// server.js (Node.js with Express and ws)

const express = require('express');
const { WebSocketServer } = require('ws');
const cors = require('cors'); // Import CORS

const { initializeApp, cert } = require('firebase-admin/app');
const { getFirestore } = require('firebase-admin/firestore');

var admin = require("firebase-admin");

const serviceAccount = require("./serviceAcc.json");

initializeApp({
  credential: cert(serviceAccount)
});


const db = getFirestore();
const app = express();
const port = process.env.PORT || 8080;

const wss = new WebSocketServer({ noServer: true });

app.use(cors());

var initialData = {};
let currentDeviceStates = {}; 

const fetchInitialData = async () => {
    const devices = [];
    const rooms = [];
    const users = [];

    try {
        const deviceSnapshot = await db.collection('Devices').get();
        deviceSnapshot.forEach(doc => devices.push({ id: doc.id, ...doc.data() }));

        const roomsSnapshot = await db.collectionGroup('Rooms').get(); // Get all rooms across hostels
        roomsSnapshot.forEach(doc => rooms.push({ id: doc.id, ...doc.data(), hostelId: doc.ref.parent.parent.id })); // Include hostelId

        const usersSnapshot = await db.collection('Users').get();
        usersSnapshot.forEach(doc => users.push({ id: doc.id, ...doc.data() }));

        initialData = { devices, rooms, users };

        // console.log("Initial data fetched:", initialData);
        //for each hostel id mantain a list of rooms with devices pertaining to that hostel
        
        //setall to off

        initialData.devices.forEach(device => {
            device.state = false;
        }  ); 

        initialData.rooms.forEach(room => {
            if (!currentDeviceStates[room.id]) {
                currentDeviceStates[room.id] = [];
            }
            
            const roomDevices = initialData.devices.filter(device => device.hostelId === room.hostelId);
            currentDeviceStates[room.id] = { ...room, devices: roomDevices };
        });




    } catch (error) {
        console.error("Error fetching initial data:", error);
        // return { devices: [], rooms: [], users: [] };
        initialData = { devices, rooms, users };
    }
};



fetchInitialData();



const connectedClients = {}; // Store connected clients per room

wss.on('connection', (ws) => {
    ws.on('message', async (message) => {
      try {
        const parsedMessage = JSON.parse(message);
        const { roomId, userId, apiKey } = parsedMessage;
  
        // Helper function to check authorization
        const isAuthorized = (roomId, userId, apiKey) => {
          return initialData.users.some(user => user.id === userId && user.roomId === roomId) || apiKey === "masterPassword@tiet@123";
        };
  
        switch (parsedMessage.type) {
          case 'joinRoom':
            if (!roomId || !userId) {
              ws.send(JSON.stringify({ error: 'Invalid room or user ID' }));
              return;
            }
  
            if (!isAuthorized(roomId, userId, apiKey)) {
              console.log("Unauthorized joinRoom attempt.");
              ws.send(JSON.stringify({ error: 'Unauthorized' }));
              return;
            }

            // Store the connected client
            if (!connectedClients[roomId]) {
                connectedClients[roomId] = [];
              }
              connectedClients[roomId].push(ws);

  
            ws.send(JSON.stringify({ type: 'roomData', roomData: currentDeviceStates[roomId], roomId: roomId }));
            break;
  
          case 'updateDeviceState':
            const { deviceId, state } = parsedMessage;
            if (!deviceId || state === undefined || !roomId || (!userId && !apiKey)) { // Check for undefined state or missing userId/apiKey
              ws.send(JSON.stringify({ error: 'Invalid device ID, state, room ID, user ID, or API key' }));
              return;
            }
  
            if (!isAuthorized(roomId, userId, apiKey)) {
              console.log("Unauthorized updateDeviceState attempt.");
              ws.send(JSON.stringify({ error: 'Unauthorized' }));
              return;
            }
  
  
            const room = currentDeviceStates[roomId];
            if (room) { // Check if the room exists
              const device = room.devices.find(dev => dev.id === deviceId);
              if (device) { // Check if the device exists
                device.state = state;

                // Broadcast to all clients in the room
                if (connectedClients[roomId]) {
                    connectedClients[roomId].forEach(client => {
                        client.send(JSON.stringify({ type: 'deviceUpdate', deviceId, state, roomId: roomId }));
                    });
                  }


              } else {
                ws.send(JSON.stringify({ error: 'Device not found' }));
              }
            } else {
              ws.send(JSON.stringify({ error: 'Room not found' }));
            }
  
            break;
  
          default:
            console.log('Unknown message type:', parsedMessage.type);
        }
  
      } catch (error) {
        console.error('Error handling message:', error);
        ws.send(JSON.stringify({ error: 'Invalid message format' })); // Send error back to client
      }
    });
  
    ws.on('close', () => {
      for (const roomId in connectedClients) {
        connectedClients[roomId] = connectedClients[roomId].filter(client => client !== ws);
      }
    });

    ws.on('error', (error) => {
        console.error('WebSocket error:', error);
      });
  });


console.log('WebSocket server started on port 8080');





const server = app.listen(port, () => console.log(`Listening on port ${port}`));

server.on('upgrade', (request, socket, head) => {
    wss.handleUpgrade(request, socket, head, ws => {
        wss.emit('connection', ws, request);
    });
});