package core

// ConnectionState represents VPN connection state.
type ConnectionState int

const (
	Disconnected ConnectionState = iota
	Connecting
	Connected
	Disconnecting
	Error
)

func (s ConnectionState) String() string {
	switch s {
	case Disconnected:
		return "Disconnected"
	case Connecting:
		return "Connecting"
	case Connected:
		return "Connected"
	case Disconnecting:
		return "Disconnecting"
	case Error:
		return "Error"
	default:
		return "Unknown"
	}
}

// ProxyLink represents a parsed VPN link (trojan://, vless://, etc.)
type ProxyLink struct {
	// Protocol: trojan, vless, vmess, shadowsocks
	Protocol string
	// Server IP or domain
	Address string
	// Server port
	Port int
	// Password (trojan) or UUID (vless/vmess)
	Credential string
	// Security type: reality, tls, none
	Security string
	// Server Name Indication for TLS/REALITY
	Sni string
	// TLS fingerprint (chrome, firefox, safari, etc.)
	Fingerprint string
	// REALITY public key
	PublicKey string
	// REALITY short ID
	ShortId string
	// Transport type: tcp, grpc, ws, h2, xhttp
	Transport string
	// gRPC service name
	ServiceName string
	// WebSocket/HTTP2 path
	Path string
	// Host header for WebSocket/HTTP2
	Host string
	// Server name from link fragment (#remark)
	Remark string
	// XTLS Flow (e.g. xtls-rprx-vision)
	Flow string
}

func (p *ProxyLink) String() string {
	return "[" + p.Protocol + "] " + p.Remark + " (" + p.Address + ":" + itoa(p.Port) + ") security=" + p.Security + " transport=" + p.Transport
}

// VpnConfig represents a saved VPN configuration.
type VpnConfig struct {
	ID   string `json:"Id"`
	Name string `json:"Name"`
	Link string `json:"Link"`
}

func (c *VpnConfig) DisplayName() string {
	if c.Name == "" {
		return "Unknown Server"
	}
	return c.Name
}

func (c *VpnConfig) ProtocolType() string {
	if len(c.Link) < 5 {
		return "UNKNOWN"
	}
	switch {
	case hasPrefix(c.Link, "vless://"):
		return "VLESS"
	case hasPrefix(c.Link, "trojan://"):
		return "TROJAN"
	case hasPrefix(c.Link, "hy2://"):
		return "HYSTERIA2"
	case hasPrefix(c.Link, "ss://"):
		return "SHADOWSOCKS"
	default:
		return "UNKNOWN"
	}
}

// ExtractNameFromLink extracts server name from a VPN link.
func ExtractNameFromLink(link string) string {
	if link == "" {
		return "New Config"
	}
	idx := lastIndexOf(link, '#')
	if idx >= 0 && idx < len(link)-1 {
		encoded := link[idx+1:]
		decoded, err := urlUnescape(encoded)
		if err != nil {
			return encoded
		}
		return decoded
	}
	parts := splitAt(link, '@')
	if len(parts) > 1 {
		addrPart := parts[1]
		for i, ch := range addrPart {
			if ch == '?' || ch == ':' || ch == '/' || ch == '#' {
				if i > 0 {
					return addrPart[:i]
				}
				break
			}
		}
	}
	return "Custom Config"
}