feat: Refactor database configuration loading and seeding logic for improved clarity and maintainability

backend/internal/config/config.go

@@ -0,0 +1,86 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+
+	"github.com/joho/godotenv"
+	"github.com/timetracker/backend/internal/models"
+	"gorm.io/gorm/logger"
+)
+
+// Config represents the application configuration
+type Config struct {
+	Database models.DatabaseConfig
+}
+
+// LoadConfig loads configuration from environment variables and .env file
+func LoadConfig() (*Config, error) {
+	// Try loading .env file, but don't fail if it doesn't exist
+	_ = godotenv.Load()
+
+	cfg := &Config{
+		Database: models.DefaultDatabaseConfig(),
+	}
+
+	// Load database configuration
+	if err := loadDatabaseConfig(cfg); err != nil {
+		return nil, fmt.Errorf("failed to load database config: %w", err)
+	}
+
+	return cfg, nil
+}
+
+// loadDatabaseConfig loads database configuration from environment
+func loadDatabaseConfig(cfg *Config) error {
+	// Required fields
+	cfg.Database.Host = getEnv("DB_HOST", cfg.Database.Host)
+	cfg.Database.User = getEnv("DB_USER", cfg.Database.User)
+	cfg.Database.Password = getEnv("DB_PASSWORD", cfg.Database.Password)
+	cfg.Database.DBName = getEnv("DB_NAME", cfg.Database.DBName)
+	cfg.Database.SSLMode = getEnv("DB_SSLMODE", cfg.Database.SSLMode)
+
+	// Optional fields with parsing
+	if port := getEnv("DB_PORT", ""); port != "" {
+		portInt, err := strconv.Atoi(port)
+		if err != nil || portInt <= 0 {
+			return errors.New("invalid DB_PORT value")
+		}
+		cfg.Database.Port = portInt
+	}
+
+	// Log level based on environment
+	if os.Getenv("ENVIRONMENT") == "production" {
+		cfg.Database.LogLevel = logger.Error
+	} else {
+		cfg.Database.LogLevel = logger.Info
+	}
+
+	// Validate required fields
+	if cfg.Database.Host == "" || cfg.Database.User == "" ||
+		cfg.Database.Password == "" || cfg.Database.DBName == "" {
+		return errors.New("missing required database configuration")
+	}
+
+	return nil
+}
+
+// getEnv gets an environment variable with fallback
+func getEnv(key, fallback string) string {
+	if value, exists := os.LookupEnv(key); exists {
+		return value
+	}
+	return fallback
+}
+
+// MustLoadConfig loads configuration or panics on failure
+func MustLoadConfig() *Config {
+	cfg, err := LoadConfig()
+	if err != nil {
+		log.Fatalf("Failed to load config: %v", err)
+	}
+	return cfg
+}