package main

import (
	"crypto/tls"
	"io/ioutil"
	"net"
	"net/http"

	"github.com/fangdingjun/go-log"
	//"github.com/fangdingjun/nghttp2-go"
	"github.com/miekg/dns"
	"golang.org/x/net/http2"
)

func (srv *server) handleHTTPSConn(c net.Conn) {
	defer c.Close()
	tlsconn := c.(*tls.Conn)
	if err := tlsconn.Handshake(); err != nil {
		log.Errorln("handshake", err)
		return
	}
	state := tlsconn.ConnectionState()
	if state.NegotiatedProtocol != "h2" {
		log.Errorln("http2 is needed")
		return
	}
	_srv := &http2.Server{}
	_srv.ServeConn(c, &http2.ServeConnOpts{
		BaseConfig: &http.Server{},
		Handler:    srv,
	})
}

func (srv *server) handleHTTP2Req(w http.ResponseWriter, r *http.Request) {
	ctype := r.Header.Get("content-type")
	if ctype != "application/dns-message" {
		http.Error(w, "dns message is required", http.StatusBadRequest)
		return
	}

	data, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Errorln("read request body", err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	msg := new(dns.Msg)
	if err := msg.Unpack(data); err != nil {
		log.Errorln("parse dns message", err)
		return
	}
	m, err := getResponseFromUpstream(msg, srv.upstreams)
	if err != nil {
		log.Debugln("query", msg.Question[0].String(), "timeout")
		w.WriteHeader(http.StatusServiceUnavailable)
		return
	}

	for _, a := range m.Answer {
		log.Debugln("result", a.String())
	}
	d, _ := m.Pack()
	w.Write(d)
}

func (srv *server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	if r.RequestURI != srv.addr.Path {
		w.WriteHeader(http.StatusNotFound)
		return
	}
	srv.handleHTTP2Req(w, r)
}