn(err) {
+          echo "Could not toggle play/pause: " <> err.details
+        })
+
+      let _ =
+        result.map(control.get_playback_time(state.socket), fn(playback) {
+          echo "playback: " <> float.to_string(playback.data)
+        })
+
+      actor.continue(state)
+    }
+    control.Exit -> {
+      process.send(state.exit, Nil)
+      actor.stop()
+    }
+  }
+}
+
+/// `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(
+  agent: 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(_) -> []
+  }
+
+  case
+    key.read_input_until_key(buffer, tap_input)
+    |> control.from_key
+  {
+    Error(_) -> Nil
+    Ok(control) -> process.send(agent, control)
+  }
+
+  read_input(agent, inject_input, tap_input)
+}

src/musicplayer.gleam

@@ -1,22 +1,8 @@
-import gleam/erlang/process.{type Name}
-
-import musicplayer/input/input.{type Listener}
-import musicplayer/input/key.{type Key}
-import musicplayer/mpv/mpv
+import gleam/erlang/process
+import mpv/mpv
 
 pub fn main() -> Nil {
   let exit = process.new_subject()
-
-  // `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
-  let inject_input_name: Name(Key) = process.new_name("inject_input")
-
-  let assert Ok(mpv_listener) = mpv.new(exit)
-
-  let listeners: List(Listener) = [mpv_listener]
-
-  input.new(listeners, inject_input_name)
+  let assert Ok(_) = mpv.new(exit)
   process.receive_forever(exit)
 }

src/musicplayer/input/input.gleam

@@ -1,59 +0,0 @@
-import gleam/erlang/process.{type Name, type Subject}
-import gleam/list
-import gleam/option.{type Option, None, Some}
-
-import musicplayer/input/key.{type Key}
-
-pub type Listener {
-  InputListener(final: Subject(Key), tap: Option(Subject(List(String))))
-}
-
-/// `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(listeners: List(Listener), inject_input_name: Name(Key)) -> Nil {
-  let _ =
-    process.spawn(fn() {
-      let inject_input: Subject(Key) = process.named_subject(inject_input_name)
-      let assert Ok(_) = process.register(process.self(), inject_input_name)
-
-      // Extract all finals and taps (that are defined)
-      let #(finals, taps) =
-        list.fold(listeners, #([], []), fn(acc, listener) {
-          let #(finals, taps) = acc
-
-          let finals = [listener.final, ..finals]
-
-          let taps = case listener.tap {
-            Some(t) -> [t, ..taps]
-            None -> taps
-          }
-
-          #(finals, taps)
-        })
-
-      read_input(finals, taps, inject_input)
-    })
-
-  Nil
-}
-
-fn read_input(
-  finals: List(Subject(Key)),
-  taps: List(Subject(List(String))),
-  inject_input: Subject(Key),
-) -> Nil {
-  let buffer = case process.receive(inject_input, 1) {
-    Ok(key.Continue(buffer)) -> buffer
-    Ok(_) | Error(_) -> []
-  }
-
-  let _ =
-    key.read_input_until_key(buffer, taps)
-    |> fn(k) { list.each(finals, process.send(_, k)) }
-
-  read_input(finals, taps, inject_input)
-}

src/musicplayer/mpv/mpv.gleam

@@ -1,89 +0,0 @@
-import gleam/erlang/process.{type Subject}
-import gleam/float
-import gleam/option.{None}
-import gleam/otp/actor
-import gleam/result
-import gleam/string
-
-import musicplayer/input/input.{type Listener, InputListener}
-import musicplayer/input/key.{type Key}
-import musicplayer/mpv/control.{type Control}
-import musicplayer/tcp/reason
-import musicplayer/tcp/tcp.{type Socket}
-
-type State(socket, exit) {
-  State(socket: Socket, exit: Subject(Nil))
-}
-
-pub fn new(exit: Subject(Nil)) -> Result(Listener, String) {
-  // TODO start up mvp here, currently hi-jacking `naviterm`s socket
-  let socket_path = "/tmp/naviterm_mpv"
-
-  case tcp.connect(socket_path) {
-    Error(r) -> Error("Could not connect to mpv: " <> reason.to_string(r))
-    Ok(socket) -> {
-      let final_input_name = process.new_name("mpv_final_input")
-      let final_input: Subject(Key) = process.named_subject(final_input_name)
-
-      case
-        actor.new(State(socket, exit))
-        |> actor.on_message(handle_message)
-        |> actor.start
-      {
-        Error(start_error) ->
-          Error("Could not start actor: " <> string.inspect(start_error))
-        Ok(actor.Started(data:, ..)) -> {
-          echo "waiting for input"
-          key.start_raw_shell()
-
-          process.spawn(fn() {
-            let assert Ok(_) =
-              process.register(process.self(), final_input_name)
-
-            handle_key(final_input, data)
-          })
-
-          Ok(InputListener(final: final_input, tap: None))
-        }
-      }
-    }
-  }
-}
-
-fn handle_message(
-  state: State(socket, exit),
-  control: Control,
-) -> actor.Next(State(socket, exit), Control) {
-  case control {
-    control.TogglePlayPause -> {
-      echo "toggling play/pause"
-
-      let _ =
-        result.map_error(control.toggle_play_pause(state.socket), fn(err) {
-          echo "Could not toggle play/pause: " <> err.details
-        })
-
-      let _ =
-        result.map(control.get_playback_time(state.socket), fn(playback) {
-          echo "playback: " <> float.to_string(playback.data)
-        })
-
-      actor.continue(state)
-    }
-    control.Exit -> {
-      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(final_input: Subject(Key), subject: Subject(Control)) -> Nil {
-  let _ =
-    process.receive_forever(final_input)
-    |> control.from_key
-    |> result.map(process.send(subject, _))
-
-  handle_key(final_input, subject)
-}

src/tcp/tcp.gleam

@@ -2,7 +2,7 @@ import gleam/bit_array
 import gleam/erlang/atom
 import gleam/result
 
-import musicplayer/tcp/reason.{type Reason}
+import tcp/reason.{type Reason}
 
 pub type Socket
 

test/echo_server.gleam

@@ -4,8 +4,8 @@ import gleam/otp/actor
 import gleam/result
 import gleam/string
 
-import musicplayer/tcp/reason.{type Reason}
-import musicplayer/tcp/tcp
+import tcp/reason.{type Reason}
+import tcp/tcp
 
 pub type Message {
   Shutdown

test/input/input_test.gleam

@@ -1,7 +1,7 @@
 import gleam/list
 import gleeunit
 
-import musicplayer/input/key.{type Key, Char, csi, esc, input_introducer as ii}
+import input/key.{type Key, Char, csi, esc, input_introducer as ii}
 
 pub fn main() -> Nil {
   gleeunit.main()
@@ -30,7 +30,6 @@ pub fn key_from_list_test() {
     TestCase([ii], key.Continue([ii])),
     TestCase([ii, "a"], key.Continue([ii, "a"])),
     TestCase([ii, "a", "b"], key.Continue([ii, "ab"])),
-    TestCase([ii, "ab", "\u{007F}"], key.Continue([ii, "a"])),
     TestCase([ii, "ab", "\r"], key.Input("ab")),
   ]
 

test/mpv/control_test.gleam

@@ -1,9 +1,9 @@
 import gleam/list
 import gleeunit
 
-import musicplayer/input/key.{type Key, Char}
-import musicplayer/mpv/control.{type Control}
-import musicplayer/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()

test/tcp/tcp_test.gleam

@@ -3,7 +3,7 @@ import gleeunit
 import simplifile
 
 import echo_server
-import musicplayer/tcp/tcp
+import tcp/tcp
 
 pub fn main() -> Nil {
   gleeunit.main()