// ws.go
package main

import (
	"encoding/json"
	"log"
	"net/http"
	"time"
	"unicode/utf8"

	"github.com/gorilla/websocket"
)

var upgrader = websocket.Upgrader{
	ReadBufferSize:  1024,
	WriteBufferSize: 1024,
	// okay while you're behind nginx/caddy
	CheckOrigin: func(r *http.Request) bool { return true },
}

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

		// Expect first message to be auth
		_, firstMsg, err := conn.ReadMessage()
		if err != nil {
			log.Printf("failed to read auth message: %v", err)
			conn.Close()
			return
		}

		var auth IncomingMessage
		if err := json.Unmarshal(firstMsg, &auth); err != nil {
			log.Printf("invalid auth json: %v", err)
			_ = conn.WriteJSON(AuthError{Type: "auth_error", Error: "bad_json"})
			conn.Close()
			return
		}

		if auth.Type != "auth" || auth.Token == "" {
			_ = conn.WriteJSON(AuthError{Type: "auth_error", Error: "missing_token"})
			conn.Close()
			return
		}

		// Lookup token
		hub.mu.RLock()
		tc, ok := hub.tokens[auth.Token]
		hub.mu.RUnlock()

		if !ok || tc.Revoked {
			_ = conn.WriteJSON(AuthError{Type: "auth_error", Error: "invalid_token"})
			conn.Close()
			return
		}

		if auth.ServerID == "" {
			auth.ServerID = "default"
		}
		if auth.Nick == "" {
			auth.Nick = tc.Name
		}

		// Enforce nickname length limit on initial/auth nick.
		if utf8.RuneCountInString(auth.Nick) > maxNickLen {
			log.Printf("auth nick %q too long, falling back to internal name %q", auth.Nick, tc.Name)
			auth.Nick = tc.Name
		}
		if utf8.RuneCountInString(auth.Nick) > maxNickLen {
			// still too long, truncate internal name
			log.Printf("internal name %q too long, truncating to %d runes", auth.Nick, maxNickLen)
			auth.Nick = truncateRunes(auth.Nick, maxNickLen)
		}

		client := &Client{
			hub:        hub,
			conn:       conn,
			send:       make(chan []byte, 32),
			token:      tc,
			nick:       auth.Nick,
			serverID:   auth.ServerID,
			playerUUID: auth.PlayerUUID,
			lastSeen:   time.Now(),
		}

		hub.register(client)

		if err := conn.WriteJSON(AuthOK{
			Type:         "auth_ok",
			InternalName: tc.Name,
		}); err != nil {
			log.Printf("failed to send auth_ok: %v", err)
			hub.unregister(client)
			conn.Close()
			return
		}

		go client.writePump()
		client.readPump()
	}
}