package tls

import (
	"context"
	tls "github.com/refraction-networking/utls"
	"net"
	"time"

	"github.com/go-gost/core/dialer"
	"github.com/go-gost/core/logger"
	md "github.com/go-gost/core/metadata"
	"github.com/go-gost/x/registry"
)

func init() {
	registry.DialerRegistry().Register("tls", NewDialer)
}

type tlsDialer struct {
	md      metadata
	logger  logger.Logger
	options dialer.Options
}

func NewDialer(opts ...dialer.Option) dialer.Dialer {
	options := dialer.Options{}
	for _, opt := range opts {
		opt(&options)
	}

	return &tlsDialer{
		logger:  options.Logger,
		options: options,
	}
}

func (d *tlsDialer) Init(md md.Metadata) (err error) {
	return d.parseMetadata(md)
}

func (d *tlsDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialOption) (net.Conn, error) {
	var options dialer.DialOptions
	for _, opt := range opts {
		opt(&options)
	}

	conn, err := options.Dialer.Dial(ctx, "tcp", addr)
	if err != nil {
		d.logger.Error(err)
	}
	return conn, err
}

// Handshake implements dialer.Handshaker
func (d *tlsDialer) Handshake(ctx context.Context, conn net.Conn, options ...dialer.HandshakeOption) (net.Conn, error) {
	if d.md.handshakeTimeout > 0 {
		conn.SetDeadline(time.Now().Add(d.md.handshakeTimeout))
		defer conn.SetDeadline(time.Time{})
	}
	tlsConfig := d.options.TLSConfig
	utlsConf := &tls.Config{InsecureSkipVerify: tlsConfig.InsecureSkipVerify, ServerName: tlsConfig.ServerName, ClientAuth: tls.ClientAuthType(tlsConfig.ClientAuth), ClientCAs: tlsConfig.ClientCAs, RootCAs: tlsConfig.RootCAs}
	if len(tlsConfig.Certificates) > 0 {
		for _, certificate := range tlsConfig.Certificates {
			utlsConf.Certificates = append(utlsConf.Certificates, tls.Certificate{
				Certificate:                 certificate.Certificate,
				PrivateKey:                  certificate.PrivateKey,
				OCSPStaple:                  certificate.OCSPStaple,
				SignedCertificateTimestamps: certificate.SignedCertificateTimestamps,
				Leaf:                        certificate.Leaf,
			})
		}
	}
	tlsConn := tls.UClient(conn, utlsConf, tls.HelloChrome_Auto)
	if err := tlsConn.HandshakeContext(ctx); err != nil {
		conn.Close()
		return nil, err
	}

	return tlsConn, nil
}