package main

import (
	"log"
	"sync"
	"time"

	"github.com/gorilla/websocket"
)

const TIMEOUT = 6
const IDLE_TIMEOUT = TIMEOUT * time.Second
const PING_INTERVAL = (TIMEOUT - 1) * time.Second

type WSConnection struct {
	url       string
	conn      *websocket.Conn
	errChan   chan error
	writeLock sync.Mutex
	ReadChan  chan string
	WriteChan chan string
}

func (ws *WSConnection) messageReader() {
	log.Printf("Reading messages")
	for {
		_, message, err := ws.conn.ReadMessage()
		ws.conn.SetReadDeadline(time.Now().Add(IDLE_TIMEOUT))
		if err != nil {
			ws.errChan <- err
			return
		}
		log.Printf("Received: %s", message)
		ws.ReadChan <- string(message)
	}
}

func (ws *WSConnection) messageSender() {
	log.Printf("Sending messages")
	for {
		msg := <-ws.WriteChan
		ws.writeLock.Lock()
		
		ws.conn.SetWriteDeadline(time.Now().Add(IDLE_TIMEOUT))
		log.Printf("Sending: %s", msg)
		err := ws.conn.WriteMessage(websocket.TextMessage, []byte(msg))
		if err != nil {
			log.Printf("Error during message writing: %v", err)
			ws.errChan <- err
			return
		}
		ws.writeLock.Unlock()
	}
}

func (ws *WSConnection) pinger() {
	log.Printf("Starting pinger, sleeping for %v", PING_INTERVAL)
	for {
		time.Sleep(PING_INTERVAL)

		// log.Printf("Ping")
		ws.writeLock.Lock()
		err := ws.conn.WriteMessage(websocket.PingMessage, nil)
		if err != nil {
			log.Println("Error during ping:", err)
			ws.errChan <- err
			return
		}
		ws.writeLock.Unlock()
	}
}

func (ws *WSConnection) handleError() {
	for {
		err := <-ws.errChan
		log.Println("Error during message reading:", err)

		time.Sleep(5 * time.Second)
		ws.Open()
	}
}

func (ws *WSConnection) Open() {
	log.Printf("Connecting to %s", ws.url)
	conn, _, err := websocket.DefaultDialer.Dial(ws.url, nil)
	if err != nil {
		log.Println("Error during connection:", err)
		ws.errChan <- err
		return
	}
	log.Printf("Connected")
	ws.conn = conn
	ws.errChan = make(chan error)
	ws.ReadChan = make(chan string, 1024)
	ws.WriteChan = make(chan string, 1024)

	ws.conn.SetReadLimit(1024)
	ws.conn.SetReadDeadline(time.Now().Add(IDLE_TIMEOUT))
	ws.conn.SetWriteDeadline(time.Now().Add(IDLE_TIMEOUT))
	ws.conn.SetPongHandler(func(string) error {
		// log.Println("Pong")
		ws.conn.SetReadDeadline(time.Now().Add(IDLE_TIMEOUT))
		ws.conn.SetWriteDeadline(time.Now().Add(IDLE_TIMEOUT))
		return nil
	})

	go ws.messageReader()
	go ws.messageSender()
	go ws.handleError()
	go ws.pinger()
}