EVBunkServiceImpl.java

package com.rest_ev.rest_ev.service;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

import org.springframework.stereotype.Service;

import com.rest_ev.rest_ev.entity.EVBunk;
import com.rest_ev.rest_ev.repository.EVBunkRepository;

import lombok.AllArgsConstructor;

@Service
@AllArgsConstructor
public class EVBunkServiceImpl implements EVBunkService {

    // Radius of the Earth in kilometers
    private static final double EARTH_RADIUS = 6371.01;

    private EVBunkRepository evBunkRepository;

    @Override
    public EVBunk createEVBunk(EVBunk details) {
        return evBunkRepository.save(details);
    }

    @Override
    public EVBunk getEVBunkById(Long id) {
        Optional<EVBunk> bunkdetails = evBunkRepository.findById(id);
        return bunkdetails.get();
    }

    @Override
    public List<EVBunk> getAllEVBunk() {
        return evBunkRepository.findAll();
    }

    @Override
    public List<EVBunk> getNearbyEVBunk(EVBunk location) {
        // all items from db
        List<EVBunk> allBunks = evBunkRepository.findAll();
        List<EVBunk> nearByBunks = new ArrayList<>();

        // location based filter here
        for (EVBunk evBunk : allBunks) {
            double distance = calculateDistance(evBunk.getLatitude(), evBunk.getLongitude(), location.getLatitude(), location.getLongitude());
            if(distance < 3) // check for within 5km radius
            {
                nearByBunks.add(evBunk);
            }
        }

        return nearByBunks;
    }

    @Override
    public EVBunk updateEVBunk(EVBunk details) {
        // TODO Auto-generated method stub
        throw new UnsupportedOperationException("Unimplemented method 'updateEVBunk'");
    }

    @Override
    public void deleteEVBunk(Long id) {
        // TODO Auto-generated method stub
        throw new UnsupportedOperationException("Unimplemented method 'deleteEVBunk'");
    }

    private static double calculateDistance(double lat1, double lon1, double lat2, double lon2) {
        // Convert degrees to radians
        double lat1Rad = Math.toRadians(lat1);
        double lon1Rad = Math.toRadians(lon1);
        double lat2Rad = Math.toRadians(lat2);
        double lon2Rad = Math.toRadians(lon2);

        // Haversine formula
        double dlat = lat2Rad - lat1Rad;
        double dlon = lon2Rad - lon1Rad;

        double a = Math.pow(Math.sin(dlat / 2), 2)
                 + Math.cos(lat1Rad) * Math.cos(lat2Rad) * Math.pow(Math.sin(dlon / 2), 2);

        double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));

        // Distance in kilometers
        return EARTH_RADIUS * c;
    }

}