Sync initial state on startup

connection.go

@@ -1,6 +1,7 @@
 package hal
 
 import (
+	"fmt"
 	"log/slog"
 	"sync"
 	"time"
@@ -96,7 +97,39 @@ func (h *Connection) Start() error {
 		return err
 	}
 
-	return h.HomeAssistant().SubscribeEvents(string(hassws.MessageTypeStateChanged), h.StateChangeEvent)
+	if err := h.HomeAssistant().SubscribeEvents(string(hassws.MessageTypeStateChanged), h.StateChangeEvent); err != nil {
+		return fmt.Errorf("failed to subscribe to state changed events: %w", err)
+	}
+
+	if err := h.syncStates(); err != nil {
+		return fmt.Errorf("failed to sync initial states: %w", err)
+	}
+
+	return nil
+}
+
+func (h *Connection) syncStates() error {
+	defer perf.Timer(func(timeTaken time.Duration) {
+		slog.Info("Initial state sync complete", "duration", timeTaken)
+	})()
+
+	states, err := h.HomeAssistant().GetStates()
+	if err != nil {
+		return err
+	}
+
+	for _, state := range states {
+		entity, ok := h.entities[state.EntityID]
+		if !ok {
+			continue
+		}
+
+		slog.Debug("Setting initial state", "EntityID", state.EntityID, "State", state)
+
+		entity.SetState(state)
+	}
+
+	return nil
 }
 
 // Process incoming state change events. Dispatch state change to the relevant

hassws/client.go

@@ -10,6 +10,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/dansimau/hal/homeassistant"
 	"github.com/gorilla/websocket"
 )
 
@@ -116,7 +117,7 @@ func (c *Client) Connect() error {
 
 // Listen for messages from the websocket and dispatch to listener channels.
 func (c *Client) listen() {
-	slog.Info("Connection established, listening for state changes")
+	slog.Info("Connection established")
 
 	for {
 		_, msgBytes, err := c.conn.ReadMessage()
@@ -311,6 +312,8 @@ func (c *Client) SubscribeEvents(eventType string, handler func(EventMessage)) e
 		}
 	}(responseChan)
 
+	slog.Info("Listening for state changes")
+
 	return nil
 }
 
@@ -336,3 +339,36 @@ func (c *Client) CallService(msg CallServiceRequest) (CallServiceResponse, error
 
 	return resp, nil
 }
+
+func (c *Client) GetStates() ([]homeassistant.State, error) {
+	msg := CommandMessage{
+		ID:   c.nextMsgID(),
+		Type: MessageTypeGetStates,
+	}
+
+	reqBytes, err := json.Marshal(msg)
+	if err != nil {
+		return nil, err
+	}
+
+	resBytes, err := c.sendMessageWaitResponse(reqBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	var resp CommandResponse
+	if err := json.Unmarshal(resBytes, &resp); err != nil {
+		return nil, err
+	}
+
+	if !resp.Success {
+		return nil, fmt.Errorf("%w: %s", ErrUnexpectedResponse, resp.Error)
+	}
+
+	var states []homeassistant.State
+	if err := json.Unmarshal(resp.Result, &states); err != nil {
+		return nil, err
+	}
+
+	return states, nil
+}

hassws/message_types.go

@@ -1,13 +1,18 @@
 package hassws
 
-import "github.com/dansimau/hal/homeassistant"
+import (
+	"encoding/json"
+
+	"github.com/dansimau/hal/homeassistant"
+)
 
 const (
 	MessageTypeAuthChallenge   MessageType = "auth_challenge"
 	MessageTypeAuthRequest     MessageType = "auth_request"
 	MessageTypeAuthResponse    MessageType = "auth_response"
 	MessageTypeCallService     MessageType = "call_service"
 	MessageTypeEvent           MessageType = "event"
+	MessageTypeGetStates       MessageType = "get_states"
 	MessageTypeResult          MessageType = "result"
 	MessageTypeStateChanged    MessageType = "state_changed"
 	MessageTypeSubscribeEvents MessageType = "subscribe_events"
@@ -20,6 +25,13 @@ type CommandMessage struct {
 	Type MessageType `json:"type"`
 }
 
+type CommandResponse struct {
+	Type    MessageType     `json:"type"`
+	Success bool            `json:"success"`
+	Result  json.RawMessage `json:"result,omitempty"`
+	Error   json.RawMessage `json:"error,omitempty"`
+}
+
 type AuthChallenge struct {
 	Type      string `json:"type"`
 	HAVersion string `json:"ha_version,omitempty"`