Add functionality to list entities from REST endpoint

internal/http/http.go

@@ -40,6 +40,14 @@ func (c *HttpClient) GetState(entityId string) ([]byte, error) {
 	return resp, nil
 }
 
+func (c *HttpClient) States() ([]byte, error) {
+	resp, err := get(c.url+"/states", c.token)
+	if err != nil {
+		return nil, err
+	}
+	return resp, nil
+}
+
 func get(url, token string) ([]byte, error) {
 	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {

state.go

@@ -16,6 +16,7 @@ type State interface {
 	BeforeSunrise(...DurationString) bool
 	AfterSunset(...DurationString) bool
 	BeforeSunset(...DurationString) bool
+	List() ([]EntityState, error)
 	Get(entityId string) (EntityState, error)
 	Equals(entityId, state string) (bool, error)
 }
@@ -74,6 +75,16 @@ func (s *StateImpl) Get(entityId string) (EntityState, error) {
 	return es, err
 }
 
+func (s *StateImpl) List() ([]EntityState, error) {
+	resp, err := s.httpClient.States()
+	if err != nil {
+		return nil, err
+	}
+	es := []EntityState{}
+	err = json.Unmarshal(resp, &es)
+	return es, err
+}
+
 func (s *StateImpl) Equals(entityId string, expectedState string) (bool, error) {
 	currentState, err := s.Get(entityId)
 	if err != nil {