mchess-server/connection/type.go

package connection

import (
	"context"
	"log"
	"mchess_server/types"

	"github.com/google/uuid"
	gorillaws "github.com/gorilla/websocket"
)

type Connection struct {
	ID                 uuid.UUID
	ws                 *gorillaws.Conn
	ctx                context.Context
	rxBuffer           *MessageBuffer
	txBuffer           *MessageBuffer
	disconnectCallback func()
	forColor           types.ChessColor
}

func NewConnection(options ...func(*Connection)) *Connection {
	connection := Connection{
		ID:       uuid.New(),
		rxBuffer: newMessageBuffer(100),
		txBuffer: newMessageBuffer(100),
	}

	for _, option := range options {
		option(&connection)
	}

	return &connection
}

func WithWebsocket(ws *gorillaws.Conn) func(*Connection) {
	return func(c *Connection) {
		c.ws = ws
	}
}

func WithContext(ctx context.Context) func(*Connection) {
	return func(c *Connection) {
		c.ctx = ctx
	}
}

func WithDisconnectCallback(cb func()) func(*Connection) {
	return func(c *Connection) {
		if cb != nil {
			c.disconnectCallback = cb
		}
	}
}

func (conn *Connection) SetForColor(color types.ChessColor) {
	conn.forColor = color
}

func (conn *Connection) SetDisconnectCallback(cb func()) {
	conn.disconnectCallback = cb
}

func (conn *Connection) HasWebsocketConnection() bool {
	return conn.ws != nil
}

func (conn *Connection) readFromRxBuffer() {
	for {
		_, msg, err := conn.ws.ReadMessage()
		if err != nil {
			conn.logConnection("while reading from websocket: %w", err)
			conn.Close("")
			conn.txBuffer.Insert("we do this to make txBuffer.Get() return")
			return
		}
		conn.rxBuffer.Insert(string(msg))
	}
}

func (conn *Connection) writeTxBuffer() {
	for {
		msg := conn.txBuffer.Get()

		if conn.ws == nil {
			return
		}

		err := conn.ws.WriteMessage(gorillaws.TextMessage, []byte(msg))
		if err != nil {
			conn.logConnection("while writing to websocket: %w", err)
			return
		}
	}
}

func (conn *Connection) SetWebsocketConnection(ws *gorillaws.Conn) {
	if ws == nil {
		conn.logConnection("ERROR: setting ws = null")
		return
	}

	conn.ws = ws

	go conn.readFromRxBuffer()
	go conn.writeTxBuffer()

	defer conn.logConnection("websocket connection set")
}

func (conn *Connection) unsetWebsocketConnection() {
	conn.logConnection("websocket connection unset")
	conn.ws = nil
}

func (conn *Connection) Write(msg string) {
	conn.logConnection("Writing message: ", string(msg))
	conn.txBuffer.Insert(msg)
}

func (conn *Connection) Read() []byte {
	msg := conn.rxBuffer.Get()

	return []byte(msg)
}

func (conn *Connection) Close(msg string) {
	conn.logConnection("closing websocket connection")
	conn.ws.WriteMessage(gorillaws.TextMessage, []byte(msg))
	conn.ws.Close()
	conn.ws = nil
}

func (con *Connection) logConnection(v ...any) {
	log.Println("on connection: ", con.ID)
	log.Println("for color: ", con.forColor.String(), v)
}