package gopher

import (
	"context"
	"errors"
	"fmt"
	"io"
	"net"
	"strings"

	"tildegit.org/tjp/gus"
	"tildegit.org/tjp/gus/internal"
	"tildegit.org/tjp/gus/logging"
)

type gopherServer struct {
	internal.Server
	handler gus.Handler
}

func (gs gopherServer) Protocol() string { return "GOPHER" }

// NewServer builds a gopher server.
func NewServer(
	ctx context.Context,
	hostname string,
	network string,
	address string,
	handler gus.Handler,
	errLog logging.Logger,
) (gus.Server, error) {
	gs := &gopherServer{handler: handler}

	if strings.IndexByte(hostname, ':') < 0 {
		hostname = net.JoinHostPort(hostname, "70")
	}

	var err error
	gs.Server, err = internal.NewServer(ctx, hostname, network, address, errLog, gs.handleConn)
	if err != nil {
		return nil, err
	}

	return gs, nil
}

func (gs *gopherServer) handleConn(conn net.Conn) {
	var response *gus.Response
	request, err := ParseRequest(conn)
	if err != nil {
		response = Error(errors.New("Malformed request.")).Response()
	} else {
		request.Server = gs
		request.RemoteAddr = conn.RemoteAddr()

		defer func() {
			if r := recover(); r != nil {
				err := fmt.Errorf("%s", r)
				_ = gs.LogError("msg", "panic in handler", "err", err)
				rdr := NewResponseReader(Error(errors.New("Server error.")).Response())
				_, _ = io.Copy(conn, rdr)
			}
		}()
		response = gs.handler(gs.Ctx, request)
		if response == nil {
			response = Error(errors.New("Resource does not exist.")).Response()
		}
	}

	defer response.Close()
	_, _ = io.Copy(conn, NewResponseReader(response))
}