Send some messages

src/ipc.gleam

@@ -0,0 +1,59 @@
+import gleam/bytes_tree
+
+pub type Socket
+
+// https://www.erlang.org/doc/apps/kernel/inet#t:address_family/0
+// local socket
+type Local {
+  Local(socket_path: String)
+}
+
+type ModeValue {
+  Binary
+}
+
+type IPCOption {
+  Active(Bool)
+  Mode(ModeValue)
+}
+
+pub type IPCError {
+  IPCError(reason: String)
+}
+
+pub fn connect(socket_path: String) -> Result(Socket, IPCError) {
+  let options = [Mode(Binary), Active(False)]
+
+  // timeout in ms
+  let timeout = 1000
+
+  gen_tcp_connect(Local(socket_path), 0, options, timeout)
+}
+
+pub fn send(socket: Socket, message: String) -> Result(Nil, IPCError) {
+  gen_tcp_send(socket, bytes_tree.from_string(message))
+}
+
+pub fn close(socket: Socket) -> Nil {
+  gen_tcp_close(socket)
+}
+
+// https://www.erlang.org/doc/apps/kernel/gen_tcp.html#connect/4
+@external(erlang, "gen_tcp", "connect")
+fn gen_tcp_connect(
+  address: Local,
+  port: Int,
+  options: List(IPCOption),
+  timeout: Int,
+) -> Result(Socket, IPCError)
+
+// https://www.erlang.org/doc/apps/kernel/gen_tcp.html#send/2
+@external(erlang, "ipc_ffi", "send")
+fn gen_tcp_send(
+  socket: Socket,
+  packet: bytes_tree.BytesTree,
+) -> Result(Nil, IPCError)
+
+// https://www.erlang.org/doc/apps/kernel/gen_tcp.html#close/1
+@external(erlang, "gen_tcp", "close")
+fn gen_tcp_close(socket: Socket) -> Nil

src/ipc_ffi.erl

@@ -0,0 +1,8 @@
+-module(ipc_ffi).
+-export([send/2]).
+
+send(Socket, Packet) ->
+  case gen_tcp:send(Socket, Packet) of
+    ok -> {ok, nil};
+    Res -> Res
+  end.

src/musicplayer.gleam

@@ -1,5 +1,37 @@
 import gleam/io
+import ipc
 
 pub fn main() -> Nil {
-  io.println("Hello from musicplayer!")
+  let socket_path = "/tmp/musicplayer.sock"
+
+  case ipc.connect(socket_path) {
+    Error(err) -> io.println("Failed to connect to socket: " <> err.reason)
+    Ok(socket) -> {
+      io.println("connected")
+
+      let messages = ["hello, \n", "world!\n"]
+
+      messages |> send_messages(socket, _)
+
+      io.println("closing")
+      ipc.close(socket)
+    }
+  }
+}
+
+fn send_messages(socket: ipc.Socket, messages: List(String)) -> Nil {
+  case messages {
+    [] -> Nil
+    [message, ..rest] -> {
+      send_message(socket, message)
+      send_messages(socket, rest)
+    }
+  }
+}
+
+fn send_message(socket: ipc.Socket, message: String) -> Nil {
+  case ipc.send(socket, message) {
+    Error(err) -> io.println("Failed to send message to socket: " <> err.reason)
+    Ok(_) -> io.println("Sent message to socket")
+  }
 }