// The MIT License (MIT)
//
// Copyright (c) 2015 xtaci
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

package kcp

import (
	"sync/atomic"

	"github.com/pkg/errors"
)

// defaultReadLoop is the standard procedure for reading from a connection
func (s *UDPSession) defaultReadLoop() {
	buf := make([]byte, mtuLimit)
	var src string
	for {
		if n, addr, err := s.conn.ReadFrom(buf); err == nil {
			if s.isClosed() {
				return
			}
			// make sure the packet is from the same source
			if src == "" { // set source address
				src = addr.String()
			} else if addr.String() != src {
				atomic.AddUint64(&DefaultSnmp.InErrs, 1)
				continue
			}
			s.packetInput(buf[:n])
		} else {
			s.notifyReadError(errors.WithStack(err))
			return
		}
	}
}

// defaultReadLoop is the standard procedure for reading and accepting connections on a listener
func (l *Listener) defaultMonitor() {
	buf := make([]byte, mtuLimit)
	for {
		if n, from, err := l.conn.ReadFrom(buf); err == nil {
			l.packetInput(buf[:n], from)
		} else {
			l.notifyReadError(errors.WithStack(err))
			return
		}
	}
}