accounts: implement CreditAccount & DebitAccount

This commit implements the `CreditAccount` and `DebitAccount` endpoints
for the accounts subsystem.

accounts/checkers_test.go

@@ -63,6 +63,18 @@ type mockService struct {
 	*requestValuesStore
 }
 
+func (m *mockService) CreditAccount(_ context.Context, _ AccountID,
+	_ lnwire.MilliSatoshi) (*OffChainBalanceAccount, error) {
+
+	return nil, nil
+}
+
+func (m *mockService) DebitAccount(_ context.Context, _ AccountID,
+	_ lnwire.MilliSatoshi) (*OffChainBalanceAccount, error) {
+
+	return nil, nil
+}
+
 func newMockService() *mockService {
 	return &mockService{
 		acctBalanceMsat:    0,

accounts/interface.go

@@ -331,6 +331,16 @@ type Service interface {
 	PaymentErrored(ctx context.Context, id AccountID,
 		hash lntypes.Hash) error
 
+	// CreditAccount increases the balance of an existing account in the
+	// database.
+	CreditAccount(ctx context.Context, accountID AccountID,
+		amount lnwire.MilliSatoshi) (*OffChainBalanceAccount, error)
+
+	// DebitAccount decreases the balance of an existing account in the
+	// database.
+	DebitAccount(ctx context.Context, accountID AccountID,
+		amount lnwire.MilliSatoshi) (*OffChainBalanceAccount, error)
+
 	RequestValuesStore
 }
 

accounts/rpcserver.go

@@ -130,6 +130,83 @@ func (s *RPCServer) UpdateAccount(ctx context.Context,
 	return marshalAccount(account), nil
 }
 
+// CreditAccount increases the balance of an existing account in the account
+// database, by the given amount.
+func (s *RPCServer) CreditAccount(ctx context.Context,
+	req *litrpc.CreditAccountRequest) (*litrpc.CreditAccountResponse,
+	error) {
+
+	if req.GetAccount() == nil {
+		return nil, fmt.Errorf("account param must be specified")
+	}
+
+	var id, label string
+
+	switch idType := req.Account.Identifier.(type) {
+	case *litrpc.AccountIdentifier_Id:
+		id = idType.Id
+	case *litrpc.AccountIdentifier_Label:
+		label = idType.Label
+	}
+
+	log.Infof("[creditaccount] id=%s, label=%v, amount=%d", id, label,
+		req.Amount)
+
+	amount := lnwire.MilliSatoshi(req.Amount * 1000)
+
+	accountID, err := s.findAccount(ctx, id, label)
+	if err != nil {
+		return nil, err
+	}
+
+	account, err := s.service.CreditAccount(ctx, accountID, amount)
+	if err != nil {
+		return nil, err
+	}
+
+	return &litrpc.CreditAccountResponse{
+		Account: marshalAccount(account),
+	}, nil
+}
+
+// DebitAccount decreases the balance of an existing account in the account
+// database, by the given amount.
+func (s *RPCServer) DebitAccount(ctx context.Context,
+	req *litrpc.DebitAccountRequest) (*litrpc.DebitAccountResponse, error) {
+
+	if req.GetAccount() == nil {
+		return nil, fmt.Errorf("account param must be specified")
+	}
+
+	var id, label string
+
+	switch idType := req.Account.Identifier.(type) {
+	case *litrpc.AccountIdentifier_Id:
+		id = idType.Id
+	case *litrpc.AccountIdentifier_Label:
+		label = idType.Label
+	}
+
+	log.Infof("[debitaccount] id=%s, label=%v, amount=%d", id, label,
+		req.Amount)
+
+	amount := lnwire.MilliSatoshi(req.Amount * 1000)
+
+	accountID, err := s.findAccount(ctx, id, label)
+	if err != nil {
+		return nil, err
+	}
+
+	account, err := s.service.DebitAccount(ctx, accountID, amount)
+	if err != nil {
+		return nil, err
+	}
+
+	return &litrpc.DebitAccountResponse{
+		Account: marshalAccount(account),
+	}, nil
+}
+
 // ListAccounts returns all accounts that are currently stored in the account
 // database.
 func (s *RPCServer) ListAccounts(ctx context.Context,

accounts/service.go

@@ -345,6 +345,56 @@ func (s *InterceptorService) UpdateAccount(ctx context.Context,
 	return s.store.Account(ctx, accountID)
 }
 
+// CreditAccount increases the balance of an existing account in the database.
+func (s *InterceptorService) CreditAccount(ctx context.Context,
+	accountID AccountID,
+	amount lnwire.MilliSatoshi) (*OffChainBalanceAccount, error) {
+
+	s.Lock()
+	defer s.Unlock()
+
+	// As this function updates account balances, we require that the
+	// service is running before we execute it.
+	if !s.isRunningUnsafe() {
+		// This case can only happen if the service is disabled while
+		// we're processing a request.
+		return nil, ErrAccountServiceDisabled
+	}
+
+	// Credit the account in the db.
+	err := s.store.CreditAccount(ctx, accountID, amount)
+	if err != nil {
+		return nil, fmt.Errorf("unable to credit account: %w", err)
+	}
+
+	return s.store.Account(ctx, accountID)
+}
+
+// DebitAccount decreases the balance of an existing account in the database.
+func (s *InterceptorService) DebitAccount(ctx context.Context,
+	accountID AccountID,
+	amount lnwire.MilliSatoshi) (*OffChainBalanceAccount, error) {
+
+	s.Lock()
+	defer s.Unlock()
+
+	// As this function updates account balances, we require that the
+	// service is running before we execute it.
+	if !s.isRunningUnsafe() {
+		// This case can only happen if the service is disabled while
+		// we're processing a request.
+		return nil, ErrAccountServiceDisabled
+	}
+
+	// Debit the account in the db.
+	err := s.store.DebitAccount(ctx, accountID, amount)
+	if err != nil {
+		return nil, fmt.Errorf("unable to debit account: %w", err)
+	}
+
+	return s.store.Account(ctx, accountID)
+}
+
 // Account retrieves an account from the bolt DB and un-marshals it. If the
 // account cannot be found, then ErrAccNotFound is returned.
 func (s *InterceptorService) Account(ctx context.Context,