Initial commit: Custom Start Page application with authentication and DynamoDB storage

pkg/config/config.go

@@ -0,0 +1,114 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+)
+
+// Config holds all application configuration
+type Config struct {
+	Server   ServerConfig
+	Database DatabaseConfig
+	OAuth    OAuthConfig
+	Session  SessionConfig
+}
+
+// ServerConfig holds server-related configuration
+type ServerConfig struct {
+	Port string
+	Host string
+}
+
+// DatabaseConfig holds DynamoDB configuration
+type DatabaseConfig struct {
+	Region          string
+	Endpoint        string // For DynamoDB local
+	TablePrefix     string
+	UseLocalDB      bool
+}
+
+// OAuthConfig holds OAuth provider configurations
+type OAuthConfig struct {
+	Google GoogleOAuthConfig
+}
+
+// GoogleOAuthConfig holds Google OAuth configuration
+type GoogleOAuthConfig struct {
+	ClientID     string
+	ClientSecret string
+	RedirectURL  string
+}
+
+// SessionConfig holds session management configuration
+type SessionConfig struct {
+	SecretKey string
+	MaxAge    int // in seconds
+}
+
+// Load loads configuration from environment variables
+func Load() (*Config, error) {
+	cfg := &Config{
+		Server: ServerConfig{
+			Port: getEnv("PORT", "8080"),
+			Host: getEnv("HOST", "localhost"),
+		},
+		Database: DatabaseConfig{
+			Region:      getEnv("AWS_REGION", "us-east-1"),
+			Endpoint:    getEnv("DYNAMODB_ENDPOINT", "http://localhost:8000"),
+			TablePrefix: getEnv("TABLE_PREFIX", "startpage_"),
+			UseLocalDB:  getEnvBool("USE_LOCAL_DB", true),
+		},
+		OAuth: OAuthConfig{
+			Google: GoogleOAuthConfig{
+				ClientID:     getEnv("GOOGLE_CLIENT_ID", ""),
+				ClientSecret: getEnv("GOOGLE_CLIENT_SECRET", ""),
+				RedirectURL:  getEnv("GOOGLE_REDIRECT_URL", "http://localhost:8080/auth/callback/google"),
+			},
+		},
+		Session: SessionConfig{
+			SecretKey: getEnv("SESSION_SECRET", "change-me-in-production"),
+			MaxAge:    getEnvInt("SESSION_MAX_AGE", 86400*7), // 7 days default
+		},
+	}
+
+	// Validate required fields
+	if cfg.OAuth.Google.ClientID == "" {
+		return nil, fmt.Errorf("GOOGLE_CLIENT_ID is required")
+	}
+	if cfg.OAuth.Google.ClientSecret == "" {
+		return nil, fmt.Errorf("GOOGLE_CLIENT_SECRET is required")
+	}
+
+	return cfg, nil
+}
+
+// getEnv gets an environment variable or returns a default value
+func getEnv(key, defaultValue string) string {
+	if value := os.Getenv(key); value != "" {
+		return value
+	}
+	return defaultValue
+}
+
+// getEnvBool gets a boolean environment variable or returns a default value
+func getEnvBool(key string, defaultValue bool) bool {
+	if value := os.Getenv(key); value != "" {
+		boolVal, err := strconv.ParseBool(value)
+		if err == nil {
+			return boolVal
+		}
+	}
+	return defaultValue
+}
+
+// getEnvInt gets an integer environment variable or returns a default value
+func getEnvInt(key string, defaultValue int) int {
+	if value := os.Getenv(key); value != "" {
+		intVal, err := strconv.Atoi(value)
+		if err == nil {
+			return intVal
+		}
+	}
+	return defaultValue
+}