Refactor for readability

internal/config/config.go

@@ -0,0 +1,25 @@
+package config
+
+import (
+	"encoding/json"
+	"os"
+)
+
+type Config struct {
+	WriteSecret   string `json:"write_secret"`
+	Addr          string `json:"addr"`
+	ChartMaxWatts int    `json:"chart_max_watts"`
+}
+
+func Load(path string) (Config, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return Config{}, err
+	}
+
+	var cfg Config
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		return Config{}, err
+	}
+	return cfg, nil
+}