TCP echo server

src/tcp/tcp.gleam

@@ -1,4 +1,6 @@
-import gleam/bytes_tree
+import gleam/bit_array
+import gleam/erlang/atom
+import gleam/result
 
 import tcp/reason.{type Reason}
 
@@ -17,25 +19,82 @@ type ModeValue {
 type TCPOption {
   Active(Bool)
   Mode(ModeValue)
+  Reuseaddr(Bool)
+  Ifaddr(Local)
+  ExitOnClose(Bool)
+}
+
+pub fn listen(socket_path: String) -> Result(Socket, Reason) {
+  let options = [
+    Mode(Binary),
+    Active(False),
+    Reuseaddr(True),
+    Ifaddr(Local(socket_path)),
+    ExitOnClose(False),
+  ]
+  // port zero with `local` address
+  let port = 0
+
+  gen_tcp_listen(port, options)
+}
+
+pub fn accept(listen_socket: Socket) -> Result(Socket, Reason) {
+  gen_tcp_accept(listen_socket)
+}
+
+pub fn receive(socket: Socket, timeout: Int) -> Result(String, Reason) {
+  // Get all bytes
+  let length = 0
+
+  use bits <- result.try(gen_tcp_recv(socket, length, timeout))
+  case bits |> bit_array.to_string {
+    // TODO what error is best?
+    Error(_) -> Error(reason.Ebadmsg)
+    Ok(s) -> Ok(s)
+  }
 }
 
 pub fn connect(socket_path: String) -> Result(Socket, Reason) {
   let options = [Mode(Binary), Active(False)]
 
+  // port zero with `local` address
+  let port = 0
+
   // timeout in ms
   let timeout = 1000
 
-  gen_tcp_connect(Local(socket_path), 0, options, timeout)
+  gen_tcp_connect(Local(socket_path), port, options, timeout)
 }
 
 pub fn send(socket: Socket, message: String) -> Result(Nil, Reason) {
-  gen_tcp_send(socket, bytes_tree.from_string(message))
+  gen_tcp_send(socket, bit_array.from_string(message))
 }
 
 pub fn close(socket: Socket) -> Nil {
   gen_tcp_close(socket)
 }
 
+pub fn shutdown(socket: Socket) -> Result(Nil, Reason) {
+  let how = atom.create("write")
+  gen_tcp_shutdown(socket, how)
+}
+
+// https://www.erlang.org/doc/apps/kernel/gen_tcp.html#listen/2
+@external(erlang, "gen_tcp", "listen")
+fn gen_tcp_listen(port: Int, option: List(TCPOption)) -> Result(Socket, Reason)
+
+// https://www.erlang.org/doc/apps/kernel/gen_tcp.html#accept/1
+@external(erlang, "gen_tcp", "accept")
+fn gen_tcp_accept(listen_socket: Socket) -> Result(Socket, Reason)
+
+// https://www.erlang.org/doc/apps/kernel/gen_tcp.html#recv/3
+@external(erlang, "gen_tcp", "recv")
+fn gen_tcp_recv(
+  socket: Socket,
+  length: Int,
+  timeout: Int,
+) -> Result(BitArray, Reason)
+
 // https://www.erlang.org/doc/apps/kernel/gen_tcp.html#connect/4
 @external(erlang, "gen_tcp", "connect")
 fn gen_tcp_connect(
@@ -47,11 +106,12 @@ fn gen_tcp_connect(
 
 // https://www.erlang.org/doc/apps/kernel/gen_tcp.html#send/2
 @external(erlang, "tcp_ffi", "send")
-fn gen_tcp_send(
-  socket: Socket,
-  packet: bytes_tree.BytesTree,
-) -> Result(Nil, Reason)
+fn gen_tcp_send(socket: Socket, packet: BitArray) -> Result(Nil, Reason)
 
 // https://www.erlang.org/doc/apps/kernel/gen_tcp.html#close/1
 @external(erlang, "gen_tcp", "close")
 fn gen_tcp_close(socket: Socket) -> Nil
+
+// https://www.erlang.org/doc/apps/kernel/gen_tcp.html#shutdown/2
+@external(erlang, "tcp_ffi", "shutdown")
+fn gen_tcp_shutdown(socket: Socket, how: atom.Atom) -> Result(Nil, Reason)