Move all code into musicplayer module

And add the ability of other modules to listen to either
the final result (a `Key`) or tap into the input as it is read

src/musicplayer.gleam

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

src/musicplayer/input/input.gleam

@@ -0,0 +1,59 @@
+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/input/key.gleam

@@ -1,7 +1,9 @@
 import gleam/erlang/atom
+import gleam/erlang/process.{type Subject}
 import gleam/list
+import gleam/string
 
-import input/internal as internal_input
+import musicplayer/input/internal as internal_input
 
 pub type Key {
   Char(String)
@@ -22,7 +24,7 @@ pub const esc = "\u{001B}"
 pub const csi = "["
 
 // input introducer
-const input_introducer = "$"
+pub const input_introducer = "::"
 
 pub fn from_list(l: List(String)) -> Key {
   case l {
@@ -35,9 +37,12 @@ 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 == "\r" {
+      case tail {
-        True -> Input(cmd)
+        // Return
-        False -> Continue([ii, cmd <> tail])
+        "\r" -> Input(cmd)
+        // Backspace
+        "\u{007F}" -> Continue([ii, string.drop_end(cmd, 1)])
+        _ -> Continue([ii, cmd <> tail])
       }
     }
 
@@ -55,14 +60,20 @@ pub fn start_raw_shell() {
   internal_input.shell_start_interactive(#(no_shell, raw))
 }
 
-pub fn read_input_until_key(l: List(String)) -> Key {
+pub fn read_input_until_key(
+  l: List(String),
+  taps: List(Subject(List(String))),
+) -> Key {
   case
     internal_input.read_input()
     |> list.wrap
     |> list.append(l, _)
     |> from_list
   {
-    Continue(l) -> read_input_until_key(l)
+    Continue(l) -> {
+      list.each(taps, process.send(_, l))
+      read_input_until_key(l, taps)
+    }
     k -> k
   }
 }

src/musicplayer/mpv/control.gleam

@@ -2,16 +2,14 @@ import gleam/json
 import gleam/result
 import gleam/string
 
-import input/key.{type Key}
+import musicplayer/input/key.{type Key}
-import mpv/internal/control as internal_control
+import musicplayer/mpv/internal as internal_control
-import tcp/reason.{type Reason}
+import musicplayer/tcp/reason.{type Reason}
-import tcp/tcp.{type Socket}
+import musicplayer/tcp/tcp.{type Socket}
 
 pub type Control {
   TogglePlayPause
 
-  Search
-
   Exit
 }
 
@@ -20,7 +18,6 @@ pub type ControlError {
 }
 
 pub fn from_key(key: Key) -> Result(Control, Nil) {
-  echo key
   case key {
     key.Char(char) -> char_control(char)
     _ -> Error(Nil)
@@ -31,7 +28,6 @@ fn char_control(char: String) -> Result(Control, Nil) {
   case char {
     " " -> Ok(TogglePlayPause)
     "q" -> Ok(Exit)
-    "/" -> Ok(Search)
     _ -> Error(Nil)
   }
 }

src/musicplayer/mpv/mpv.gleam

@@ -1,25 +1,30 @@
 import gleam/erlang/process.{type Subject}
 import gleam/float
+import gleam/option.{None}
 import gleam/otp/actor
 import gleam/result
 import gleam/string
 
-import input/key
+import musicplayer/input/input.{type Listener, InputListener}
-import mpv/control.{type Control}
+import musicplayer/input/key.{type Key}
-import tcp/reason
+import musicplayer/mpv/control.{type Control}
-import tcp/tcp.{type Socket}
+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(Nil, String) {
+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)
@@ -30,13 +35,15 @@ pub fn new(exit: Subject(Nil)) -> Result(Nil, String) {
         Ok(actor.Started(data:, ..)) -> {
           echo "waiting for input"
           key.start_raw_shell()
-          let input = process.new_subject()
-          process.self()
-          process.receive
 
-          process.spawn(fn() { input_handler(input, data) })
+          process.spawn(fn() {
-          process.spawn(fn() { read_input(data) })
+            let assert Ok(_) =
-          Ok(Nil)
+              process.register(process.self(), final_input_name)
+
+            handle_key(final_input, data)
+          })
+
+          Ok(InputListener(final: final_input, tap: None))
         }
       }
     }
@@ -48,7 +55,6 @@ fn handle_message(
   control: Control,
 ) -> actor.Next(State(socket, exit), Control) {
   case control {
-    control.Search -> todo
     control.TogglePlayPause -> {
       echo "toggling play/pause"
 
@@ -71,32 +77,13 @@ fn handle_message(
   }
 }
 
-// TODO create new input_handler_loop that recieves on a subject and 
+/// `handle_key` listens to a subject onto which `input` will send messages with
-// TODO read_input reads until a key is found, and then sends it to
+/// parsed `Key`s which will be mapped to `Control`s (if possible)
-
+fn handle_key(final_input: Subject(Key), subject: Subject(Control)) -> Nil {
-// TODO a function that can recieve on a subject, and it can receive two types of messages:
+  let _ =
-// 1. a Control message from read_input
+    process.receive_forever(final_input)
-// 2. an injected controlMessage with pre-defined buffer
-// it then forwards the message to the actor subject
-
-fn read_input(input_handler: Subject(Control)) -> Nil {
-  case
-    key.read_input_until_key([])
     |> control.from_key
-  {
+    |> result.map(process.send(subject, _))
-    Error(_) -> Nil
-    Ok(control) -> process.send(input_handler, control)
-  }
 
-  read_input(input_handler)
+  handle_key(final_input, subject)
-}
-
-fn input_handler(
-  input: Subject(Control),
-  actor_subject: Subject(Control),
-) -> Nil {
-  case process.receive(input, 1000) {
-    Error(_) -> Nil
-    Ok(control) -> process.send(actor_subject, control)
-  }
 }

src/musicplayer/tcp/tcp.gleam

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

test/musicplayer/input/input_test.gleam

@@ -1,7 +1,7 @@
 import gleam/list
 import gleeunit
 
-import input/key.{type Key, Char, csi, esc}
+import musicplayer/input/key.{type Key, Char, csi, esc, input_introducer as ii}
 
 pub fn main() -> Nil {
   gleeunit.main()
@@ -27,10 +27,11 @@ pub fn key_from_list_test() {
   ]
 
   let input_tests = [
-    TestCase(["$"], key.Continue(["$"])),
+    TestCase([ii], key.Continue([ii])),
-    TestCase(["$", "a"], key.Continue(["$", "a"])),
+    TestCase([ii, "a"], key.Continue([ii, "a"])),
-    TestCase(["$", "a", "b"], key.Continue(["$", "ab"])),
+    TestCase([ii, "a", "b"], key.Continue([ii, "ab"])),
-    TestCase(["$", "ab", "\r"], key.Input("ab")),
+    TestCase([ii, "ab", "\u{007F}"], key.Continue([ii, "a"])),
+    TestCase([ii, "ab", "\r"], key.Input("ab")),
   ]
 
   let test_cases = [base_tests, char_tests, escape_tests, input_tests]

test/musicplayer/mpv/control_test.gleam

@@ -1,9 +1,9 @@
 import gleam/list
 import gleeunit
 
-import input/key.{type Key, Char}
+import musicplayer/input/key.{type Key, Char}
-import mpv/control.{type Control}
+import musicplayer/mpv/control.{type Control}
-import mpv/internal/control as control_internal
+import musicplayer/mpv/internal as control_internal
 
 pub fn main() -> Nil {
   gleeunit.main()

test/musicplayer/tcp/tcp_test.gleam

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