From 7b01faa2776addd86019864568eea6c554ee4e69 Mon Sep 17 00:00:00 2001
From: Pieter Hollander <git@pieterhollander.nl>
Date: Thu, 25 Jul 2024 23:00:09 +0200
Subject: [PATCH] Move initial configuration to separate loadConfig function.
 Add support for HA options.json.

---
 main.go | 99 +++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 86 insertions(+), 13 deletions(-)

diff --git a/main.go b/main.go
index 2c7a5b5..1e9c8b0 100644
--- a/main.go
+++ b/main.go
@@ -7,6 +7,7 @@ import (
 	"log"
 	"log/slog"
 	"os"
+	"strconv"
 	"time"
 	_ "time/tzdata"
 
@@ -107,17 +108,91 @@ type Payload struct {
 	R3  *int   `json:"r3"`  // Returning / exporting L3 (W)
 }
 
+type Config struct {
+	MQTTBroker   string `json:"mqtt_broker"`
+	MQTTTopic    string `json:"mqtt_topic"`
+	MQTTUser     string `json:"mqtt_user"`
+	MQTTPassword string `json:"mqtt_password"`
+	DB           string `json:"DB"`
+	TimescaleDB  bool   `json:"timescaledb"`
+	LogLevel     string `json:"log_level"`
+	TZ           string `json:"timezone"`
+}
+
 var db *sql.DB
 var logger = slog.New(slog.NewJSONHandler(os.Stdout, nil))
+var config Config
+
+func loadConfig() Config {
+	configFilePath := os.Getenv("CONFIG_FILE")
+	if configFilePath == "" {
+		configFilePath = "/data/options.json"
+	}
+
+	data, err := os.ReadFile(configFilePath)
+	if err == nil {
+		// Successfully read the file, parse the JSON
+		err = json.Unmarshal(data, &config)
+		if err != nil {
+			log.Fatalf("Error parsing config file: %v", err)
+		}
+	} else {
+		// Load environment variables from .env file if it exists
+		if err := godotenv.Load(); err != nil {
+			logger.Info("No .env file found or error loading .env file (ignore this message when using container)", "error", err)
+		}
+
+		// Fallback to environment variables
+		config.MQTTBroker = os.Getenv("MQTT_BROKER")
+		if config.MQTTBroker == "" {
+			log.Fatal("MQTT_BROKER environment variable is not set.")
+		}
+		config.MQTTTopic = os.Getenv("MQTT_TOPIC")
+		if config.MQTTTopic == "" {
+			log.Fatal("MQTT_TOPIC environment variable is not set.")
+		}
+		config.MQTTUser = os.Getenv("MQTT_USERNAME")
+		if config.MQTTUser == "" {
+			log.Fatal("MQTT_USERNAME environment variable is not set.")
+		}
+		config.MQTTPassword = os.Getenv("MQTT_PASSWORD")
+		if config.MQTTPassword == "" {
+			log.Fatal("MQTT_PASSWORD environment variable is not set.")
+		}
+		config.DB = os.Getenv("PG_DB")
+		if config.DB == "" {
+			log.Fatal("PG_DB environment variable is not set.")
+		}
+
+		timescaleDBStr := os.Getenv("TIMESCALEDB_ENABLED")
+		if timescaleDBStr != "" {
+			timescaleDB, err := strconv.ParseBool(timescaleDBStr)
+			if err != nil {
+				log.Fatalf("Error parsing TIMESCALEDB_ENABLED: %v", err)
+			}
+			config.TimescaleDB = timescaleDB
+		}
+		config.LogLevel = os.Getenv("LOG_LEVEL")
+		if config.DB == "" {
+			log.Fatal("LOG_LEVEL environment variable is not set.")
+		}
+
+		config.TZ = os.Getenv("TZ")
+		if config.DB == "" {
+			log.Fatal("TZ environment variable is not set.")
+		}
+
+	}
+
+	return config
+
+}
 
 func main() {
 	// Initial logger setup
 	slog.SetDefault(logger)
 
-	// Load environment variables from .env file if it exists
-	if err := godotenv.Load(); err != nil {
-		logger.Info("No .env file found or error loading .env file (ignore this message when using container)", "error", err)
-	}
+	loadConfig()
 
 	// Update the logger based on the LOG_LEVEL environment variable
 	logLevel := getLogLevelFromEnv(slog.LevelInfo) // Default to info level
@@ -127,22 +202,22 @@ func main() {
 	logger.Info("Logger initialized with dynamic log level")
 
 	// Connect to PostgreSQL
-	pgConnStr := os.Getenv("PG_DB")
+	pgConnStr := config.DB
 	if err := connectToPostgreSQL(pgConnStr); err != nil {
 		log.Fatal("Error connecting to PostgreSQL", "error", err)
 	}
 
 	// Initialize MQTT options
 	opts := mqtt.NewClientOptions()
-	opts.AddBroker(os.Getenv("MQTT_BROKER"))
-	opts.SetUsername(os.Getenv("MQTT_USERNAME"))
-	opts.SetPassword(os.Getenv("MQTT_PASSWORD"))
+	opts.AddBroker(config.MQTTBroker)
+	opts.SetUsername(config.MQTTUser)
+	opts.SetPassword(config.MQTTPassword)
 	opts.SetAutoReconnect(true)
 	opts.SetConnectionLostHandler(func(client mqtt.Client, err error) {
 		logger.Error("Connection lost", "error", err)
 	})
 	opts.SetOnConnectHandler(func(client mqtt.Client) {
-		topic := os.Getenv("MQTT_TOPIC")
+		topic := config.MQTTTopic
 		logger.Info("Connected to MQTT broker, subscribing to topic...", "topic", topic)
 		if token := client.Subscribe(topic, 0, mqttMessageHandler); token.Wait() && token.Error() != nil {
 			logger.Error("Error subscribing to MQTT topic", "topic", topic, "error", token.Error())
@@ -161,7 +236,7 @@ func main() {
 
 // Helper function to map environment variable to slog.Level
 func getLogLevelFromEnv(defaultLevel slog.Level) slog.Level {
-	logLevelStr := os.Getenv("LOG_LEVEL")
+	logLevelStr := config.LogLevel
 	switch logLevelStr {
 	case "DEBUG":
 		return slog.LevelDebug
@@ -428,9 +503,7 @@ func connectToPostgreSQL(pgConnStr string) error {
 		log.Fatal("Error creating table:", err)
 	}
 
-	timescaleDBEnabled := os.Getenv("TIMESCALEDB_ENABLED")
-
-	if timescaleDBEnabled == "true" {
+	if config.TimescaleDB {
 		// Enable TimescaleDB
 		_, err = db.Exec(`
 		SELECT create_hypertable('p1', 'timestamp', if_not_exists => TRUE, migrate_data => TRUE);