package spartan

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

	"tildegit.org/tjp/sliderule/internal/types"
	"tildegit.org/tjp/sliderule/internal"
	"tildegit.org/tjp/sliderule/logging"
)

type spartanServer struct {
	internal.Server
	handler types.Handler
}

func (ss spartanServer) Protocol() string { return "SPARTAN" }

// NewServer builds a spartan server.
func NewServer(
	ctx context.Context,
	hostname string,
	network string,
	address string,
	handler types.Handler,
	baseLog logging.Logger,
) (types.Server, error) {
	ss := &spartanServer{handler: handler}

	hostname = internal.JoinDefaultPort(hostname, "300")
	address = internal.JoinDefaultPort(address, "300")

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

	return ss, nil
}

func (ss *spartanServer) handleConn(conn net.Conn) {
	buf := bufio.NewReader(conn)

	var response *types.Response
	request, clen, err := ParseRequest(buf)
	if err != nil {
		response = ClientError(err)
	} else {
		request.Server = ss
		request.RemoteAddr = conn.RemoteAddr()

		var body io.Reader = nil
		if clen > 0 {
			body = io.LimitReader(buf, int64(clen))
		}
		request.Meta = body

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

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