initial commit

src/main/java/com/rit/whatsapp/WhatsappBotApplication.java

@@ -0,0 +1,13 @@
+package com.rit.whatsapp;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class WhatsappBotApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(WhatsappBotApplication.class, args);
+	}
+
+}

src/main/java/com/rit/whatsapp/controller/WebhookController.java

@@ -0,0 +1,178 @@
+package com.rit.whatsapp.controller;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.rit.whatsapp.handler.GrievanceHandler;
+import com.rit.whatsapp.handler.LoginHandler;
+import com.rit.whatsapp.handler.StudentMenuHandler;
+import com.rit.whatsapp.model.UserState;
+import com.rit.whatsapp.service.SessionService;
+import com.rit.whatsapp.service.WhatsAppMessageService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+@RestController
+@RequestMapping("/webhook")
+public class WebhookController {
+
+    @Value("${whatsapp.verify-token:my_secure_verify_token}")
+    private String verifyToken;
+
+    private final WhatsAppMessageService messageService;
+    private final SessionService sessionService;
+    private final StudentMenuHandler studentMenuHandler;
+    private final GrievanceHandler grievanceHandler;
+    private final LoginHandler loginHandler;
+    private final ObjectMapper objectMapper;
+
+    @Autowired
+    public WebhookController(WhatsAppMessageService messageService, 
+                             SessionService sessionService,
+                             StudentMenuHandler studentMenuHandler,
+                             GrievanceHandler grievanceHandler,
+                             LoginHandler loginHandler) {
+        this.messageService = messageService;
+        this.sessionService = sessionService;
+        this.studentMenuHandler = studentMenuHandler;
+        this.grievanceHandler = grievanceHandler;
+        this.loginHandler = loginHandler;
+        this.objectMapper = new ObjectMapper();
+    }
+
+    @GetMapping
+    public ResponseEntity<String> verifyWebhook(
+            @RequestParam(name = "hub.mode", required = false) String mode,
+            @RequestParam(name = "hub.verify_token", required = false) String token,
+            @RequestParam(name = "hub.challenge", required = false) String challenge) {
+
+        if ("subscribe".equals(mode) && verifyToken.equals(token)) {
+            return ResponseEntity.ok(challenge);
+        } else {
+            return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
+        }
+    }
+
+    @PostMapping
+    public ResponseEntity<String> receiveMessage(@RequestBody String payload) {
+        System.out.println("Received Webhook Payload: " + payload);
+        try {
+            JsonNode rootNode = objectMapper.readTree(payload);
+            
+            if (rootNode.has("entry") && rootNode.get("entry").isArray()) {
+                JsonNode entryNode = rootNode.get("entry").get(0);
+                
+                if (entryNode.has("changes") && entryNode.get("changes").isArray()) {
+                    JsonNode changesNode = entryNode.get("changes").get(0);
+                    JsonNode valueNode = changesNode.get("value");
+                    
+                    if (valueNode != null && valueNode.has("messages") && valueNode.get("messages").isArray()) {
+                        JsonNode messageNode = valueNode.get("messages").get(0);
+                        
+                        String fromPhoneNumber = messageNode.get("from").asText();
+                        String messageType = messageNode.get("type").asText();
+                        
+                        UserState currentState = sessionService.getUserState(fromPhoneNumber);
+                        boolean isAuthenticated = sessionService.isAuthenticated(fromPhoneNumber);
+
+                        // Global reset command
+                        if ("text".equals(messageType) && messageNode.get("text").get("body").asText().trim().equalsIgnoreCase("reset")) {
+                            sessionService.resetState(fromPhoneNumber);
+                            if (isAuthenticated) {
+                                studentMenuHandler.sendMainMenu(fromPhoneNumber);
+                            } else {
+                                loginHandler.startLoginFlow(fromPhoneNumber);
+                            }
+                            return ResponseEntity.ok("EVENT_RECEIVED");
+                        }
+
+                        // Route unauthenticated users strictly to Login Flow
+                        if (!isAuthenticated) {
+                            if ("text".equals(messageType)) {
+                                String body = messageNode.get("text").get("body").asText();
+                                handleUnauthenticatedUser(fromPhoneNumber, body, currentState);
+                            } else {
+                                // If they send a sticker/image/etc before logging in, force login
+                                handleUnauthenticatedUser(fromPhoneNumber, "", currentState);
+                            }
+                            return ResponseEntity.ok("EVENT_RECEIVED");
+                        }
+
+                        // Authenticated users flow
+                        if ("text".equals(messageType)) {
+                            String messageBody = messageNode.get("text").get("body").asText();
+                            handleAuthenticatedTextMessage(fromPhoneNumber, messageBody, currentState);
+                        } else if ("interactive".equals(messageType)) {
+                            JsonNode interactiveNode = messageNode.get("interactive");
+                            String interactiveType = interactiveNode.get("type").asText();
+                            
+                            if ("list_reply".equals(interactiveType)) {
+                                String selectedListId = interactiveNode.get("list_reply").get("id").asText();
+                                handleInteractiveListSelection(fromPhoneNumber, selectedListId, currentState);
+                            } else if ("button_reply".equals(interactiveType)) {
+                                String selectedButtonId = interactiveNode.get("button_reply").get("id").asText();
+                                handleInteractiveButtonSelection(fromPhoneNumber, selectedButtonId, currentState);
+                            }
+                        }
+                    }
+                }
+            }
+        } catch (Exception e) {
+            System.err.println("Error processing webhook payload: " + e.getMessage());
+        }
+        
+        return ResponseEntity.ok("EVENT_RECEIVED");
+    }
+
+    private void handleUnauthenticatedUser(String phoneNumber, String messageBody, UserState currentState) {
+        switch (currentState) {
+            case AWAITING_LOGIN_ID:
+                loginHandler.handleLoginIdInput(phoneNumber, messageBody);
+                break;
+            case AWAITING_LOGIN_PASSCODE:
+                loginHandler.handlePasscodeInput(phoneNumber, messageBody);
+                break;
+            default:
+                // Trigger the start of the login flow
+                loginHandler.startLoginFlow(phoneNumber);
+                break;
+        }
+    }
+
+    private void handleAuthenticatedTextMessage(String phoneNumber, String messageBody, UserState currentState) {
+        switch (currentState) {
+            case AWAITING_GRIEVANCE_DESC:
+                grievanceHandler.handleGrievanceDescription(phoneNumber, messageBody);
+                break;
+            case MAIN_MENU:
+            default:
+                // Fallback to main menu
+                studentMenuHandler.sendMainMenu(phoneNumber);
+                break;
+        }
+    }
+
+    private void handleInteractiveListSelection(String phoneNumber, String selectedListId, UserState currentState) {
+        if (currentState == UserState.MAIN_MENU) {
+            studentMenuHandler.handleMenuSelection(phoneNumber, selectedListId);
+        } else {
+            studentMenuHandler.sendMainMenu(phoneNumber);
+        }
+    }
+
+    private void handleInteractiveButtonSelection(String phoneNumber, String selectedButtonId, UserState currentState) {
+        if ("student_logout".equals(selectedButtonId)) {
+            sessionService.logoutUser(phoneNumber);
+            messageService.sendMessage(phoneNumber, "You have been logged out successfully. Type 'Hi' to log in again.");
+            return;
+        }
+
+        if (currentState == UserState.AWAITING_GRIEVANCE_CATEGORY) {
+            grievanceHandler.handleCategorySelection(phoneNumber, selectedButtonId);
+        } else {
+            studentMenuHandler.sendMainMenu(phoneNumber);
+        }
+    }
+}

src/main/java/com/rit/whatsapp/handler/GrievanceHandler.java

@@ -0,0 +1,71 @@
+package com.rit.whatsapp.handler;
+
+import com.rit.whatsapp.model.UserState;
+import com.rit.whatsapp.service.SessionService;
+import com.rit.whatsapp.service.WhatsAppMessageBuilder;
+import com.rit.whatsapp.service.WhatsAppMessageService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+@Component
+public class GrievanceHandler {
+
+    private final WhatsAppMessageService messageService;
+    private final SessionService sessionService;
+
+    @Autowired
+    public GrievanceHandler(WhatsAppMessageService messageService, SessionService sessionService) {
+        this.messageService = messageService;
+        this.sessionService = sessionService;
+    }
+
+    public void startGrievanceFlow(String phoneNumber) {
+        sessionService.setUserState(phoneNumber, UserState.AWAITING_GRIEVANCE_CATEGORY);
+
+        List<Map<String, String>> buttons = new ArrayList<>();
+        buttons.add(createButton("grievance_academic", "Academic"));
+        buttons.add(createButton("grievance_hostel", "Hostel"));
+        buttons.add(createButton("grievance_other", "Other"));
+
+        Map<String, Object> buttonMessage = WhatsAppMessageBuilder.buildButtonMessage(
+                "Please select the category for your grievance:",
+                buttons
+        );
+
+        messageService.sendInteractiveMessage(phoneNumber, buttonMessage);
+    }
+
+    public void handleCategorySelection(String phoneNumber, String selectedCategory) {
+        sessionService.setUserState(phoneNumber, UserState.AWAITING_GRIEVANCE_DESC);
+        messageService.sendMessage(phoneNumber, "You selected " + selectedCategory + ". Please type a brief description of your issue:");
+    }
+
+    public void handleGrievanceDescription(String phoneNumber, String description) {
+        // Generate a mock ticket ID
+        String ticketId = "TKT-" + UUID.randomUUID().toString().substring(0, 6).toUpperCase();
+        
+        String confirmationMessage = "Thank you. Your grievance has been recorded.\n\n" +
+                "Ticket ID: *" + ticketId + "*\n" +
+                "Department Notified: Yes\n" +
+                "Status: Open\n\n" +
+                "You can check the status of this ticket anytime using the main menu.";
+
+        messageService.sendMessage(phoneNumber, confirmationMessage);
+        
+        // Reset state back to main menu
+        sessionService.resetState(phoneNumber);
+    }
+
+    private Map<String, String> createButton(String id, String title) {
+        Map<String, String> btn = new HashMap<>();
+        btn.put("id", id);
+        btn.put("title", title);
+        return btn;
+    }
+}

src/main/java/com/rit/whatsapp/handler/LoginHandler.java

@@ -0,0 +1,64 @@
+package com.rit.whatsapp.handler;
+
+import com.rit.whatsapp.model.UserState;
+import com.rit.whatsapp.service.ImsApiService;
+import com.rit.whatsapp.service.SessionService;
+import com.rit.whatsapp.service.WhatsAppMessageService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class LoginHandler {
+
+    private final WhatsAppMessageService messageService;
+    private final SessionService sessionService;
+    private final ImsApiService imsApiService;
+    private final StudentMenuHandler studentMenuHandler;
+
+    @Autowired
+    public LoginHandler(WhatsAppMessageService messageService, 
+                        SessionService sessionService, 
+                        ImsApiService imsApiService,
+                        StudentMenuHandler studentMenuHandler) {
+        this.messageService = messageService;
+        this.sessionService = sessionService;
+        this.imsApiService = imsApiService;
+        this.studentMenuHandler = studentMenuHandler;
+    }
+
+    public void startLoginFlow(String phoneNumber) {
+        sessionService.setUserState(phoneNumber, UserState.AWAITING_LOGIN_ID);
+        messageService.sendMessage(phoneNumber, "Welcome to RIT Digital Assistant! 🎓\n\nPlease enter your IMS User ID to login:");
+    }
+
+    public void handleLoginIdInput(String phoneNumber, String imsId) {
+        sessionService.setTempLoginId(phoneNumber, imsId);
+        sessionService.setUserState(phoneNumber, UserState.AWAITING_LOGIN_PASSCODE);
+        messageService.sendMessage(phoneNumber, "Thanks. Now, please enter your IMS Passcode:");
+    }
+
+    public void handlePasscodeInput(String phoneNumber, String passcode) {
+        String imsId = sessionService.getTempLoginId(phoneNumber);
+        
+        messageService.sendMessage(phoneNumber, "Authenticating with IMS... ⏳");
+
+        String imsSessionToken = imsApiService.authenticate(imsId, passcode);
+
+        if (imsSessionToken != null) {
+            // Authentication successful
+            sessionService.authenticateUser(phoneNumber, imsId, passcode, imsSessionToken);
+            sessionService.clearTempLoginId(phoneNumber);
+            sessionService.resetState(phoneNumber); // Reset the flow state
+            
+            messageService.sendMessage(phoneNumber, "✅ Login Successful!");
+            
+            // Show the main menu
+            studentMenuHandler.sendMainMenu(phoneNumber);
+        } else {
+            // Authentication failed
+            sessionService.clearTempLoginId(phoneNumber);
+            sessionService.setUserState(phoneNumber, UserState.AWAITING_LOGIN_ID);
+            messageService.sendMessage(phoneNumber, "❌ Login Failed. Invalid ID or Passcode. Please try again.\n\nEnter your IMS User ID:");
+        }
+    }
+}

src/main/java/com/rit/whatsapp/handler/StudentMenuHandler.java

@@ -0,0 +1,117 @@
+package com.rit.whatsapp.handler;
+
+import com.rit.whatsapp.model.UserState;
+import com.rit.whatsapp.service.ImsApiService;
+import com.rit.whatsapp.service.SessionService;
+import com.rit.whatsapp.service.WhatsAppMessageBuilder;
+import com.rit.whatsapp.service.WhatsAppMessageService;
+import com.rit.whatsapp.util.MessageFormatter;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@Component
+public class StudentMenuHandler {
+
+    private final WhatsAppMessageService messageService;
+    private final SessionService sessionService;
+    private final GrievanceHandler grievanceHandler;
+    private final ImsApiService imsApiService;
+
+    @Autowired
+    public StudentMenuHandler(WhatsAppMessageService messageService, 
+                              SessionService sessionService, 
+                              GrievanceHandler grievanceHandler,
+                              ImsApiService imsApiService) {
+        this.messageService = messageService;
+        this.sessionService = sessionService;
+        this.grievanceHandler = grievanceHandler;
+        this.imsApiService = imsApiService;
+    }
+
+    public void sendMainMenu(String phoneNumber) {
+        sessionService.setUserState(phoneNumber, UserState.MAIN_MENU);
+
+        List<Map<String, String>> rows = new ArrayList<>();
+        rows.add(createRow("student_attendance", "Attendance", "Overall % and Subject-wise"));
+        rows.add(createRow("student_timetable", "Timetable", "Today's classes and Weekly"));
+        rows.add(createRow("student_internal_marks", "Internal marks", "CAT 1, CAT 2, Overall"));
+        rows.add(createRow("student_semester_results", "Semester results", "Latest result and CGPA"));
+        rows.add(createRow("student_fee_details", "Fee details & receipt", "Fee paid, Pending, Due date"));
+        rows.add(createRow("student_academic_calendar", "Academic calendar", "Holidays and Important dates"));
+        rows.add(createRow("student_exam_schedule", "Exam schedule", "Upcoming exams and Hall details"));
+        rows.add(createRow("student_circulars", "Circulars & Notices", "Department circulars"));
+        rows.add(createRow("student_raise_grievance", "Raise a grievance \u2B50", "Submit an issue ticket"));
+        rows.add(createRow("student_contact_department", "Contact department", "Faculty mentor, HOD, etc."));
+
+        Map<String, Object> interactiveList = WhatsAppMessageBuilder.buildListMessage(
+                "RIT Digital Assistant",
+                "Welcome to the RITz Student Portal! Please select an option from the menu below.",
+                "Student Menu",
+                rows
+        );
+
+        messageService.sendInteractiveMessage(phoneNumber, interactiveList);
+
+        // Send a separate Logout button since the list is maxed out at 10 items
+        List<Map<String, String>> logoutBtn = new ArrayList<>();
+        Map<String, String> btn = new HashMap<>();
+        btn.put("id", "student_logout");
+        btn.put("title", "Logout");
+        logoutBtn.add(btn);
+
+        Map<String, Object> logoutMessage = WhatsAppMessageBuilder.buildButtonMessage(
+                "Need to switch accounts?",
+                logoutBtn
+        );
+        messageService.sendInteractiveMessage(phoneNumber, logoutMessage);
+    }
+
+    public void handleMenuSelection(String phoneNumber, String selectedOptionId) {
+        String token = sessionService.getImsToken(phoneNumber);
+        if (token == null) {
+            messageService.sendMessage(phoneNumber, "Your session has expired. Please type 'Reset' to login again.");
+            return;
+        }
+
+        switch (selectedOptionId) {
+            case "student_attendance":
+                String rawAttendance = imsApiService.getAttendance(token);
+                messageService.sendMessage(phoneNumber, MessageFormatter.formatAttendance(rawAttendance));
+                break;
+                
+            case "student_timetable":
+                String rawTimetable = imsApiService.getTimetable(token);
+                messageService.sendMessage(phoneNumber, MessageFormatter.formatTimetable(rawTimetable));
+                break;
+                
+            case "student_semester_results":
+                // Defaulting to semester 1 for now
+                String rawResults = imsApiService.getResults(token, 1);
+                messageService.sendMessage(phoneNumber, MessageFormatter.formatResults(rawResults, 1));
+                break;
+
+            case "student_raise_grievance":
+                grievanceHandler.startGrievanceFlow(phoneNumber);
+                break;
+                
+            default:
+                messageService.sendMessage(phoneNumber, "You selected an option that is currently under development. Please check back later!");
+                // Resend main menu
+                sendMainMenu(phoneNumber);
+                break;
+        }
+    }
+
+    private Map<String, String> createRow(String id, String title, String description) {
+        Map<String, String> row = new HashMap<>();
+        row.put("id", id);
+        row.put("title", title);
+        row.put("description", description);
+        return row;
+    }
+}

src/main/java/com/rit/whatsapp/model/UserEntity.java

@@ -0,0 +1,50 @@
+package com.rit.whatsapp.model;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+
+@Entity
+@Table(name = "users")
+public class UserEntity {
+
+    @Id
+    private String phoneNumber;
+    
+    private String imsId;
+    
+    private String encryptedPasscode;
+
+    public UserEntity() {
+    }
+
+    public UserEntity(String phoneNumber, String imsId, String encryptedPasscode) {
+        this.phoneNumber = phoneNumber;
+        this.imsId = imsId;
+        this.encryptedPasscode = encryptedPasscode;
+    }
+
+    public String getPhoneNumber() {
+        return phoneNumber;
+    }
+
+    public void setPhoneNumber(String phoneNumber) {
+        this.phoneNumber = phoneNumber;
+    }
+
+    public String getImsId() {
+        return imsId;
+    }
+
+    public void setImsId(String imsId) {
+        this.imsId = imsId;
+    }
+
+    public String getEncryptedPasscode() {
+        return encryptedPasscode;
+    }
+
+    public void setEncryptedPasscode(String encryptedPasscode) {
+        this.encryptedPasscode = encryptedPasscode;
+    }
+}

src/main/java/com/rit/whatsapp/model/UserState.java

@@ -0,0 +1,9 @@
+package com.rit.whatsapp.model;
+
+public enum UserState {
+    MAIN_MENU,
+    AWAITING_LOGIN_ID,
+    AWAITING_LOGIN_PASSCODE,
+    AWAITING_GRIEVANCE_CATEGORY,
+    AWAITING_GRIEVANCE_DESC
+}

src/main/java/com/rit/whatsapp/repository/UserRepository.java

@@ -0,0 +1,9 @@
+package com.rit.whatsapp.repository;
+
+import com.rit.whatsapp.model.UserEntity;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface UserRepository extends JpaRepository<UserEntity, String> {
+}

src/main/java/com/rit/whatsapp/service/ImsApiService.java

@@ -0,0 +1,105 @@
+package com.rit.whatsapp.service;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Service
+public class ImsApiService {
+
+    private final String BASE_URL = "https://ims-api.sidharthprabhu.co.in";
+    private final RestTemplate restTemplate;
+    private final ObjectMapper objectMapper;
+
+    public ImsApiService() {
+        this.restTemplate = new RestTemplate();
+        this.objectMapper = new ObjectMapper();
+    }
+
+    /**
+     * Authenticates the user against the real IMS backend.
+     * @param imsId The user ID
+     * @param passcode The passcode
+     * @return The API session token if successful, null otherwise.
+     */
+    public String authenticate(String imsId, String passcode) {
+        String url = BASE_URL + "/api/auth/login";
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_JSON);
+
+        Map<String, String> requestBody = new HashMap<>();
+        requestBody.put("username", imsId);
+        requestBody.put("password", passcode);
+
+        HttpEntity<Map<String, String>> request = new HttpEntity<>(requestBody, headers);
+
+        try {
+            ResponseEntity<String> response = restTemplate.postForEntity(url, request, String.class);
+            if (response.getStatusCode().is2xxSuccessful() && response.getBody() != null) {
+                JsonNode rootNode = objectMapper.readTree(response.getBody());
+                if (rootNode.has("success") && rootNode.get("success").asBoolean()) {
+                    if (rootNode.has("session")) {
+                        return rootNode.get("session").asText();
+                    }
+                }
+            }
+        } catch (Exception e) {
+            System.err.println("Failed to authenticate with IMS API: " + e.getMessage());
+        }
+        
+        return null;
+    }
+
+    private String fetchFromIms(String endpoint, String token) {
+        String url = BASE_URL + endpoint;
+        HttpHeaders headers = new HttpHeaders();
+        headers.setBearerAuth(token);
+        
+        HttpEntity<String> request = new HttpEntity<>(headers);
+        
+        try {
+            ResponseEntity<String> response = restTemplate.exchange(url, org.springframework.http.HttpMethod.GET, request, String.class);
+            if (response.getStatusCode().is2xxSuccessful()) {
+                return response.getBody();
+            }
+        } catch (Exception e) {
+            System.err.println("Failed to fetch from IMS API (" + endpoint + "): " + e.getMessage());
+        }
+        return null;
+    }
+
+    public String getAttendance(String token) {
+        return fetchFromIms("/api/student/attendance", token);
+    }
+
+    public String getTimetable(String token) {
+        return fetchFromIms("/api/student/timetable", token);
+    }
+
+    public String getResults(String token, int semester) {
+        return fetchFromIms("/api/student/results?semester=" + semester, token);
+    }
+
+    public void logout(String token) {
+        String url = BASE_URL + "/api/auth/logout";
+        HttpHeaders headers = new HttpHeaders();
+        headers.setBearerAuth(token);
+        
+        HttpEntity<String> request = new HttpEntity<>(headers);
+        
+        try {
+            restTemplate.postForEntity(url, request, String.class);
+        } catch (Exception e) {
+            System.err.println("Failed to logout from IMS API: " + e.getMessage());
+        }
+    }
+}

src/main/java/com/rit/whatsapp/service/SessionService.java

@@ -0,0 +1,107 @@
+package com.rit.whatsapp.service;
+
+import com.rit.whatsapp.model.UserEntity;
+import com.rit.whatsapp.model.UserState;
+import com.rit.whatsapp.repository.UserRepository;
+import com.rit.whatsapp.util.EncryptionUtils;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+
+@Service
+public class SessionService {
+
+    private final Map<String, UserState> userStates = new ConcurrentHashMap<>();
+    
+    // In-memory cache for API session tokens
+    private final Map<String, String> sessionTokens = new ConcurrentHashMap<>();
+    private final Map<String, String> temporaryLoginIds = new ConcurrentHashMap<>();
+
+    private final UserRepository userRepository;
+    private final EncryptionUtils encryptionUtils;
+    private final ImsApiService imsApiService;
+
+    @Autowired
+    public SessionService(UserRepository userRepository, 
+                          EncryptionUtils encryptionUtils,
+                          ImsApiService imsApiService) {
+        this.userRepository = userRepository;
+        this.encryptionUtils = encryptionUtils;
+        this.imsApiService = imsApiService;
+    }
+
+    public UserState getUserState(String phoneNumber) {
+        return userStates.getOrDefault(phoneNumber, UserState.MAIN_MENU);
+    }
+
+    public void setUserState(String phoneNumber, UserState state) {
+        userStates.put(phoneNumber, state);
+    }
+    
+    public void resetState(String phoneNumber) {
+        userStates.remove(phoneNumber);
+    }
+
+    public boolean isAuthenticated(String phoneNumber) {
+        if (sessionTokens.containsKey(phoneNumber)) {
+            return true;
+        }
+
+        // Check database for persistent session
+        Optional<UserEntity> userOpt = userRepository.findById(phoneNumber);
+        if (userOpt.isPresent()) {
+            UserEntity user = userOpt.get();
+            String decryptedPasscode = encryptionUtils.decrypt(user.getEncryptedPasscode());
+            
+            // Silent background login
+            String token = imsApiService.authenticate(user.getImsId(), decryptedPasscode);
+            if (token != null) {
+                sessionTokens.put(phoneNumber, token);
+                return true;
+            }
+        }
+        
+        return false;
+    }
+
+    public void authenticateUser(String phoneNumber, String imsId, String passcode, String token) {
+        sessionTokens.put(phoneNumber, token);
+        
+        // Persist to database
+        String encryptedPasscode = encryptionUtils.encrypt(passcode);
+        UserEntity user = new UserEntity(phoneNumber, imsId, encryptedPasscode);
+        userRepository.save(user);
+    }
+
+    public String getImsToken(String phoneNumber) {
+        // Ensure they are authenticated (which populates the token cache if needed)
+        if (isAuthenticated(phoneNumber)) {
+            return sessionTokens.get(phoneNumber);
+        }
+        return null;
+    }
+
+    public void logoutUser(String phoneNumber) {
+        String token = sessionTokens.remove(phoneNumber);
+        if (token != null) {
+            imsApiService.logout(token);
+        }
+        userRepository.deleteById(phoneNumber);
+        resetState(phoneNumber);
+    }
+
+    public void setTempLoginId(String phoneNumber, String tempId) {
+        temporaryLoginIds.put(phoneNumber, tempId);
+    }
+
+    public String getTempLoginId(String phoneNumber) {
+        return temporaryLoginIds.get(phoneNumber);
+    }
+
+    public void clearTempLoginId(String phoneNumber) {
+        temporaryLoginIds.remove(phoneNumber);
+    }
+}

src/main/java/com/rit/whatsapp/service/WhatsAppMessageBuilder.java

@@ -0,0 +1,66 @@
+package com.rit.whatsapp.service;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class WhatsAppMessageBuilder {
+
+    public static Map<String, Object> buildListMessage(String header, String body, String buttonText, List<Map<String, String>> rows) {
+        Map<String, Object> interactive = new HashMap<>();
+        interactive.put("type", "list");
+
+        if (header != null && !header.isEmpty()) {
+            Map<String, Object> headerMap = new HashMap<>();
+            headerMap.put("type", "text");
+            headerMap.put("text", header);
+            interactive.put("header", headerMap);
+        }
+
+        Map<String, Object> bodyMap = new HashMap<>();
+        bodyMap.put("text", body);
+        interactive.put("body", bodyMap);
+
+        Map<String, Object> action = new HashMap<>();
+        action.put("button", buttonText);
+
+        List<Map<String, Object>> sections = new ArrayList<>();
+        Map<String, Object> section = new HashMap<>();
+        section.put("title", "Options"); // Default section title
+        section.put("rows", rows);
+        sections.add(section);
+
+        action.put("sections", sections);
+        interactive.put("action", action);
+
+        return interactive;
+    }
+
+    public static Map<String, Object> buildButtonMessage(String body, List<Map<String, String>> buttons) {
+        Map<String, Object> interactive = new HashMap<>();
+        interactive.put("type", "button");
+
+        Map<String, Object> bodyMap = new HashMap<>();
+        bodyMap.put("text", body);
+        interactive.put("body", bodyMap);
+
+        Map<String, Object> action = new HashMap<>();
+        List<Map<String, Object>> actionButtons = new ArrayList<>();
+
+        for (Map<String, String> btn : buttons) {
+            Map<String, Object> buttonWrapper = new HashMap<>();
+            buttonWrapper.put("type", "reply");
+            Map<String, String> reply = new HashMap<>();
+            reply.put("id", btn.get("id"));
+            reply.put("title", btn.get("title"));
+            buttonWrapper.put("reply", reply);
+            actionButtons.add(buttonWrapper);
+        }
+
+        action.put("buttons", actionButtons);
+        interactive.put("action", action);
+
+        return interactive;
+    }
+}

src/main/java/com/rit/whatsapp/service/WhatsAppMessageService.java

@@ -0,0 +1,68 @@
+package com.rit.whatsapp.service;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Service
+public class WhatsAppMessageService {
+
+    @Value("${whatsapp.api-token}")
+    private String apiToken;
+
+    @Value("${whatsapp.phone-number-id}")
+    private String phoneNumberId;
+
+    private final RestTemplate restTemplate;
+
+    public WhatsAppMessageService() {
+        this.restTemplate = new RestTemplate();
+    }
+
+    public void sendMessage(String toPhoneNumber, String messageText) {
+        Map<String, Object> payload = new HashMap<>();
+        payload.put("messaging_product", "whatsapp");
+        payload.put("to", toPhoneNumber);
+        payload.put("type", "text");
+
+        Map<String, String> textPayload = new HashMap<>();
+        textPayload.put("body", messageText);
+        payload.put("text", textPayload);
+        
+        executePost(payload);
+    }
+
+    public void sendInteractiveMessage(String toPhoneNumber, Map<String, Object> interactiveObject) {
+        Map<String, Object> payload = new HashMap<>();
+        payload.put("messaging_product", "whatsapp");
+        payload.put("to", toPhoneNumber);
+        payload.put("type", "interactive");
+        payload.put("interactive", interactiveObject);
+
+        executePost(payload);
+    }
+
+    private void executePost(Map<String, Object> payload) {
+        String url = "https://graph.facebook.com/v19.0/" + phoneNumberId + "/messages";
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_JSON);
+        headers.setBearerAuth(apiToken);
+
+        HttpEntity<Map<String, Object>> request = new HttpEntity<>(payload, headers);
+
+        try {
+            ResponseEntity<String> response = restTemplate.postForEntity(url, request, String.class);
+            System.out.println("Message sent successfully. Response: " + response.getBody());
+        } catch (Exception e) {
+            System.err.println("Failed to send message: " + e.getMessage());
+        }
+    }
+}

src/main/java/com/rit/whatsapp/util/EncryptionUtils.java

@@ -0,0 +1,43 @@
+package com.rit.whatsapp.util;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import javax.crypto.Cipher;
+import javax.crypto.spec.SecretKeySpec;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
+
+@Component
+public class EncryptionUtils {
+
+    @Value("${bot.encryption.secret}")
+    private String secretKey;
+
+    private static final String ALGORITHM = "AES";
+
+    public String encrypt(String value) {
+        try {
+            SecretKeySpec key = new SecretKeySpec(secretKey.getBytes(StandardCharsets.UTF_8), ALGORITHM);
+            Cipher cipher = Cipher.getInstance(ALGORITHM);
+            cipher.init(Cipher.ENCRYPT_MODE, key);
+            byte[] encryptedValue = cipher.doFinal(value.getBytes(StandardCharsets.UTF_8));
+            return Base64.getEncoder().encodeToString(encryptedValue);
+        } catch (Exception e) {
+            throw new RuntimeException("Error encrypting value", e);
+        }
+    }
+
+    public String decrypt(String value) {
+        try {
+            SecretKeySpec key = new SecretKeySpec(secretKey.getBytes(StandardCharsets.UTF_8), ALGORITHM);
+            Cipher cipher = Cipher.getInstance(ALGORITHM);
+            cipher.init(Cipher.DECRYPT_MODE, key);
+            byte[] decodedValue = Base64.getDecoder().decode(value);
+            byte[] decryptedValue = cipher.doFinal(decodedValue);
+            return new String(decryptedValue, StandardCharsets.UTF_8);
+        } catch (Exception e) {
+            throw new RuntimeException("Error decrypting value", e);
+        }
+    }
+}

src/main/java/com/rit/whatsapp/util/MessageFormatter.java

@@ -0,0 +1,104 @@
+package com.rit.whatsapp.util;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class MessageFormatter {
+
+    private static final ObjectMapper mapper = new ObjectMapper();
+
+    public static String formatAttendance(String rawJson) {
+        if (rawJson == null) return "❌ Failed to retrieve attendance data.";
+        
+        try {
+            JsonNode root = mapper.readTree(rawJson);
+            // Assuming the JSON has an array of subjects or an overall percentage
+            // Since we don't have the exact schema, this is a best-effort template.
+            
+            StringBuilder sb = new StringBuilder();
+            sb.append("\ud83d\udcca *Your Attendance Report*\n\n");
+            
+            if (root.has("overall_percentage")) {
+                sb.append("*Overall Attendance:* ").append(root.get("overall_percentage").asText()).append("% \ud83d\udfe2\n\n");
+            } else {
+                sb.append("*Overall Attendance:* Data unavailable\n\n");
+            }
+            
+            sb.append("*Subject-wise Breakdown:*\n");
+            if (root.has("data") && root.get("data").isArray()) {
+                for (JsonNode subject : root.get("data")) {
+                    String name = subject.has("course_name") ? subject.get("course_name").asText() : "Unknown";
+                    String percentage = subject.has("percentage") ? subject.get("percentage").asText() : "0";
+                    sb.append("- ").append(name).append(": ").append(percentage).append("%\n");
+                }
+            } else {
+                sb.append("- Details not available in this format.\n");
+            }
+            
+            sb.append("\n_Keep up the good work!_");
+            return sb.toString();
+        } catch (Exception e) {
+            return "⚠️ Error formatting attendance data.";
+        }
+    }
+
+    public static String formatTimetable(String rawJson) {
+        if (rawJson == null) return "❌ Failed to retrieve timetable data.";
+        
+        try {
+            JsonNode root = mapper.readTree(rawJson);
+            StringBuilder sb = new StringBuilder();
+            sb.append("\ud83d\uddd3\ufe0f *Today's Classes*\n\n");
+            
+            if (root.has("data") && root.get("data").isArray()) {
+                for (JsonNode classNode : root.get("data")) {
+                    String time = classNode.has("time") ? classNode.get("time").asText() : "TBA";
+                    String course = classNode.has("course_name") ? classNode.get("course_name").asText() : "Unknown";
+                    String room = classNode.has("room") ? classNode.get("room").asText() : "Unknown";
+                    
+                    sb.append("*").append(time).append(":* ").append(course).append(" (Room ").append(room).append(")\n");
+                }
+            } else {
+                sb.append("No classes scheduled for today.\n");
+            }
+            
+            return sb.toString();
+        } catch (Exception e) {
+            return "⚠️ Error formatting timetable data.";
+        }
+    }
+
+    public static String formatResults(String rawJson, int semester) {
+        if (rawJson == null) return "❌ Failed to retrieve semester results.";
+        
+        try {
+            JsonNode root = mapper.readTree(rawJson);
+            StringBuilder sb = new StringBuilder();
+            sb.append("\ud83c\udf93 *Semester ").append(semester).append(" Results*\n\n");
+            
+            boolean passedAll = true;
+            
+            if (root.has("data") && root.get("data").isArray()) {
+                for (JsonNode courseNode : root.get("data")) {
+                    String name = courseNode.has("course_name") ? courseNode.get("course_name").asText() : "Unknown";
+                    String total = courseNode.has("total_mark") ? courseNode.get("total_mark").asText() : "0";
+                    String grade = courseNode.has("grade") ? courseNode.get("grade").asText() : "N/A";
+                    String result = courseNode.has("result") ? courseNode.get("result").asText() : "N/A";
+                    
+                    if (!"PASS".equalsIgnoreCase(result)) {
+                        passedAll = false;
+                    }
+                    
+                    sb.append("*").append(name).append(":* ").append(total).append("/100 (Grade: ").append(grade).append(")\n");
+                }
+            } else {
+                sb.append("No results found for this semester.\n");
+            }
+            
+            sb.append("\n*Result:* ").append(passedAll ? "PASS \ud83c\udf89" : "Arrears \u26a0\ufe0f");
+            return sb.toString();
+        } catch (Exception e) {
+            return "⚠️ Error formatting results data.";
+        }
+    }
+}