Add Tasmota timezone handling and dashboard updates

internal/config/config.go

@@ -39,12 +39,13 @@ type InfluxConfig struct {
 }
 
 type AppConfig struct {
-	BatchSize     int           `json:"batch_size"`
-	BufferSize    int           `json:"buffer_size"`
-	FlushInterval DurationValue `json:"flush_interval"`
-	FlushTimeout  DurationValue `json:"flush_timeout"`
-	LogLevel      string        `json:"log_level"`
-	HealthAddress string        `json:"health_address"`
+	BatchSize       int           `json:"batch_size"`
+	BufferSize      int           `json:"buffer_size"`
+	FlushInterval   DurationValue `json:"flush_interval"`
+	FlushTimeout    DurationValue `json:"flush_timeout"`
+	LogLevel        string        `json:"log_level"`
+	HealthAddress   string        `json:"health_address"`
+	TasmotaTimeZone string        `json:"tasmota_time_zone"`
 }
 
 type DurationValue struct {
@@ -124,6 +125,9 @@ func (cfg Config) Validate() error {
 	if cfg.App.FlushTimeout.Duration <= 0 {
 		return errors.New("app flush_timeout must be greater than zero")
 	}
+	if _, err := loadConfiguredLocation(cfg.App.TasmotaTimeZone); err != nil {
+		return err
+	}
 
 	return nil
 }
@@ -145,12 +149,13 @@ func defaultConfig() Config {
 			Precision: "ns",
 		},
 		App: AppConfig{
-			BatchSize:     200,
-			BufferSize:    1000,
-			FlushInterval: DurationValue{Duration: 10 * time.Second},
-			FlushTimeout:  DurationValue{Duration: 10 * time.Second},
-			LogLevel:      "info",
-			HealthAddress: ":8080",
+			BatchSize:       200,
+			BufferSize:      1000,
+			FlushInterval:   DurationValue{Duration: 10 * time.Second},
+			FlushTimeout:    DurationValue{Duration: 10 * time.Second},
+			LogLevel:        "info",
+			HealthAddress:   ":8080",
+			TasmotaTimeZone: "UTC",
 		},
 	}
 }
@@ -166,6 +171,7 @@ func applyEnvOverrides(cfg *Config) error {
 	setString(&cfg.Influx.Precision, envPrefix+"INFLUX_PRECISION")
 	setString(&cfg.App.LogLevel, envPrefix+"APP_LOG_LEVEL")
 	setString(&cfg.App.HealthAddress, envPrefix+"APP_HEALTH_ADDRESS")
+	setString(&cfg.App.TasmotaTimeZone, envPrefix+"APP_TASMOTA_TIME_ZONE")
 
 	if raw, ok := os.LookupEnv(envPrefix + "DEVICE_ALIASES"); ok {
 		if strings.TrimSpace(raw) == "" {
@@ -276,3 +282,29 @@ func normalizeDeviceKey(value string) string {
 	normalized = strings.Trim(normalized, "_")
 	return normalized
 }
+
+func (cfg AppConfig) TasmotaLocation() *time.Location {
+	location, err := loadConfiguredLocation(cfg.TasmotaTimeZone)
+	if err != nil {
+		return time.UTC
+	}
+
+	return location
+}
+
+func loadConfiguredLocation(name string) (*time.Location, error) {
+	trimmed := strings.TrimSpace(name)
+	if trimmed == "" || strings.EqualFold(trimmed, "utc") {
+		return time.UTC, nil
+	}
+	if strings.EqualFold(trimmed, "local") {
+		return time.Local, nil
+	}
+
+	location, err := time.LoadLocation(trimmed)
+	if err != nil {
+		return nil, fmt.Errorf("app tasmota_time_zone %q is invalid: %w", trimmed, err)
+	}
+
+	return location, nil
+}