package main

import (
	"crypto/tls"
	"net"
	"time"
)

// Advanced security and authentication
type SecurityConfig struct {
	RateLimit struct {
		Enable      bool `json:"enable"`
		MaxRequests int  `json:"max_requests"`
		Window      int  `json:"window_seconds"`
		BanDuration int  `json:"ban_duration"`
	} `json:"rate_limit"`

	GeoBlocking struct {
		Enable    bool     `json:"enable"`
		Whitelist []string `json:"whitelist_countries"`
		Blacklist []string `json:"blacklist_countries"`
	} `json:"geo_blocking"`

	TwoFactor struct {
		Enable   bool     `json:"enable"`
		Methods  []string `json:"methods"` // totp, sms, email
		Required bool     `json:"required_for_opers"`
	} `json:"two_factor"`

	SASL struct {
		Enable     bool     `json:"enable"`
		Mechanisms []string `json:"mechanisms"` // PLAIN, EXTERNAL, SCRAM-SHA-256
		Required   bool     `json:"required"`
	} `json:"sasl"`
}

// Rate limiting per IP/user
type RateLimiter struct {
	connections map[string]*ConnectionLimit
	messages    map[string]*MessageLimit
}

type ConnectionLimit struct {
	IP       net.IP
	Count    int
	LastSeen time.Time
	Banned   bool
	BanUntil time.Time
}

type MessageLimit struct {
	Count      int
	LastReset  time.Time
	Violations int
}

// Certificate-based authentication
type CertAuth struct {
	Enable      bool              `json:"enable"`
	RequiredCAs []string          `json:"required_cas"`
	UserMapping map[string]string `json:"user_mapping"` // cert fingerprint -> username
	AutoOper    bool              `json:"auto_oper"`
}

// OAuth integration
type OAuthConfig struct {
	Providers map[string]OAuthProvider `json:"providers"`
}

type OAuthProvider struct {
	ClientID     string `json:"client_id"`
	ClientSecret string `json:"client_secret"`
	AuthURL      string `json:"auth_url"`
	TokenURL     string `json:"token_url"`
	UserInfoURL  string `json:"user_info_url"`
}

// DDoS protection
type DDoSProtection struct {
	Enable             bool `json:"enable"`
	MaxConnections     int  `json:"max_connections_per_ip"`
	ConnectionRate     int  `json:"max_connections_per_minute"`
	SynFloodProtection bool `json:"syn_flood_protection"`
}

// Implement security features
func (s *Server) CheckRateLimit(ip net.IP) bool {
	// Check if IP is rate limited
	return true
}

func (s *Server) ValidateCertificate(cert *tls.Certificate) bool {
	// Validate client certificate
	return true
}

func (s *Server) AuthenticateOAuth(provider, token string) (*UserInfo, error) {
	// OAuth authentication
	return nil, nil
}

type UserInfo struct {
	Username string
	Email    string
	Verified bool
}