package signaling

import (
	"bytes"
	"time"

	"github.com/adalkiran/webrtc-nuts-and-bolts/src/conference"
	"github.com/adalkiran/webrtc-nuts-and-bolts/src/logging"
	"github.com/gorilla/websocket"
)

// See: https://github.com/gorilla/websocket/tree/master/examples/chat

const (
	// Time allowed to write a message to the peer.
	writeWait = 10 * time.Second

	// Time allowed to read the next pong message from the peer.
	pongWait = 60 * 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 = 81920
)

var (
	newline = []byte{'\n'}
	space   = []byte{' '}
)

var upgrader = websocket.Upgrader{
	ReadBufferSize:  1024,
	WriteBufferSize: 1024,
}

// Client is a middleman between the websocket connection and the hub.
type WsClient struct {
	id int

	wsHub *WsHub

	// The websocket connection.
	conn *websocket.Conn

	// Buffered channel of outbound messages.
	send chan []byte

	conference *conference.Conference
}

type ReceivedMessage struct {
	Sender  *WsClient
	Message []byte
}

type ClientWelcomeMessage struct {
	Id      int    `json:"id"`
	Message string `json:"message"`
}

type ClientErrorMessage struct {
	ErrorCode string `json:"errorCode"`
	Message   string `json:"message"`
}

// 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() {
		c.wsHub.unregister <- c
		c.conn.Close()
	}()
	c.conn.SetReadLimit(maxMessageSize)
	c.conn.SetReadDeadline(time.Now().Add(pongWait))
	c.conn.SetPongHandler(func(string) error { c.conn.SetReadDeadline(time.Now().Add(pongWait)); return nil })
	for {
		_, message, err := c.conn.ReadMessage()
		if err != nil {
			logging.Errorf(logging.ProtoWS, "Receive error: %s", err)
			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
				logging.Errorf(logging.ProtoWS, "Unexpected error: %v", err)
			} else {
				c.conn.WriteJSON(ClientErrorMessage{
					ErrorCode: "receive-error",
					Message:   err.Error(),
				})
			}
			break
		}
		message = bytes.TrimSpace(bytes.Replace(message, newline, space, -1))

		//c.hub.broadcast <- message
		c.wsHub.messageReceived <- &ReceivedMessage{
			Sender:  c,
			Message: message,
		}
	}
}

// writePump pumps messages from the hub to the websocket connection.
//
// A goroutine running writePump is started for each connection. The
// application ensures that there is at most one writer to a connection by
// executing all writes from this goroutine.
func (c *WsClient) writePump() {
	ticker := time.NewTicker(pingPeriod)
	defer func() {
		ticker.Stop()
		c.conn.Close()
	}()
	for {
		select {
		case message, ok := <-c.send:
			c.conn.SetWriteDeadline(time.Now().Add(writeWait))
			if !ok {
				// The hub closed the channel.
				c.conn.WriteMessage(websocket.CloseMessage, []byte{})
				return
			}

			w, err := c.conn.NextWriter(websocket.TextMessage)
			if err != nil {
				return
			}
			w.Write(message)

			// Add queued chat messages to the current websocket message.
			n := len(c.send)
			for i := 0; i < n; i++ {
				w.Write(newline)
				w.Write(<-c.send)
			}

			if err := w.Close(); err != nil {
				return
			}
		case <-ticker.C:
			c.conn.SetWriteDeadline(time.Now().Add(writeWait))
			if err := c.conn.WriteMessage(websocket.PingMessage, nil); err != nil {
				return
			}
		}
	}
}

func (c *WsClient) RemoteAddrStr() string {
	if c.conn == nil {
		return "<nil>"
	}
	return c.conn.RemoteAddr().String()
}
