From 6230869120c0823822a18b5ccd068b432331659b Mon Sep 17 00:00:00 2001
From: Pieter Hollander <git@pieterhollander.nl>
Date: Thu, 25 Jul 2024 19:15:11 +0200
Subject: [PATCH] Add capability to read from options.json to provide Home
 Assistant support.

---
 main.go | 57 +++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 49 insertions(+), 8 deletions(-)

diff --git a/main.go b/main.go
index abce7c6..5a58c20 100644
--- a/main.go
+++ b/main.go
@@ -143,14 +143,59 @@ type InverterSettingsData struct {
 	Inverters []InverterSettings `json:"inverter"`
 }
 
+// Config settings struct
+type Config struct {
+	DB                 string `json:"db"`
+	OpenDTU            string `json:"opendtu"`
+	TimescaleDBEnabled string `json:"timescaledb"`
+	TZ                 string `json:"tz"`
+}
+
 var logger = slog.New(slog.NewJSONHandler(os.Stdout, nil))
+var config Config
+
+// LoadConfig attempts to read the configuration from options.json
+// If it fails, it falls back to using environment variables
+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 {
+		// Fallback to environment variables
+		config.DB = os.Getenv("DB_URL")
+		if config.DB == "" {
+			log.Fatal("DB_URL environment variable is not set.")
+		}
+		config.OpenDTU = os.Getenv("REMOTE_URL")
+		if config.OpenDTU == "" {
+			log.Fatal("REMOTE_URL environment variable is not set.")
+		}
+
+		config.TimescaleDBEnabled = os.Getenv("TIMESCALEDB_ENABLED")
+		config.TZ = os.Getenv("TZ")
+	}
+
+	return config
+}
 
 // Main program
 func main() {
 	// Initial logger setup
 	slog.SetDefault(logger)
 
-	dbConnStr := (os.Getenv("DB_URL"))
+	// Load the configuration
+	config := LoadConfig()
+
+	dbConnStr := config.DB
 	// Connect to PostgreSQL
 	db, err := sql.Open("postgres", dbConnStr)
 	if err != nil {
@@ -161,12 +206,8 @@ func main() {
 	// Create tables if they don't exist
 	createTables(db)
 
-	// Get WebSocket URL from environment variable
-	RemoteURL := os.Getenv("REMOTE_URL")
-	wsURL := "ws://" + RemoteURL + "/livedata"
-	if wsURL == "" {
-		log.Fatal("WEBSOCKET_URL environment variable is not set.")
-	}
+	// Create WebSocket URL from config variable
+	wsURL := "ws://" + config.OpenDTU + "/livedata"
 
 	// Establish WebSocket connection
 	c, _, err := websocket.DefaultDialer.Dial(wsURL, nil)
@@ -353,7 +394,7 @@ func createTables(db *sql.DB) {
 	if err != nil {
 		log.Fatal("Error creating tables: ", err)
 	}
-	timescaleEnabled := os.Getenv("TIMESCALEDB_ENABLED")
+	timescaleEnabled := config.TimescaleDBEnabled
 
 	enableTimescaleDB := `
 	-- CREATE EXTENSION IF NOT EXISTS timescaledb;