Initial commit

src/main/java/com/example/service/DialogflowClientService.java

@@ -0,0 +1,120 @@
+package com.example.service;
+
+import com.example.dto.dialogflow.DetectIntentRequestDTO;
+import com.example.dto.dialogflow.DetectIntentResponseDTO;
+import com.example.mapper.DialogflowRequestMapper;
+import com.example.mapper.DialogflowResponseMapper;
+import com.example.exception.DialogflowClientException;
+
+import com.google.api.gax.rpc.ApiException;
+import com.google.cloud.dialogflow.cx.v3.DetectIntentRequest;
+import com.google.cloud.dialogflow.cx.v3.SessionsClient;
+import com.google.cloud.dialogflow.cx.v3.SessionName;
+import com.google.cloud.dialogflow.cx.v3.SessionsSettings;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Mono;
+
+import javax.annotation.PreDestroy;
+
+import java.io.IOException;
+import java.util.Objects;
+
+@Service
+public class DialogflowClientService {
+
+    private static final Logger logger = LoggerFactory.getLogger(DialogflowClientService.class);
+
+    private final String dialogflowCxProjectId;
+    private final String dialogflowCxLocation;
+    private final String dialogflowCxAgentId;
+
+    private final DialogflowRequestMapper dialogflowRequestMapper;
+    private final DialogflowResponseMapper dialogflowResponseMapper;
+    private SessionsClient sessionsClient;
+    
+    public DialogflowClientService(
+
+        @org.springframework.beans.factory.annotation.Value("${dialogflow.cx.project-id}") String dialogflowCxProjectId,
+        @org.springframework.beans.factory.annotation.Value("${dialogflow.cx.location}") String dialogflowCxLocation,
+        @org.springframework.beans.factory.annotation.Value("${dialogflow.cx.agent-id}") String dialogflowCxAgentId,
+        DialogflowRequestMapper dialogflowRequestMapper,
+        DialogflowResponseMapper dialogflowResponseMapper)
+        throws IOException {
+
+        this.dialogflowCxProjectId = dialogflowCxProjectId;
+        this.dialogflowCxLocation = dialogflowCxLocation;
+        this.dialogflowCxAgentId = dialogflowCxAgentId;
+        this.dialogflowRequestMapper = dialogflowRequestMapper;
+        this.dialogflowResponseMapper = dialogflowResponseMapper;
+
+        try {
+            String regionalEndpoint = String.format("%s-dialogflow.googleapis.com:443", dialogflowCxLocation);
+            SessionsSettings sessionsSettings = SessionsSettings.newBuilder()
+                .setEndpoint(regionalEndpoint)
+                .build();
+            this.sessionsClient = SessionsClient.create(sessionsSettings);
+            logger.info("Dialogflow CX SessionsClient initialized successfully for endpoint: {}", regionalEndpoint);
+        } catch (IOException e) {
+            logger.error("Failed to create Dialogflow CX SessionsClient: {}", e.getMessage(), e);
+            throw e;
+        }
+    }
+
+    @PreDestroy
+    public void closeSessionsClient() {
+        if (sessionsClient != null) {
+            sessionsClient.close();
+            logger.info("Dialogflow CX SessionsClient closed.");
+        }
+    }
+
+    public Mono<DetectIntentResponseDTO> detectIntent(
+            String sessionId,
+            DetectIntentRequestDTO request) {
+
+        Objects.requireNonNull(sessionId, "Dialogflow session ID cannot be null.");
+        Objects.requireNonNull(request, "Dialogflow request DTO cannot be null.");
+
+        logger.info("Initiating detectIntent for session: {}", sessionId);
+
+        DetectIntentRequest.Builder detectIntentRequestBuilder;
+        try {
+            detectIntentRequestBuilder = dialogflowRequestMapper.mapToDetectIntentRequestBuilder(request);
+            logger.debug("Obtained partial DetectIntentRequest.Builder from mapper for session: {}", sessionId);
+        } catch (IllegalArgumentException e) {
+            logger.error(" Failed to map DTO to partial Protobuf request for session {}: {}", sessionId, e.getMessage());
+            return Mono.error(new IllegalArgumentException("Invalid Dialogflow request input: " + e.getMessage()));
+        }
+
+        SessionName sessionName = SessionName.newBuilder()
+                .setProject(dialogflowCxProjectId)
+                .setLocation(dialogflowCxLocation)
+                .setAgent(dialogflowCxAgentId)
+                .setSession(sessionId)
+                .build();
+        detectIntentRequestBuilder.setSession(sessionName.toString());
+        logger.debug("Set session path {} on the request builder for session: {}", sessionName.toString(), sessionId);
+
+        // Build the final DetectIntentRequest Protobuf object
+        DetectIntentRequest detectIntentRequest = detectIntentRequestBuilder.build();
+
+        return Mono.fromCallable(() -> {
+            logger.debug("Calling Dialogflow CX detectIntent for session: {}", sessionId);
+            return sessionsClient.detectIntent(detectIntentRequest);
+        })
+        .onErrorMap(ApiException.class, e -> {
+            logger.error("Dialogflow CX API error for session {}: status={}, message={}",
+                    sessionId, e.getStatusCode().getCode(), e.getMessage(), e);
+            return new DialogflowClientException(
+                    "Dialogflow CX API error: " + e.getStatusCode().getCode() + " - " + e.getMessage(), e);
+        })
+        .onErrorMap(IOException.class, e -> {
+            logger.error("IO error when calling Dialogflow CX for session {}: {}", sessionId, e.getMessage(),e);
+            return new RuntimeException("IO error with Dialogflow CX API: " + e.getMessage(), e);
+        })
+        .map(dfResponse -> this.dialogflowResponseMapper.mapFromDialogflowResponse(dfResponse, sessionId));
+    }
+}