package config

import (
	"fmt"
	"os"
	"strconv"
)

// Config is the top-level server configuration.
type Config struct {
	Server  ServerConfig
	Auth    AuthConfig
	Storage StorageConfig
	Logging LoggingConfig
}

type ServerConfig struct {
	Host    string
	Port    int
	BaseURL string
}

type AuthConfig struct {
	Realm string
}

type StorageConfig struct {
	DataDir string
}

type LoggingConfig struct {
	Level  string
	Format string
}

// Load reads and parses environment variables to create the configuration.
func Load() (*Config, error) {
	cfg := &Config{}
	cfg.applyDefaults()
	return cfg, nil
}

func (c *Config) applyDefaults() {
	c.Server.Host = getEnv("NIDUS_HOST", "0.0.0.0")
	c.Server.Port = getEnvInt("NIDUS_PORT", 8080)
	c.Server.BaseURL = getEnv("NIDUS_BASE_URL", "")

	if c.Server.BaseURL == "" {
		c.Server.BaseURL = fmt.Sprintf("http://%s:%d", c.Server.Host, c.Server.Port)
	}

	c.Auth.Realm = getEnv("NIDUS_AUTH_REALM", "DAV Server")
	c.Storage.DataDir = getEnv("NIDUS_DATA_DIR", "./data")
	c.Logging.Level = getEnv("NIDUS_LOG_LEVEL", "info")
	c.Logging.Format = getEnv("NIDUS_LOG_FORMAT", "text")
}

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

func getEnvInt(key string, defaultValue int) int {
	if val := os.Getenv(key); val != "" {
		if intVal, err := strconv.Atoi(val); err == nil {
			return intVal
		}
	}
	return defaultValue
}