EasyDelivery/src/main/java/com/deliveryproject/easydelivery/MainController.java

package com.deliveryproject.easydelivery;

import com.deliveryproject.easydelivery.Models.Coordinate;
import com.deliveryproject.easydelivery.Models.OSMRClass.Intersection;
import com.deliveryproject.easydelivery.Models.OSMRClass.Root;
import com.deliveryproject.easydelivery.Models.OSMRClass.Step;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.web.bind.annotation.*;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

@CrossOrigin
@RestController
public class MainController {
    //@PreAuthorize("hasRole('User')")
    @GetMapping("/route/nodes")
    @ResponseBody
    public ArrayList<ArrayList<Double>> getNodesBetweenTwoCoordinates(@RequestParam double lon1, @RequestParam double lat1, @RequestParam double lon2, @RequestParam double lat2) throws IOException {
        System.out.println(lon1);
        String url = "http://router.project-osrm.org/route/v1/driving/" + lon1 + "," + lat1 + ";" + lon2 + "," + lat2 + "?steps=true&geometries=geojson";
        System.out.println(url);
        URL osrmEndpoint = new URL(url);
        HttpURLConnection connection = (HttpURLConnection) osrmEndpoint.openConnection();
        connection.setRequestMethod("GET");
        connection.setRequestProperty("Content-Type", "application/json");

        BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        String inputLine;
        StringBuilder response = new StringBuilder();
        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();

        ObjectMapper om = new ObjectMapper();
        Root root = om.readValue(response.toString(), Root.class);

        ArrayList<Step> steps = root.routes.get(0).legs.get(0).steps;

        ArrayList<ArrayList<Double>> coordinates = new ArrayList<>();

        for (Step step : steps) {
            ArrayList<Intersection> intersections = step.intersections;
            for (Intersection intersection : intersections) {
                ArrayList<Double> location = new ArrayList<>();
                location.add(intersection.location.get(1));
                location.add(intersection.location.get(0));
                coordinates.add(location);
            }

        }
        System.out.println(coordinates);
        return coordinates;
    }
    @GetMapping("/optimize-delivery-route")
    @ResponseBody
    public List<Coordinate> optimizeDeliveryRoute(List<Coordinate> coordinates) {

        List<Integer> optimizedRoute = new ArrayList<>();
        List<Coordinate> optimizedRouteCoordinates = new ArrayList<>();
        boolean[] visited = new boolean[coordinates.size()];

        int currentCoordinateIndex = 0;
        optimizedRoute.add(currentCoordinateIndex);
        visited[currentCoordinateIndex] = true;

        while (optimizedRoute.size() < coordinates.size()) {
            double minDistance = Double.MAX_VALUE;
            int nearestCoordinateIndex = -1;

            for (int i = 0; i < coordinates.size(); i++) {
                if (!visited[i]) {
                    double distance = calculateDistance(coordinates.get(currentCoordinateIndex), coordinates.get(i));
                    if (distance < minDistance) {
                        minDistance = distance;
                        nearestCoordinateIndex = i;
                    }
                }
            }
            optimizedRoute.add(nearestCoordinateIndex);
            visited[nearestCoordinateIndex] = true;
            currentCoordinateIndex = nearestCoordinateIndex;
        }
        for (Integer integer : optimizedRoute) {
            optimizedRouteCoordinates.add(coordinates.get(integer));
        }
        return optimizedRouteCoordinates;
    }

    private double calculateDistance(Coordinate c1, Coordinate c2) {
        ArrayList<ArrayList<Double>> nodes;
        try {
            nodes = getNodesBetweenTwoCoordinates(c1.lat, c1.lon, c2.lat, c2.lon);
        } catch (IOException e) {
            e.printStackTrace();
            return Double.MAX_VALUE;
        }

        double sumDistance = 0.0;

        for (int i = 0; i < nodes.size() - 1; i++) {
            ArrayList<Double> current = nodes.get(i);
            ArrayList<Double> next = nodes.get(i + 1);
            double dx = next.get(0) - current.get(0);
            double dy = next.get(1) - current.get(1);
            double distance = Math.sqrt(dx * dx + dy * dy);
            sumDistance += distance;
        }

        return sumDistance;
    }

}