package ws

import (
	"crypto/rand"
	"encoding/hex"
	"net/http"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/gorilla/websocket"
	"go.uber.org/zap"
)

type Controller struct {
	hub      *Hub
	upgrader websocket.Upgrader
}

func NewController(hub *Hub) *Controller {
	return &Controller{
		hub: hub,
		upgrader: websocket.Upgrader{
			ReadBufferSize:  1024,
			WriteBufferSize: 1024,
		},
	}
}

// Connect 升级 HTTP 连接并加入指定房间。
// 浏览器连接示例：new WebSocket("ws://localhost:8080/api/ws?room=lobby&client_id=demo")
func (c *Controller) Connect(ctx *gin.Context) {
	room := strings.TrimSpace(ctx.DefaultQuery("room", "lobby"))
	clientID := strings.TrimSpace(ctx.Query("client_id"))
	if room == "" || len(room) > 64 || len(clientID) > 64 {
		ctx.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "room 或 client_id 不合法", "data": nil})
		return
	}
	if clientID == "" {
		clientID = randomClientID()
	}

	conn, err := c.upgrader.Upgrade(ctx.Writer, ctx.Request, nil)
	if err != nil {
		zap.L().Warn("WebSocket升级失败", zap.Error(err))
		return
	}
	client := NewClient(c.hub, conn, room, clientID)
	online := c.hub.Register(client)
	client.send <- OutgoingMessage{
		Type: EventWelcome, Room: room, ClientID: clientID,
		Data: "connected", Online: online, Timestamp: time.Now(),
	}
	c.hub.Broadcast(room, presenceMessage(room, clientID, "joined", online))

	go client.WritePump()
	client.ReadPump()
}

func randomClientID() string {
	value := make([]byte, 8)
	if _, err := rand.Read(value); err != nil {
		return "anonymous"
	}
	return hex.EncodeToString(value)
}