Add configurable device aliases

internal/config/config.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -12,10 +13,13 @@ import (
 
 const envPrefix = "MQTT_SCRUBBER_"
 
+var invalidDeviceCharacters = regexp.MustCompile(`[^a-z0-9_]+`)
+
 type Config struct {
-	MQTT   MQTTConfig   `json:"mqtt"`
-	Influx InfluxConfig `json:"influx"`
-	App    AppConfig    `json:"app"`
+	MQTT          MQTTConfig        `json:"mqtt"`
+	Influx        InfluxConfig      `json:"influx"`
+	App           AppConfig         `json:"app"`
+	DeviceAliases map[string]string `json:"device_aliases"`
 }
 
 type MQTTConfig struct {
@@ -80,6 +84,8 @@ func Load(path string) (Config, error) {
 		return Config{}, err
 	}
 
+	cfg.DeviceAliases = normalizeDeviceAliases(cfg.DeviceAliases)
+
 	if err := cfg.Validate(); err != nil {
 		return Config{}, err
 	}
@@ -161,6 +167,18 @@ func applyEnvOverrides(cfg *Config) error {
 	setString(&cfg.App.LogLevel, envPrefix+"APP_LOG_LEVEL")
 	setString(&cfg.App.HealthAddress, envPrefix+"APP_HEALTH_ADDRESS")
 
+	if raw, ok := os.LookupEnv(envPrefix + "DEVICE_ALIASES"); ok {
+		if strings.TrimSpace(raw) == "" {
+			cfg.DeviceAliases = nil
+		} else {
+			aliases := make(map[string]string)
+			if err := json.Unmarshal([]byte(raw), &aliases); err != nil {
+				return fmt.Errorf("parse %sDEVICE_ALIASES: %w", envPrefix, err)
+			}
+			cfg.DeviceAliases = aliases
+		}
+	}
+
 	if raw, ok := os.LookupEnv(envPrefix + "MQTT_TOPICS"); ok {
 		cfg.MQTT.Topics = splitAndTrim(raw)
 	}
@@ -227,3 +245,34 @@ func splitAndTrim(value string) []string {
 
 	return result
 }
+
+func normalizeDeviceAliases(aliases map[string]string) map[string]string {
+	if len(aliases) == 0 {
+		return nil
+	}
+
+	normalized := make(map[string]string, len(aliases))
+	for device, alias := range aliases {
+		cleanDevice := normalizeDeviceKey(device)
+		cleanAlias := strings.TrimSpace(alias)
+		if cleanDevice == "" || cleanAlias == "" {
+			continue
+		}
+		normalized[cleanDevice] = cleanAlias
+	}
+
+	if len(normalized) == 0 {
+		return nil
+	}
+
+	return normalized
+}
+
+func normalizeDeviceKey(value string) string {
+	normalized := strings.ToLower(strings.TrimSpace(value))
+	normalized = strings.ReplaceAll(normalized, "-", "_")
+	normalized = strings.ReplaceAll(normalized, " ", "_")
+	normalized = invalidDeviceCharacters.ReplaceAllString(normalized, "_")
+	normalized = strings.Trim(normalized, "_")
+	return normalized
+}