package agent_server

import (
	"errors"
	"github.com/gorilla/websocket"
	"github.com/hashicorp/go-uuid"
	"log"
	"nginx-ui/server/models"
	"sync"
	"time"
)

const (
	// Time allowed to write a message to the peer.
	writeWait = 12 * time.Second
	readWait  = 12 * time.Second

	// Time allowed to read the next pong message from the peer. ping period must be less
	pongWait = 10 * time.Second

	// Send pings to peer with this period. Must be less than pongWait.
	pingPeriod = (pongWait * 9) / 10

	// Maximum message size allowed from peer.
	maxMessageSize = 4096
)

// WsClient is a middleman between the websocket connection and the hub.
type WsClient struct {
	Token string `json:"id"`
	// The websocket connection.
	conn *websocket.Conn
	// Buffered channel of outbound messages.
	send      chan []byte
	callbacks map[string]chan *models.AgentData
	lock      *sync.Mutex
}

func NewWsClient(token string, conn *websocket.Conn) *WsClient {
	return &WsClient{
		Token:     token,
		conn:      conn,
		send:      make(chan []byte, 4096),
		callbacks: make(map[string]chan *models.AgentData),
	}
}

// readPump pumps messages from the websocket connection to the hub.
//
// The application runs readPump in a per-connection goroutine. The application
// ensures that there is at most one reader on a connection by executing all
// reads from this goroutine.
func (c *WsClient) readPump() {
	defer func() {
		AgentHub.unregister <- c
		log.Printf("readPump closed")
	}()
	c.conn.SetReadLimit(maxMessageSize)
	_ = c.conn.SetReadDeadline(time.Now().Add(readWait))
	_ = c.conn.SetWriteDeadline(time.Now().Add(writeWait))
	c.conn.SetPingHandler(func(string) error {
		log.Printf("ping: %v", time.Now())
		_ = c.conn.SetReadDeadline(time.Now().Add(readWait))
		_ = c.conn.SetWriteDeadline(time.Now().Add(writeWait))
		_ = c.conn.WriteMessage(websocket.PongMessage, []byte{})
		return nil
	})
	for {
		agentData := &models.AgentData{}
		err := c.conn.ReadJSON(&agentData)
		log.Printf("recv: %v", err)
		if err != nil {
			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
				log.Printf("error: %v", err)
			}
			log.Printf("read message: %v", err)
			break
		}
		r, ok := c.callbacks[agentData.RequestId]
		if ok {
			r <- agentData
			continue
		}
		handler, ok := AgentHub.handlers[agentData.Type]
		if ok {
			go func() {
				result, err := handler(c, agentData)
				log.Printf("result: %v,err: %v", result, err)
				if err != nil {
					agentData.Success = false
					agentData.Data = make(map[string]interface{})
					agentData.Msg = err.Error()
				} else {
					agentData.Success = true
					agentData.Data = result
					agentData.Msg = ""
				}
				c.JustSend(agentData)
			}()
		}
	}
}

/*
Send 发送消息
参数：

	message - 消息体
	result	- 返回结构体指针
	timeout - 超时时间

返回值：

	error - 错误
*/
func (c *WsClient) Send(data *models.AgentData, timeout time.Duration) (*models.AgentData, error) {
	var rec = make(chan *models.AgentData)
	if data.RequestId == "" {
		id, _ := uuid.GenerateUUID()
		data.RequestId = id
	}
	c.callbacks[data.RequestId] = rec

	timer := time.NewTimer(timeout)
	defer func() {
		delete(c.callbacks, data.RequestId)
		timer.Stop()
	}()
	err := c.conn.WriteJSON(data)
	if err != nil {
		return nil, err
	}

	for {
		select {
		case res, ok := <-rec:
			if !ok {
				return nil, errors.New("receive data fail")
			}
			return res, nil

		case <-timer.C:
			return nil, errors.New("timeout")
		}
	}
}

// JustSend 仅发送，不管是否成功，用于消息回复
func (c *WsClient) JustSend(message interface{}) {
	err := c.conn.WriteJSON(message)
	log.Printf("JustSend: message: %s, %v", message, err)
}

func (c *WsClient) Close() {
	_ = c.conn.Close()
	close(c.send)
}