package internet

import (
	"crypto/tls"
	"errors"
	"net"

	v2net "github.com/v2ray/v2ray-core/common/net"
	v2tls "github.com/v2ray/v2ray-core/transport/internet/tls"
)

var (
	ErrUnsupportedStreamType = errors.New("Unsupported stream type.")
)

type Dialer func(src v2net.Address, dest v2net.Destination) (Connection, error)

var (
	TCPDialer    Dialer
	KCPDialer    Dialer
	RawTCPDialer Dialer
	UDPDialer    Dialer
	WSDialer     Dialer
)

func Dial(src v2net.Address, dest v2net.Destination, settings *StreamSettings) (Connection, error) {

	var connection Connection
	var err error
	if dest.IsTCP() {
		switch {
		case settings.IsCapableOf(StreamConnectionTypeTCP):
			connection, err = TCPDialer(src, dest)
		case settings.IsCapableOf(StreamConnectionTypeKCP):
			connection, err = KCPDialer(src, dest)
		case settings.IsCapableOf(StreamConnectionTypeWebSocket):
			connection, err = WSDialer(src, dest)

		/*Warning: Hours wasted: the following item must be last one

		internet.StreamConnectionType have a default value of 1,
		so the following attempt will catch all.
		*/

		case settings.IsCapableOf(StreamConnectionTypeRawTCP):
			connection, err = RawTCPDialer(src, dest)
		default:
			return nil, ErrUnsupportedStreamType
		}
		if err != nil {
			return nil, err
		}

		if settings.Security == StreamSecurityTypeNone {
			return connection, nil
		}

		config := settings.TLSSettings.GetTLSConfig()
		if dest.Address().Family().IsDomain() {
			config.ServerName = dest.Address().Domain()
		}
		tlsConn := tls.Client(connection, config)
		return v2tls.NewConnection(tlsConn), nil
	}

	return UDPDialer(src, dest)
}

func DialToDest(src v2net.Address, dest v2net.Destination) (net.Conn, error) {
	return effectiveSystemDialer.Dial(src, dest)
}