feat: add redis cache to transaction summary endpoint

docker-compose.yml

@@ -16,6 +16,11 @@ services:
       interval: 5s
       timeout: 5s
       retries: 5
+  redis:
+    image: redis:7-alpine
+    container_name: redis
+    ports:
+      - "6379:6379"
 
   app:
     build: .

pom.xml

@@ -49,6 +49,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-amqp</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-redis</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>io.jsonwebtoken</groupId>
 			<artifactId>jjwt-api</artifactId>

src/main/java/com/guilherme/finance_api/config/RedisConfig.java

@@ -0,0 +1,34 @@
+package com.guilherme.finance_api.config;
+
+import org.springframework.cache.annotation.EnableCaching;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
+import org.springframework.data.redis.cache.RedisCacheConfiguration;
+import org.springframework.data.redis.cache.RedisCacheManager;
+import org.springframework.data.redis.connection.RedisConnectionFactory;
+import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
+import org.springframework.data.redis.serializer.RedisSerializationContext;
+
+import java.time.Duration;
+
+@Configuration
+@EnableCaching
+public class RedisConfig {
+
+    @Bean
+    @Primary
+    public RedisCacheManager cacheManager(RedisConnectionFactory connectionFactory) {
+        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
+                .entryTtl(Duration.ofMinutes(5))
+                .serializeValuesWith(
+                        RedisSerializationContext.SerializationPair.fromSerializer(
+                                new GenericJackson2JsonRedisSerializer()
+                        )
+                );
+
+        return RedisCacheManager.builder(connectionFactory)
+                .cacheDefaults(config)
+                .build();
+    }
+}

src/main/java/com/guilherme/finance_api/controller/TransactionController.java

@@ -3,6 +3,7 @@
 import com.guilherme.finance_api.dto.TransactionFilter;
 import com.guilherme.finance_api.dto.TransactionRequest;
 import com.guilherme.finance_api.dto.TransactionResponse;
+import com.guilherme.finance_api.dto.TransactionSummary;
 import com.guilherme.finance_api.entity.TransactionType;
 import com.guilherme.finance_api.service.TransactionService;
 import jakarta.validation.Valid;
@@ -13,6 +14,7 @@
 import org.springframework.format.annotation.DateTimeFormat;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.web.bind.annotation.*;
 
 import org.springframework.data.domain.Pageable;
@@ -60,6 +62,15 @@ public ResponseEntity<TransactionResponse> save(@Valid @RequestBody TransactionR
         return ResponseEntity.status(HttpStatus.CREATED).body(savedTransaction);
     }
 
+    @GetMapping("/summary")
+    public ResponseEntity<TransactionSummary> getSummary(
+            @RequestParam(required = false) String month) {
+        String email = SecurityContextHolder.getContext()
+                .getAuthentication()
+                .getName();
+        return ResponseEntity.ok(transactionService.getSummary(month, email));
+    }
+
     @DeleteMapping("/{id}")
     public ResponseEntity<Void> delete(@PathVariable Long id) {
         transactionService.delete(id);

src/main/java/com/guilherme/finance_api/dto/TransactionSummary.java

@@ -0,0 +1,17 @@
+package com.guilherme.finance_api.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.math.BigDecimal;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class TransactionSummary {
+    private BigDecimal totalIncome;
+    private BigDecimal totalExpense;
+    private BigDecimal balance;
+    private String month;
+}

src/main/java/com/guilherme/finance_api/service/TransactionService.java

@@ -3,8 +3,10 @@
 import com.guilherme.finance_api.dto.TransactionFilter;
 import com.guilherme.finance_api.dto.TransactionRequest;
 import com.guilherme.finance_api.dto.TransactionResponse;
+import com.guilherme.finance_api.dto.TransactionSummary;
 import com.guilherme.finance_api.entity.Category;
 import com.guilherme.finance_api.entity.Transaction;
+import com.guilherme.finance_api.entity.TransactionType;
 import com.guilherme.finance_api.entity.User;
 import com.guilherme.finance_api.event.TransactionEvent;
 import com.guilherme.finance_api.event.TransactionPublisher;
@@ -13,15 +15,23 @@
 import com.guilherme.finance_api.repository.TransactionRepository;
 import com.guilherme.finance_api.repository.UserRepository;
 import com.guilherme.finance_api.specification.TransactionSpecification;
+import org.springframework.cache.annotation.Cacheable;
 import lombok.Data;
 import lombok.RequiredArgsConstructor;
+import org.springframework.cache.annotation.CacheEvict;
 import org.springframework.data.domain.Page;
 import org.springframework.data.jpa.domain.Specification;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.stereotype.Service;
 
 import org.springframework.data.domain.Pageable;
 
+import java.math.BigDecimal;
+import java.time.LocalDate;
+import java.time.YearMonth;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
 
 @Data
 @Service
@@ -80,6 +90,7 @@ public TransactionResponse update(Long id, TransactionRequest request) {
         return toResponse(savedTransaction);
     }
 
+    @CacheEvict(value = "transaction-summary", allEntries = true)
     public TransactionResponse save(TransactionRequest request) {
         Transaction transaction = new Transaction();
         transaction.setDescription(request.getDescription());
@@ -114,6 +125,42 @@ public TransactionResponse save(TransactionRequest request) {
         return toResponse(savedTransaction);
     }
 
+    @Cacheable(value = "transaction-summary", key = "#month ?: 'current' + '::' + #email")
+    public TransactionSummary getSummary(String month, String email) {
+        User user = userRepository.findByEmail(email)
+                .orElseThrow(() -> new ResourceNotFoundException("User not found"));
+
+        YearMonth yearMonth = month != null
+                ? YearMonth.parse(month)
+                : YearMonth.now();
+
+        LocalDate start = yearMonth.atDay(1);
+        LocalDate end = yearMonth.atEndOfMonth();
+
+        Specification<Transaction> spec = Specification.<Transaction>unrestricted()
+                .and(TransactionSpecification.hasUser(user.getId()))
+                .and(TransactionSpecification.dateBetween(start, end));
+
+        List<Transaction> transactions = transactionRepository.findAll(spec);
+
+        BigDecimal totalIncome = transactions.stream()
+                .filter(t -> t.getType() == TransactionType.INCOME)
+                .map(Transaction::getAmount)
+                .reduce(BigDecimal.ZERO, BigDecimal::add);
+
+        BigDecimal totalExpense = transactions.stream()
+                .filter(t -> t.getType() == TransactionType.EXPENSE)
+                .map(Transaction::getAmount)
+                .reduce(BigDecimal.ZERO, BigDecimal::add);
+
+        return new TransactionSummary(
+                totalIncome,
+                totalExpense,
+                totalIncome.subtract(totalExpense),
+                yearMonth.format(DateTimeFormatter.ofPattern("yyyy-MM"))
+        );
+    }
+
     public void delete(Long id) {
         if (!transactionRepository.existsById(id)) {
             throw new ResourceNotFoundException("Transaction not found");

src/main/resources/application.properties

@@ -13,3 +13,5 @@ spring.rabbitmq.username=${RABBITMQ_USER:guest}
 spring.rabbitmq.password=${RABBITMQ_PASSWORD:guest}
 rabbitmq.exchange=transactions.exchange
 rabbitmq.routing-key=transactions.created
+spring.data.redis.host=${REDIS_HOST:localhost}
+spring.data.redis.port=${REDIS_PORT:6379}