feat: Google Distance Matrix API 클라이언트 및 응답 파서 구현

Author: leesanghuu

src/main/java/com/ODG/ODG_back/external/google/GoogleMatrixApiClient.java

@@ -1,8 +1,9 @@
 package com.ODG.ODG_back.external.google;
 
-import java.math.BigDecimal;
+import com.ODG.ODG_back.domain.enums.TransportType;
+
 import java.util.List;
 
 public interface GoogleMatrixApiClient {
-    int[][] getTimeMatrix(List<List<BigDecimal>> origins, List<List<BigDecimal>> destinations);
+    int[][] getTimeMatrix(List<String> origins, List<String> destinations, TransportType transport);
 }

src/main/java/com/ODG/ODG_back/external/google/GoogleMatrixApiClientImpl.java

@@ -1,22 +1,55 @@
 package com.ODG.ODG_back.external.google;
 
+import com.ODG.ODG_back.domain.enums.TransportType;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.reactive.function.client.WebClient;
 
-import java.math.BigDecimal;
 import java.util.List;
+import java.util.Map;
+
+import static com.ODG.ODG_back.external.google.parser.GoogleMatrixResponseParser.parseTimeMatrix;
 
 @Component("googleMatrixApiClient")
 public class GoogleMatrixApiClientImpl implements GoogleMatrixApiClient {
 
-    @Value("{google.api.key}")
-    private String googleApiKey;
+    private final String googleApiKey;
+    private final WebClient webClient;
 
-    private final RestTemplate restTemplate = new RestTemplate();
+    public GoogleMatrixApiClientImpl(WebClient.Builder builder, @Value("${google.api.key}") String googleApiKey) {
+        this.webClient = builder.build();
+        this.googleApiKey = googleApiKey;
+    }
 
     @Override
-    public int[][] getTimeMatrix(List<List<BigDecimal>> origins, List<List<BigDecimal>> destinations) {
-        return new int[0][];
+    public int[][] getTimeMatrix(List<String> origins, List<String> destinations, TransportType transport) {
+
+        String url = buildUrl(origins, destinations, transport);
+        Map<String, Object> response = fetchApiResponse(url);
+
+        return parseTimeMatrix(response, origins.size(), destinations.size());
+    }
+
+    private String buildUrl(List<String> origins, List<String> destinations, TransportType transport) {
+
+        String originsParam = String.join("|", origins);
+        String destinationsParam = String.join("|", destinations);
+        String mode = transport == TransportType.CAR ? "driving" : "transit";
+
+        String url = String.format(
+                "https://maps.googleapis.com/maps/api/distancematrix/json?" +
+                        "origins=%s&destinations=%s&mode=%s&key=%s",
+                originsParam, destinationsParam, mode, googleApiKey
+        );
+
+        return url;
+    }
+
+    private Map<String, Object> fetchApiResponse(String url) {
+        return webClient.get()
+                .uri(url)
+                .retrieve()
+                .bodyToMono(Map.class)
+                .block();
     }
 }

src/main/java/com/ODG/ODG_back/external/google/parser/GoogleMatrixResponseParser.java

@@ -0,0 +1,29 @@
+package com.ODG.ODG_back.external.google.parser;
+
+import java.util.List;
+import java.util.Map;
+
+public class GoogleMatrixResponseParser {
+    public static int[][] parseTimeMatrix(Map<String, Object> response, int originSize, int destinationSize) {
+        List<Map<String, Object>> rows = (List<Map<String, Object>>) response.get("rows");
+
+        int[][] timeMatrix = new int[originSize][destinationSize];
+
+        for (int i = 0; i < originSize; i++) {
+            Map<String, Object> row = rows.get(i);
+            List<Map<String, Object>> elements = (List<Map<String, Object>>) row.get("elements");
+
+            for (int j = 0; j < destinationSize; j++) {
+                Map<String, Object> element = elements.get(j);
+                Map<String, Object> duration = (Map<String, Object>) element.get("duration");
+
+                if (duration != null) {
+                    timeMatrix[i][j] = (int) duration.get("value");
+                } else {
+                    timeMatrix[i][j] = Integer.MAX_VALUE; // unreachable destination
+                }
+            }
+        }
+        return timeMatrix;
+    }
+}

src/test/java/com/ODG/ODG_back/external/google/GoogleMatrixApiClientImplTest.java

@@ -0,0 +1,74 @@
+package com.ODG.ODG_back.external.google;
+
+import com.ODG.ODG_back.domain.enums.TransportType;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.*;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(MockitoExtension.class)
+class GoogleMatrixApiClientImplTest {
+
+    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
+    private WebClient mockWebClient;
+
+    @Mock
+    private WebClient.Builder mockBuilder;
+
+    private GoogleMatrixApiClientImpl client;
+
+    @BeforeEach
+    void setUp() {
+        when(mockBuilder.build()).thenReturn(mockWebClient);
+        client = new GoogleMatrixApiClientImpl(mockBuilder, "fake-api-key");
+    }
+
+    @Test
+    @DisplayName("Google API - 예상 소요 시간 행렬 반환")
+    void testGetTimeMatrix() {
+
+        // given
+        List<String> origins = List.of("37.5665, 126.9780", "37.5596,126.9900");
+        List<String> destinations = List.of("37.5700,126.9780", "37.5651,126.9895");
+
+        Map<String, Object> fakeResponse = Map.of(
+                "rows", List.of(
+                        Map.of("elements", List.of(
+                                Map.of("duration", Map.of("value", 1000)),
+                                Map.of("duration", Map.of("value", 1200))
+                        )),
+                        Map.of("elements", List.of(
+                                Map.of("duration", Map.of("value", 1300)),
+                                Map.of("duration", Map.of("value", 1500))
+                        ))
+                )
+        );
+
+        when(mockWebClient.get()
+                .uri(anyString())
+                .retrieve()
+                .bodyToMono(Map.class))
+                .thenReturn(Mono.just(fakeResponse));
+
+        // when
+       int[][] matrix = client.getTimeMatrix(origins, destinations, TransportType.PUBLIC);
+
+        // then
+        assertEquals(2, matrix.length);
+        assertEquals(2, matrix[0].length);
+        assertEquals(1000, matrix[0][0]);
+        assertEquals(1200, matrix[0][1]);
+    }
+
+}