package ws

import (
	"time"

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

const (
	writeWait      = 10 * time.Second
	pongWait       = 60 * time.Second
	pingPeriod     = pongWait * 9 / 10
	maxMessageSize = 8 * 1024
)

type Client struct {
	hub      *Hub
	conn     *websocket.Conn
	send     chan OutgoingMessage
	room     string
	clientID string
}

func NewClient(hub *Hub, conn *websocket.Conn, room, clientID string) *Client {
	return &Client{
		hub: hub, conn: conn, send: make(chan OutgoingMessage, 64),
		room: room, clientID: clientID,
	}
}

func (c *Client) ReadPump() {
	defer func() {
		remaining := c.hub.Unregister(c)
		_ = c.conn.Close()
		c.hub.Broadcast(c.room, presenceMessage(c.room, c.clientID, "left", remaining))
	}()

	c.conn.SetReadLimit(maxMessageSize)
	_ = c.conn.SetReadDeadline(time.Now().Add(pongWait))
	c.conn.SetPongHandler(func(string) error {
		return c.conn.SetReadDeadline(time.Now().Add(pongWait))
	})

	for {
		var incoming IncomingMessage
		if err := c.conn.ReadJSON(&incoming); err != nil {
			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
				zap.L().Warn("WebSocket读取失败", zap.String("client_id", c.clientID), zap.Error(err))
			}
			return
		}
		if incoming.Type != EventMessage || incoming.Data == "" {
			c.send <- OutgoingMessage{Type: EventError, Data: "仅支持非空 message 事件", Timestamp: time.Now()}
			continue
		}
		c.hub.Broadcast(c.room, OutgoingMessage{
			Type: EventMessage, Room: c.room, ClientID: c.clientID,
			Data: incoming.Data, Timestamp: time.Now(),
		})
	}
}

func (c *Client) 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 {
				_ = c.conn.WriteMessage(websocket.CloseMessage, []byte{})
				return
			}
			if err := c.conn.WriteJSON(message); 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 presenceMessage(room, clientID, action string, online int) OutgoingMessage {
	return OutgoingMessage{
		Type: EventPresence, Room: room, ClientID: clientID,
		Data: action, Online: online, Timestamp: time.Now(),
	}
}