Add current expenses to the overview

The period start is configurable.

financer-server/src/main/java/de/financer/config/FinancerConfig.java

@@ -21,6 +21,7 @@ public class FinancerConfig {
     private String dateFormat;
     private Collection<String> mailRecipients;
     private String fromAddress;
+    private Integer monthPeriodStartDay;
 
     /**
      * @return the raw country code, mostly an uppercase ISO 3166 2-letter code
@@ -109,4 +110,32 @@ public class FinancerConfig {
     public void setFromAddress(String fromAddress) {
         this.fromAddress = fromAddress;
     }
+
+    /**
+     * The day of month that indicates a start of an expense period. Valid values range from 1-28. There is no special
+     * handling for months with more days.
+     * If the value is 15 for example an expense period is always from the 15th of the current month to the 15th of the
+     * next month:
+     * <ul>
+     *     <li>15.01.2019 - 15.02.2019</li>
+     *     <li>15.02.2019 - 15.03.2019</li>
+     *     <li>...</li>
+     * </ul>
+     *
+     * @return the day of month indicating the start of an expense period
+     */
+    public Integer getMonthPeriodStartDay() {
+        return monthPeriodStartDay;
+    }
+
+    public void setMonthPeriodStartDay(Integer monthPeriodStartDay) {
+        if (monthPeriodStartDay == null) {
+            throw new IllegalArgumentException("Parameter 'financer.monthPeriodStartDay' is not set!");
+        }
+        else if (monthPeriodStartDay < 1 || monthPeriodStartDay > 28) {
+            throw new IllegalArgumentException("Parameter 'financer.monthPeriodStartDay' is out of range! Valid range from 1-28");
+        }
+
+        this.monthPeriodStartDay = monthPeriodStartDay;
+    }
 }

financer-server/src/main/java/de/financer/controller/TransactionController.java

@@ -79,4 +79,19 @@ public class TransactionController {
 
         return responseReason.toResponseEntity();
     }
+
+    @RequestMapping("getExpensesCurrentPeriod")
+    public Long getExpensesCurrentPeriod() {
+        if (LOGGER.isDebugEnabled()) {
+            LOGGER.debug("/transactions/getExpensesCurrentPeriod called");
+        }
+
+        final Long response = this.transactionService.getExpensesCurrentPeriod();
+
+        if (LOGGER.isDebugEnabled()) {
+            LOGGER.debug(String.format("/transactions/getExpensesCurrentPeriod returns with %s", response));
+        }
+
+        return response;
+    }
 }

financer-server/src/main/java/de/financer/dba/TransactionRepository.java

@@ -1,12 +1,19 @@
 package de.financer.dba;
 
 import de.financer.model.Account;
+import de.financer.model.AccountType;
 import de.financer.model.Transaction;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.CrudRepository;
 import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.time.LocalDate;
+
 @Transactional(propagation = Propagation.REQUIRED)
 public interface TransactionRepository extends CrudRepository<Transaction, Long> {
     Iterable<Transaction> findTransactionsByFromAccountOrToAccount(Account fromAccount, Account toAccount);
+
+    @Query("SELECT SUM(t.amount) FROM Transaction t JOIN t.toAccount a WHERE t.date BETWEEN :periodStart AND :periodEnd AND a.type IN :expenseTypes")
+    Long getExpensesCurrentPeriod(LocalDate periodStart, LocalDate periodEnd, AccountType... expenseTypes);
 }

financer-server/src/main/java/de/financer/service/TransactionService.java

@@ -66,8 +66,8 @@ public class TransactionService {
 
     @Transactional(propagation = Propagation.REQUIRED)
     public ResponseReason createTransaction(String fromAccountKey, String toAccountKey, Long amount, String date,
-                                            String description)
-    {
+                                            String description
+    ) {
         return this.createTransaction(fromAccountKey, toAccountKey, amount, date, description, null);
     }
 
@@ -95,8 +95,7 @@ public class TransactionService {
             if (AccountType.START.equals(fromAccount.getType()) && AccountType.LIABILITY.equals(toAccount.getType())) {
                 toAccount.setCurrentBalance(toAccount.getCurrentBalance() + (this.ruleService
                         .getMultiplierToAccount(toAccount) * amount * -1));
-            }
-            else {
+            } else {
                 toAccount.setCurrentBalance(toAccount.getCurrentBalance() + (this.ruleService
                         .getMultiplierToAccount(toAccount) * amount));
             }
@@ -216,8 +215,7 @@ public class TransactionService {
 
             this.accountService.saveAccount(fromAccount);
             this.accountService.saveAccount(toAccount);
-        }
-        catch (Exception e) {
+        } catch (Exception e) {
             LOGGER.error("Could not delete transaction!", e);
 
             response = ResponseReason.UNKNOWN_ERROR;
@@ -225,4 +223,14 @@ public class TransactionService {
 
         return response;
     }
+
+    public Long getExpensesCurrentPeriod() {
+        final LocalDate periodStart = LocalDate.now().withDayOfMonth(this.financerConfig.getMonthPeriodStartDay());
+        final LocalDate periodEnd = periodStart.plusMonths(1);
+
+        final Long expensesCurrentPeriod = this.transactionRepository
+                .getExpensesCurrentPeriod(periodStart, periodEnd, AccountType.EXPENSE, AccountType.LIABILITY);
+
+        return Optional.ofNullable(expensesCurrentPeriod).orElse(Long.valueOf(0l));
+    }
 }

financer-server/src/main/resources/config/application.properties

@@ -46,4 +46,7 @@ spring.mail.host=localhost
 
 # Disable JMX as we don't need it and it blocks parallel deployment on Tomcat
 # because the connection pool cannot shutdown properly
-spring.jmx.enabled=false
+spring.jmx.enabled=false
+
+# The day of month indicating the start of an expense period. Valid values range from 1-28
+financer.monthPeriodStartDay=15