package handlers

import (
	"log"
	"net/http"

	"aroll/ws"

	gws "github.com/gorilla/websocket"
)

var upgrader = gws.Upgrader{
	ReadBufferSize:  1024,
	WriteBufferSize: 4096,
	CheckOrigin:     func(r *http.Request) bool { return true },
}

func WSHandler(hub *ws.Hub) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		conn, err := upgrader.Upgrade(w, r, nil)
		if err != nil {
			log.Printf("ws upgrade: %v", err)
			return
		}

		client := &ws.Client{Send: make(chan []byte, 256)}
		hub.Register <- client

		// Writer goroutine: pumps messages from hub → WebSocket
		go func() {
			defer conn.Close()
			for msg := range client.Send {
				if err := conn.WriteMessage(gws.TextMessage, msg); err != nil {
					return
				}
			}
		}()

		// Reader loop: keeps the connection alive and detects close frames
		for {
			if _, _, err := conn.ReadMessage(); err != nil {
				break
			}
		}
		hub.Unregister <- client
	}
}