✨ feat : 최적 경로 API 구현

build.gradle

@@ -28,6 +28,7 @@ dependencies {
 	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
 
 	implementation 'org.springframework.boot:spring-boot-starter-web'
+	implementation 'org.springframework.boot:spring-boot-starter-webflux'
 
 	// Lombok
 	compileOnly 'org.projectlombok:lombok'

src/main/java/com/example/Centralthon/domain/route/algo/PathStitcher.java

@@ -0,0 +1,43 @@
+package com.example.Centralthon.domain.route.algo;
+import com.example.Centralthon.domain.route.exception.RouteSegmentMissingException;
+import com.example.Centralthon.domain.route.model.*;
+import com.example.Centralthon.domain.route.web.dto.LocationRes;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public class PathStitcher {
+
+    public static CombinedPath stitch(List<Integer> order, Map<SegmentKey, PedSegment> segs) {
+        long distSum = 0, durSum = 0;
+        List<LocationRes> merged = new ArrayList<>();
+
+        for (int t = 0; t < order.size() - 1; t++) {
+            int i = order.get(t), j = order.get(t + 1);
+
+            PedSegment seg = segs.get(SegmentKey.of(i, j));
+            if (seg == null) throw new RouteSegmentMissingException();
+
+            List<LocationRes> p = seg.path();
+            if (merged.isEmpty()) merged.addAll(p);
+            else {
+                if (!p.isEmpty() && !merged.isEmpty()
+                        && equalsPoint(merged.get(merged.size()-1), p.get(0))) {
+                    merged.addAll(p.subList(1, p.size()));
+                } else merged.addAll(p);
+            }
+            distSum += seg.distance();
+            durSum  += seg.duration();
+        }
+        return new CombinedPath(distSum, durSum, merged);
+    }
+
+    // 좌표 중복 여부 확인
+    private static boolean equalsPoint(LocationRes a, LocationRes b) {
+        return Double.compare(a.lng(), b.lng()) == 0 && Double.compare(a.lat(), b.lat()) == 0;
+    }
+}

src/main/java/com/example/Centralthon/domain/route/algo/TspSolver.java

@@ -0,0 +1,62 @@
+package com.example.Centralthon.domain.route.algo;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public final class TspSolver {
+
+    public static List<Integer> solveOpenTour(double[][] d) {
+        int k = d.length;
+        // 초기화 작업
+        boolean[] used = new boolean[k];
+        List<Integer> path = new ArrayList<>();
+        int cur = 0;
+        used[0] = true;
+        path.add(0);
+
+        // 최근접 이웃 초기 해 구성
+        for (int step = 1; step < k; step++) {
+            int best = -1;
+            double bestD = Double.POSITIVE_INFINITY;
+            for (int j = 1; j < k; j++) if (!used[j]) {
+                double cand = d[cur][j];
+                if (cand < bestD) {
+                    bestD = cand;
+                    best = j;
+                }
+            }
+            used[best] = true;
+            path.add(best);
+            cur = best;
+        }
+
+        return twoOpt(path, d);
+    }
+
+    // 교차 제거를 통한 로컬 개선
+    private static List<Integer> twoOpt(List<Integer> tour, double[][] d) {
+        boolean improved = true;
+        int n = tour.size();
+        while (improved) {
+            improved = false;
+            for (int i = 1; i < n - 2; i++) {
+                for (int k = i + 1; k < n - 1; k++) {
+                    double delta =
+                            - d[tour.get(i - 1)][tour.get(i)]
+                                    - d[tour.get(k)][tour.get(k + 1)]
+                                    + d[tour.get(i - 1)][tour.get(k)]
+                                    + d[tour.get(i)][tour.get(k + 1)];
+                    if (delta < -1e-6) {
+                        Collections.reverse(tour.subList(i, k + 1));
+                        improved = true;
+                    }
+                }
+            }
+        }
+        return tour;
+    }
+}

src/main/java/com/example/Centralthon/domain/route/client/TmapPedestrianClient.java

@@ -0,0 +1,41 @@
+package com.example.Centralthon.domain.route.client;
+
+import com.example.Centralthon.domain.route.model.PedSegment;
+import com.example.Centralthon.domain.route.port.PedestrianRoutingPort;
+import com.example.Centralthon.domain.route.web.dto.LocationRes;
+import lombok.RequiredArgsConstructor;
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+import java.util.Map;
+
+@Component
+@RequiredArgsConstructor
+public class TmapPedestrianClient implements PedestrianRoutingPort {
+    private final WebClient tmapWebClient;
+    private final TmapPedestrianParser parser;
+
+    @Override
+    public Mono<PedSegment> fetchSegment(LocationRes a, LocationRes b) {
+        // 1. Tmap 보행자 경로 API 요청 바디 생성
+        Map<String, Object> body = Map.of(
+                "startX", String.valueOf(a.lng()),
+                "startY", String.valueOf(a.lat()),
+                "endX",   String.valueOf(b.lng()),
+                "endY",   String.valueOf(b.lat()),
+                "reqCoordType", "WGS84GEO",
+                "resCoordType", "WGS84GEO",
+                "startName", "S", "endName", "E"
+        );
+
+        // 2. API 호출 → JSON 응답 수신 → parser로 PedSegment 변환
+        return tmapWebClient.post()
+                .uri(ub -> ub.path("/tmap/routes/pedestrian").queryParam("version","1").build())
+                .bodyValue(body)
+                .retrieve()
+                .bodyToMono(new ParameterizedTypeReference<Map<String,Object>>() {})
+                .map(parser::parsePedestrian);
+    }
+}

src/main/java/com/example/Centralthon/domain/route/client/TmapPedestrianParser.java

@@ -0,0 +1,79 @@
+package com.example.Centralthon.domain.route.client;
+
+import com.example.Centralthon.domain.route.model.PedSegment;
+import com.example.Centralthon.domain.route.web.dto.LocationRes;
+import com.example.Centralthon.global.util.geo.GeoUtils;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+@Component
+public class TmapPedestrianParser {
+    public PedSegment parsePedestrian(Map<String, Object> pedRes) {
+        long totalDistance = 0L;
+        long totalDuration = 0L;
+        List<LocationRes> path = new ArrayList<>();
+
+        List<Map<String, Object>> features =
+                (List<Map<String, Object>>) pedRes.getOrDefault("features", List.of());
+
+        // 1) 총거리/시간 추출
+        for (Map<String, Object> f : features) {
+            Map<String, Object> props = (Map<String, Object>) f.get("properties");
+            if (props == null) continue;
+
+            Object d = props.get("totalDistance");
+            long candDist = asLong(d);
+            if (candDist > 0) totalDistance = candDist;
+
+            Object t = props.get("totalTime");
+            long candTime = asLong(t);
+            if (candTime > 0) totalDuration = candTime;
+            if (totalDistance > 0 && totalDuration > 0) break;
+        }
+
+        // 2) LineString 경로 좌표 이어붙이기 (중복점 제거)
+        for (Map<String, Object> f : features) {
+            Map<String, Object> geom = (Map<String, Object>) f.get("geometry");
+            if (geom == null) continue;
+            String type = String.valueOf(geom.get("type"));
+            if (!"LineString".equalsIgnoreCase(type)) continue;
+
+            List<List<Number>> coords = (List<List<Number>>) geom.get("coordinates");
+            if (coords == null) continue;
+
+            for (List<Number> xy : coords) {
+                if (xy.size() < 2) continue;
+                double x = xy.get(0).doubleValue(); // lon
+                double y = xy.get(1).doubleValue(); // lat
+                LocationRes p = new LocationRes(x, y); // (lng, lat)
+
+                if (path.isEmpty()) {
+                    path.add(p);
+                } else {
+                    LocationRes last = path.get(path.size() - 1);
+                    if (Double.compare(last.lng(), p.lng()) != 0 || Double.compare(last.lat(), p.lat()) != 0) {
+                        path.add(p);
+                    }
+                }
+            }
+        }
+        // 3) 총거리 누락 시 하버사인 합으로 보정
+        if (totalDistance <= 0 && path.size() >= 2) {
+            totalDistance = Math.round(GeoUtils.sumHaversineMeters(path));
+        }
+
+        return new PedSegment(totalDistance, totalDuration, path);
+    }
+
+    private static long asLong(Object v) {
+        if (v == null) return 0L;
+        if (v instanceof Number n) return n.longValue();
+        if (v instanceof String s && !s.isBlank()) {
+            try { return Long.parseLong(s.trim()); } catch (NumberFormatException ignored) {}
+        }
+        return 0L;
+    }
+}

src/main/java/com/example/Centralthon/domain/route/exception/RouteErrorCode.java

@@ -0,0 +1,16 @@
+package com.example.Centralthon.domain.route.exception;
+
+import com.example.Centralthon.global.response.code.BaseResponseCode;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public enum RouteErrorCode implements BaseResponseCode {
+    ROUTE_SEGMENT_MISSING("ROUTE_500_1", 500, "서버에서 세그먼트가 누락되었습니다."),
+    ROUTE_NOT_CREATED("ROUTE_500_2",500,"서버에서 보행자 경로를 생성하지 못했습니다.");
+
+    private final String code;
+    private final int httpStatus;
+    private final String message;
+}

src/main/java/com/example/Centralthon/domain/route/exception/RouteNotCreatedException.java

@@ -0,0 +1,9 @@
+package com.example.Centralthon.domain.route.exception;
+
+import com.example.Centralthon.global.exception.BaseException;
+
+public class RouteNotCreatedException extends BaseException {
+    public RouteNotCreatedException() {
+        super(RouteErrorCode.ROUTE_NOT_CREATED);
+    }
+}

src/main/java/com/example/Centralthon/domain/route/exception/RouteSegmentMissingException.java

@@ -0,0 +1,9 @@
+package com.example.Centralthon.domain.route.exception;
+
+import com.example.Centralthon.global.exception.BaseException;
+
+public class RouteSegmentMissingException extends BaseException {
+    public RouteSegmentMissingException() {
+        super(RouteErrorCode.ROUTE_SEGMENT_MISSING);
+    }
+}

src/main/java/com/example/Centralthon/domain/route/model/CombinedPath.java

@@ -0,0 +1,11 @@
+package com.example.Centralthon.domain.route.model;
+
+import com.example.Centralthon.domain.route.web.dto.LocationRes;
+import java.util.List;
+
+// 최종 합성 경로 (사용자 출발 → 경유지들 → 도착)
+public record CombinedPath(
+        long distanceMeters,
+        long durationSeconds,
+        List<LocationRes> path) {
+}

src/main/java/com/example/Centralthon/domain/route/model/PedMatrix.java

@@ -0,0 +1,8 @@
+package com.example.Centralthon.domain.route.model;
+import java.util.Map;
+
+// 보행 경로 행렬 (Pedestrian Matrix)
+public record PedMatrix(
+        double[][] distMatrix, // 비용(거리/시간) 테이블
+        Map<SegmentKey, PedSegment> segments) {
+}

src/main/java/com/example/Centralthon/domain/route/model/PedSegment.java

@@ -0,0 +1,11 @@
+package com.example.Centralthon.domain.route.model;
+
+import com.example.Centralthon.domain.route.web.dto.LocationRes;
+import java.util.List;
+
+// 보행 경로 세그먼트 (두 지점 A→B 사이)
+public record PedSegment(
+        long distance,
+        long duration,
+        List<LocationRes> path // A -> B까지의 보행 경로 좌표 리스트
+) {}

src/main/java/com/example/Centralthon/domain/route/model/SegmentKey.java

@@ -0,0 +1,18 @@
+package com.example.Centralthon.domain.route.model;
+
+// 경로 행렬의 키 (두 노드 간 구간을 고유하게 식별)
+public record SegmentKey(
+        int i,
+        int j) {
+    public SegmentKey {
+        if (i > j) {
+            int tmp = i;
+            i = j;
+            j = tmp;
+        }
+    }
+
+    public static SegmentKey of(int a, int b) {
+        return new SegmentKey(a, b);
+    }
+}

src/main/java/com/example/Centralthon/domain/route/port/PedestrianRoutingPort.java

@@ -0,0 +1,9 @@
+package com.example.Centralthon.domain.route.port;
+
+import com.example.Centralthon.domain.route.model.PedSegment;
+import com.example.Centralthon.domain.route.web.dto.LocationRes;
+import reactor.core.publisher.Mono;
+
+public interface PedestrianRoutingPort {
+    Mono<PedSegment> fetchSegment(LocationRes a, LocationRes b);
+}