package core

import (
	"fmt"
	"github.com/gofiber/fiber/v2"
	ws "github.com/gofiber/websocket/v2"
	"github.com/gorilla/websocket"
	"html/template"
	"log"
	"net/http"
)

func echo(sub Subscriber) func(w http.ResponseWriter, r *http.Request) {
	var upgrader = websocket.Upgrader{} // use default options
	return func(w http.ResponseWriter, r *http.Request) {
		fmt.Println("upgrading to ws")
		c, err := upgrader.Upgrade(w, r, nil)
		if err != nil {
			log.Print("upgrade:", err)
			return
		}
		//defer c.Close()
		go func() {
			for {
				if _, _, err := c.NextReader(); err != nil {
					c.Close()
					break
				}
			}
		}()

		dispatcherId, channel := sub.Subscribe()
		defer sub.Unsubscribe(dispatcherId)
		for {
			//log.Println("")
			//if err != nil {
			//	log.Println("read:", err)
			//	break
			//}
			cmsg := <-channel
			err = c.WriteMessage(websocket.TextMessage, []byte(cmsg))
			if err != nil {
				log.Println("write:", err)

				break
			}
		}
	}
}

func home(w http.ResponseWriter, r *http.Request) {
	//var homeTemplate = template.Must(template.NewDispatcher("").ParseFiles("index.html"))
	tpl, err := template.ParseFiles("static/index.html")
	if err != nil {
		log.Fatalln(err)
	}
	err = tpl.Execute(w, "ws://"+r.Host+"/echo")
	if err != nil {
		log.Fatalln(err)
	}
}

func HttpListenAndServe(sub Subscriber, httpPort string) {
	log.Println("register websocket handler")
	http.HandleFunc("/echo", echo(sub))
	log.Println("register index handler")
	http.HandleFunc("/", home)
	log.Println("register static file handler")
	http.Handle("/static/", http.FileServer(http.Dir(".")))

	log.Println("start server")
	log.Fatal(http.ListenAndServe(httpPort, nil))
}

func FiberListen(sub Subscriber) {
	app := fiber.New()
	app.Static("/static", "static")

	// Application Main Page
	app.Get("/", fiberHomeHandler)

	// Websocket
	app.Get("/ws", ws.New(createFiberWebsocketHandler(sub)))

	// TODO: Get all SerialPorts
	app.Get("/serialports")

	// Tracking persistence controls
	trackings := app.Group("/trackings")
	trackings.Get("/")    // Get all trackings Metadata
	trackings.Post("/")   // Initialize new tracking, open websocket and prepare for automatic recording. Toggle ?serial=true and ?tcp=true. Returns trackingId
	trackings.Patch("/")  // Starts recording
	trackings.Put("/")    // Stops current recording. Returns trackingId if record was successful
	trackings.Delete("/") // Stops websocket connection, pipelines and collectors

	trackings.Get("/:trackingId")    // Gets Tracking Metadata and loads sensorRecords from database.
	trackings.Post("/:trackingId")   // Starts Replay.
	trackings.Patch("/:trackingId")  // Pauses Replay.
	trackings.Put("/:trackingId")    // Stops Replay.
	trackings.Delete("/:trackingId") // Deletes Tracking from database

	log.Fatal(app.Listen(":3011"))
}

func createFiberWebsocketHandler(s Subscriber) func(conn *ws.Conn) {
	return func(c *ws.Conn) {
		// Handle and discard inbound messages
		go func() {
			for {
				if _, _, err := c.NextReader(); err != nil {
					c.Close()
					break
				}
			}
		}()

		dispatcherId, channel := s.Subscribe()
		defer s.Unsubscribe(dispatcherId)
		for {
			cmsg := <-channel
			err := c.WriteMessage(ws.TextMessage, []byte(cmsg))
			if err != nil {
				log.Println("write:", err)

				break
			}
		}
	}

}

func fiberHomeHandler(c *fiber.Ctx) error {
	tpl, err := template.ParseFiles("static/index.html")
	if err != nil {
		return err
	}
	err = tpl.Execute(c, "ws://"+c.Hostname()+"/ws")
	if err != nil {
		return err
	}
	return nil
}