package config

import (
	"os"
	"path/filepath"
	"strconv"
)

// Config 包含 Web 管理界面的运行时配置。
// 数据目录结构:
//   <DataDir>/
//     config.yaml       - 全局配置
//     db.json           - 用户/实例元数据(简化存储)
//     pki/              - CA 与证书(PKI 基础设施)
//       ca.crt / ca.key / dh.pem / ta.key
//     instances/<name>/ - 每个 OpenVPN 实例的目录
//       server.conf
//       pki/{issued,private,csd}
//       ccd/             - 客户端配置目录
//       status.log       - openvpn --status 周期输出
//       logs/            - openvpn 运行日志
//     clients/<inst>/<user>/ - 生成的 .ovpn 文件
//     backups/          - 备份归档

type Config struct {
	Host       string `yaml:"host"`
	Port       int    `yaml:"port"`
	DataDir    string `yaml:"data_dir"`
	JWTSecret  string `yaml:"jwt_secret"`
	AdminUser  string `yaml:"admin_user"`
	AdminPass  string `yaml:"admin_pass"`
	LogLevel   string `yaml:"log_level"`
	OpenVPNBin string `yaml:"openvpn_bin"`
	EasyrsaBin string `yaml:"easyrsa_bin"`
}

func Load(dataDir string) *Config {
	c := &Config{
		Host:       getenv("OVPNMGR_HOST", "0.0.0.0"),
		Port:       getenvInt("OVPNMGR_PORT", 8089),
		DataDir:    dataDir,
		JWTSecret:  getenv("OVPNMGR_JWT_SECRET", "change-me-in-prod-please"),
		AdminUser:  getenv("OVPNMGR_ADMIN_USER", "admin"),
		AdminPass:  getenv("OVPNMGR_ADMIN_PASS", "admin123"),
		LogLevel:   getenv("OVPNMGR_LOG_LEVEL", "info"),
		OpenVPNBin: getenv("OVPNMGR_OPENVPN_BIN", "openvpn"),
		EasyrsaBin: getenv("OVPNMGR_EASYRSA_BIN", "easyrsa"),
	}
	return c
}

func (c *Config) PKIDir() string      { return filepath.Join(c.DataDir, "pki") }
func (c *Config) InstancesDir() string { return filepath.Join(c.DataDir, "instances") }
func (c *Config) InstanceDir(name string) string {
	return filepath.Join(c.InstancesDir(), name)
}
func (c *Config) ClientsDir() string { return filepath.Join(c.DataDir, "clients") }
func (c *Config) BackupsDir() string { return filepath.Join(c.DataDir, "backups") }
func (c *Config) DBFile() string     { return filepath.Join(c.DataDir, "db.json") }

func getenv(k, def string) string {
	if v := os.Getenv(k); v != "" {
		return v
	}
	return def
}

func getenvInt(k string, def int) int {
	v := os.Getenv(k)
	if v == "" {
		return def
	}
	n, err := strconv.Atoi(v)
	if err != nil {
		return def
	}
	return n
}