// Frontend: Connection functions for programs using the safcm library

// Copyright (C) 2021  Simon Ruderich
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package frontend

import (
	"fmt"

	"ruderich.org/simon/safcm"
	"ruderich.org/simon/safcm/rpc"
)

// SendRecv sends a message for host over conn and waits for the response. Any
// MsgLog messages received before the final (non MsgLog) response are passed
// to l.Log.
func (l *Loop) SendRecv(host Host, conn *rpc.Conn, msg safcm.Msg) (
	safcm.Msg, error) {

	err := conn.Send(msg)
	if err != nil {
		return nil, err
	}
	for {
		x, err := conn.Recv()
		if err != nil {
			return nil, err
		}
		log, ok := x.(safcm.MsgLog)
		if ok {
			l.Log(host, log.Level, false, log.Text)
			continue
		}
		return x, nil
	}
}

// HostInfoMsg sends a MsgInfoReq for host via conn and returns the resulting
// MsgInfoResp.
func (l *Loop) HostInfoMsg(host Host, conn *rpc.Conn, req safcm.MsgInfoReq) (
	safcm.MsgInfoResp, error) {

	var empty safcm.MsgInfoResp
	x, err := l.SendRecv(host, conn, req)
	if err != nil {
		return empty, err
	}
	resp, ok := x.(safcm.MsgInfoResp)
	if !ok {
		return empty, fmt.Errorf("unexpected response %v", x)
	}
	return resp, nil
}

// HostSyncMsg sends a MsgSyncReq for host via conn and returns the resulting
// MsgSyncResp.
func (l *Loop) HostSyncMsg(host Host, conn *rpc.Conn, req safcm.MsgSyncReq) (
	safcm.MsgSyncResp, error) {

	var empty safcm.MsgSyncResp
	x, err := l.SendRecv(host, conn, req)
	if err != nil {
		return empty, err
	}
	resp, ok := x.(safcm.MsgSyncResp)
	if !ok {
		return empty, fmt.Errorf("unexpected response %v", x)
	}
	return resp, nil
}