From ff9f6cb95e9addc21c0f5435de29fb181a170a11 Mon Sep 17 00:00:00 2001
From: Lubos Dolezel <lubos@dolezel.info>
Date: Wed, 24 May 2023 17:23:50 +0200
Subject: [PATCH] Fix a crash in State.getLatLong()

---
 app.go   |  5 ++++-
 state.go | 32 ++++++++++++++++++++++++--------
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/app.go b/app.go
index 4866b56..3497c53 100644
--- a/app.go
+++ b/app.go
@@ -98,7 +98,10 @@ func NewApp(request NewAppRequest) (*App, error) {
 
 	wsWriter := &ws.WebsocketWriter{Conn: conn}
 	service := newService(wsWriter, ctx, httpClient)
-	state := newState(httpClient, request.HomeZoneEntityId)
+	state, err := newState(httpClient, request.HomeZoneEntityId)
+	if err != nil {
+		return nil, err
+	}
 
 	return &App{
 		conn:            conn,
diff --git a/state.go b/state.go
index e07c4b7..b37705c 100644
--- a/state.go
+++ b/state.go
@@ -2,7 +2,8 @@ package gomeassistant
 
 import (
 	"encoding/json"
-	"log"
+	"errors"
+	"fmt"
 	"time"
 
 	"github.com/golang-module/carbon"
@@ -23,19 +24,34 @@ type EntityState struct {
 	LastChanged time.Time      `json:"last_changed"`
 }
 
-func newState(c *http.HttpClient, homeZoneEntityId string) *State {
+func newState(c *http.HttpClient, homeZoneEntityId string) (*State, error) {
 	state := &State{httpClient: c}
-	state.getLatLong(c, homeZoneEntityId)
-	return state
+	err := state.getLatLong(c, homeZoneEntityId)
+	if err != nil {
+		return nil, err
+	}
+	return state, nil
 }
 
-func (s *State) getLatLong(c *http.HttpClient, homeZoneEntityId string) {
+func (s *State) getLatLong(c *http.HttpClient, homeZoneEntityId string) error {
 	resp, err := s.Get(homeZoneEntityId)
 	if err != nil {
-		log.Fatalf("Couldn't get latitude/longitude from home assistant entity '%s'. Did you type it correctly? It should be a zone like 'zone.home'.\n", homeZoneEntityId)
+		return errors.New(fmt.Sprintf("couldn't get latitude/longitude from home assistant entity '%s'. Did you type it correctly? It should be a zone like 'zone.home'.\n", homeZoneEntityId))
 	}
-	s.latitude = resp.Attributes["latitude"].(float64)
-	s.longitude = resp.Attributes["longitude"].(float64)
+
+	if resp.Attributes["latitude"] != nil {
+		s.latitude = resp.Attributes["latitude"].(float64)
+	} else {
+		return errors.New("server returned nil latitude")
+	}
+
+	if resp.Attributes["longitude"] != nil {
+		s.longitude = resp.Attributes["longitude"].(float64)
+	} else {
+		return errors.New("server returned nil longitude")
+	}
+
+	return nil
 }
 
 func (s *State) Get(entityId string) (EntityState, error) {