package config

import (
	"encoding/base64"
	"fmt"
	"os"
)

type Config struct {
	DBDSN      string
	EncKey     []byte
	ListenAddr string
}

func Load() (*Config, error) {
	dsn := os.Getenv("DNS_AR_DB_DSN")
	if dsn == "" {
		return nil, fmt.Errorf("config: DNS_AR_DB_DSN is required")
	}
	rawKey := os.Getenv("DNS_AR_ENC_KEY")
	if rawKey == "" {
		return nil, fmt.Errorf("config: DNS_AR_ENC_KEY is required")
	}
	key, err := base64.StdEncoding.DecodeString(rawKey)
	if err != nil {
		return nil, fmt.Errorf("config: DNS_AR_ENC_KEY must be base64: %w", err)
	}
	if len(key) != 32 {
		return nil, fmt.Errorf("config: DNS_AR_ENC_KEY must decode to 32 bytes, got %d", len(key))
	}
	listen := os.Getenv("DNS_AR_LISTEN")
	if listen == "" {
		listen = ":8080"
	}
	return &Config{DBDSN: dsn, EncKey: key, ListenAddr: listen}, nil
}