package config

import (
	"os"
	"strconv"

	"github.com/joho/godotenv"
)

// Config holds the application configuration
type Config struct {
	Server   ServerConfig
	Database DatabaseConfig
	Auth     AuthConfig
	App      AppConfig
}

// ServerConfig holds server-related configuration
type ServerConfig struct {
	Host string
	Port int
	Mode string // debug, release, test
}

// DatabaseConfig holds database-related configuration
type DatabaseConfig struct {
	Name string // SQLite database file path
}

// AuthConfig holds authentication-related configuration
type AuthConfig struct {
	JWTSecret     string
	TokenExpiry   int  // in hours
	SecureCookies bool
}

// AppConfig holds application-specific configuration
type AppConfig struct {
	Name             string
	TimeZone         string
	OpenSignups      bool
	AdminEmail       string
	SecretToken      string
	ForceSSL         bool
	UploadPath       string
	MaxUploadSizeMB  int64
}

// Load reads configuration from environment variables
func Load() (*Config, error) {
	// Try to load .env file if it exists
	_ = godotenv.Load()

	cfg := &Config{
		Server: ServerConfig{
			Host: getEnv("SERVER_HOST", "0.0.0.0"),
			Port: getEnvAsInt("SERVER_PORT", 3000),
			Mode: getEnv("GIN_MODE", "debug"),
		},
		Database: DatabaseConfig{
			Name: getEnv("DB_NAME", "tracks.db"),
		},
		Auth: AuthConfig{
			JWTSecret:     getEnv("JWT_SECRET", "change-me-in-production"),
			TokenExpiry:   getEnvAsInt("TOKEN_EXPIRY_HOURS", 24),
			SecureCookies: getEnvAsBool("SECURE_COOKIES", false),
		},
		App: AppConfig{
			Name:             getEnv("APP_NAME", "Tracks"),
			TimeZone:         getEnv("TZ", "UTC"),
			OpenSignups:      getEnvAsBool("OPEN_SIGNUPS", false),
			AdminEmail:       getEnv("ADMIN_EMAIL", ""),
			SecretToken:      getEnv("SECRET_TOKEN", "change-me-in-production"),
			ForceSSL:         getEnvAsBool("FORCE_SSL", false),
			UploadPath:       getEnv("UPLOAD_PATH", "./uploads"),
			MaxUploadSizeMB:  getEnvAsInt64("MAX_UPLOAD_SIZE_MB", 10),
		},
	}

	return cfg, nil
}

// Helper functions

func getEnv(key, defaultValue string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}
	return defaultValue
}

func getEnvAsInt(key string, defaultValue int) int {
	valueStr := getEnv(key, "")
	if value, err := strconv.Atoi(valueStr); err == nil {
		return value
	}
	return defaultValue
}

func getEnvAsInt64(key string, defaultValue int64) int64 {
	valueStr := getEnv(key, "")
	if value, err := strconv.ParseInt(valueStr, 10, 64); err == nil {
		return value
	}
	return defaultValue
}

func getEnvAsBool(key string, defaultValue bool) bool {
	valueStr := getEnv(key, "")
	if value, err := strconv.ParseBool(valueStr); err == nil {
		return value
	}
	return defaultValue
}