Add ability to get playback-time

src/mpv/control.gleam

@@ -1,5 +1,8 @@
 import gleam/json
 import gleam/result
+import gleam/string
+
+import mpv/internal/control as internal_control
 import mpv/key.{type Key, Char}
 import tcp/reason.{type Reason}
 import tcp/tcp.{type Socket}
@@ -38,6 +41,30 @@ pub fn toggle_play_pause(socket: Socket) -> Result(Nil, ControlError) {
   }
 }
 
+// https://mpv.io/manual/master/#command-interface-playback-time
+pub type PlaybackTime {
+  PlaybackTime(data: Float)
+}
+
+pub fn get_playback_time(socket: Socket) -> Result(PlaybackTime, ControlError) {
+  let command =
+    json.object([
+      #(
+        "command",
+        json.array(["get_property_string", "playback-time"], of: json.string),
+      ),
+    ])
+
+  case send_command(socket, command) {
+    Error(r) -> Error(ControlError(reason.to_string(r)))
+    Ok(json_string) ->
+      case internal_control.parse_playback_time(json_string) {
+        Error(e) -> Error(ControlError(string.inspect(e)))
+        Ok(data) -> Ok(PlaybackTime(data))
+      }
+  }
+}
+
 fn send_command(socket: Socket, command: json.Json) -> Result(String, Reason) {
   result.try(tcp.send(socket, json.to_string(command) <> "\n"), fn(_) {
     let timeout_ms = 10_000

src/mpv/internal/control.gleam

@@ -0,0 +1,25 @@
+import gleam/dynamic/decode
+import gleam/float
+import gleam/json
+import gleam/string
+
+pub fn parse_playback_time(
+  json_string: String,
+) -> Result(Float, json.DecodeError) {
+  let decoder = {
+    let float_dececoder = fn(data_string) {
+      case float.parse(data_string) {
+        Error(_) -> decode.failure(0.0, "data")
+        Ok(float_value) -> decode.success(float_value)
+      }
+    }
+    use data <- decode.field(
+      "data",
+      decode.then(decode.string, float_dececoder),
+    )
+
+    decode.success(data)
+  }
+
+  json.parse(from: string.trim(json_string), using: decoder)
+}

src/mpv/mpv.gleam

@@ -1,4 +1,5 @@
 import gleam/erlang/process.{type Subject}
+import gleam/float
 import gleam/otp/actor
 import gleam/result
 import gleam/string
@@ -44,10 +45,17 @@ fn handle_message(
   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 -> {

test/mpv/control_test.gleam

@@ -2,6 +2,7 @@ import gleam/list
 import gleeunit
 
 import mpv/control.{type Control}
+import mpv/internal/control as control_internal
 import mpv/key.{type Key, Char}
 
 pub fn main() -> Nil {
@@ -22,3 +23,11 @@ pub fn control_from_key_test() {
     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"
+
+  let assert Ok(data) = control_internal.parse_playback_time(json_string)
+  assert data == 123.456789
+}