package main

import (
	"crypto/tls"
	"fmt"
	"git.wamblee.org/converge/pkg/support/iowrappers"
	"git.wamblee.org/converge/pkg/support/websocketutil"
	"github.com/gorilla/websocket"
	"log"
	"net"
	"net/http"
	"os"
	"time"
)

func closeConnection(conn net.Conn) {
	if tcpConn, ok := conn.(*net.TCPConn); ok {
		tcpConn.SetLinger(0)
	}
	_ = conn.Close()
}

func handleConnection(conn net.Conn, wsURL string, insecure bool) {
	defer closeConnection(conn)

	log.Printf("Connecting to '%s'\n", wsURL)
	dialer := websocket.Dialer{
		Proxy:            http.ProxyFromEnvironment,
		HandshakeTimeout: 45 * time.Second,
	}
	if insecure {
		dialer.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
	}
	_wsConn, _, err := dialer.Dial(wsURL, nil)
	if err != nil {
		log.Println("WebSocket connection error:", err)
		return
	}
	wsConn := websocketutil.NewWebSocketConn(_wsConn, false)
	defer wsConn.Close()

	iowrappers.SynchronizeStreams(wsURL+" -- localport", wsConn, conn)
}

func main() {
	usage := "Usage: tcptows [--insecure] <localport> ws[s]://<host>[:port]/client/<ID>\n" +
		"\n" +
		"Here <ID> is the rendez-vous id of a continuous integratio job\n"
	insecure := false

	args := os.Args[1:]

	if len(args) == 3 && args[0] == "--insecure" {
		insecure = true
		args = args[1:]
	}

	if len(args) != 2 {
		fmt.Fprintf(os.Stderr, usage)
		os.Exit(1)
	}
	tcpPort := args[0]
	wsURL := args[1]

	listener, err := net.Listen("tcp", ":"+tcpPort)
	if err != nil {
		log.Fatal(err)
	}
	defer listener.Close()

	log.Printf("TCP server listening on port %s\n", tcpPort)
	log.Printf("Forwarding connections to WebSocket server at %s\n", wsURL)

	for {
		conn, err := listener.Accept()
		if err != nil {
			log.Println(err)
			continue
		}
		go handleConnection(conn, wsURL, insecure)
	}
}