feat: create accounts to partition money

internal/service/money_account.go

@@ -0,0 +1,173 @@
+package service
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"git.juancwu.dev/juancwu/budgit/internal/model"
+	"git.juancwu.dev/juancwu/budgit/internal/repository"
+	"github.com/google/uuid"
+)
+
+type CreateMoneyAccountDTO struct {
+	SpaceID   string
+	Name      string
+	CreatedBy string
+}
+
+type UpdateMoneyAccountDTO struct {
+	ID   string
+	Name string
+}
+
+type CreateTransferDTO struct {
+	AccountID string
+	Amount    int
+	Direction model.TransferDirection
+	Note      string
+	CreatedBy string
+}
+
+type MoneyAccountService struct {
+	accountRepo repository.MoneyAccountRepository
+}
+
+func NewMoneyAccountService(accountRepo repository.MoneyAccountRepository) *MoneyAccountService {
+	return &MoneyAccountService{
+		accountRepo: accountRepo,
+	}
+}
+
+func (s *MoneyAccountService) CreateAccount(dto CreateMoneyAccountDTO) (*model.MoneyAccount, error) {
+	name := strings.TrimSpace(dto.Name)
+	if name == "" {
+		return nil, fmt.Errorf("account name cannot be empty")
+	}
+
+	now := time.Now()
+	account := &model.MoneyAccount{
+		ID:        uuid.NewString(),
+		SpaceID:   dto.SpaceID,
+		Name:      name,
+		CreatedBy: dto.CreatedBy,
+		CreatedAt: now,
+		UpdatedAt: now,
+	}
+
+	err := s.accountRepo.Create(account)
+	if err != nil {
+		return nil, err
+	}
+
+	return account, nil
+}
+
+func (s *MoneyAccountService) GetAccountsForSpace(spaceID string) ([]model.MoneyAccountWithBalance, error) {
+	accounts, err := s.accountRepo.GetBySpaceID(spaceID)
+	if err != nil {
+		return nil, err
+	}
+
+	result := make([]model.MoneyAccountWithBalance, len(accounts))
+	for i, acct := range accounts {
+		balance, err := s.accountRepo.GetAccountBalance(acct.ID)
+		if err != nil {
+			return nil, err
+		}
+		result[i] = model.MoneyAccountWithBalance{
+			MoneyAccount: *acct,
+			BalanceCents: balance,
+		}
+	}
+
+	return result, nil
+}
+
+func (s *MoneyAccountService) GetAccount(id string) (*model.MoneyAccount, error) {
+	return s.accountRepo.GetByID(id)
+}
+
+func (s *MoneyAccountService) UpdateAccount(dto UpdateMoneyAccountDTO) (*model.MoneyAccount, error) {
+	name := strings.TrimSpace(dto.Name)
+	if name == "" {
+		return nil, fmt.Errorf("account name cannot be empty")
+	}
+
+	account, err := s.accountRepo.GetByID(dto.ID)
+	if err != nil {
+		return nil, err
+	}
+
+	account.Name = name
+
+	err = s.accountRepo.Update(account)
+	if err != nil {
+		return nil, err
+	}
+
+	return account, nil
+}
+
+func (s *MoneyAccountService) DeleteAccount(id string) error {
+	return s.accountRepo.Delete(id)
+}
+
+func (s *MoneyAccountService) CreateTransfer(dto CreateTransferDTO, availableSpaceBalance int) (*model.AccountTransfer, error) {
+	if dto.Amount <= 0 {
+		return nil, fmt.Errorf("amount must be positive")
+	}
+
+	if dto.Direction != model.TransferDirectionDeposit && dto.Direction != model.TransferDirectionWithdrawal {
+		return nil, fmt.Errorf("invalid transfer direction")
+	}
+
+	if dto.Direction == model.TransferDirectionDeposit {
+		if dto.Amount > availableSpaceBalance {
+			return nil, fmt.Errorf("insufficient available balance")
+		}
+	}
+
+	if dto.Direction == model.TransferDirectionWithdrawal {
+		accountBalance, err := s.accountRepo.GetAccountBalance(dto.AccountID)
+		if err != nil {
+			return nil, err
+		}
+		if dto.Amount > accountBalance {
+			return nil, fmt.Errorf("insufficient account balance")
+		}
+	}
+
+	transfer := &model.AccountTransfer{
+		ID:          uuid.NewString(),
+		AccountID:   dto.AccountID,
+		AmountCents: dto.Amount,
+		Direction:   dto.Direction,
+		Note:        strings.TrimSpace(dto.Note),
+		CreatedBy:   dto.CreatedBy,
+		CreatedAt:   time.Now(),
+	}
+
+	err := s.accountRepo.CreateTransfer(transfer)
+	if err != nil {
+		return nil, err
+	}
+
+	return transfer, nil
+}
+
+func (s *MoneyAccountService) GetTransfersForAccount(accountID string) ([]*model.AccountTransfer, error) {
+	return s.accountRepo.GetTransfersByAccountID(accountID)
+}
+
+func (s *MoneyAccountService) DeleteTransfer(id string) error {
+	return s.accountRepo.DeleteTransfer(id)
+}
+
+func (s *MoneyAccountService) GetAccountBalance(accountID string) (int, error) {
+	return s.accountRepo.GetAccountBalance(accountID)
+}
+
+func (s *MoneyAccountService) GetTotalAllocatedForSpace(spaceID string) (int, error) {
+	return s.accountRepo.GetTotalAllocatedForSpace(spaceID)
+}