Added Reconcilation Report Generation Fetaure

pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <parent>
         <groupId>org.springframework.boot</groupId>
@@ -16,7 +16,30 @@
     <description>Demo project for Spring Boot</description>
     <properties>
         <java.version>17</java.version>
+        <langgraph4j.version>1.7.0-beta2</langgraph4j.version>
+        <langchain4j.version>0.33.0</langchain4j.version>
     </properties>
+    <dependencyManagement>
+        <dependencies>
+            <!-- LangGraph4j BOM -->
+            <dependency>
+                <groupId>org.bsc.langgraph4j</groupId>
+                <artifactId>langgraph4j-bom</artifactId>
+                <version>${langgraph4j.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+
+            <!-- LangChain4j BOM -->
+            <dependency>
+                <groupId>dev.langchain4j</groupId>
+                <artifactId>langchain4j-bom</artifactId>
+                <version>${langchain4j.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
     <dependencies>
         <dependency>
             <groupId>org.projectlombok</groupId>
@@ -145,6 +168,25 @@
             <scope>runtime</scope>
             <optional>true</optional>
         </dependency>
+        <!-- LangGraph4j -->
+        <dependency>
+            <groupId>org.bsc.langgraph4j</groupId>
+            <artifactId>langgraph4j-core</artifactId>
+        </dependency>
+
+        <!-- LangChain4j -->
+        <dependency>
+            <groupId>dev.langchain4j</groupId>
+            <artifactId>langchain4j-core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>dev.langchain4j</groupId>
+            <artifactId>langchain4j-open-ai</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>dev.langchain4j</groupId>
+            <artifactId>langchain4j</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/com/webapp/bankingportal/config/LLMConfig.java

@@ -0,0 +1,28 @@
+package com.webapp.bankingportal.config;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import dev.langchain4j.model.openai.OpenAiChatModel;
+
+@Configuration
+public class LLMConfig {
+
+    @Value("${groq.api.key}")
+    private String apiKey;
+
+    @Value("${groq.api.model}")
+    private String modelName;
+
+    @Value("${groq.api.endpoint}")
+    private String baseUrl;
+
+    @Bean
+    public OpenAiChatModel openAiChatModel() {
+        return OpenAiChatModel.builder()
+                .apiKey(apiKey)
+                .baseUrl(baseUrl)
+                .modelName(modelName)
+                .build();
+    }
+}

src/main/java/com/webapp/bankingportal/controller/WorkFlowController.java

@@ -0,0 +1,35 @@
+package com.webapp.bankingportal.controller;
+
+import com.webapp.bankingportal.workflow.graph.GraphBuilder;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api/workflow")
+public class WorkFlowController {
+
+    private final GraphBuilder graphBuilder;
+
+    public WorkFlowController(GraphBuilder graphBuilder) {
+        this.graphBuilder = graphBuilder;
+    }
+
+    /**
+     * Run the reconciliation workflow end-to-end.
+     * Example: GET /api/workflow/run
+     */
+    @GetMapping("/run")
+    public ResponseEntity<String> runWorkflow() {
+        try {
+            graphBuilder.runGraph();
+            return ResponseEntity.ok("Workflow executed successfully");
+        } catch (Exception e) {
+            e.printStackTrace();
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body("Workflow execution failed: " + e.getMessage());
+        }
+    }
+}

src/main/java/com/webapp/bankingportal/service/EmailService.java

@@ -2,6 +2,7 @@
 
 import java.util.concurrent.CompletableFuture;
 
+import com.webapp.bankingportal.dto.UserResponse;
 import org.springframework.scheduling.annotation.Async;
 
 public interface EmailService {
@@ -14,4 +15,8 @@ public interface EmailService {
     public String getOtpLoginEmailTemplate(String name, String accountNumber, String otp);
 
     public String getBankStatementEmailTemplate(String name, String statementText);
+
+    String getReconciliationReportTemplate(String user,
+                                           String introSentence,
+                                           String reportContent);
 }

src/main/java/com/webapp/bankingportal/service/EmailServiceImpl.java

@@ -3,6 +3,7 @@
 import java.io.File;
 import java.util.concurrent.CompletableFuture;
 
+import com.webapp.bankingportal.dto.UserResponse;
 import org.springframework.mail.MailException;
 import org.springframework.mail.javamail.JavaMailSender;
 import org.springframework.mail.javamail.MimeMessageHelper;
@@ -102,7 +103,7 @@ public String getOtpLoginEmailTemplate(String name, String accountNumber, String
 
     @Override
     public String getBankStatementEmailTemplate(String name, String statementText) {
-         return "<div style=\"font-family: Arial, sans-serif; padding: 20px;\">" +
+        return "<div style=\"font-family: Arial, sans-serif; padding: 20px;\">" +
                 "<h2>Bank Statement</h2>" +
                 "<p>Dear " + name + ",</p>" +
                 "<p>Here is your latest bank statement:</p>" +
@@ -113,6 +114,25 @@ public String getBankStatementEmailTemplate(String name, String statementText) {
                 "</div>";
     }
 
+    public String getReconciliationReportTemplate(String user,
+                                                  String introSentence,
+                                                  String reportContent) {
+        return """
+                <html>
+                  <body style="font-family: Arial, sans-serif;">
+                    <h2>Dear %s,</h2>
+                    <p>%s</p>
+                    <h3>Your Reconciliation Report</h3>
+                    <pre style="background-color:#f4f4f4;padding:10px;border:1px solid #ddd;">
+                    %s
+                    </pre>
+                    <p>Thank you for banking with OneStopBank.</p>
+                    <p>Regards,<br/>OneStopBank Team</p>
+                  </body>
+                </html>
+                """.formatted(user, introSentence, reportContent);
+    }
+
     public void sendEmailWithAttachment(String to, String subject, String text, String attachmentFilePath) {
         try {
             val message = mailSender.createMimeMessage();

src/main/java/com/webapp/bankingportal/workflow/graph/GraphBuilder.java

@@ -0,0 +1,69 @@
+package com.webapp.bankingportal.workflow.graph;
+
+import com.webapp.bankingportal.workflow.nodes.MailReportNode;
+import com.webapp.bankingportal.workflow.nodes.ReportGenerationNode;
+import com.webapp.bankingportal.workflow.nodes.TransactionFetchNode;
+import com.webapp.bankingportal.workflow.state.ReconState;
+import org.bsc.langgraph4j.GraphStateException;
+import org.bsc.langgraph4j.StateGraph;
+import org.bsc.langgraph4j.CompiledGraph;
+
+import static org.bsc.langgraph4j.StateGraph.START;
+import static org.bsc.langgraph4j.StateGraph.END;
+import static org.bsc.langgraph4j.action.AsyncNodeAction.node_async;
+
+import java.util.Map;
+
+import com.webapp.bankingportal.service.DashboardService;
+import com.webapp.bankingportal.service.EmailService;
+import com.webapp.bankingportal.service.TransactionService;
+import dev.langchain4j.model.openai.OpenAiChatModel;
+import org.springframework.stereotype.Component;
+
+@Component
+public class GraphBuilder {
+
+    private final TransactionService transactionService;
+    private final DashboardService dashboardService;
+    private final EmailService emailService;
+    private final OpenAiChatModel chatModel;
+
+    public GraphBuilder(TransactionService transactionService,
+                        DashboardService dashboardService,
+                        EmailService emailService,
+                        OpenAiChatModel chatModel) {
+        this.transactionService = transactionService;
+        this.dashboardService = dashboardService;
+        this.emailService = emailService;
+        this.chatModel = chatModel;
+    }
+
+    /** Build and return the compiled graph */
+    public CompiledGraph<ReconState> buildGraph() throws GraphStateException {
+        var fetchNode = new TransactionFetchNode(transactionService, dashboardService);
+        var reportNode = new ReportGenerationNode(chatModel);
+        var mailNode = new MailReportNode(emailService);
+
+        var stateGraph = new StateGraph<>(
+                ReconState.SCHEMA,
+                ReconState::new
+        )
+                .addNode("fetchTransactions", node_async(fetchNode))
+                .addNode("generateReport", node_async(reportNode))
+                .addNode("mailReport", node_async(mailNode))
+                .addEdge(START, "fetchTransactions")
+                .addEdge("fetchTransactions", "generateReport")
+                .addEdge("generateReport", "mailReport")
+                .addEdge("mailReport", END);
+
+        return stateGraph.compile();
+    }
+
+    /** Run the compiled graph */
+    public void runGraph() throws GraphStateException {
+        var compiled = buildGraph();
+        for (var item : compiled.stream(Map.of())) {
+            System.out.println("State after step: " + item);
+        }
+    }
+}

src/main/java/com/webapp/bankingportal/workflow/nodes/MailReportNode.java

@@ -0,0 +1,48 @@
+package com.webapp.bankingportal.workflow.nodes;
+
+import com.webapp.bankingportal.service.EmailService;
+import com.webapp.bankingportal.workflow.state.ReconState;
+import org.bsc.langgraph4j.action.NodeAction;
+
+import java.util.*;
+
+// --- Node 3: Mail Report ---
+public class MailReportNode implements NodeAction<ReconState> {
+
+    private final EmailService emailService;
+
+    // Constructor injection (instead of @Autowired for clarity in workflow wiring)
+    public MailReportNode(EmailService emailService) {
+        this.emailService = emailService;
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public Map<String, Object> apply(ReconState state) {
+        String report = state.report().orElse("No report generated");
+        String account = state.accountNumber().orElse("UNKNOWN");
+
+        // Because USER_KEY uses an appender channel, unwrap the list and take the latest map
+        List<Map<String, String>> userList = (List<Map<String, String>>) state.value(ReconState.USER_KEY)
+                .orElseThrow(() -> new IllegalStateException("User info not found in state"));
+
+        Map<String, String> userMap = userList.get(userList.size() - 1);
+
+        String email = userMap.getOrDefault("email", "[email protected]");
+        String name  = userMap.getOrDefault("name", "Customer");
+
+        // Build email body using template
+        String emailBody = emailService.getReconciliationReportTemplate(
+                name,
+                "Here is your latest reconciliation report for account " + account + ".",
+                report
+        );
+
+        // Send email
+        emailService.sendEmail(email, "Your Reconciliation Report - OneStopBank", emailBody);
+
+        System.out.println("Mailing report for account " + account + " to " + email);
+
+        return Map.of();
+    }
+}

src/main/java/com/webapp/bankingportal/workflow/nodes/ReportGenerationNode.java

@@ -0,0 +1,65 @@
+package com.webapp.bankingportal.workflow.nodes;
+
+import com.webapp.bankingportal.workflow.state.ReconState;
+import dev.langchain4j.model.openai.OpenAiChatModel;
+import org.bsc.langgraph4j.action.NodeAction;
+
+import java.util.*;
+
+// --- Node 2: Report Generation with LLM ---
+public class ReportGenerationNode implements NodeAction<ReconState> {
+    private final OpenAiChatModel model;
+
+    public ReportGenerationNode(OpenAiChatModel model) {
+        this.model = model;
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public Map<String, Object> apply(ReconState state) {
+        // Transactions are stored as List<String>
+        List<String> txns = (List<String>) state.value(ReconState.TXNS_KEY)
+                .orElse(List.of());
+        String account = state.accountNumber().orElse("UNKNOWN");
+
+        // Join the stringified transactions into one block
+        String txnSummary = String.join("\n", txns);
+
+        String prompt = """
+You are a financial reconciliation assistant. 
+Generate a clear, easy-to-read reconciliation report for account %s based on the following transactions:
+
+%s
+
+Rules for formatting and tone:
+1. Do NOT use markdown symbols like **, ##, or bullet markers (*, -). 
+   Use plain text headings such as "Balance Check", "Narrative", "Alerts", "Trends", "Summary".
+2. Do NOT include technical details like transaction IDs, codes, or field names. 
+   Just describe deposits and withdrawals in plain, everyday language.
+3. Balance Check:
+   - Show opening balance (if available), total deposits, total withdrawals, and closing balance.
+   - If the math doesn’t add up, clearly flag it.
+4. Narrative:
+   - Tell the story of the day in natural language, like a diary. 
+   Example: "You added ₹10,000 in the morning, withdrew ₹2,000 at lunch, and sent ₹5,000 in the evening. That left you with ₹53,700."
+5. Alerts:
+   - If any withdrawal is larger than ₹10,000, add: "Heads up, you withdrew a large amount today."
+   - If balance drops below ₹1,000, add: "Low balance warning."
+6. Trends:
+   - Provide weekly or monthly summaries in plain language. 
+   Example: "This week you deposited ₹25,000 and withdrew ₹18,000. Net savings: ₹7,000."
+7. Overall Summary:
+   - End with a simple, encouraging statement about the account’s health and spending habits.
+8. Make the tone friendly, professional, and easy for a non-technical person to understand.
+""".formatted(account, txnSummary);
+
+
+
+        // Call LLM
+        String report = model.generate(prompt);
+
+        System.out.println("Generated report:\n" + report);
+
+        return Map.of(ReconState.REPORT_KEY, report);
+    }
+}