Fix panics due to concurrent websocket writes

app.go

@@ -19,6 +19,10 @@ type App struct {
 	ctx       context.Context
 	ctxCancel context.CancelFunc
 	conn      *websocket.Conn
+
+	// Wraps the ws connection with added mutex locking
+	wsWriter *ws.WebsocketWriter
+
 	httpClient *http.HttpClient
 
 	service *Service
@@ -85,11 +89,13 @@ func NewApp(request NewAppRequest) *App {
 
 	httpClient := http.NewHttpClient(request.IpAddress, port, request.HAAuthToken)
 
-	service := newService(conn, ctx, httpClient)
+	wsWriter := &ws.WebsocketWriter{Conn: conn}
+	service := newService(wsWriter, ctx, httpClient)
 	state := newState(httpClient, request.HomeZoneEntityId)
 
 	return &App{
 		conn:            conn,
+		wsWriter:        wsWriter,
 		ctx:             ctx,
 		ctxCancel:       ctxCancel,
 		httpClient:      httpClient,
@@ -169,7 +175,7 @@ func (a *App) RegisterEventListeners(evls ...EventListener) {
 			if elList, ok := a.eventListeners[eventType]; ok {
 				a.eventListeners[eventType] = append(elList, &evl)
 			} else {
-				ws.SubscribeToEventType(eventType, a.conn, a.ctx)
+				ws.SubscribeToEventType(eventType, a.wsWriter, a.ctx)
 				a.eventListeners[eventType] = []*EventListener{&evl}
 			}
 		}
@@ -227,7 +233,7 @@ func (a *App) Start() {
 
 	// subscribe to state_changed events
 	id := internal.GetId()
-	ws.SubscribeToStateChangedEvents(id, a.conn, a.ctx)
+	ws.SubscribeToStateChangedEvents(id, a.wsWriter, a.ctx)
 	a.entityListenersId = id
 
 	// entity listeners runOnStartup

internal/services/alarm_control_panel.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type AlarmControlPanel struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -27,7 +26,7 @@ func (acp AlarmControlPanel) ArmAway(entityId string, serviceData ...map[string]
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, acp.conn, acp.ctx)
+	acp.conn.WriteMessage(req, acp.ctx)
 }
 
 // Send the alarm the command for arm away.
@@ -41,7 +40,7 @@ func (acp AlarmControlPanel) ArmWithCustomBypass(entityId string, serviceData ..
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, acp.conn, acp.ctx)
+	acp.conn.WriteMessage(req, acp.ctx)
 }
 
 // Send the alarm the command for arm home.
@@ -55,7 +54,7 @@ func (acp AlarmControlPanel) ArmHome(entityId string, serviceData ...map[string]
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, acp.conn, acp.ctx)
+	acp.conn.WriteMessage(req, acp.ctx)
 }
 
 // Send the alarm the command for arm night.
@@ -69,7 +68,7 @@ func (acp AlarmControlPanel) ArmNight(entityId string, serviceData ...map[string
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, acp.conn, acp.ctx)
+	acp.conn.WriteMessage(req, acp.ctx)
 }
 
 // Send the alarm the command for arm vacation.
@@ -83,7 +82,7 @@ func (acp AlarmControlPanel) ArmVacation(entityId string, serviceData ...map[str
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, acp.conn, acp.ctx)
+	acp.conn.WriteMessage(req, acp.ctx)
 }
 
 // Send the alarm the command for disarm.
@@ -97,7 +96,7 @@ func (acp AlarmControlPanel) Disarm(entityId string, serviceData ...map[string]a
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, acp.conn, acp.ctx)
+	acp.conn.WriteMessage(req, acp.ctx)
 }
 
 // Send the alarm the command for trigger.
@@ -111,5 +110,5 @@ func (acp AlarmControlPanel) Trigger(entityId string, serviceData ...map[string]
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, acp.conn, acp.ctx)
+	acp.conn.WriteMessage(req, acp.ctx)
 }

internal/services/cover.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type Cover struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -22,7 +21,7 @@ func (c Cover) Close(entityId string) {
 	req.Domain = "cover"
 	req.Service = "close_cover"
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }
 
 // Close all or specified cover tilt. Takes an entityId.
@@ -31,7 +30,7 @@ func (c Cover) CloseTilt(entityId string) {
 	req.Domain = "cover"
 	req.Service = "close_cover_tilt"
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }
 
 // Open all or specified cover. Takes an entityId.
@@ -40,7 +39,7 @@ func (c Cover) Open(entityId string) {
 	req.Domain = "cover"
 	req.Service = "open_cover"
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }
 
 // Open all or specified cover tilt. Takes an entityId.
@@ -49,7 +48,7 @@ func (c Cover) OpenTilt(entityId string) {
 	req.Domain = "cover"
 	req.Service = "open_cover_tilt"
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }
 
 // Move to specific position all or specified cover. Takes an entityId and an optional
@@ -62,7 +61,7 @@ func (c Cover) SetPosition(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }
 
 // Move to specific position all or specified cover tilt. Takes an entityId and an optional
@@ -75,7 +74,7 @@ func (c Cover) SetTiltPosition(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }
 
 // Stop a cover entity. Takes an entityId.
@@ -84,7 +83,7 @@ func (c Cover) Stop(entityId string) {
 	req.Domain = "cover"
 	req.Service = "stop_cover"
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }
 
 // Stop a cover entity tilt. Takes an entityId.
@@ -93,7 +92,7 @@ func (c Cover) StopTilt(entityId string) {
 	req.Domain = "cover"
 	req.Service = "stop_cover_tilt"
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }
 
 // Toggle a cover open/closed. Takes an entityId.
@@ -102,7 +101,7 @@ func (c Cover) Toggle(entityId string) {
 	req.Domain = "cover"
 	req.Service = "toggle"
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }
 
 // Toggle a cover tilt open/closed. Takes an entityId.
@@ -111,5 +110,5 @@ func (c Cover) ToggleTilt(entityId string) {
 	req.Domain = "cover"
 	req.Service = "toggle_cover_tilt"
 
-	ws.WriteMessage(req, c.conn, c.ctx)
+	c.conn.WriteMessage(req, c.ctx)
 }

internal/services/homeassistant.go

@@ -3,12 +3,11 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 type HomeAssistant struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -22,7 +21,7 @@ func (ha *HomeAssistant) TurnOn(entityId string, serviceData ...map[string]any)
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, ha.conn, ha.ctx)
+	ha.conn.WriteMessage(req, ha.ctx)
 }
 
 // Toggle a Home Assistant entity. Takes an entityId and an optional
@@ -35,7 +34,7 @@ func (ha *HomeAssistant) Toggle(entityId string, serviceData ...map[string]any)
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, ha.conn, ha.ctx)
+	ha.conn.WriteMessage(req, ha.ctx)
 }
 
 func (ha *HomeAssistant) TurnOff(entityId string) {
@@ -43,5 +42,5 @@ func (ha *HomeAssistant) TurnOff(entityId string) {
 	req.Domain = "homeassistant"
 	req.Service = "turn_off"
 
-	ws.WriteMessage(req, ha.conn, ha.ctx)
+	ha.conn.WriteMessage(req, ha.ctx)
 }

internal/services/input_boolean.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type InputBoolean struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -21,7 +20,7 @@ func (ib InputBoolean) TurnOn(entityId string) {
 	req.Domain = "input_boolean"
 	req.Service = "turn_on"
 
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }
 
 func (ib InputBoolean) Toggle(entityId string) {
@@ -29,19 +28,19 @@ func (ib InputBoolean) Toggle(entityId string) {
 	req.Domain = "input_boolean"
 	req.Service = "toggle"
 
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }
 
 func (ib InputBoolean) TurnOff(entityId string) {
 	req := NewBaseServiceRequest(entityId)
 	req.Domain = "input_boolean"
 	req.Service = "turn_off"
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }
 
 func (ib InputBoolean) Reload() {
 	req := NewBaseServiceRequest("")
 	req.Domain = "input_boolean"
 	req.Service = "reload"
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }

internal/services/input_button.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type InputButton struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -21,12 +20,12 @@ func (ib InputButton) Press(entityId string) {
 	req.Domain = "input_button"
 	req.Service = "press"
 
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }
 
 func (ib InputButton) Reload() {
 	req := NewBaseServiceRequest("")
 	req.Domain = "input_button"
 	req.Service = "reload"
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }

internal/services/input_datetime.go

@@ -5,14 +5,13 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type InputDatetime struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -26,12 +25,12 @@ func (ib InputDatetime) Set(entityId string, value time.Time) {
 		"timestamp": fmt.Sprint(value.Unix()),
 	}
 
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }
 
 func (ib InputDatetime) Reload() {
 	req := NewBaseServiceRequest("")
 	req.Domain = "input_datetime"
 	req.Service = "reload"
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }

internal/services/input_number.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type InputNumber struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -22,7 +21,7 @@ func (ib InputNumber) Set(entityId string, value float32) {
 	req.Service = "set_value"
 	req.ServiceData = map[string]any{"value": value}
 
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }
 
 func (ib InputNumber) Increment(entityId string) {
@@ -30,7 +29,7 @@ func (ib InputNumber) Increment(entityId string) {
 	req.Domain = "input_number"
 	req.Service = "increment"
 
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }
 
 func (ib InputNumber) Decrement(entityId string) {
@@ -38,12 +37,12 @@ func (ib InputNumber) Decrement(entityId string) {
 	req.Domain = "input_number"
 	req.Service = "decrement"
 
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }
 
 func (ib InputNumber) Reload() {
 	req := NewBaseServiceRequest("")
 	req.Domain = "input_number"
 	req.Service = "reload"
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }

internal/services/input_text.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type InputText struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -24,12 +23,12 @@ func (ib InputText) Set(entityId string, value string) {
 		"value": value,
 	}
 
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }
 
 func (ib InputText) Reload() {
 	req := NewBaseServiceRequest("")
 	req.Domain = "input_text"
 	req.Service = "reload"
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }

internal/services/light.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type Light struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -26,7 +25,7 @@ func (l Light) TurnOn(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, l.conn, l.ctx)
+	l.conn.WriteMessage(req, l.ctx)
 }
 
 // Toggle a light entity. Takes an entityId and an optional
@@ -39,12 +38,12 @@ func (l Light) Toggle(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, l.conn, l.ctx)
+	l.conn.WriteMessage(req, l.ctx)
 }
 
 func (l Light) TurnOff(entityId string) {
 	req := NewBaseServiceRequest(entityId)
 	req.Domain = "light"
 	req.Service = "turn_off"
-	ws.WriteMessage(req, l.conn, l.ctx)
+	l.conn.WriteMessage(req, l.ctx)
 }

internal/services/lock.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type Lock struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -26,7 +25,7 @@ func (l Lock) Lock(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, l.conn, l.ctx)
+	l.conn.WriteMessage(req, l.ctx)
 }
 
 // Unlock a lock entity. Takes an entityId and an optional
@@ -39,5 +38,5 @@ func (l Lock) Unlock(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, l.conn, l.ctx)
+	l.conn.WriteMessage(req, l.ctx)
 }

internal/services/media_player.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type MediaPlayer struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -23,7 +22,7 @@ func (mp MediaPlayer) ClearPlaylist(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "clear_playlist"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Group players together. Only works on platforms with support for player groups.
@@ -37,7 +36,7 @@ func (mp MediaPlayer) Join(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Send the media player the command for next track.
@@ -47,7 +46,7 @@ func (mp MediaPlayer) Next(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "media_next_track"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Send the media player the command for pause.
@@ -57,7 +56,7 @@ func (mp MediaPlayer) Pause(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "media_pause"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Send the media player the command for play.
@@ -67,7 +66,7 @@ func (mp MediaPlayer) Play(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "media_play"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Toggle media player play/pause state.
@@ -77,7 +76,7 @@ func (mp MediaPlayer) PlayPause(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "media_play_pause"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Send the media player the command for previous track.
@@ -87,7 +86,7 @@ func (mp MediaPlayer) Previous(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "media_previous_track"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Send the media player the command to seek in current playing media.
@@ -101,7 +100,7 @@ func (mp MediaPlayer) Seek(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Send the media player the stop command.
@@ -111,7 +110,7 @@ func (mp MediaPlayer) Stop(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "media_stop"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Send the media player the command for playing media.
@@ -125,7 +124,7 @@ func (mp MediaPlayer) PlayMedia(entityId string, serviceData ...map[string]any)
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Set repeat mode. Takes an entityId and an optional
@@ -138,7 +137,7 @@ func (mp MediaPlayer) RepeatSet(entityId string, serviceData ...map[string]any)
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Send the media player the command to change sound mode.
@@ -152,7 +151,7 @@ func (mp MediaPlayer) SelectSoundMode(entityId string, serviceData ...map[string
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Send the media player the command to change input source.
@@ -166,7 +165,7 @@ func (mp MediaPlayer) SelectSource(entityId string, serviceData ...map[string]an
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Set shuffling state.
@@ -180,7 +179,7 @@ func (mp MediaPlayer) Shuffle(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Toggles a media player power state.
@@ -190,7 +189,7 @@ func (mp MediaPlayer) Toggle(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "toggle"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Turn a media player power off.
@@ -200,7 +199,7 @@ func (mp MediaPlayer) TurnOff(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "turn_off"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Turn a media player power on.
@@ -210,7 +209,7 @@ func (mp MediaPlayer) TurnOn(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "turn_on"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Unjoin the player from a group. Only works on
@@ -221,7 +220,7 @@ func (mp MediaPlayer) Unjoin(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "unjoin"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Turn a media player volume down.
@@ -231,7 +230,7 @@ func (mp MediaPlayer) VolumeDown(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "volume_down"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Mute a media player's volume.
@@ -245,7 +244,7 @@ func (mp MediaPlayer) VolumeMute(entityId string, serviceData ...map[string]any)
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Set a media player's volume level.
@@ -259,7 +258,7 @@ func (mp MediaPlayer) VolumeSet(entityId string, serviceData ...map[string]any)
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }
 
 // Turn a media player volume up.
@@ -269,5 +268,5 @@ func (mp MediaPlayer) VolumeUp(entityId string) {
 	req.Domain = "media_player"
 	req.Service = "volume_up"
 
-	ws.WriteMessage(req, mp.conn, mp.ctx)
+	mp.conn.WriteMessage(req, mp.ctx)
 }

internal/services/notify.go

@@ -3,13 +3,12 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 	"saml.dev/gome-assistant/types"
 )
 
 type Notify struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -27,5 +26,5 @@ func (ha *Notify) Notify(reqData types.NotifyRequest) {
 	}
 
 	req.ServiceData = serviceData
-	ws.WriteMessage(req, ha.conn, ha.ctx)
+	ha.conn.WriteMessage(req, ha.ctx)
 }

internal/services/number.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type Number struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -22,5 +21,5 @@ func (ib Number) SetValue(entityId string, value int) {
 	req.Service = "set_value"
 	req.ServiceData = map[string]any{"value": value}
 
-	ws.WriteMessage(req, ib.conn, ib.ctx)
+	ib.conn.WriteMessage(req, ib.ctx)
 }

internal/services/scene.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type Scene struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -25,7 +24,7 @@ func (s Scene) Apply(serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, s.conn, s.ctx)
+	s.conn.WriteMessage(req, s.ctx)
 }
 
 // Create a scene entity. Takes an entityId and an optional
@@ -38,7 +37,7 @@ func (s Scene) Create(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, s.conn, s.ctx)
+	s.conn.WriteMessage(req, s.ctx)
 }
 
 // Reload the scenes.
@@ -47,7 +46,7 @@ func (s Scene) Reload() {
 	req.Domain = "scene"
 	req.Service = "reload"
 
-	ws.WriteMessage(req, s.conn, s.ctx)
+	s.conn.WriteMessage(req, s.ctx)
 }
 
 // TurnOn a scene entity. Takes an entityId and an optional
@@ -60,5 +59,5 @@ func (s Scene) TurnOn(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, s.conn, s.ctx)
+	s.conn.WriteMessage(req, s.ctx)
 }

internal/services/services.go

@@ -4,8 +4,8 @@ import (
 	"context"
 	"fmt"
 
-	"github.com/gorilla/websocket"
 	"saml.dev/gome-assistant/internal"
+	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 func BuildService[
@@ -26,7 +26,7 @@ func BuildService[
 		Scene |
 		TTS |
 		Vacuum,
-](conn *websocket.Conn, ctx context.Context) *T {
+](conn *ws.WebsocketWriter, ctx context.Context) *T {
 	return &T{conn: conn, ctx: ctx}
 }
 

internal/services/switch.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type Switch struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -21,7 +20,7 @@ func (s Switch) TurnOn(entityId string) {
 	req.Domain = "switch"
 	req.Service = "turn_on"
 
-	ws.WriteMessage(req, s.conn, s.ctx)
+	s.conn.WriteMessage(req, s.ctx)
 }
 
 func (s Switch) Toggle(entityId string) {
@@ -29,12 +28,12 @@ func (s Switch) Toggle(entityId string) {
 	req.Domain = "switch"
 	req.Service = "toggle"
 
-	ws.WriteMessage(req, s.conn, s.ctx)
+	s.conn.WriteMessage(req, s.ctx)
 }
 
 func (s Switch) TurnOff(entityId string) {
 	req := NewBaseServiceRequest(entityId)
 	req.Domain = "switch"
 	req.Service = "turn_off"
-	ws.WriteMessage(req, s.conn, s.ctx)
+	s.conn.WriteMessage(req, s.ctx)
 }

internal/services/tts.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type TTS struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -22,7 +21,7 @@ func (tts TTS) ClearCache() {
 	req.Domain = "tts"
 	req.Service = "clear_cache"
 
-	ws.WriteMessage(req, tts.conn, tts.ctx)
+	tts.conn.WriteMessage(req, tts.ctx)
 }
 
 // Say something using text-to-speech on a media player with cloud.
@@ -36,7 +35,7 @@ func (tts TTS) CloudSay(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, tts.conn, tts.ctx)
+	tts.conn.WriteMessage(req, tts.ctx)
 }
 
 // Say something using text-to-speech on a media player with google_translate.
@@ -50,5 +49,5 @@ func (tts TTS) GoogleTranslateSay(entityId string, serviceData ...map[string]any
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, tts.conn, tts.ctx)
+	tts.conn.WriteMessage(req, tts.ctx)
 }

internal/services/vacuum.go

@@ -3,14 +3,13 @@ package services
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 /* Structs */
 
 type Vacuum struct {
-	conn *websocket.Conn
+	conn *ws.WebsocketWriter
 	ctx  context.Context
 }
 
@@ -23,7 +22,7 @@ func (v Vacuum) CleanSpot(entityId string) {
 	req.Domain = "vacuum"
 	req.Service = "clean_spot"
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Locate the vacuum cleaner robot.
@@ -33,7 +32,7 @@ func (v Vacuum) Locate(entityId string) {
 	req.Domain = "vacuum"
 	req.Service = "locate"
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Pause the cleaning task.
@@ -43,7 +42,7 @@ func (v Vacuum) Pause(entityId string) {
 	req.Domain = "vacuum"
 	req.Service = "pause"
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Tell the vacuum cleaner to return to its dock.
@@ -53,7 +52,7 @@ func (v Vacuum) ReturnToBase(entityId string) {
 	req.Domain = "vacuum"
 	req.Service = "return_to_base"
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Send a raw command to the vacuum cleaner. Takes an entityId and an optional
@@ -66,7 +65,7 @@ func (v Vacuum) SendCommand(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Set the fan speed of the vacuum cleaner. Takes an entityId and an optional
@@ -80,7 +79,7 @@ func (v Vacuum) SetFanSpeed(entityId string, serviceData ...map[string]any) {
 		req.ServiceData = serviceData[0]
 	}
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Start or resume the cleaning task.
@@ -90,7 +89,7 @@ func (v Vacuum) Start(entityId string) {
 	req.Domain = "vacuum"
 	req.Service = "start"
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Start, pause, or resume the cleaning task.
@@ -100,7 +99,7 @@ func (v Vacuum) StartPause(entityId string) {
 	req.Domain = "vacuum"
 	req.Service = "start_pause"
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Stop the current cleaning task.
@@ -110,7 +109,7 @@ func (v Vacuum) Stop(entityId string) {
 	req.Domain = "vacuum"
 	req.Service = "stop"
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Stop the current cleaning task and return to home.
@@ -120,7 +119,7 @@ func (v Vacuum) TurnOff(entityId string) {
 	req.Domain = "vacuum"
 	req.Service = "turn_off"
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }
 
 // Start a new cleaning task.
@@ -130,5 +129,5 @@ func (v Vacuum) TurnOn(entityId string) {
 	req.Domain = "vacuum"
 	req.Service = "turn_on"
 
-	ws.WriteMessage(req, v.conn, v.ctx)
+	v.conn.WriteMessage(req, v.ctx)
 }

internal/websocket/websocket.go

@@ -10,6 +10,7 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"sync"
 	"time"
 
 	"github.com/gorilla/websocket"
@@ -21,16 +22,16 @@ type AuthMessage struct {
 	AccessToken string `json:"access_token"`
 }
 
-// TODO: use a mutex to prevent concurrent writes panic here
+type WebsocketWriter struct {
-// https://github.com/gorilla/websocket/issues/119
+	Conn  *websocket.Conn
-func WriteMessage[T any](msg T, conn *websocket.Conn, ctx context.Context) error {
+	mutex sync.Mutex
-	msgJson, err := json.Marshal(msg)
-	// fmt.Println(string(msgJson))
-	if err != nil {
-		return err
 }
 
-	err = conn.WriteMessage(websocket.TextMessage, msgJson)
+func (w *WebsocketWriter) WriteMessage(msg interface{}, ctx context.Context) error {
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+
+	err := w.Conn.WriteJSON(msg)
 	if err != nil {
 		return err
 	}
@@ -82,7 +83,7 @@ func SetupConnection(ip, port, authToken string) (*websocket.Conn, context.Conte
 }
 
 func SendAuthMessage(conn *websocket.Conn, ctx context.Context, token string) error {
-	err := WriteMessage(AuthMessage{MsgType: "auth", AccessToken: token}, conn, ctx)
+	err := conn.WriteJSON(AuthMessage{MsgType: "auth", AccessToken: token})
 	if err != nil {
 		return err
 	}
@@ -116,11 +117,11 @@ type SubEvent struct {
 	EventType string `json:"event_type"`
 }
 
-func SubscribeToStateChangedEvents(id int64, conn *websocket.Conn, ctx context.Context) {
+func SubscribeToStateChangedEvents(id int64, conn *WebsocketWriter, ctx context.Context) {
 	SubscribeToEventType("state_changed", conn, ctx, id)
 }
 
-func SubscribeToEventType(eventType string, conn *websocket.Conn, ctx context.Context, id ...int64) {
+func SubscribeToEventType(eventType string, conn *WebsocketWriter, ctx context.Context, id ...int64) {
 	var finalId int64
 	if len(id) == 0 {
 		finalId = i.GetId()
@@ -132,7 +133,7 @@ func SubscribeToEventType(eventType string, conn *websocket.Conn, ctx context.Co
 		Type:      "subscribe_events",
 		EventType: eventType,
 	}
-	err := WriteMessage(e, conn, ctx)
+	err := conn.WriteMessage(e, ctx)
 	if err != nil {
 		log.Fatalf("Error writing to websocket: %s\n", err)
 	}

service.go

@@ -3,9 +3,9 @@ package gomeassistant
 import (
 	"context"
 
-	"github.com/gorilla/websocket"
 	"saml.dev/gome-assistant/internal/http"
 	"saml.dev/gome-assistant/internal/services"
+	ws "saml.dev/gome-assistant/internal/websocket"
 )
 
 type Service struct {
@@ -28,7 +28,7 @@ type Service struct {
 	Vacuum            *services.Vacuum
 }
 
-func newService(conn *websocket.Conn, ctx context.Context, httpClient *http.HttpClient) *Service {
+func newService(conn *ws.WebsocketWriter, ctx context.Context, httpClient *http.HttpClient) *Service {
 	return &Service{
 		AlarmControlPanel: services.BuildService[services.AlarmControlPanel](conn, ctx),
 		Cover:             services.BuildService[services.Cover](conn, ctx),