package serverevents

import (
	gocontext "context"
	"fmt"
	di "git.apihub24.de/admin/generic-di"
	"github.com/coder/websocket"
	"github.com/coder/websocket/wsjson"
	"net/http"
	"time"
)

func init() {
	di.Injectable(newServerEventsMiddleware)
}

type MiddlewareOptions struct {
	Path            string
	ContextLifetime time.Duration
	KeepAliveTime   time.Duration
}

type IMiddleware interface {
	Use(options MiddlewareOptions, mux *http.ServeMux) *http.ServeMux
}

type serverEventsMiddleware struct {
	hub IEventHub
}

func newServerEventsMiddleware() IMiddleware {
	return &serverEventsMiddleware{
		hub: di.Inject[IEventHub](),
	}
}

func (middleware *serverEventsMiddleware) Use(options MiddlewareOptions, muxer *http.ServeMux) *http.ServeMux {
	if muxer == nil {
		muxer = http.NewServeMux()
	}

	eventHub := di.Inject[IEventHub]()
	muxer.HandleFunc(options.Path, func(w http.ResponseWriter, r *http.Request) {
		id := r.URL.Query().Get("id")
		if len(id) < 1 {
			println(fmt.Sprintf("no id found in query websocket closed"))
			return
		}
		c, connectionErr := websocket.Accept(w, r, nil)
		if connectionErr != nil {
			println(fmt.Sprintf("[Error on connect Websocket]: %v", connectionErr))
			return
		}
		defer func() {
			println("Websocket disconnect")
			eventHub.OnDisconnected(id)
			_ = c.CloseNow()
		}()

		eventHub.OnConnected(id, c)

		for {
			err := readMessage(c, eventHub, id)
			if err != nil {
				return
			}
		}
	})

	return muxer
}

func readMessage(c *websocket.Conn, eventHub IEventHub, id string) error {
	var message Event
	readErr := wsjson.Read(gocontext.Background(), c, &message)
	if readErr != nil {
		println(fmt.Sprintf("[Error on read from Websocket]: %v", readErr))
		return readErr
	}

	eventHub.Event(message, id)
	return nil
}