Fix Split Bill

internal/app/app.go

@@ -135,6 +135,7 @@ type repositories struct {
 	orderRepo             *repository.OrderRepositoryImpl
 	orderItemRepo         *repository.OrderItemRepositoryImpl
 	paymentRepo           *repository.PaymentRepositoryImpl
+	paymentOrderItemRepo  *repository.PaymentOrderItemRepositoryImpl
 	paymentMethodRepo     *repository.PaymentMethodRepositoryImpl
 	fileRepo              *repository.FileRepositoryImpl
 	customerRepo          *repository.CustomerRepository
@@ -158,6 +159,7 @@ func (a *App) initRepositories() *repositories {
 		orderRepo:             repository.NewOrderRepositoryImpl(a.db),
 		orderItemRepo:         repository.NewOrderItemRepositoryImpl(a.db),
 		paymentRepo:           repository.NewPaymentRepositoryImpl(a.db),
+		paymentOrderItemRepo:  repository.NewPaymentOrderItemRepositoryImpl(a.db),
 		paymentMethodRepo:     repository.NewPaymentMethodRepositoryImpl(a.db),
 		fileRepo:              repository.NewFileRepositoryImpl(a.db),
 		customerRepo:          repository.NewCustomerRepository(a.db),
@@ -199,7 +201,7 @@ func (a *App) initProcessors(cfg *config.Config, repos *repositories) *processor
 		productProcessor:        processor.NewProductProcessorImpl(repos.productRepo, repos.categoryRepo, repos.productVariantRepo, repos.inventoryRepo, repos.outletRepo),
 		productVariantProcessor: processor.NewProductVariantProcessorImpl(repos.productVariantRepo, repos.productRepo),
 		inventoryProcessor:      processor.NewInventoryProcessorImpl(repos.inventoryRepo, repos.productRepo, repos.outletRepo),
-		orderProcessor:          processor.NewOrderProcessorImpl(repos.orderRepo, repos.orderItemRepo, repos.paymentRepo, repos.productRepo, repos.paymentMethodRepo, repos.inventoryRepo, repos.inventoryMovementRepo, repos.productVariantRepo, repos.outletRepo, repos.customerRepo),
+		orderProcessor:          processor.NewOrderProcessorImpl(repos.orderRepo, repos.orderItemRepo, repos.paymentRepo, repos.paymentOrderItemRepo, repos.productRepo, repos.paymentMethodRepo, repos.inventoryRepo, repos.inventoryMovementRepo, repos.productVariantRepo, repos.outletRepo, repos.customerRepo),
 		paymentMethodProcessor:  processor.NewPaymentMethodProcessorImpl(repos.paymentMethodRepo),
 		fileProcessor:           processor.NewFileProcessorImpl(repos.fileRepo, fileClient),
 		customerProcessor:       processor.NewCustomerProcessor(repos.customerRepo),

internal/contract/order_contract.go

@@ -67,12 +67,27 @@ type OrderResponse struct {
 	TaxAmount       float64                `json:"tax_amount"`
 	DiscountAmount  float64                `json:"discount_amount"`
 	TotalAmount     float64                `json:"total_amount"`
+	TotalCost       float64                `json:"total_cost"`
+	RemainingAmount float64                `json:"remaining_amount"`
+	PaymentStatus   string                 `json:"payment_status"`
+	RefundAmount    float64                `json:"refund_amount"`
+	IsVoid          bool                   `json:"is_void"`
+	IsRefund        bool                   `json:"is_refund"`
+	VoidReason      *string                `json:"void_reason,omitempty"`
+	VoidedAt        *time.Time             `json:"voided_at,omitempty"`
+	VoidedBy        *uuid.UUID             `json:"voided_by,omitempty"`
+	RefundReason    *string                `json:"refund_reason,omitempty"`
+	RefundedAt      *time.Time             `json:"refunded_at,omitempty"`
+	RefundedBy      *uuid.UUID             `json:"refunded_by,omitempty"`
 	Notes           *string                `json:"notes"`
 	Metadata        map[string]interface{} `json:"metadata,omitempty"`
 	CreatedAt       time.Time              `json:"created_at"`
 	UpdatedAt       time.Time              `json:"updated_at"`
 	OrderItems      []OrderItemResponse    `json:"order_items,omitempty"`
-	IsRefund       bool                   `json:"is_refund"`
+	Payments        []PaymentResponse      `json:"payments,omitempty"`
+	TotalPaid       float64                `json:"total_paid"`
+	PaymentCount    int                    `json:"payment_count"`
+	SplitType       *string                `json:"split_type,omitempty"`
 }
 
 type OrderItemResponse struct {
@@ -124,6 +139,7 @@ type ListOrdersRequest struct {
 
 type ListOrdersResponse struct {
 	Orders     []OrderResponse   `json:"orders"`
+	Payments   []PaymentResponse `json:"payments"`
 	TotalCount int               `json:"total_count"`
 	Page       int               `json:"page"`
 	Limit      int               `json:"limit"`
@@ -152,7 +168,6 @@ type SetOrderCustomerResponse struct {
 	Message    string    `json:"message"`
 }
 
-// Payment-related contracts
 type CreatePaymentRequest struct {
 	OrderID           uuid.UUID                       `json:"order_id" validate:"required"`
 	PaymentMethodID   uuid.UUID                       `json:"payment_method_id" validate:"required"`
@@ -160,6 +175,7 @@ type CreatePaymentRequest struct {
 	TransactionID     *string                         `json:"transaction_id,omitempty" validate:"omitempty"`
 	SplitNumber       int                             `json:"split_number,omitempty" validate:"omitempty,min=1"`
 	SplitTotal        int                             `json:"split_total,omitempty" validate:"omitempty,min=1"`
+	SplitType         *string                         `json:"split_type,omitempty" validate:"omitempty,oneof=AMOUNT ITEM"`
 	SplitDescription  *string                         `json:"split_description,omitempty" validate:"omitempty,max=255"`
 	PaymentOrderItems []CreatePaymentOrderItemRequest `json:"payment_order_items,omitempty" validate:"omitempty,dive"`
 	Metadata          map[string]interface{}          `json:"metadata,omitempty"`
@@ -174,11 +190,14 @@ type PaymentResponse struct {
 	ID                uuid.UUID                  `json:"id"`
 	OrderID           uuid.UUID                  `json:"order_id"`
 	PaymentMethodID   uuid.UUID                  `json:"payment_method_id"`
+	PaymentMethodName string                     `json:"payment_method_name"`
+	PaymentMethodType string                     `json:"payment_method_type"`
 	Amount            float64                    `json:"amount"`
 	Status            string                     `json:"status"`
 	TransactionID     *string                    `json:"transaction_id,omitempty"`
 	SplitNumber       int                        `json:"split_number"`
 	SplitTotal        int                        `json:"split_total"`
+	SplitType         *string                    `json:"split_type,omitempty"`
 	SplitDescription  *string                    `json:"split_description,omitempty"`
 	RefundAmount      float64                    `json:"refund_amount"`
 	RefundReason      *string                    `json:"refund_reason,omitempty"`
@@ -216,3 +235,33 @@ type RefundPaymentRequest struct {
 	RefundAmount float64 `json:"refund_amount" validate:"required,min=0"`
 	Reason       string  `json:"reason" validate:"omitempty,max=255"`
 }
+
+type SplitBillRequest struct {
+	OrderID         uuid.UUID              `json:"order_id" validate:"required"`
+	OrganizationID  uuid.UUID              `json:"organization_id"`
+	PaymentMethodID uuid.UUID              `json:"payment_method_id" validate:"required"`
+	CustomerID      uuid.UUID              `json:"customer_id"`
+	Type            string                 `json:"type" validate:"required,oneof=ITEM AMOUNT"`
+	Items           []SplitBillItemRequest `json:"items,omitempty" validate:"required_if=Type ITEM,dive"`
+	Amount          float64                `json:"amount,omitempty" validate:"required_if=Type AMOUNT,min=0"`
+}
+
+type SplitBillItemRequest struct {
+	OrderItemID uuid.UUID `json:"order_item_id" validate:"required"`
+	Amount      float64   `json:"amount" validate:"required,min=0"`
+}
+
+type SplitBillResponse struct {
+	PaymentID  uuid.UUID               `json:"payment_id"`
+	OrderID    uuid.UUID               `json:"order_id"`
+	CustomerID uuid.UUID               `json:"customer_id"`
+	Type       string                  `json:"type"`
+	Amount     float64                 `json:"amount"`
+	Items      []SplitBillItemResponse `json:"items,omitempty"`
+	Message    string                  `json:"message"`
+}
+
+type SplitBillItemResponse struct {
+	OrderItemID uuid.UUID `json:"order_item_id"`
+	Amount      float64   `json:"amount"`
+}

internal/entities/order.go

@@ -28,6 +28,7 @@ const (
 
 const (
 	PaymentStatusPending           PaymentStatus = "pending"
+	PaymentStatusPartial           PaymentStatus = "partial"
 	PaymentStatusCompleted         PaymentStatus = "completed"
 	PaymentStatusFailed            PaymentStatus = "failed"
 	PaymentStatusRefunded          PaymentStatus = "refunded"
@@ -49,6 +50,7 @@ type Order struct {
 	DiscountAmount  float64       `gorm:"type:decimal(10,2);default:0.00" json:"discount_amount" validate:"min=0"`
 	TotalAmount     float64       `gorm:"type:decimal(10,2);not null" json:"total_amount" validate:"required,min=0"`
 	TotalCost       float64       `gorm:"type:decimal(10,2);default:0.00" json:"total_cost"`
+	RemainingAmount float64       `gorm:"type:decimal(10,2);default:0.00" json:"remaining_amount"`
 	PaymentStatus   PaymentStatus `gorm:"default:'pending';size:50" json:"payment_status"`
 	RefundAmount    float64       `gorm:"type:decimal(10,2);default:0.00" json:"refund_amount"`
 	IsVoid          bool          `gorm:"default:false" json:"is_void"`

internal/entities/payment.go

@@ -50,6 +50,13 @@ const (
 	PaymentTransactionStatusRefunded  PaymentTransactionStatus = "refunded"
 )
 
+type SplitType string
+
+const (
+	SplitTypeAmount SplitType = "AMOUNT"
+	SplitTypeItem   SplitType = "ITEM"
+)
+
 type Payment struct {
 	ID               uuid.UUID                `gorm:"type:uuid;primary_key;default:gen_random_uuid()" json:"id"`
 	OrderID          uuid.UUID                `gorm:"type:uuid;not null;index" json:"order_id" validate:"required"`
@@ -59,6 +66,7 @@ type Payment struct {
 	TransactionID    *string                  `gorm:"size:255" json:"transaction_id"`
 	SplitNumber      int                      `gorm:"default:1" json:"split_number"`
 	SplitTotal       int                      `gorm:"default:1" json:"split_total"`
+	SplitType        *SplitType               `gorm:"size:20" json:"split_type,omitempty"`
 	SplitDescription *string                  `gorm:"size:255" json:"split_description,omitempty"`
 	RefundAmount     float64                  `gorm:"type:decimal(10,2);default:0.00" json:"refund_amount"`
 	RefundReason     *string                  `gorm:"size:255" json:"refund_reason,omitempty"`

internal/handler/order_handler.go

@@ -265,7 +265,6 @@ func (h *OrderHandler) SetOrderCustomer(c *gin.Context) {
 	ctx := c.Request.Context()
 	contextInfo := appcontext.FromGinContext(ctx)
 
-	// Parse order ID from URL parameter
 	orderIDStr := c.Param("id")
 	orderID, err := uuid.Parse(orderIDStr)
 	if err != nil {
@@ -273,24 +272,47 @@ func (h *OrderHandler) SetOrderCustomer(c *gin.Context) {
 		return
 	}
 
-	// Parse request body
 	var req contract.SetOrderCustomerRequest
 	if err := c.ShouldBindJSON(&req); err != nil {
 		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{contract.NewResponseError("invalid_request", "OrderHandler::SetOrderCustomer", err.Error())}), "OrderHandler::SetOrderCustomer")
 		return
 	}
 
-	// Transform contract to model
 	modelReq := transformer.SetOrderCustomerContractToModel(&req)
 
-	// Call service
 	response, err := h.orderService.SetOrderCustomer(ctx, orderID, modelReq, contextInfo.OrganizationID)
 	if err != nil {
 		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{contract.NewResponseError("internal_error", "OrderHandler::SetOrderCustomer", err.Error())}), "OrderHandler::SetOrderCustomer")
 		return
 	}
 
-	// Transform model to contract
 	contractResp := transformer.SetOrderCustomerModelToContract(response)
 	util.HandleResponse(c.Writer, c.Request, contract.BuildSuccessResponse(contractResp), "OrderHandler::SetOrderCustomer")
 }
+
+func (h *OrderHandler) SplitBill(c *gin.Context) {
+	ctx := c.Request.Context()
+	contextInfo := appcontext.FromGinContext(ctx)
+
+	var req contract.SplitBillRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{contract.NewResponseError("invalid_request", "OrderHandler::SplitBill", err.Error())}), "OrderHandler::SplitBill")
+		return
+	}
+
+	if err := h.validator.Validate(&req); err != nil {
+		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{contract.NewResponseError("validation_failed", "OrderHandler::SplitBill", err.Error())}), "OrderHandler::SplitBill")
+		return
+	}
+
+	req.OrganizationID = contextInfo.OrganizationID
+	modelReq := transformer.SplitBillContractToModel(&req)
+	response, err := h.orderService.SplitBill(c.Request.Context(), modelReq)
+	if err != nil {
+		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{contract.NewResponseError("internal_error", "OrderHandler::SplitBill", err.Error())}), "OrderHandler::SplitBill")
+		return
+	}
+
+	contractResp := transformer.SplitBillModelToContract(response)
+	util.HandleResponse(c.Writer, c.Request, contract.BuildSuccessResponse(contractResp), "OrderHandler::SplitBill")
+}

internal/handler/outlet_handler.go

@@ -36,7 +36,6 @@ func (h *OutletHandler) ListOutlets(c *gin.Context) {
 		OrganizationID: contextInfo.OrganizationID,
 	}
 
-	// Parse query parameters
 	if pageStr := c.Query("page"); pageStr != "" {
 		if page, err := strconv.Atoi(pageStr); err == nil {
 			req.Page = page

internal/mappers/order_mapper.go

@@ -8,7 +8,6 @@ import (
 	"github.com/google/uuid"
 )
 
-// Entity to Response mappers
 func OrderEntityToResponse(order *entities.Order) *models.OrderResponse {
 	if order == nil {
 		return nil
@@ -29,6 +28,7 @@ func OrderEntityToResponse(order *entities.Order) *models.OrderResponse {
 		DiscountAmount:  order.DiscountAmount,
 		TotalAmount:     order.TotalAmount,
 		TotalCost:       order.TotalCost,
+		RemainingAmount: order.RemainingAmount,
 		PaymentStatus:   constants.PaymentStatus(order.PaymentStatus),
 		RefundAmount:    order.RefundAmount,
 		IsVoid:          order.IsVoid,
@@ -44,6 +44,29 @@ func OrderEntityToResponse(order *entities.Order) *models.OrderResponse {
 		UpdatedAt:       order.UpdatedAt,
 	}
 
+	// Calculate payment summary and determine split type
+	var totalPaid float64
+	var paymentCount int
+	var splitType *string
+
+	if order.Payments != nil {
+		paymentCount = len(order.Payments)
+		for _, payment := range order.Payments {
+			if payment.Status == entities.PaymentTransactionStatusCompleted {
+				totalPaid += payment.Amount
+			}
+			// Determine split type from the first split payment
+			if splitType == nil && payment.SplitType != nil && payment.SplitTotal > 1 {
+				st := string(*payment.SplitType)
+				splitType = &st
+			}
+		}
+	}
+
+	response.TotalPaid = totalPaid
+	response.PaymentCount = paymentCount
+	response.SplitType = splitType
+
 	// Map order items
 	if order.OrderItems != nil {
 		response.OrderItems = make([]models.OrderItemResponse, len(order.OrderItems))
@@ -119,6 +142,7 @@ func PaymentEntityToResponse(payment *entities.Payment) *models.PaymentResponse
 		TransactionID:    payment.TransactionID,
 		SplitNumber:      payment.SplitNumber,
 		SplitTotal:       payment.SplitTotal,
+		SplitType:        (*string)(payment.SplitType),
 		SplitDescription: payment.SplitDescription,
 		RefundAmount:     payment.RefundAmount,
 		RefundReason:     payment.RefundReason,
@@ -129,6 +153,12 @@ func PaymentEntityToResponse(payment *entities.Payment) *models.PaymentResponse
 		UpdatedAt:        payment.UpdatedAt,
 	}
 
+	// Add payment method information if available
+	if payment.PaymentMethod.ID != uuid.Nil {
+		response.PaymentMethodName = payment.PaymentMethod.Name
+		response.PaymentMethodType = constants.PaymentMethodType(payment.PaymentMethod.Type)
+	}
+
 	// Map payment order items
 	if payment.PaymentOrderItems != nil {
 		response.PaymentOrderItems = make([]models.PaymentOrderItemResponse, len(payment.PaymentOrderItems))
@@ -201,6 +231,12 @@ func CreatePaymentRequestToEntity(req *models.CreatePaymentRequest) *entities.Pa
 		return nil
 	}
 
+	var splitType *entities.SplitType
+	if req.SplitType != nil {
+		st := entities.SplitType(*req.SplitType)
+		splitType = &st
+	}
+
 	payment := &entities.Payment{
 		OrderID:          req.OrderID,
 		PaymentMethodID:  req.PaymentMethodID,
@@ -209,6 +245,7 @@ func CreatePaymentRequestToEntity(req *models.CreatePaymentRequest) *entities.Pa
 		TransactionID:    req.TransactionID,
 		SplitNumber:      req.SplitNumber,
 		SplitTotal:       req.SplitTotal,
+		SplitType:        splitType,
 		SplitDescription: req.SplitDescription,
 		Metadata:         entities.Metadata(req.Metadata),
 	}

internal/models/order.go

@@ -22,6 +22,7 @@ type Order struct {
 	DiscountAmount  float64
 	TotalAmount     float64
 	TotalCost       float64
+	RemainingAmount float64
 	PaymentStatus   constants.PaymentStatus
 	RefundAmount    float64
 	IsVoid          bool
@@ -156,6 +157,7 @@ type OrderResponse struct {
 	DiscountAmount  float64
 	TotalAmount     float64
 	TotalCost       float64
+	RemainingAmount float64
 	PaymentStatus   constants.PaymentStatus
 	RefundAmount    float64
 	IsVoid          bool
@@ -172,6 +174,9 @@ type OrderResponse struct {
 	UpdatedAt       time.Time
 	OrderItems      []OrderItemResponse
 	Payments        []PaymentResponse
+	TotalPaid       float64
+	PaymentCount    int
+	SplitType       *string
 }
 
 type OrderItemResponse struct {
@@ -230,6 +235,7 @@ type ListOrdersRequest struct {
 
 type ListOrdersResponse struct {
 	Orders     []OrderResponse
+	Payments   []PaymentResponse
 	TotalCount int
 	Page       int
 	Limit      int

internal/models/payment.go

@@ -16,6 +16,7 @@ type Payment struct {
 	TransactionID    *string
 	SplitNumber      int
 	SplitTotal       int
+	SplitType        *string
 	SplitDescription *string
 	RefundAmount     float64
 	RefundReason     *string
@@ -33,6 +34,7 @@ type CreatePaymentRequest struct {
 	TransactionID     *string                         `validate:"omitempty"`
 	SplitNumber       int                             `validate:"omitempty,min=1"`
 	SplitTotal        int                             `validate:"omitempty,min=1"`
+	SplitType         *string                         `validate:"omitempty,oneof=AMOUNT ITEM"`
 	SplitDescription  *string                         `validate:"omitempty,max=255"`
 	PaymentOrderItems []CreatePaymentOrderItemRequest `validate:"omitempty,dive"`
 	Metadata          map[string]interface{}
@@ -48,11 +50,14 @@ type PaymentResponse struct {
 	ID                uuid.UUID
 	OrderID           uuid.UUID
 	PaymentMethodID   uuid.UUID
+	PaymentMethodName string
+	PaymentMethodType constants.PaymentMethodType
 	Amount            float64
 	Status            constants.PaymentTransactionStatus
 	TransactionID     *string
 	SplitNumber       int
 	SplitTotal        int
+	SplitType         *string
 	SplitDescription  *string
 	RefundAmount      float64
 	RefundReason      *string

internal/models/split_bill.go

@@ -0,0 +1,46 @@
+package models
+
+import "github.com/google/uuid"
+
+const (
+	Amount = "AMOUNT"
+	Item   = "ITEM"
+)
+
+type SplitBillRequest struct {
+	OrderID         uuid.UUID              `validate:"required"`
+	PaymentMethodID uuid.UUID              `validate:"required"`
+	CustomerID      uuid.UUID              `validate:"required"`
+	Type            string                 `validate:"required,oneof=ITEM AMOUNT"`
+	Items           []SplitBillItemRequest `validate:"required_if=Type ITEM,dive"`
+	Amount          float64                `validate:"required_if=Type AMOUNT,min=0"`
+	OrganizationID  uuid.UUID
+}
+
+func (s *SplitBillRequest) IsItem() bool {
+	return s.Type == Item
+}
+
+func (s *SplitBillRequest) IsAmount() bool {
+	return s.Type == Amount
+}
+
+type SplitBillItemRequest struct {
+	OrderItemID uuid.UUID `validate:"required"`
+	Amount      float64   `validate:"required,min=0"`
+}
+
+type SplitBillResponse struct {
+	PaymentID  uuid.UUID               `json:"payment_id"`
+	OrderID    uuid.UUID               `json:"order_id"`
+	CustomerID uuid.UUID               `json:"customer_id"`
+	Type       string                  `json:"type"`
+	Amount     float64                 `json:"amount"`
+	Items      []SplitBillItemResponse `json:"items,omitempty"`
+	Message    string                  `json:"message"`
+}
+
+type SplitBillItemResponse struct {
+	OrderItemID uuid.UUID `json:"order_item_id"`
+	Amount      float64   `json:"amount"`
+}

internal/processor/order_processor.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"fmt"
 
+	"gorm.io/gorm"
+
 	"apskel-pos-be/internal/constants"
 	"apskel-pos-be/internal/entities"
 	"apskel-pos-be/internal/mappers"
@@ -24,6 +26,7 @@ type OrderProcessor interface {
 	CreatePayment(ctx context.Context, req *models.CreatePaymentRequest) (*models.PaymentResponse, error)
 	RefundPayment(ctx context.Context, paymentID uuid.UUID, refundAmount float64, reason string, refundedBy uuid.UUID) error
 	SetOrderCustomer(ctx context.Context, orderID uuid.UUID, req *models.SetOrderCustomerRequest, organizationID uuid.UUID) (*models.SetOrderCustomerResponse, error)
+	SplitBill(ctx context.Context, req *models.SplitBillRequest) (*models.SplitBillResponse, error)
 }
 
 type OrderRepository interface {
@@ -67,6 +70,14 @@ type PaymentRepository interface {
 	RefundPaymentWithInventoryMovement(ctx context.Context, paymentID uuid.UUID, refundAmount float64, reason string, refundedBy uuid.UUID, order *entities.Payment) error
 }
 
+type PaymentOrderItemRepository interface {
+	Create(ctx context.Context, paymentOrderItem *entities.PaymentOrderItem) error
+	GetByID(ctx context.Context, id uuid.UUID) (*entities.PaymentOrderItem, error)
+	GetByPaymentID(ctx context.Context, paymentID uuid.UUID) ([]*entities.PaymentOrderItem, error)
+	Update(ctx context.Context, paymentOrderItem *entities.PaymentOrderItem) error
+	Delete(ctx context.Context, id uuid.UUID) error
+}
+
 type PaymentMethodRepository interface {
 	GetByID(ctx context.Context, id uuid.UUID) (*entities.PaymentMethod, error)
 }
@@ -95,6 +106,7 @@ type OrderProcessorImpl struct {
 	orderRepo             OrderRepository
 	orderItemRepo         OrderItemRepository
 	paymentRepo           PaymentRepository
+	paymentOrderItemRepo  PaymentOrderItemRepository
 	productRepo           ProductRepository
 	paymentMethodRepo     PaymentMethodRepository
 	inventoryRepo         repository.InventoryRepository
@@ -108,6 +120,7 @@ func NewOrderProcessorImpl(
 	orderRepo OrderRepository,
 	orderItemRepo OrderItemRepository,
 	paymentRepo PaymentRepository,
+	paymentOrderItemRepo PaymentOrderItemRepository,
 	productRepo ProductRepository,
 	paymentMethodRepo PaymentMethodRepository,
 	inventoryRepo repository.InventoryRepository,
@@ -120,6 +133,7 @@ func NewOrderProcessorImpl(
 		orderRepo:             orderRepo,
 		orderItemRepo:         orderItemRepo,
 		paymentRepo:           paymentRepo,
+		paymentOrderItemRepo:  paymentOrderItemRepo,
 		productRepo:           productRepo,
 		paymentMethodRepo:     paymentMethodRepo,
 		inventoryRepo:         inventoryRepo,
@@ -216,6 +230,7 @@ func (p *OrderProcessorImpl) CreateOrder(ctx context.Context, req *models.Create
 		DiscountAmount:  0,
 		TotalAmount:     totalAmount,
 		TotalCost:       totalCost,
+		RemainingAmount: totalAmount, // Initialize remaining amount equal to total amount
 		PaymentStatus:   entities.PaymentStatusPending,
 		IsVoid:          false,
 		IsRefund:        false,
@@ -325,6 +340,17 @@ func (p *OrderProcessorImpl) AddToOrder(ctx context.Context, orderID uuid.UUID,
 	order.TaxAmount = order.Subtotal * outlet.TaxRate
 	order.TotalAmount = order.Subtotal + order.TaxAmount - order.DiscountAmount
 
+	// Recalculate remaining amount when items are added
+	totalPaid, err := p.paymentRepo.GetTotalPaidByOrderID(ctx, orderID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get total paid amount: %w", err)
+	}
+
+	order.RemainingAmount = order.TotalAmount - totalPaid
+	if order.RemainingAmount < 0 {
+		order.RemainingAmount = 0
+	}
+
 	if req.Metadata != nil {
 		if order.Metadata == nil {
 			order.Metadata = make(entities.Metadata)
@@ -409,6 +435,17 @@ func (p *OrderProcessorImpl) UpdateOrder(ctx context.Context, id uuid.UUID, req
 		order.DiscountAmount = *req.DiscountAmount
 		// Recalculate total amount
 		order.TotalAmount = order.Subtotal + order.TaxAmount - order.DiscountAmount
+
+		// Recalculate remaining amount when discount is applied
+		totalPaid, err := p.paymentRepo.GetTotalPaidByOrderID(ctx, id)
+		if err != nil {
+			return nil, fmt.Errorf("failed to get total paid amount: %w", err)
+		}
+
+		order.RemainingAmount = order.TotalAmount - totalPaid
+		if order.RemainingAmount < 0 {
+			order.RemainingAmount = 0
+		}
 	}
 	if req.Metadata != nil {
 		if order.Metadata == nil {
@@ -489,16 +526,20 @@ func (p *OrderProcessorImpl) ListOrders(ctx context.Context, req *models.ListOrd
 		return nil, fmt.Errorf("failed to list orders: %w", err)
 	}
 
-	// Convert to responses
 	orderResponses := make([]models.OrderResponse, len(orders))
+	allPayments := make([]models.PaymentResponse, 0)
+
 	for i, order := range orders {
 		response := mappers.OrderEntityToResponse(order)
 		if response != nil {
 			orderResponses[i] = *response
+			// Add payments from this order to the allPayments list
+			if response.Payments != nil {
+				allPayments = append(allPayments, response.Payments...)
+			}
 		}
 	}
 
-	// Calculate total pages
 	totalPages := int(total) / req.Limit
 	if int(total)%req.Limit > 0 {
 		totalPages++
@@ -506,6 +547,7 @@ func (p *OrderProcessorImpl) ListOrders(ctx context.Context, req *models.ListOrd
 
 	return &models.ListOrdersResponse{
 		Orders:     orderResponses,
+		Payments:   allPayments,
 		TotalCount: int(total),
 		Page:       req.Page,
 		Limit:      req.Limit,
@@ -738,6 +780,21 @@ func (p *OrderProcessorImpl) CreatePayment(ctx context.Context, req *models.Crea
 		return nil, err
 	}
 
+	// Update order payment status and remaining amount in processor layer
+	newTotalPaid := totalPaid + req.Amount
+	order.RemainingAmount = order.TotalAmount - newTotalPaid
+
+	if newTotalPaid >= order.TotalAmount {
+		order.PaymentStatus = entities.PaymentStatusCompleted
+		order.RemainingAmount = 0
+	} else {
+		order.PaymentStatus = entities.PaymentStatusPartial
+	}
+
+	if err := p.orderRepo.Update(ctx, order); err != nil {
+		return nil, fmt.Errorf("failed to update order payment status: %w", err)
+	}
+
 	paymentWithRelations, err := p.paymentRepo.GetByID(ctx, payment.ID)
 	if err != nil {
 		return nil, fmt.Errorf("failed to retrieve created payment: %w", err)
@@ -769,18 +826,15 @@ func (p *OrderProcessorImpl) RefundPayment(ctx context.Context, paymentID uuid.U
 }
 
 func (p *OrderProcessorImpl) SetOrderCustomer(ctx context.Context, orderID uuid.UUID, req *models.SetOrderCustomerRequest, organizationID uuid.UUID) (*models.SetOrderCustomerResponse, error) {
-	// Get the order
 	order, err := p.orderRepo.GetByID(ctx, orderID)
 	if err != nil {
 		return nil, fmt.Errorf("order not found: %w", err)
 	}
 
-	// Verify order belongs to the organization
 	if order.OrganizationID != organizationID {
 		return nil, fmt.Errorf("order does not belong to the organization")
 	}
 
-	// Check if order status is pending (only pending orders can have customer set)
 	if order.Status != entities.OrderStatusPending {
 		return nil, fmt.Errorf("customer can only be set for pending orders")
 	}
@@ -805,3 +859,255 @@ func (p *OrderProcessorImpl) SetOrderCustomer(ctx context.Context, orderID uuid.
 
 	return response, nil
 }
+
+func (p *OrderProcessorImpl) SplitBill(ctx context.Context, req *models.SplitBillRequest) (*models.SplitBillResponse, error) {
+	order, err := p.orderRepo.GetWithRelations(ctx, req.OrderID)
+	if err != nil {
+		return nil, fmt.Errorf("order not found: %w", err)
+	}
+
+	if order.IsVoid {
+		return nil, fmt.Errorf("cannot split voided order")
+	}
+
+	if order.PaymentStatus == entities.PaymentStatusCompleted {
+		return nil, fmt.Errorf("cannot split fully paid order")
+	}
+
+	existingPayments, err := p.paymentRepo.GetByOrderID(ctx, req.OrderID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get existing payments: %w", err)
+	}
+
+	var existingSplitType *entities.SplitType
+	for _, payment := range existingPayments {
+		if payment.SplitType != nil && payment.SplitTotal > 1 {
+			existingSplitType = payment.SplitType
+			break
+		}
+	}
+
+	if existingSplitType != nil {
+		requestedSplitType := entities.SplitTypeAmount
+		if req.IsItem() {
+			requestedSplitType = entities.SplitTypeItem
+		}
+
+		if *existingSplitType != requestedSplitType {
+			return nil, fmt.Errorf("order already has %s split payments. Subsequent payments must use the same split type", *existingSplitType)
+		}
+	}
+
+	payment, err := p.paymentMethodRepo.GetByID(ctx, req.PaymentMethodID)
+	if err != nil {
+		return nil, fmt.Errorf("payment method not found: %w", err)
+	}
+
+	customer := &entities.Customer{}
+	if req.CustomerID != uuid.Nil {
+		customer, err = p.customerRepo.GetByIDAndOrganization(ctx, req.CustomerID, order.OrganizationID)
+
+		if err != nil && err != gorm.ErrRecordNotFound {
+			return nil, fmt.Errorf("customer not found or does not belong to the organization: %w", err)
+		}
+	}
+
+	var response *models.SplitBillResponse
+	if req.IsAmount() {
+		response, err = p.splitBillByAmount(ctx, req, order, payment, customer)
+	} else if req.IsItem() {
+		response, err = p.splitBillByItem(ctx, req, order, payment, customer)
+	} else {
+		return nil, fmt.Errorf("invalid split type: must be AMOUNT or ITEM")
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+func (p *OrderProcessorImpl) splitBillByAmount(ctx context.Context, req *models.SplitBillRequest, order *entities.Order, payment *entities.PaymentMethod, customer *entities.Customer) (*models.SplitBillResponse, error) {
+	totalPaid, err := p.paymentRepo.GetTotalPaidByOrderID(ctx, req.OrderID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get total paid amount: %w", err)
+	}
+
+	remainingBalance := order.TotalAmount - totalPaid
+	if req.Amount > remainingBalance {
+		return nil, fmt.Errorf("split amount %.2f cannot exceed remaining balance %.2f", req.Amount, remainingBalance)
+	}
+
+	existingPayments, err := p.paymentRepo.GetByOrderID(ctx, req.OrderID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get existing payments: %w", err)
+	}
+
+	splitNumber := len(existingPayments) + 1
+	splitTotal := splitNumber + 1
+
+	splitType := entities.SplitTypeAmount
+	splitPayment := &entities.Payment{
+		OrderID:          req.OrderID,
+		PaymentMethodID:  payment.ID,
+		Amount:           req.Amount,
+		Status:           entities.PaymentTransactionStatusCompleted,
+		SplitNumber:      splitNumber,
+		SplitTotal:       splitTotal,
+		SplitType:        &splitType,
+		SplitDescription: stringPtr(fmt.Sprint("Split payment for customer")),
+		Metadata: entities.Metadata{
+			"split_type": "AMOUNT",
+		},
+	}
+
+	if err := p.paymentRepo.Create(ctx, splitPayment); err != nil {
+		return nil, fmt.Errorf("failed to create split payment: %w", err)
+	}
+
+	if order.Metadata == nil {
+		order.Metadata = make(entities.Metadata)
+	}
+
+	order.Metadata["last_split_payment_id"] = splitPayment.ID.String()
+	order.Metadata["last_split_customer_id"] = req.CustomerID.String()
+	order.Metadata["last_split_amount"] = req.Amount
+	order.Metadata["last_split_type"] = "AMOUNT"
+
+	newTotalPaid := totalPaid + req.Amount
+	order.RemainingAmount = order.TotalAmount - newTotalPaid
+
+	if newTotalPaid >= order.TotalAmount {
+		order.PaymentStatus = entities.PaymentStatusCompleted
+		order.Status = entities.OrderStatusCompleted
+		order.RemainingAmount = 0
+	} else {
+		order.PaymentStatus = entities.PaymentStatusPartial
+	}
+
+	if err := p.orderRepo.Update(ctx, order); err != nil {
+		return nil, fmt.Errorf("failed to update order: %w", err)
+	}
+
+	return &models.SplitBillResponse{
+		PaymentID:  splitPayment.ID,
+		OrderID:    req.OrderID,
+		CustomerID: req.CustomerID,
+		Type:       "AMOUNT",
+		Amount:     req.Amount,
+		Message:    fmt.Sprintf("Successfully split payment by amount %.2f for customer %s. Remaining balance: %.2f", req.Amount, customer.Name, order.RemainingAmount),
+	}, nil
+}
+
+func (p *OrderProcessorImpl) splitBillByItem(ctx context.Context, req *models.SplitBillRequest, order *entities.Order, payment *entities.PaymentMethod, customer *entities.Customer) (*models.SplitBillResponse, error) {
+	totalSplitAmount := float64(0)
+	for _, item := range req.Items {
+		totalSplitAmount += item.Amount
+	}
+
+	totalPaid, err := p.paymentRepo.GetTotalPaidByOrderID(ctx, req.OrderID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get total paid amount: %w", err)
+	}
+
+	remainingBalance := order.TotalAmount - totalPaid
+
+	if totalSplitAmount > remainingBalance {
+		return nil, fmt.Errorf("split amount %.2f cannot exceed remaining balance %.2f", totalSplitAmount, remainingBalance)
+	}
+
+	for _, item := range req.Items {
+		orderItem, err := p.orderItemRepo.GetByID(ctx, item.OrderItemID)
+		if err != nil {
+			return nil, fmt.Errorf("order item not found: %w", err)
+		}
+		if orderItem.OrderID != req.OrderID {
+			return nil, fmt.Errorf("order item does not belong to this order")
+		}
+	}
+
+	existingPayments, err := p.paymentRepo.GetByOrderID(ctx, req.OrderID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get existing payments: %w", err)
+	}
+
+	splitNumber := len(existingPayments) + 1
+	splitTotal := splitNumber + 1
+
+	splitType := entities.SplitTypeItem
+	splitPayment := &entities.Payment{
+		OrderID:          req.OrderID,
+		PaymentMethodID:  payment.ID,
+		Amount:           totalSplitAmount,
+		Status:           entities.PaymentTransactionStatusCompleted,
+		SplitNumber:      splitNumber,
+		SplitTotal:       splitTotal,
+		SplitType:        &splitType,
+		SplitDescription: stringPtr(fmt.Sprintf("Split payment by items for customer: %s", customer.Name)),
+		Metadata: entities.Metadata{
+			"split_type":    "ITEM",
+			"customer_id":   req.CustomerID.String(),
+			"customer_name": customer.Name,
+		},
+	}
+
+	if err := p.paymentRepo.Create(ctx, splitPayment); err != nil {
+		return nil, fmt.Errorf("failed to create split payment: %w", err)
+	}
+
+	for _, item := range req.Items {
+		paymentOrderItem := &entities.PaymentOrderItem{
+			PaymentID:   splitPayment.ID,
+			OrderItemID: item.OrderItemID,
+			Amount:      item.Amount,
+		}
+
+		if err := p.paymentOrderItemRepo.Create(ctx, paymentOrderItem); err != nil {
+			return nil, fmt.Errorf("failed to create payment order item: %w", err)
+		}
+	}
+
+	if order.Metadata == nil {
+		order.Metadata = make(entities.Metadata)
+	}
+
+	order.Metadata["last_split_payment_id"] = splitPayment.ID.String()
+	order.Metadata["last_split_customer_id"] = req.CustomerID.String()
+	order.Metadata["last_split_customer_name"] = customer.Name
+	order.Metadata["last_split_amount"] = totalSplitAmount
+	order.Metadata["last_split_type"] = "ITEM"
+
+	newTotalPaid := totalPaid + totalSplitAmount
+	order.RemainingAmount = order.TotalAmount - newTotalPaid
+
+	if newTotalPaid >= order.TotalAmount {
+		order.PaymentStatus = entities.PaymentStatusCompleted
+		order.Status = entities.OrderStatusCompleted
+		order.RemainingAmount = 0
+	} else {
+		order.PaymentStatus = entities.PaymentStatusPartial
+	}
+
+	if err := p.orderRepo.Update(ctx, order); err != nil {
+		return nil, fmt.Errorf("failed to update order: %w", err)
+	}
+
+	responseItems := make([]models.SplitBillItemResponse, len(req.Items))
+	for i, item := range req.Items {
+		responseItems[i] = models.SplitBillItemResponse{
+			OrderItemID: item.OrderItemID,
+			Amount:      item.Amount,
+		}
+	}
+
+	return &models.SplitBillResponse{
+		PaymentID:  splitPayment.ID,
+		OrderID:    req.OrderID,
+		CustomerID: req.CustomerID,
+		Type:       "ITEM",
+		Amount:     totalSplitAmount,
+		Items:      responseItems,
+		Message:    fmt.Sprintf("Successfully split payment by items (%.2f) for customer %s. Remaining balance: %.2f", totalSplitAmount, customer.Name, order.RemainingAmount),
+	}, nil
+}

internal/processor/outlet_processor.go

@@ -31,10 +31,8 @@ func NewOutletProcessorImpl(outletRepo *repository.OutletRepositoryImpl) *Outlet
 }
 
 func (p *OutletProcessorImpl) ListOutletsByOrganization(ctx context.Context, organizationID uuid.UUID, page, limit int) ([]*models.OutletResponse, int64, error) {
-
 	offset := (page - 1) * limit
 
-	// Get outlets with pagination
 	outlets, total, err := p.outletRepo.GetByOrganizationIDWithPagination(ctx, organizationID, limit, offset)
 	if err != nil {
 		return nil, 0, fmt.Errorf("failed to get outlets: %w", err)

internal/repository/order_repository.go

@@ -90,7 +90,8 @@ func (r *OrderRepositoryImpl) List(ctx context.Context, filters map[string]inter
 		Preload("OrderItems.Product").
 		Preload("OrderItems.ProductVariant").
 		Preload("Payments").
-		Preload("Payments.PaymentMethod")
+		Preload("Payments.PaymentMethod").
+		Preload("Payments.PaymentOrderItems")
 
 	for key, value := range filters {
 		switch key {

internal/repository/payment_order_item_repository.go

@@ -0,0 +1,62 @@
+package repository
+
+import (
+	"context"
+
+	"apskel-pos-be/internal/entities"
+
+	"github.com/google/uuid"
+	"gorm.io/gorm"
+)
+
+type PaymentOrderItemRepository interface {
+	Create(ctx context.Context, paymentOrderItem *entities.PaymentOrderItem) error
+	GetByID(ctx context.Context, id uuid.UUID) (*entities.PaymentOrderItem, error)
+	GetByPaymentID(ctx context.Context, paymentID uuid.UUID) ([]*entities.PaymentOrderItem, error)
+	Update(ctx context.Context, paymentOrderItem *entities.PaymentOrderItem) error
+	Delete(ctx context.Context, id uuid.UUID) error
+}
+
+type PaymentOrderItemRepositoryImpl struct {
+	db *gorm.DB
+}
+
+func NewPaymentOrderItemRepositoryImpl(db *gorm.DB) *PaymentOrderItemRepositoryImpl {
+	return &PaymentOrderItemRepositoryImpl{
+		db: db,
+	}
+}
+
+func (r *PaymentOrderItemRepositoryImpl) Create(ctx context.Context, paymentOrderItem *entities.PaymentOrderItem) error {
+	return r.db.WithContext(ctx).Create(paymentOrderItem).Error
+}
+
+func (r *PaymentOrderItemRepositoryImpl) GetByID(ctx context.Context, id uuid.UUID) (*entities.PaymentOrderItem, error) {
+	var paymentOrderItem entities.PaymentOrderItem
+	err := r.db.WithContext(ctx).
+		Preload("Payment").
+		Preload("OrderItem").
+		First(&paymentOrderItem, "id = ?", id).Error
+	if err != nil {
+		return nil, err
+	}
+	return &paymentOrderItem, nil
+}
+
+func (r *PaymentOrderItemRepositoryImpl) GetByPaymentID(ctx context.Context, paymentID uuid.UUID) ([]*entities.PaymentOrderItem, error) {
+	var paymentOrderItems []*entities.PaymentOrderItem
+	err := r.db.WithContext(ctx).
+		Preload("Payment").
+		Preload("OrderItem").
+		Where("payment_id = ?", paymentID).
+		Find(&paymentOrderItems).Error
+	return paymentOrderItems, err
+}
+
+func (r *PaymentOrderItemRepositoryImpl) Update(ctx context.Context, paymentOrderItem *entities.PaymentOrderItem) error {
+	return r.db.WithContext(ctx).Save(paymentOrderItem).Error
+}
+
+func (r *PaymentOrderItemRepositoryImpl) Delete(ctx context.Context, id uuid.UUID) error {
+	return r.db.WithContext(ctx).Delete(&entities.PaymentOrderItem{}, "id = ?", id).Error
+}

internal/repository/payment_repository.go

@@ -122,17 +122,9 @@ func (r *PaymentRepositoryImpl) CreatePaymentWithInventoryMovement(ctx context.C
 			if order.PaymentStatus != entities.PaymentStatusCompleted {
 				orderJustCompleted = true
 			}
-			if err := tx.Model(&entities.Order{}).Where("id = ?", req.OrderID).Update("payment_status", entities.PaymentStatusCompleted).Error; err != nil {
-				return fmt.Errorf("failed to update order payment status: %w", err)
-			}
-
 			if err := tx.Model(&entities.Order{}).Where("id = ?", req.OrderID).Update("status", entities.OrderStatusCompleted).Error; err != nil {
 				return fmt.Errorf("failed to update order status: %w", err)
 			}
-		} else {
-			if err := tx.Model(&entities.Order{}).Where("id = ?", req.OrderID).Update("payment_status", entities.PaymentStatusPartiallyRefunded).Error; err != nil {
-				return fmt.Errorf("failed to update order payment status: %w", err)
-			}
 		}
 
 		if orderJustCompleted {

internal/router/router.go

@@ -211,6 +211,7 @@ func (r *Router) addAppRoutes(rg *gin.Engine) {
 				orders.PUT("/:id/customer", r.orderHandler.SetOrderCustomer)
 				orders.POST("/void", r.orderHandler.VoidOrder)
 				orders.POST("/:id/refund", r.orderHandler.RefundOrder)
+				orders.POST("/split-bill", r.orderHandler.SplitBill)
 			}
 
 			payments := protected.Group("/payments")

internal/service/order_service.go

@@ -21,6 +21,7 @@ type OrderService interface {
 	CreatePayment(ctx context.Context, req *models.CreatePaymentRequest) (*models.PaymentResponse, error)
 	RefundPayment(ctx context.Context, paymentID uuid.UUID, refundAmount float64, reason string, refundedBy uuid.UUID) error
 	SetOrderCustomer(ctx context.Context, orderID uuid.UUID, req *models.SetOrderCustomerRequest, organizationID uuid.UUID) (*models.SetOrderCustomerResponse, error)
+	SplitBill(ctx context.Context, req *models.SplitBillRequest) (*models.SplitBillResponse, error)
 }
 
 type OrderServiceImpl struct {
@@ -95,12 +96,10 @@ func (s *OrderServiceImpl) GetOrderByID(ctx context.Context, id uuid.UUID) (*mod
 }
 
 func (s *OrderServiceImpl) ListOrders(ctx context.Context, req *models.ListOrdersRequest) (*models.ListOrdersResponse, error) {
-	// Validate request
 	if err := s.validateListOrdersRequest(req); err != nil {
 		return nil, fmt.Errorf("validation error: %w", err)
 	}
 
-	// Process order listing
 	response, err := s.orderProcessor.ListOrders(ctx, req)
 	if err != nil {
 		return nil, fmt.Errorf("failed to list orders: %w", err)
@@ -384,3 +383,65 @@ func (s *OrderServiceImpl) validateSetOrderCustomerRequest(req *models.SetOrderC
 
 	return nil
 }
+
+func (s *OrderServiceImpl) SplitBill(ctx context.Context, req *models.SplitBillRequest) (*models.SplitBillResponse, error) {
+	if err := s.validateSplitBillRequest(req); err != nil {
+		return nil, fmt.Errorf("validation error: %w", err)
+	}
+
+	response, err := s.orderProcessor.SplitBill(ctx, req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to split bill: %w", err)
+	}
+
+	return response, nil
+}
+
+func (s *OrderServiceImpl) validateSplitBillRequest(req *models.SplitBillRequest) error {
+	if req == nil {
+		return fmt.Errorf("request cannot be nil")
+	}
+
+	if req.OrderID == uuid.Nil {
+		return fmt.Errorf("order ID is required")
+	}
+
+	if req.PaymentMethodID == uuid.Nil {
+		return fmt.Errorf("payment ID is required")
+	}
+
+	if req.Type != "ITEM" && req.Type != "AMOUNT" {
+		return fmt.Errorf("split type must be either ITEM or AMOUNT")
+	}
+
+	if req.Type == "ITEM" {
+		if len(req.Items) == 0 {
+			return fmt.Errorf("items are required when splitting by ITEM")
+		}
+
+		totalItemAmount := float64(0)
+		for i, item := range req.Items {
+			if item.OrderItemID == uuid.Nil {
+				return fmt.Errorf("order item ID is required for item %d", i+1)
+			}
+
+			if item.Amount <= 0 {
+				return fmt.Errorf("amount must be greater than zero for item %d", i+1)
+			}
+
+			totalItemAmount += item.Amount
+		}
+
+		if totalItemAmount <= 0 {
+			return fmt.Errorf("total item amount must be greater than zero")
+		}
+	}
+
+	if req.Type == "AMOUNT" {
+		if req.Amount <= 0 {
+			return fmt.Errorf("amount must be greater than zero when splitting by AMOUNT")
+		}
+	}
+
+	return nil
+}

internal/service/outlet_service.go

@@ -29,7 +29,6 @@ func NewOutletService(outletProcessor processor.OutletProcessor) *OutletServiceI
 }
 
 func (s *OutletServiceImpl) ListOutlets(ctx context.Context, req *contract.ListOutletsRequest) *contract.Response {
-	// Validate request
 	if req.Page < 1 {
 		req.Page = 1
 	}
@@ -51,7 +50,6 @@ func (s *OutletServiceImpl) ListOutlets(ctx context.Context, req *contract.ListO
 		contractOutlets[i] = transformer.OutletModelResponseToResponse(outlet)
 	}
 
-	// Create paginated response
 	response := transformer.CreateListOutletsResponse(contractOutlets, int(total), req.Page, req.Limit)
 	return contract.BuildSuccessResponse(response)
 }

internal/transformer/order_transformer.go

@@ -111,6 +111,12 @@ func OrderModelToContract(resp *models.OrderResponse) *contract.OrderResponse {
 			PrinterType:        item.PrinterType,
 		}
 	}
+	// Map payments
+	payments := make([]contract.PaymentResponse, len(resp.Payments))
+	for i, payment := range resp.Payments {
+		payments[i] = *PaymentModelToContract(&payment)
+	}
+
 	return &contract.OrderResponse{
 		ID:              resp.ID,
 		OrderNumber:     resp.OrderNumber,
@@ -123,12 +129,27 @@ func OrderModelToContract(resp *models.OrderResponse) *contract.OrderResponse {
 		TaxAmount:       resp.TaxAmount,
 		DiscountAmount:  resp.DiscountAmount,
 		TotalAmount:     resp.TotalAmount,
+		TotalCost:       resp.TotalCost,
+		RemainingAmount: resp.RemainingAmount,
+		PaymentStatus:   string(resp.PaymentStatus),
+		RefundAmount:    resp.RefundAmount,
+		IsVoid:          resp.IsVoid,
+		IsRefund:        resp.IsRefund,
+		VoidReason:      resp.VoidReason,
+		VoidedAt:        resp.VoidedAt,
+		VoidedBy:        resp.VoidedBy,
+		RefundReason:    resp.RefundReason,
+		RefundedAt:      resp.RefundedAt,
+		RefundedBy:      resp.RefundedBy,
 		Notes:           resp.Notes,
 		Metadata:        resp.Metadata,
 		CreatedAt:       resp.CreatedAt,
 		UpdatedAt:       resp.UpdatedAt,
 		OrderItems:      items,
-		IsRefund:       resp.IsRefund,
+		Payments:        payments,
+		TotalPaid:       resp.TotalPaid,
+		PaymentCount:    resp.PaymentCount,
+		SplitType:       resp.SplitType,
 	}
 }
 
@@ -257,8 +278,14 @@ func ListOrdersModelToContract(resp *models.ListOrdersResponse) *contract.ListOr
 		orders[i] = *OrderModelToContract(&order)
 	}
 
+	payments := make([]contract.PaymentResponse, len(resp.Payments))
+	for i, payment := range resp.Payments {
+		payments[i] = *PaymentModelToContract(&payment)
+	}
+
 	return &contract.ListOrdersResponse{
 		Orders:     orders,
+		Payments:   payments,
 		TotalCount: resp.TotalCount,
 		Page:       resp.Page,
 		Limit:      resp.Limit,
@@ -309,11 +336,14 @@ func PaymentModelToContract(resp *models.PaymentResponse) *contract.PaymentRespo
 		ID:                resp.ID,
 		OrderID:           resp.OrderID,
 		PaymentMethodID:   resp.PaymentMethodID,
+		PaymentMethodName: resp.PaymentMethodName,
+		PaymentMethodType: string(resp.PaymentMethodType),
 		Amount:            resp.Amount,
 		Status:            string(resp.Status),
 		TransactionID:     resp.TransactionID,
 		SplitNumber:       resp.SplitNumber,
 		SplitTotal:        resp.SplitTotal,
+		SplitType:         resp.SplitType,
 		SplitDescription:  resp.SplitDescription,
 		RefundAmount:      resp.RefundAmount,
 		RefundReason:      resp.RefundReason,
@@ -342,3 +372,46 @@ func RefundOrderContractToModel(req *contract.RefundOrderRequest) *models.Refund
 		OrderItems:   orderItems,
 	}
 }
+
+func SplitBillContractToModel(req *contract.SplitBillRequest) *models.SplitBillRequest {
+	items := make([]models.SplitBillItemRequest, len(req.Items))
+	for i, item := range req.Items {
+		items[i] = models.SplitBillItemRequest{
+			OrderItemID: item.OrderItemID,
+			Amount:      item.Amount,
+		}
+	}
+	return &models.SplitBillRequest{
+		OrderID:         req.OrderID,
+		PaymentMethodID: req.PaymentMethodID,
+		CustomerID:      req.CustomerID,
+		Type:            req.Type,
+		Items:           items,
+		Amount:          req.Amount,
+		OrganizationID:  req.OrganizationID,
+	}
+}
+
+func SplitBillModelToContract(resp *models.SplitBillResponse) *contract.SplitBillResponse {
+	if resp == nil {
+		return nil
+	}
+
+	items := make([]contract.SplitBillItemResponse, len(resp.Items))
+	for i, item := range resp.Items {
+		items[i] = contract.SplitBillItemResponse{
+			OrderItemID: item.OrderItemID,
+			Amount:      item.Amount,
+		}
+	}
+
+	return &contract.SplitBillResponse{
+		PaymentID:  resp.PaymentID,
+		OrderID:    resp.OrderID,
+		CustomerID: resp.CustomerID,
+		Type:       resp.Type,
+		Amount:     resp.Amount,
+		Items:      items,
+		Message:    resp.Message,
+	}
+}

internal/transformer/outlet_transformer.go

@@ -35,7 +35,7 @@ func OutletModelResponseToResponse(model *models.OutletResponse) contract.Outlet
 		OrganizationID: model.OrganizationID,
 		Name:           model.Name,
 		Address:        *model.Address,
-		BusinessType:   string(constants.BusinessTypeRestaurant), // Default business type
+		BusinessType:   string(constants.BusinessTypeRestaurant),
 		Currency:       model.Currency,
 		TaxRate:        model.TaxRate,
 		IsActive:       model.IsActive,

migrations/000033_add_remaining_amount_to_orders.down.sql

@@ -0,0 +1,5 @@
+-- Remove constraint
+ALTER TABLE orders DROP CONSTRAINT IF EXISTS check_remaining_amount_non_negative;
+
+-- Remove remaining_amount column from orders table
+ALTER TABLE orders DROP COLUMN IF EXISTS remaining_amount; 

migrations/000033_add_remaining_amount_to_orders.up.sql

@@ -0,0 +1,8 @@
+-- Add remaining_amount column to orders table
+ALTER TABLE orders ADD COLUMN remaining_amount DECIMAL(10,2) DEFAULT 0.00;
+
+-- Update existing orders to set remaining_amount equal to total_amount
+UPDATE orders SET remaining_amount = total_amount WHERE remaining_amount = 0.00;
+
+-- Add constraint to ensure remaining_amount is not negative
+ALTER TABLE orders ADD CONSTRAINT check_remaining_amount_non_negative CHECK (remaining_amount >= 0.00); 

migrations/000034_add_split_type_to_payments.down.sql

@@ -0,0 +1,8 @@
+-- Remove constraint
+ALTER TABLE payments DROP CONSTRAINT IF EXISTS check_split_type_valid;
+
+-- Remove index
+DROP INDEX IF EXISTS idx_payments_split_type;
+
+-- Remove split_type column from payments table
+ALTER TABLE payments DROP COLUMN IF EXISTS split_type; 

migrations/000034_add_split_type_to_payments.up.sql

@@ -0,0 +1,8 @@
+-- Add split_type column to payments table
+ALTER TABLE payments ADD COLUMN split_type VARCHAR(20);
+
+-- Add index for better query performance
+CREATE INDEX idx_payments_split_type ON payments(split_type);
+
+-- Add constraint to ensure split_type is valid
+ALTER TABLE payments ADD CONSTRAINT check_split_type_valid CHECK (split_type IS NULL OR split_type IN ('AMOUNT', 'ITEM'));