package conn

import (
	"git.noahlan.cn/noahlan/nnet/session"
	"net"
	"sync/atomic"
)

type (
	Connection struct {
		session *session.Session // Session

		status int32    // 连接状态
		conn   net.Conn // low-level conn fd
		typ    ConnType // 连接类型

		lastMid uint64 // 最近一次消息ID

		chDie   chan struct{}       // 停止通道
		chSend  chan PendingMessage // 消息发送通道（结构化消息）
		chWrite chan []byte         // 消息发送通道（二进制消息）
	}
)

func NewConnection(id int64, rawC net.Conn, sendSize, writeSize int) *Connection {
	r := &Connection{
		session: session.NewSession(id),

		status: StatusStart,
		conn:   rawC,
		typ:    ConnTypeTCP,

		lastMid: 0,

		chDie:   make(chan struct{}),
		chSend:  make(chan PendingMessage, sendSize),
		chWrite: make(chan []byte, writeSize),
	}
	if _, ok := rawC.(*WSConn); ok {
		r.typ = ConnTypeWS
		return r
	}
	if _, ok := rawC.(*SerialConn); ok {
		r.typ = ConnTypeSerial
		return r
	}
	return r
}

func (r *Connection) Send(header, payload any) (err error) {
	defer func() {
		if e := recover(); e != nil {
			err = ErrBrokenPipe
		}
	}()
	r.chSend <- PendingMessage{
		Header:  header,
		Payload: payload,
	}
	return err
}

func (r *Connection) SendBytes(data []byte) (err error) {
	defer func() {
		if e := recover(); e != nil {
			err = ErrBrokenPipe
		}
	}()
	r.chWrite <- data
	return err
}

func (r *Connection) Status() int32 {
	return atomic.LoadInt32(&r.status)
}

func (r *Connection) SetStatus(s int32) {
	atomic.StoreInt32(&r.status, s)
}

func (r *Connection) Type() ConnType {
	return r.typ
}

func (r *Connection) Conn() net.Conn {
	return r.conn
}

func (r *Connection) WsConn() *WSConn {
	if r.typ == ConnTypeWS {
		return r.conn.(*WSConn)
	}
	return nil
}

func (r *Connection) SerialConn() *SerialConn {
	if r.typ == ConnTypeSerial {
		return r.conn.(*SerialConn)
	}
	return nil
}

func (r *Connection) ID() int64 {
	return r.session.ID()
}

func (r *Connection) Session() *session.Session {
	return r.session
}

func (r *Connection) LastMID() uint64 {
	return r.lastMid
}

func (r *Connection) SetLastMID(mid uint64) {
	atomic.StoreUint64(&r.lastMid, mid)
}

func (r *Connection) ChDie() chan struct{} {
	return r.chDie
}

func (r *Connection) ChSend() chan PendingMessage {
	return r.chSend
}

func (r *Connection) ChWrite() chan []byte {
	return r.chWrite
}

func (r *Connection) Close() error {
	if r.Status() == StatusClosed {
		return ErrCloseClosedSession
	}
	r.SetStatus(StatusClosed)

	select {
	case <-r.chDie:
		close(r.chSend)
		close(r.chWrite)
	default:
		close(r.chDie)
	}

	r.session.Close()
	return r.conn.Close()
}