AccountService.java

package de.japrost.jabudget.service;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

import de.japrost.jabudget.domain.DomainException;
import de.japrost.jabudget.domain.DomainFailure;
import de.japrost.jabudget.domain.account.Account;
import de.japrost.jabudget.domain.account.Entry;
import de.japrost.jabudget.repository.AccountRepository;

/**
 * Business service for {@link Account}s.
 */
public class AccountService {

    private final AccountRepository accountRepository;

    /**
     * Initialize with all dependencies.
     *
     * @param accountRepository the {@link AccountRepository} to use.
     */
    public AccountService(final AccountRepository accountRepository) {
        this.accountRepository = accountRepository;
    }

    /**
     * Create a new {@link Account}.
     *
     * @param account the Account to be created
     * @return the new Account.
     * @throws DomainException when the Account already exists.
     */
    public Account create(final Account account) throws DomainException {
        // TODO the service creates the ID. Do not use create to import an existing account (e.g. created in an offline application).
        return accountRepository.create(account);
    }

    /**
     * Update an existing {@link Account}.
     *
     * @param account the Account to be updated
     * @return the updated Account.
     * @throws DomainException when the Account does not exist.
     */
    public Account update(final Account account) throws DomainException {
        return accountRepository.update(account);
    }

    /**
     * Retrieve all accounts.
     *
     * @return all available accounts.
     */
    public List<Account> retrieveAll() {
        return new ArrayList<>(accountRepository.findAll());
    }

    /**
     * Retrieve a single {@link Account} by its id.
     *
     * @param id the id of the {@link Account}.
     * @return the {@link Account} with the id. An empty {@link Optional} if no {@link Account} is available for the given
     *         id.
     */
    public Optional<Account> retrieveById(final String id) {
        return accountRepository.findById(id);
    }

    /**
     * Delete a single {@link Account} by its id.
     *
     * @param id of the {@link Account} to delete.
     * @return {@link Boolean#TRUE} if the account is removed after this operation.
     */
    public Boolean erase(final String id) {
        return accountRepository.delete(id);
    }

    /**
     * Create a new {@link Entry} with the given values.
     *
     * @param entry the entry to create.
     * @return The entry as stored in the repository.
     * @throws DomainException with {@link DomainFailure#DUPLICATE_ENTITY} if the given entry already exists.
     * @throws DomainException with {@link DomainFailure#MISSING_ENTITY_REFERENCE} if the account for the entry does not exists.
     */
    public Entry create(final Entry entry) throws DomainException {
        // TODO who creates the Entry-Code.
        return accountRepository.create(entry);
    }

}