// server.js

const ttn = require("ttn")
const express = require("express")
const ws = require("express-ws")
console.log("Starting server...")
const appID = "XXXXXXX" // Change this to your app ID
const accessKey = "ttn-account-v2.XXXXXXX" // Change this to your access key
const deviceID = "XXXXXXX"

// create a new http server
const server = express()

// install the websocket plugin
ws(server)

server.use(express.static("public"))

server.ws("/data", function (ws, req) {
  console.log("New websocket opened")
  ttn.data(appID, accessKey)
    .then(function (client) {
      client.on("uplink", function (devID, payload) {
        console.log("Received uplink from", devID)
        ws.send(JSON.stringify(payload))
      })

      ws.on("close", function () {
        client.close()
      })

      // Listen to WebSocket events coming from the client.
      ws.on("message", function (payload) {
        const parsed = JSON.parse(payload)
        console.log("Received websocket message", parsed)
        // checking if the message comming from the websocket is indead a "downlink" event
        if (parsed && parsed.type == "downlink") {
          console.log("Scheduling downlink", parsed)
          client.send(deviceID, parsed.fields)
        }
      })
    })
    .catch(function (error) {
      console.error(error)
      ws.close()
    })
})

console.log("HTTP server listening on 4000 ...")

server.listen(4000)