/*
   Copyright 2020 XiaochengTech

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package connections

import (
	"io"
	"net"
	"time"
)

// 默认连接结构体，必须继承后实现缺少的接口才能使用
type DefaultConnection struct {
	// 内部属性
	identifier     string        // 唯一标志
	isPassive      bool          // 是否是被动连接(不重连)，还是主动连接(自动重连)
	conn           net.Conn      // 底层连接
	address        string        // 底层地址
	closed         bool          // 是否已关闭
	connectTimeout time.Duration // 连接超时时间
	readTimeout    time.Duration // 读超时
	writeTimeout   time.Duration // 写超时
	// 信息通道
	readBuf   chan []byte // 正常消息的读取通道
	readError chan error  // 错误消息的读取通道
	// 事件回调
	onConnect func(id string, addr string)
	onWrite   func(id string, buf []byte, n int, err error)
	onClose   func(id string)
}

// (接口)读取信息
func (m DefaultConnection) Read() (buf []byte, err error) {
	// 从正常信息通道和错误信息通道读取信息
	var ok bool
	select {
	case buf, ok = <-m.readBuf:
	case err, ok = <-m.readError:
	}
	// 如果连接已关闭
	if m.closed || !ok {
		err = io.EOF
		return
	}
	return
}

// (接口)关闭连接
func (m *DefaultConnection) Close() {
	// 已关闭
	if m.closed {
		return
	}
	// 置标志为关闭状态
	m.closed = true
	// 关闭连接
	_ = m.conn.Close()
	// 通知外界
	if m.onClose != nil {
		m.onClose(m.identifier)
	}
	return
}

// (接口)设置连接超时
func (m *DefaultConnection) SetConnectTimeout(d time.Duration) {
	m.connectTimeout = d
}

// (接口)设置读超时
func (m *DefaultConnection) SetReadTimeout(d time.Duration) {
	m.readTimeout = d
}

// (接口)设置写超时
func (m *DefaultConnection) SetWriteTimeout(d time.Duration) {
	m.writeTimeout = d
}

// (接口)唯一标志
func (m DefaultConnection) Identifier() string {
	return m.identifier
}

// (接口)是否是被动连接/主动连接
func (m DefaultConnection) IsPassive() bool {
	return m.isPassive
}

// (接口)底层连接
func (m DefaultConnection) Conn() net.Conn {
	return m.conn
}

// (接口)是否已关闭
func (m DefaultConnection) IsClosed() bool {
	return m.closed
}