package client

import (
	"crypto/tls"
	"fmt"
	"net"
	"sync"
	"sync/atomic"
	"time"

	olog "git.loafle.net/overflow/log-go"
	"git.loafle.net/overflow/server-go/socket"
	"git.loafle.net/overflow/server-go/socket/client"
)

type Connectors struct {
	client.Connectors

	Network      string   `json:"network,omitempty"`
	Address      string   `json:"address,omitempty"`
	LocalAddress net.Addr `json:"-"`

	stopChan chan struct{}
	stopWg   sync.WaitGroup

	readChan  chan socket.SocketMessage
	writeChan chan socket.SocketMessage

	disconnectedChan chan struct{}
	reconnectedChan  chan socket.Conn

	crw socket.ClientReadWriter

	validated atomic.Value
}

func (c *Connectors) Connect() (readChan <-chan socket.SocketMessage, writeChan chan<- socket.SocketMessage, err error) {
	var (
		conn socket.Conn
	)

	if nil != c.stopChan {
		return nil, nil, fmt.Errorf("%s already connected", c.logHeader())
	}

	conn, err = c.connect()
	if nil != err {
		return nil, nil, err
	}

	c.readChan = make(chan socket.SocketMessage, 256)
	c.writeChan = make(chan socket.SocketMessage, 256)
	c.disconnectedChan = make(chan struct{})
	c.reconnectedChan = make(chan socket.Conn)
	c.stopChan = make(chan struct{})

	c.crw.ReadwriteHandler = c
	c.crw.ReadChan = c.readChan
	c.crw.WriteChan = c.writeChan
	c.crw.ClientStopChan = c.stopChan
	c.crw.ClientStopWg = &c.stopWg
	c.crw.DisconnectedChan = c.disconnectedChan
	c.crw.ReconnectedChan = c.reconnectedChan

	c.stopWg.Add(1)
	go c.handleReconnect()
	c.stopWg.Add(1)
	go c.crw.HandleConnection(conn)

	return c.readChan, c.writeChan, nil
}

func (c *Connectors) Disconnect() error {
	if c.stopChan == nil {
		return fmt.Errorf("%s must be connected before disconnection it", c.logHeader())
	}
	close(c.stopChan)
	c.stopWg.Wait()

	c.stopChan = nil

	return nil
}

func (c *Connectors) logHeader() string {
	return fmt.Sprintf("Connector[%s]: ", c.Name)
}

func (c *Connectors) onDisconnected() {
	close(c.readChan)
	close(c.writeChan)

	c.reconnectedChan <- nil

	onDisconnected := c.OnDisconnected
	if nil != onDisconnected {
		go func() {
			onDisconnected(c)
		}()
	}
}

func (c *Connectors) handleReconnect() {
	defer func() {
		c.stopWg.Done()
	}()

RC_LOOP:
	for {
		select {
		case <-c.disconnectedChan:
		case <-c.stopChan:
			return
		}

		if 0 >= c.GetReconnectTryTime() {
			c.onDisconnected()
			return
		}

		olog.Logger().Debugf("%s connection lost", c.logHeader())

		for indexI := 0; indexI < c.GetReconnectTryTime(); indexI++ {
			olog.Logger().Debugf("%s trying reconnect[%d]", c.logHeader(), indexI)

			conn, err := c.connect()
			if nil == err {
				olog.Logger().Debugf("reconnected")
				c.reconnectedChan <- conn
				continue RC_LOOP
			}
			time.Sleep(c.GetReconnectInterval())
		}

		olog.Logger().Debugf("%s reconnecting has been failed", c.logHeader())
		c.onDisconnected()
		return
	}
}

func (c *Connectors) connect() (socket.Conn, error) {
	netConn, err := c.dial()
	if nil != err {
		return nil, err
	}

	conn := socket.NewConn(netConn, false, c.GetReadBufferSize(), c.GetWriteBufferSize())
	conn.SetCloseHandler(func(code int, text string) error {
		olog.Logger().Debugf("%s close", c.logHeader())
		return nil
	})
	return conn, nil
}

func (c *Connectors) dial() (net.Conn, error) {
	var deadline time.Time
	if 0 != c.GetHandshakeTimeout() {
		deadline = time.Now().Add(c.GetHandshakeTimeout())
	}

	d := &net.Dialer{
		KeepAlive: c.GetKeepAlive(),
		Deadline:  deadline,
		LocalAddr: c.LocalAddress,
	}

	conn, err := d.Dial(c.Network, c.Address)
	if nil != err {
		return nil, err
	}

	if nil != c.GetTLSConfig() {
		cfg := c.GetTLSConfig().Clone()
		tlsConn := tls.Client(conn, cfg)
		if err := tlsConn.Handshake(); err != nil {
			tlsConn.Close()
			return nil, err
		}
		if !cfg.InsecureSkipVerify {
			if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
				return nil, err
			}
		}
		conn = tlsConn
	}

	return conn, nil
}

func (c *Connectors) Clone() client.Connector {
	return &Connectors{
		Connectors:   *c.Connectors.Clone(),
		Network:      c.Network,
		Address:      c.Address,
		LocalAddress: c.LocalAddress,
		validated:    c.validated,
	}
}

func (c *Connectors) Validate() error {
	if nil != c.validated.Load() {
		return nil
	}
	c.validated.Store(true)

	if err := c.Connectors.Validate(); nil != err {
		return err
	}

	if "" == c.Network {
		return fmt.Errorf("%s Network is not valid", c.logHeader())
	}

	if "" == c.Address {
		return fmt.Errorf("%s Address is not valid", c.logHeader())
	}

	return nil
}