add email flows

backend/pom.xml

@@ -96,6 +96,12 @@
             <version>25.3.0</version>
         </dependency>
 
+        <dependency>
+            <groupId>com.resend</groupId>
+            <artifactId>resend-java</artifactId>
+            <version>3.1.0</version>
+        </dependency>
+
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>

backend/src/main/java/com/petshop/backend/controller/AuthController.java

@@ -17,6 +17,7 @@ import com.petshop.backend.repository.UserRepository;
 import com.petshop.backend.security.JwtUtil;
 import com.petshop.backend.service.ActivityLogService;
 import com.petshop.backend.service.AvatarStorageService;
+import com.petshop.backend.service.EmailService;
 import com.petshop.backend.service.PasswordResetService;
 import com.petshop.backend.util.AuthenticationHelper;
 import com.petshop.backend.util.PhoneUtils;
@@ -55,8 +56,9 @@ public class AuthController {
     private final AvatarStorageService avatarStorageService;
     private final ActivityLogService activityLogService;
     private final PasswordResetService passwordResetService;
+    private final EmailService emailService;
 
-    public AuthController(AuthenticationManager authenticationManager, UserRepository userRepository, JwtUtil jwtUtil, PasswordEncoder passwordEncoder, AvatarStorageService avatarStorageService, ActivityLogService activityLogService, PasswordResetService passwordResetService) {
+    public AuthController(AuthenticationManager authenticationManager, UserRepository userRepository, JwtUtil jwtUtil, PasswordEncoder passwordEncoder, AvatarStorageService avatarStorageService, ActivityLogService activityLogService, PasswordResetService passwordResetService, EmailService emailService) {
         this.authenticationManager = authenticationManager;
         this.userRepository = userRepository;
         this.jwtUtil = jwtUtil;
@@ -64,6 +66,7 @@ public class AuthController {
         this.avatarStorageService = avatarStorageService;
         this.activityLogService = activityLogService;
         this.passwordResetService = passwordResetService;
+        this.emailService = emailService;
     }
 
     @PostMapping("/register")
@@ -107,6 +110,8 @@ public class AuthController {
 
         User savedUser = userRepository.save(user);
 
+        emailService.sendWelcome(savedUser);
+
         String token = jwtUtil.generateToken(savedUser);
 
         return ResponseEntity.status(HttpStatus.CREATED).body(new RegisterResponse(

backend/src/main/java/com/petshop/backend/repository/AdoptionRepository.java

@@ -40,4 +40,6 @@ public interface AdoptionRepository extends JpaRepository<Adoption, Long> {
     boolean existsByPet_IdAndAdoptionStatusIgnoreCase(Long petId, String adoptionStatus);
 
     List<Adoption> findByCustomer_IdAndAdoptionStatusIgnoreCase(Long customerId, String adoptionStatus);
+
+    List<Adoption> findByAdoptionDateAndAdoptionStatusIgnoreCase(LocalDate date, String status);
 }

backend/src/main/java/com/petshop/backend/repository/AppointmentRepository.java

@@ -50,4 +50,6 @@ public interface AppointmentRepository extends JpaRepository<Appointment, Long>
 
     @Query("SELECT a FROM Appointment a WHERE (a.appointmentDate < :currentDate OR (a.appointmentDate = :currentDate AND a.appointmentTime < :currentTime)) AND LOWER(a.appointmentStatus) = 'booked'")
     List<Appointment> findPastBookedAppointments(@Param("currentDate") LocalDate currentDate, @Param("currentTime") LocalTime currentTime);
+
+    List<Appointment> findByAppointmentDateAndAppointmentStatusIgnoreCase(LocalDate date, String status);
 }

backend/src/main/java/com/petshop/backend/service/AdoptionService.java

@@ -39,13 +39,15 @@ public class AdoptionService {
     private final UserRepository userRepository;
     private final StoreRepository storeRepository;
     private final SaleRepository saleRepository;
+    private final EmailService emailService;
 
-    public AdoptionService(AdoptionRepository adoptionRepository, PetRepository petRepository, UserRepository userRepository, StoreRepository storeRepository, SaleRepository saleRepository) {
+    public AdoptionService(AdoptionRepository adoptionRepository, PetRepository petRepository, UserRepository userRepository, StoreRepository storeRepository, SaleRepository saleRepository, EmailService emailService) {
         this.adoptionRepository = adoptionRepository;
         this.petRepository = petRepository;
         this.userRepository = userRepository;
         this.storeRepository = storeRepository;
         this.saleRepository = saleRepository;
+        this.emailService = emailService;
     }
 
     public Page<AdoptionResponse> getAllAdoptions(String query, Long customerId, String status, Long storeId, LocalDate date, Pageable pageable) {
@@ -106,6 +108,9 @@ public class AdoptionService {
         if (ADOPTION_STATUS_COMPLETED.equalsIgnoreCase(adoptionStatus)) {
             createSaleForAdoption(adoption, request.getPaymentMethod());
         }
+        if (ADOPTION_STATUS_PENDING.equalsIgnoreCase(adoptionStatus) || ADOPTION_STATUS_COMPLETED.equalsIgnoreCase(adoptionStatus)) {
+            emailService.sendAdoptionConfirmation(adoption);
+        }
         return mapToResponse(adoption);
     }
 
@@ -125,6 +130,7 @@ public class AdoptionService {
                         .orElseThrow(() -> new ResourceNotFoundException("Store not found with id: " + request.getSourceStoreId()))
                 : null;
         boolean wasCompleted = ADOPTION_STATUS_COMPLETED.equalsIgnoreCase(adoption.getAdoptionStatus());
+        String previousStatus = adoption.getAdoptionStatus();
         String adoptionStatus = normalizeAdoptionStatus(request.getAdoptionStatus());
         Long currentPetId = adoption.getPet() != null ? adoption.getPet().getPetId() : null;
         validatePetAvailability(pet, adoption.getAdoptionId(), currentPetId);
@@ -144,6 +150,10 @@ public class AdoptionService {
         if (!wasCompleted && ADOPTION_STATUS_COMPLETED.equalsIgnoreCase(adoptionStatus)) {
             createSaleForAdoption(adoption, request.getPaymentMethod());
         }
+        boolean statusChanged = !adoptionStatus.equalsIgnoreCase(previousStatus);
+        if (statusChanged && (ADOPTION_STATUS_PENDING.equalsIgnoreCase(adoptionStatus) || ADOPTION_STATUS_COMPLETED.equalsIgnoreCase(adoptionStatus))) {
+            emailService.sendAdoptionConfirmation(adoption);
+        }
         return mapToResponse(adoption);
     }
 
@@ -258,7 +268,8 @@ public class AdoptionService {
         sale.setPaymentMethod(paymentMethod != null && !paymentMethod.isBlank() ? paymentMethod : "Cash");
         sale.setIsRefund(false);
         sale.setChannel("ADOPTION");
-        saleRepository.save(sale);
+        Sale savedSale = saleRepository.save(sale);
+        emailService.sendPurchaseReceipt(savedSale);
     }
 
     private void syncPetStatus(Pet pet, String adoptionStatus, Long adoptionId, User customer) {

backend/src/main/java/com/petshop/backend/service/AppointmentService.java

@@ -3,11 +3,13 @@ package com.petshop.backend.service;
 import com.petshop.backend.dto.appointment.AppointmentRequest;
 import com.petshop.backend.dto.appointment.AppointmentResponse;
 import com.petshop.backend.dto.common.BulkDeleteRequest;
+import com.petshop.backend.entity.Adoption;
 import com.petshop.backend.entity.Appointment;
 import com.petshop.backend.entity.Pet;
 import com.petshop.backend.entity.StoreLocation;
 import com.petshop.backend.entity.User;
 import com.petshop.backend.exception.ResourceNotFoundException;
+import com.petshop.backend.repository.AdoptionRepository;
 import com.petshop.backend.repository.AppointmentRepository;
 import com.petshop.backend.repository.PetRepository;
 import com.petshop.backend.repository.ServiceRepository;
@@ -36,13 +38,17 @@ public class AppointmentService {
     private final PetRepository petRepository;
     private final StoreRepository storeRepository;
     private final UserRepository userRepository;
+    private final AdoptionRepository adoptionRepository;
+    private final EmailService emailService;
 
-    public AppointmentService(AppointmentRepository appointmentRepository, ServiceRepository serviceRepository, PetRepository petRepository, StoreRepository storeRepository, UserRepository userRepository) {
+    public AppointmentService(AppointmentRepository appointmentRepository, ServiceRepository serviceRepository, PetRepository petRepository, StoreRepository storeRepository, UserRepository userRepository, AdoptionRepository adoptionRepository, EmailService emailService) {
         this.appointmentRepository = appointmentRepository;
         this.serviceRepository = serviceRepository;
         this.petRepository = petRepository;
         this.storeRepository = storeRepository;
         this.userRepository = userRepository;
+        this.adoptionRepository = adoptionRepository;
+        this.emailService = emailService;
     }
 
     @Transactional(readOnly = true)
@@ -115,6 +121,7 @@ public class AppointmentService {
         appointment.setPet(pet);
 
         appointment = appointmentRepository.save(appointment);
+        emailService.sendAppointmentConfirmation(appointment);
         return mapToResponse(appointment);
     }
 
@@ -152,6 +159,7 @@ public class AppointmentService {
         appointment.setEmployee(employee);
 
         appointment = appointmentRepository.save(appointment);
+        emailService.sendAppointmentConfirmation(appointment);
         return mapToResponse(appointment);
     }
 
@@ -210,7 +218,7 @@ public class AppointmentService {
         return availableSlots;
     }
 
-    //Update booked status to completed at every midnight
+    //Update booked status to completed at every midnight, and send 24h reminders
     @Scheduled(cron = "0 0 0 * * ?")
     @Transactional
     public void updatePastAppointmentsStatus() {
@@ -222,6 +230,20 @@ public class AppointmentService {
             appointment.setAppointmentStatus("COMPLETED");
             appointmentRepository.save(appointment);
         }
+
+        LocalDate tomorrow = currentDate.plusDays(1);
+
+        List<Appointment> tomorrowAppointments = appointmentRepository
+                .findByAppointmentDateAndAppointmentStatusIgnoreCase(tomorrow, "Booked");
+        for (Appointment appointment : tomorrowAppointments) {
+            emailService.sendAppointmentReminder(appointment);
+        }
+
+        List<Adoption> tomorrowAdoptions = adoptionRepository
+                .findByAdoptionDateAndAdoptionStatusIgnoreCase(tomorrow, "Pending");
+        for (Adoption adoption : tomorrowAdoptions) {
+            emailService.sendAdoptionReminder(adoption);
+        }
     }
 
     private String normalizeFilter(String value) {

backend/src/main/java/com/petshop/backend/service/ChatService.java

@@ -31,17 +31,20 @@ public class ChatService {
     private final UserRepository userRepository;
     private final AvatarStorageService avatarStorageService;
     private final ChatAttachmentStorageService attachmentStorageService;
+    private final EmailService emailService;
 
     public ChatService(ConversationRepository conversationRepository,
                       MessageRepository messageRepository,
                       UserRepository userRepository,
                       AvatarStorageService avatarStorageService,
-                      ChatAttachmentStorageService attachmentStorageService) {
+                      ChatAttachmentStorageService attachmentStorageService,
+                      EmailService emailService) {
         this.conversationRepository = conversationRepository;
         this.messageRepository = messageRepository;
         this.userRepository = userRepository;
         this.avatarStorageService = avatarStorageService;
         this.attachmentStorageService = attachmentStorageService;
+        this.emailService = emailService;
     }
 
     @Transactional
@@ -261,13 +264,19 @@ public class ChatService {
         }
 
         conversation.setStatus(Conversation.ConversationStatus.valueOf(request.getStatus()));
-        conversation = conversationRepository.save(conversation);
+        Conversation savedConversation = conversationRepository.save(conversation);
 
         List<Message> messages = messageRepository.findByConversationIdOrderByTimestampAsc(conversationId);
+
+        if (Conversation.ConversationStatus.CLOSED.name().equals(request.getStatus())) {
+            userRepository.findById(savedConversation.getCustomerId()).ifPresent(customer ->
+                    emailService.sendChatTranscript(savedConversation, messages, customer));
+        }
+
         Message last = messages.isEmpty() ? null : messages.get(messages.size() - 1);
         String lastMessage = last != null && last.getContent() != null ? last.getContent() : "";
         Long lastSenderId = last != null ? last.getSenderId() : null;
-        return ConversationResponse.fromEntity(conversation, lastMessage, lastSenderId);
+        return ConversationResponse.fromEntity(savedConversation, lastMessage, lastSenderId);
     }
 
     public List<MessageResponse> getMessages(Long conversationId, Long userId, User.Role role) {

backend/src/main/java/com/petshop/backend/service/EmailService.java

@@ -0,0 +1,308 @@
+package com.petshop.backend.service;
+
+import com.petshop.backend.entity.Adoption;
+import com.petshop.backend.entity.Appointment;
+import com.petshop.backend.entity.Conversation;
+import com.petshop.backend.entity.Message;
+import com.petshop.backend.entity.Sale;
+import com.petshop.backend.entity.SaleItem;
+import com.petshop.backend.entity.User;
+import com.resend.Resend;
+import com.resend.services.emails.model.CreateEmailOptions;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+
+import java.math.BigDecimal;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+@Service
+public class EmailService {
+
+    private static final Logger log = LoggerFactory.getLogger(EmailService.class);
+    private static final DateTimeFormatter DATE_FMT = DateTimeFormatter.ofPattern("MMMM d, yyyy");
+    private static final DateTimeFormatter TIME_FMT = DateTimeFormatter.ofPattern("h:mm a");
+
+    private final Resend resend;
+    private final String from;
+    private final String frontendUrl;
+    private final ActivityLogService activityLogService;
+
+    public EmailService(
+            @Value("${resend.api-key}") String apiKey,
+            @Value("${resend.from}") String from,
+            @Value("${app.frontend-url}") String frontendUrl,
+            ActivityLogService activityLogService) {
+        this.resend = new Resend(apiKey);
+        this.from = from;
+        this.frontendUrl = frontendUrl;
+        this.activityLogService = activityLogService;
+    }
+
+    public void sendWelcome(User user) {
+        if (user.getEmail() == null || user.getEmail().isBlank()) return;
+        String subject = "Welcome to PetShop!";
+        String html = """
+                <div style="font-family:sans-serif;max-width:600px;margin:auto">
+                  <h2>Welcome to PetShop, %s!</h2>
+                  <p>Your account has been created successfully.</p>
+                  <p>You can now log in and start exploring our pets, products, and services.</p>
+                  <p>Thank you for joining us!</p>
+                </div>""".formatted(firstName(user));
+        send(user.getId(), user.getEmail(), subject, html);
+    }
+
+    public void sendPasswordResetLink(User user, String rawToken) {
+        if (user.getEmail() == null || user.getEmail().isBlank()) return;
+        String link = frontendUrl + "/reset-password?token=" + rawToken;
+        String subject = "Reset your PetShop password";
+        String html = """
+                <div style="font-family:sans-serif;max-width:600px;margin:auto">
+                  <h2>Password Reset Request</h2>
+                  <p>Hi %s,</p>
+                  <p>We received a request to reset your password. Click the button below to proceed.</p>
+                  <p><a href="%s" style="background:#2563eb;color:#fff;padding:10px 20px;border-radius:4px;text-decoration:none;display:inline-block">Reset Password</a></p>
+                  <p>This link expires in <strong>30 minutes</strong>. If you did not request a reset, you can safely ignore this email.</p>
+                </div>""".formatted(firstName(user), link);
+        send(user.getId(), user.getEmail(), subject, html);
+    }
+
+    public void sendPurchaseReceipt(Sale sale) {
+        User customer = sale.getCustomer();
+        if (customer == null || customer.getEmail() == null || customer.getEmail().isBlank()) return;
+        String subject = "Your PetShop receipt";
+        String html = buildReceiptHtml(sale);
+        send(customer.getId(), customer.getEmail(), subject, html);
+    }
+
+    public void sendAdoptionConfirmation(Adoption adoption) {
+        User customer = adoption.getCustomer();
+        if (customer != null && customer.getEmail() != null && !customer.getEmail().isBlank()) {
+            String subject = "Your adoption — " + adoption.getPet().getPetName();
+            send(customer.getId(), customer.getEmail(), subject, buildAdoptionHtml(adoption, customer));
+        }
+        User employee = adoption.getEmployee();
+        if (employee != null && employee.getEmail() != null && !employee.getEmail().isBlank()) {
+            String subject = "Adoption assigned — " + adoption.getPet().getPetName();
+            send(employee.getId(), employee.getEmail(), subject, buildAdoptionHtml(adoption, customer));
+        }
+    }
+
+    public void sendAdoptionReminder(Adoption adoption) {
+        User customer = adoption.getCustomer();
+        if (customer != null && customer.getEmail() != null && !customer.getEmail().isBlank()) {
+            String subject = "Reminder: adoption tomorrow — " + adoption.getPet().getPetName();
+            send(customer.getId(), customer.getEmail(), subject, buildAdoptionReminderHtml(adoption));
+        }
+        User employee = adoption.getEmployee();
+        if (employee != null && employee.getEmail() != null && !employee.getEmail().isBlank()) {
+            String subject = "Reminder: adoption tomorrow — " + adoption.getPet().getPetName();
+            send(employee.getId(), employee.getEmail(), subject, buildAdoptionReminderHtml(adoption));
+        }
+    }
+
+    public void sendAppointmentConfirmation(Appointment appointment) {
+        User customer = appointment.getCustomer();
+        if (customer != null && customer.getEmail() != null && !customer.getEmail().isBlank()) {
+            String subject = "Appointment confirmed — " + appointment.getService().getServiceName();
+            send(customer.getId(), customer.getEmail(), subject, buildAppointmentHtml(appointment));
+        }
+        User employee = appointment.getEmployee();
+        if (employee != null && employee.getEmail() != null && !employee.getEmail().isBlank()) {
+            String subject = "Appointment assigned — " + appointment.getService().getServiceName();
+            send(employee.getId(), employee.getEmail(), subject, buildAppointmentHtml(appointment));
+        }
+    }
+
+    public void sendAppointmentReminder(Appointment appointment) {
+        User customer = appointment.getCustomer();
+        if (customer != null && customer.getEmail() != null && !customer.getEmail().isBlank()) {
+            String subject = "Reminder: appointment tomorrow — " + appointment.getService().getServiceName();
+            send(customer.getId(), customer.getEmail(), subject, buildAppointmentReminderHtml(appointment));
+        }
+        User employee = appointment.getEmployee();
+        if (employee != null && employee.getEmail() != null && !employee.getEmail().isBlank()) {
+            String subject = "Reminder: appointment tomorrow — " + appointment.getService().getServiceName();
+            send(employee.getId(), employee.getEmail(), subject, buildAppointmentReminderHtml(appointment));
+        }
+    }
+
+    public void sendChatTranscript(Conversation conversation, List<Message> messages, User customer) {
+        if (customer == null || customer.getEmail() == null || customer.getEmail().isBlank()) return;
+        String subject = "Your PetShop support transcript";
+        String html = buildTranscriptHtml(conversation, messages, customer);
+        send(customer.getId(), customer.getEmail(), subject, html);
+    }
+
+    private void send(Long recipientUserId, String to, String subject, String html) {
+        try {
+            CreateEmailOptions options = CreateEmailOptions.builder()
+                    .from(from)
+                    .to(List.of(to))
+                    .subject(subject)
+                    .html(html)
+                    .build();
+            resend.emails().send(options);
+            activityLogService.record(recipientUserId, "Email sent: " + subject + " → " + to);
+        } catch (Exception ex) {
+            log.error("Failed to send email '{}' to {}: {}", subject, to, ex.getMessage());
+            activityLogService.record(recipientUserId, "Email failed: " + subject + " → " + to);
+        }
+    }
+
+    private String buildReceiptHtml(Sale sale) {
+        StringBuilder rows = new StringBuilder();
+        List<SaleItem> items = sale.getItems();
+        if (items != null) {
+            for (SaleItem item : items) {
+                String name = item.getProduct() != null ? item.getProduct().getProdName() : "—";
+                rows.append("<tr><td style='padding:6px 8px'>").append(esc(name)).append("</td>")
+                    .append("<td style='padding:6px 8px;text-align:center'>").append(item.getQuantity()).append("</td>")
+                    .append("<td style='padding:6px 8px;text-align:right'>$").append(fmt(item.getUnitPrice())).append("</td>")
+                    .append("<td style='padding:6px 8px;text-align:right'>$").append(fmt(item.getUnitPrice().multiply(BigDecimal.valueOf(item.getQuantity())))).append("</td></tr>");
+            }
+        }
+        String date = sale.getSaleDate() != null ? sale.getSaleDate().format(DateTimeFormatter.ofPattern("MMMM d, yyyy h:mm a")) : "—";
+        return """
+                <div style="font-family:sans-serif;max-width:600px;margin:auto">
+                  <h2>Thank you for your purchase!</h2>
+                  <p><strong>Date:</strong> %s</p>
+                  <p><strong>Payment method:</strong> %s</p>
+                  <table style="width:100%%;border-collapse:collapse;margin:16px 0">
+                    <thead><tr style="background:#f3f4f6">
+                      <th style="padding:6px 8px;text-align:left">Item</th>
+                      <th style="padding:6px 8px;text-align:center">Qty</th>
+                      <th style="padding:6px 8px;text-align:right">Unit price</th>
+                      <th style="padding:6px 8px;text-align:right">Total</th>
+                    </tr></thead>
+                    <tbody>%s</tbody>
+                  </table>
+                  <p><strong>Subtotal:</strong> $%s</p>
+                  %s
+                  %s
+                  %s
+                  <p style="font-size:1.1em"><strong>Total:</strong> $%s</p>
+                  %s
+                </div>""".formatted(
+                date,
+                esc(sale.getPaymentMethod()),
+                rows.toString(),
+                fmt(sale.getSubtotalAmount()),
+                discountLine("Coupon discount", sale.getCouponDiscountAmount()),
+                discountLine("Employee discount", sale.getEmployeeDiscountAmount()),
+                discountLine("Loyalty discount", sale.getLoyaltyDiscountAmount()),
+                fmt(sale.getTotalAmount()),
+                sale.getPointsEarned() != null && sale.getPointsEarned() > 0
+                        ? "<p>You earned <strong>" + sale.getPointsEarned() + " loyalty points</strong> on this order.</p>"
+                        : ""
+        );
+    }
+
+    private String buildAdoptionHtml(Adoption adoption, User customer) {
+        String petName = adoption.getPet() != null ? adoption.getPet().getPetName() : "—";
+        String storeName = adoption.getSourceStore() != null ? adoption.getSourceStore().getStoreName() : "—";
+        String date = adoption.getAdoptionDate() != null ? adoption.getAdoptionDate().format(DATE_FMT) : "—";
+        String customerName = customer != null ? firstName(customer) : "—";
+        return """
+                <div style="font-family:sans-serif;max-width:600px;margin:auto">
+                  <h2>Adoption update — %s</h2>
+                  <p><strong>Customer:</strong> %s</p>
+                  <p><strong>Pet:</strong> %s</p>
+                  <p><strong>Date:</strong> %s</p>
+                  <p><strong>Store:</strong> %s</p>
+                  <p><strong>Status:</strong> %s</p>
+                </div>""".formatted(esc(petName), esc(customerName), esc(petName), date, esc(storeName), esc(adoption.getAdoptionStatus()));
+    }
+
+    private String buildAdoptionReminderHtml(Adoption adoption) {
+        String petName = adoption.getPet() != null ? adoption.getPet().getPetName() : "—";
+        String storeName = adoption.getSourceStore() != null ? adoption.getSourceStore().getStoreName() : "—";
+        String date = adoption.getAdoptionDate() != null ? adoption.getAdoptionDate().format(DATE_FMT) : "—";
+        return """
+                <div style="font-family:sans-serif;max-width:600px;margin:auto">
+                  <h2>Reminder: adoption tomorrow</h2>
+                  <p>This is a reminder that the adoption of <strong>%s</strong> is scheduled for <strong>%s</strong> at <strong>%s</strong>.</p>
+                </div>""".formatted(esc(petName), date, esc(storeName));
+    }
+
+    private String buildAppointmentHtml(Appointment appointment) {
+        String service = appointment.getService() != null ? appointment.getService().getServiceName() : "—";
+        String store = appointment.getStore() != null ? appointment.getStore().getStoreName() : "—";
+        String date = appointment.getAppointmentDate() != null ? appointment.getAppointmentDate().format(DATE_FMT) : "—";
+        String time = appointment.getAppointmentTime() != null ? appointment.getAppointmentTime().format(TIME_FMT) : "—";
+        String employee = appointment.getEmployee() != null
+                ? appointment.getEmployee().getFirstName() + " " + appointment.getEmployee().getLastName() : "—";
+        String pet = appointment.getPet() != null ? appointment.getPet().getPetName() : null;
+        return """
+                <div style="font-family:sans-serif;max-width:600px;margin:auto">
+                  <h2>Appointment confirmed</h2>
+                  <p><strong>Service:</strong> %s</p>
+                  <p><strong>Date:</strong> %s</p>
+                  <p><strong>Time:</strong> %s</p>
+                  <p><strong>Location:</strong> %s</p>
+                  <p><strong>Staff:</strong> %s</p>
+                  %s
+                </div>""".formatted(esc(service), date, time, esc(store), esc(employee),
+                pet != null ? "<p><strong>Pet:</strong> " + esc(pet) + "</p>" : "");
+    }
+
+    private String buildAppointmentReminderHtml(Appointment appointment) {
+        String service = appointment.getService() != null ? appointment.getService().getServiceName() : "—";
+        String store = appointment.getStore() != null ? appointment.getStore().getStoreName() : "—";
+        String time = appointment.getAppointmentTime() != null ? appointment.getAppointmentTime().format(TIME_FMT) : "—";
+        return """
+                <div style="font-family:sans-serif;max-width:600px;margin:auto">
+                  <h2>Reminder: appointment tomorrow</h2>
+                  <p>Your <strong>%s</strong> appointment is scheduled for tomorrow at <strong>%s</strong> at <strong>%s</strong>.</p>
+                </div>""".formatted(esc(service), time, esc(store));
+    }
+
+    private String buildTranscriptHtml(Conversation conversation, List<Message> messages, User customer) {
+        StringBuilder rows = new StringBuilder();
+        for (Message msg : messages) {
+            String sender = msg.getSenderId() != null && msg.getSenderId().equals(customer.getId())
+                    ? firstName(customer) : "Support";
+            String ts = msg.getTimestamp() != null
+                    ? msg.getTimestamp().format(DateTimeFormatter.ofPattern("MMM d, h:mm a")) : "";
+            String content = msg.getContent() != null ? esc(msg.getContent()) : "";
+            rows.append("<tr><td style='padding:6px 8px;white-space:nowrap'>").append(ts).append("</td>")
+                .append("<td style='padding:6px 8px;white-space:nowrap'>").append(esc(sender)).append("</td>")
+                .append("<td style='padding:6px 8px'>").append(content).append("</td></tr>");
+        }
+        return """
+                <div style="font-family:sans-serif;max-width:700px;margin:auto">
+                  <h2>Support chat transcript</h2>
+                  <p>Hi %s, here is the transcript of your support conversation.</p>
+                  <table style="width:100%%;border-collapse:collapse;margin:16px 0;font-size:0.9em">
+                    <thead><tr style="background:#f3f4f6">
+                      <th style="padding:6px 8px;text-align:left">Time</th>
+                      <th style="padding:6px 8px;text-align:left">Sender</th>
+                      <th style="padding:6px 8px;text-align:left">Message</th>
+                    </tr></thead>
+                    <tbody>%s</tbody>
+                  </table>
+                </div>""".formatted(firstName(customer), rows.toString());
+    }
+
+    private String firstName(User user) {
+        if (user.getFirstName() != null && !user.getFirstName().isBlank()) return esc(user.getFirstName());
+        if (user.getFullName() != null && !user.getFullName().isBlank()) return esc(user.getFullName().split("\\s+")[0]);
+        return esc(user.getUsername());
+    }
+
+    private String fmt(BigDecimal value) {
+        return value != null ? String.format("%.2f", value) : "0.00";
+    }
+
+    private String discountLine(String label, BigDecimal value) {
+        if (value == null || value.compareTo(BigDecimal.ZERO) == 0) return "";
+        return "<p><strong>" + label + ":</strong> -$" + fmt(value) + "</p>";
+    }
+
+    private String esc(String s) {
+        if (s == null) return "";
+        return s.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;").replace("\"", "&quot;");
+    }
+}

backend/src/main/java/com/petshop/backend/service/PasswordResetService.java

@@ -28,14 +28,17 @@ public class PasswordResetService {
     private final PasswordResetTokenRepository passwordResetTokenRepository;
     private final UserRepository userRepository;
     private final PasswordEncoder passwordEncoder;
+    private final EmailService emailService;
     private final SecureRandom secureRandom = new SecureRandom();
 
     public PasswordResetService(PasswordResetTokenRepository passwordResetTokenRepository,
                                 UserRepository userRepository,
-                                PasswordEncoder passwordEncoder) {
+                                PasswordEncoder passwordEncoder,
+                                EmailService emailService) {
         this.passwordResetTokenRepository = passwordResetTokenRepository;
         this.userRepository = userRepository;
         this.passwordEncoder = passwordEncoder;
+        this.emailService = emailService;
     }
 
     @Transactional
@@ -66,9 +69,11 @@ public class PasswordResetService {
         resetToken.setExpiresAt(now.plusMinutes(RESET_TOKEN_MINUTES));
         passwordResetTokenRepository.save(resetToken);
 
+        emailService.sendPasswordResetLink(managedUser, rawToken);
+
         return new ForgotPasswordResponse(
-                "If an account matches that username or email, a reset token has been generated.",
+                "If an account matches that username or email, a reset link has been sent.",
-                rawToken
+                null
         );
     }
 

backend/src/main/java/com/petshop/backend/service/SaleService.java

@@ -31,8 +31,9 @@ public class SaleService {
     private final UserRepository userRepository;
     private final CouponRepository couponRepository;
     private final CartRepository cartRepository;
+    private final EmailService emailService;
 
-    public SaleService(SaleRepository saleRepository, ProductRepository productRepository, StoreRepository storeRepository, InventoryRepository inventoryRepository, UserRepository userRepository, CouponRepository couponRepository, CartRepository cartRepository) {
+    public SaleService(SaleRepository saleRepository, ProductRepository productRepository, StoreRepository storeRepository, InventoryRepository inventoryRepository, UserRepository userRepository, CouponRepository couponRepository, CartRepository cartRepository, EmailService emailService) {
         this.saleRepository = saleRepository;
         this.productRepository = productRepository;
         this.storeRepository = storeRepository;
@@ -40,6 +41,7 @@ public class SaleService {
         this.userRepository = userRepository;
         this.couponRepository = couponRepository;
         this.cartRepository = cartRepository;
+        this.emailService = emailService;
     }
 
     @Transactional(readOnly = true)
@@ -268,6 +270,11 @@ public class SaleService {
         sale.setItems(saleItems);
 
         Sale savedSale = saleRepository.save(sale);
+
+        if (!Boolean.TRUE.equals(savedSale.getIsRefund()) && savedSale.getCustomer() != null) {
+            emailService.sendPurchaseReceipt(savedSale);
+        }
+
         return mapToResponse(savedSale);
     }
 

backend/src/main/resources/application.yml

@@ -50,6 +50,11 @@ springdoc:
 app:
   upload:
     base-dir: ${UPLOAD_BASE_DIR:uploads}
+  frontend-url: ${FRONTEND_URL:http://localhost:3000}
+
+resend:
+  api-key: ${RESEND_API_KEY:}
+  from: ${RESEND_FROM:PetShop <onboarding@resend.dev>}
 
 jwt:
   secret: ${JWT_SECRET}