add purchasing in analytics endpoint

internal/contract/analytics_contract.go

@@ -83,6 +83,63 @@ type SalesAnalyticsData struct {
 	NetSales float64   `json:"net_sales"`
 }
 
+type PurchasingAnalyticsRequest struct {
+	OrganizationID uuid.UUID
+	OutletID       *string `form:"outlet_id,omitempty"`
+	DateFrom       string  `form:"date_from" validate:"required"`
+	DateTo         string  `form:"date_to" validate:"required"`
+	GroupBy        string  `form:"group_by,default=day" validate:"omitempty,oneof=day hour week month"`
+}
+
+type PurchasingAnalyticsResponse struct {
+	OrganizationID uuid.UUID                  `json:"organization_id"`
+	OutletID       *uuid.UUID                 `json:"outlet_id,omitempty"`
+	OutletName     *string                    `json:"outlet_name,omitempty"`
+	DateFrom       time.Time                  `json:"date_from"`
+	DateTo         time.Time                  `json:"date_to"`
+	GroupBy        string                     `json:"group_by"`
+	Summary        PurchasingSummary          `json:"summary"`
+	Data           []PurchasingAnalyticsData  `json:"data"`
+	IngredientData []PurchasingIngredientData `json:"ingredient_data"`
+	VendorData     []PurchasingVendorData     `json:"vendor_data"`
+}
+
+type PurchasingSummary struct {
+	TotalPurchases            float64 `json:"total_purchases"`
+	TotalPurchaseOrders       int64   `json:"total_purchase_orders"`
+	TotalQuantity             float64 `json:"total_quantity"`
+	AveragePurchaseOrderValue float64 `json:"average_purchase_order_value"`
+	TotalIngredients          int64   `json:"total_ingredients"`
+	TotalVendors              int64   `json:"total_vendors"`
+}
+
+type PurchasingAnalyticsData struct {
+	Date           time.Time `json:"date"`
+	Purchases      float64   `json:"purchases"`
+	PurchaseOrders int64     `json:"purchase_orders"`
+	Quantity       float64   `json:"quantity"`
+	Ingredients    int64     `json:"ingredients"`
+	Vendors        int64     `json:"vendors"`
+}
+
+type PurchasingIngredientData struct {
+	IngredientID       uuid.UUID `json:"ingredient_id"`
+	IngredientName     string    `json:"ingredient_name"`
+	Quantity           float64   `json:"quantity"`
+	TotalCost          float64   `json:"total_cost"`
+	AverageUnitCost    float64   `json:"average_unit_cost"`
+	PurchaseOrderCount int64     `json:"purchase_order_count"`
+}
+
+type PurchasingVendorData struct {
+	VendorID           uuid.UUID `json:"vendor_id"`
+	VendorName         string    `json:"vendor_name"`
+	TotalCost          float64   `json:"total_cost"`
+	PurchaseOrderCount int64     `json:"purchase_order_count"`
+	IngredientCount    int64     `json:"ingredient_count"`
+	Quantity           float64   `json:"quantity"`
+}
+
 // ProductAnalyticsRequest represents the request for product analytics
 type ProductAnalyticsRequest struct {
 	OrganizationID uuid.UUID

internal/entities/analytics.go

@@ -27,6 +27,51 @@ type SalesAnalytics struct {
 	NetSales float64   `json:"net_sales"`
 }
 
+// PurchasingAnalytics represents purchasing analytics data
+type PurchasingAnalytics struct {
+	OutletName     *string                    `json:"outlet_name,omitempty"`
+	Summary        PurchasingSummary          `json:"summary"`
+	Data           []PurchasingAnalyticsData  `json:"data"`
+	IngredientData []PurchasingIngredientData `json:"ingredient_data"`
+	VendorData     []PurchasingVendorData     `json:"vendor_data"`
+}
+
+type PurchasingSummary struct {
+	TotalPurchases            float64 `json:"total_purchases"`
+	TotalPurchaseOrders       int64   `json:"total_purchase_orders"`
+	TotalQuantity             float64 `json:"total_quantity"`
+	AveragePurchaseOrderValue float64 `json:"average_purchase_order_value"`
+	TotalIngredients          int64   `json:"total_ingredients"`
+	TotalVendors              int64   `json:"total_vendors"`
+}
+
+type PurchasingAnalyticsData struct {
+	Date           time.Time `json:"date"`
+	Purchases      float64   `json:"purchases"`
+	PurchaseOrders int64     `json:"purchase_orders"`
+	Quantity       float64   `json:"quantity"`
+	Ingredients    int64     `json:"ingredients"`
+	Vendors        int64     `json:"vendors"`
+}
+
+type PurchasingIngredientData struct {
+	IngredientID       uuid.UUID `json:"ingredient_id"`
+	IngredientName     string    `json:"ingredient_name"`
+	Quantity           float64   `json:"quantity"`
+	TotalCost          float64   `json:"total_cost"`
+	AverageUnitCost    float64   `json:"average_unit_cost"`
+	PurchaseOrderCount int64     `json:"purchase_order_count"`
+}
+
+type PurchasingVendorData struct {
+	VendorID           uuid.UUID `json:"vendor_id"`
+	VendorName         string    `json:"vendor_name"`
+	TotalCost          float64   `json:"total_cost"`
+	PurchaseOrderCount int64     `json:"purchase_order_count"`
+	IngredientCount    int64     `json:"ingredient_count"`
+	Quantity           float64   `json:"quantity"`
+}
+
 type ProductAnalytics struct {
 	ProductID               uuid.UUID `json:"product_id"`
 	ProductName             string    `json:"product_name"`

internal/handler/analytics_handler.go

@@ -85,6 +85,30 @@ func (h *AnalyticsHandler) GetSalesAnalytics(c *gin.Context) {
 	util.HandleResponse(c.Writer, c.Request, contract.BuildSuccessResponse(contractResp), "AnalyticsHandler::GetSalesAnalytics")
 }
 
+func (h *AnalyticsHandler) GetPurchasingAnalytics(c *gin.Context) {
+	ctx := c.Request.Context()
+	contextInfo := appcontext.FromGinContext(ctx)
+
+	var req contract.PurchasingAnalyticsRequest
+	if err := c.ShouldBindQuery(&req); err != nil {
+		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{contract.NewResponseError("invalid_request", "AnalyticsHandler::GetPurchasingAnalytics", err.Error())}), "AnalyticsHandler::GetPurchasingAnalytics")
+		return
+	}
+
+	req.OrganizationID = contextInfo.OrganizationID
+	req.OutletID = h.resolveOutletID(c, contextInfo.OutletID)
+	modelReq := transformer.PurchasingAnalyticsContractToModel(&req)
+
+	response, err := h.analyticsService.GetPurchasingAnalytics(ctx, modelReq)
+	if err != nil {
+		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{contract.NewResponseError("internal_error", "AnalyticsHandler::GetPurchasingAnalytics", err.Error())}), "AnalyticsHandler::GetPurchasingAnalytics")
+		return
+	}
+
+	contractResp := transformer.PurchasingAnalyticsModelToContract(response)
+	util.HandleResponse(c.Writer, c.Request, contract.BuildSuccessResponse(contractResp), "AnalyticsHandler::GetPurchasingAnalytics")
+}
+
 func (h *AnalyticsHandler) GetProductAnalytics(c *gin.Context) {
 	ctx := c.Request.Context()
 	contextInfo := appcontext.FromGinContext(ctx)

internal/models/analytics.go

@@ -87,6 +87,69 @@ type SalesAnalyticsData struct {
 	NetSales float64   `json:"net_sales"`
 }
 
+// PurchasingAnalyticsRequest represents the request for purchasing analytics
+type PurchasingAnalyticsRequest struct {
+	OrganizationID uuid.UUID  `validate:"required"`
+	OutletID       *uuid.UUID `validate:"omitempty"`
+	DateFrom       time.Time  `validate:"required"`
+	DateTo         time.Time  `validate:"required"`
+	GroupBy        string     `validate:"omitempty,oneof=day hour week month"`
+}
+
+// PurchasingAnalyticsResponse represents the response for purchasing analytics
+type PurchasingAnalyticsResponse struct {
+	OrganizationID uuid.UUID                  `json:"organization_id"`
+	OutletID       *uuid.UUID                 `json:"outlet_id,omitempty"`
+	OutletName     *string                    `json:"outlet_name,omitempty"`
+	DateFrom       time.Time                  `json:"date_from"`
+	DateTo         time.Time                  `json:"date_to"`
+	GroupBy        string                     `json:"group_by"`
+	Summary        PurchasingSummary          `json:"summary"`
+	Data           []PurchasingAnalyticsData  `json:"data"`
+	IngredientData []PurchasingIngredientData `json:"ingredient_data"`
+	VendorData     []PurchasingVendorData     `json:"vendor_data"`
+}
+
+// PurchasingSummary represents the summary of purchasing analytics
+type PurchasingSummary struct {
+	TotalPurchases            float64 `json:"total_purchases"`
+	TotalPurchaseOrders       int64   `json:"total_purchase_orders"`
+	TotalQuantity             float64 `json:"total_quantity"`
+	AveragePurchaseOrderValue float64 `json:"average_purchase_order_value"`
+	TotalIngredients          int64   `json:"total_ingredients"`
+	TotalVendors              int64   `json:"total_vendors"`
+}
+
+// PurchasingAnalyticsData represents purchasing analytics by time period
+type PurchasingAnalyticsData struct {
+	Date           time.Time `json:"date"`
+	Purchases      float64   `json:"purchases"`
+	PurchaseOrders int64     `json:"purchase_orders"`
+	Quantity       float64   `json:"quantity"`
+	Ingredients    int64     `json:"ingredients"`
+	Vendors        int64     `json:"vendors"`
+}
+
+// PurchasingIngredientData represents purchasing analytics for an ingredient
+type PurchasingIngredientData struct {
+	IngredientID       uuid.UUID `json:"ingredient_id"`
+	IngredientName     string    `json:"ingredient_name"`
+	Quantity           float64   `json:"quantity"`
+	TotalCost          float64   `json:"total_cost"`
+	AverageUnitCost    float64   `json:"average_unit_cost"`
+	PurchaseOrderCount int64     `json:"purchase_order_count"`
+}
+
+// PurchasingVendorData represents purchasing analytics for a vendor
+type PurchasingVendorData struct {
+	VendorID           uuid.UUID `json:"vendor_id"`
+	VendorName         string    `json:"vendor_name"`
+	TotalCost          float64   `json:"total_cost"`
+	PurchaseOrderCount int64     `json:"purchase_order_count"`
+	IngredientCount    int64     `json:"ingredient_count"`
+	Quantity           float64   `json:"quantity"`
+}
+
 // ProductAnalyticsRequest represents the request for product analytics
 type ProductAnalyticsRequest struct {
 	OrganizationID uuid.UUID  `validate:"required"`

internal/processor/analytics_processor.go

@@ -12,6 +12,7 @@ import (
 type AnalyticsProcessor interface {
 	GetPaymentMethodAnalytics(ctx context.Context, req *models.PaymentMethodAnalyticsRequest) (*models.PaymentMethodAnalyticsResponse, error)
 	GetSalesAnalytics(ctx context.Context, req *models.SalesAnalyticsRequest) (*models.SalesAnalyticsResponse, error)
+	GetPurchasingAnalytics(ctx context.Context, req *models.PurchasingAnalyticsRequest) (*models.PurchasingAnalyticsResponse, error)
 	GetProductAnalytics(ctx context.Context, req *models.ProductAnalyticsRequest) (*models.ProductAnalyticsResponse, error)
 	GetProductAnalyticsPerCategory(ctx context.Context, req *models.ProductAnalyticsPerCategoryRequest) (*models.ProductAnalyticsPerCategoryResponse, error)
 	GetDashboardAnalytics(ctx context.Context, req *models.DashboardAnalyticsRequest) (*models.DashboardAnalyticsResponse, error)
@@ -164,6 +165,77 @@ func (p *AnalyticsProcessorImpl) GetSalesAnalytics(ctx context.Context, req *mod
 	}, nil
 }
 
+func (p *AnalyticsProcessorImpl) GetPurchasingAnalytics(ctx context.Context, req *models.PurchasingAnalyticsRequest) (*models.PurchasingAnalyticsResponse, error) {
+	if req.DateFrom.After(req.DateTo) {
+		return nil, fmt.Errorf("date_from cannot be after date_to")
+	}
+
+	if req.GroupBy == "" {
+		req.GroupBy = "day"
+	}
+
+	result, err := p.analyticsRepo.GetPurchasingAnalytics(ctx, req.OrganizationID, req.OutletID, req.DateFrom, req.DateTo, req.GroupBy)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get purchasing analytics: %w", err)
+	}
+
+	data := make([]models.PurchasingAnalyticsData, len(result.Data))
+	for i, item := range result.Data {
+		data[i] = models.PurchasingAnalyticsData{
+			Date:           item.Date,
+			Purchases:      item.Purchases,
+			PurchaseOrders: item.PurchaseOrders,
+			Quantity:       item.Quantity,
+			Ingredients:    item.Ingredients,
+			Vendors:        item.Vendors,
+		}
+	}
+
+	ingredientData := make([]models.PurchasingIngredientData, len(result.IngredientData))
+	for i, item := range result.IngredientData {
+		ingredientData[i] = models.PurchasingIngredientData{
+			IngredientID:       item.IngredientID,
+			IngredientName:     item.IngredientName,
+			Quantity:           item.Quantity,
+			TotalCost:          item.TotalCost,
+			AverageUnitCost:    item.AverageUnitCost,
+			PurchaseOrderCount: item.PurchaseOrderCount,
+		}
+	}
+
+	vendorData := make([]models.PurchasingVendorData, len(result.VendorData))
+	for i, item := range result.VendorData {
+		vendorData[i] = models.PurchasingVendorData{
+			VendorID:           item.VendorID,
+			VendorName:         item.VendorName,
+			TotalCost:          item.TotalCost,
+			PurchaseOrderCount: item.PurchaseOrderCount,
+			IngredientCount:    item.IngredientCount,
+			Quantity:           item.Quantity,
+		}
+	}
+
+	return &models.PurchasingAnalyticsResponse{
+		OrganizationID: req.OrganizationID,
+		OutletID:       req.OutletID,
+		OutletName:     result.OutletName,
+		DateFrom:       req.DateFrom,
+		DateTo:         req.DateTo,
+		GroupBy:        req.GroupBy,
+		Summary: models.PurchasingSummary{
+			TotalPurchases:            result.Summary.TotalPurchases,
+			TotalPurchaseOrders:       result.Summary.TotalPurchaseOrders,
+			TotalQuantity:             result.Summary.TotalQuantity,
+			AveragePurchaseOrderValue: result.Summary.AveragePurchaseOrderValue,
+			TotalIngredients:          result.Summary.TotalIngredients,
+			TotalVendors:              result.Summary.TotalVendors,
+		},
+		Data:           data,
+		IngredientData: ingredientData,
+		VendorData:     vendorData,
+	}, nil
+}
+
 func (p *AnalyticsProcessorImpl) GetProductAnalytics(ctx context.Context, req *models.ProductAnalyticsRequest) (*models.ProductAnalyticsResponse, error) {
 	// Validate date range
 	if req.DateFrom.After(req.DateTo) {

internal/processor/analytics_processor_test.go

@@ -0,0 +1,73 @@
+package processor
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"apskel-pos-be/internal/entities"
+	"apskel-pos-be/internal/models"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+)
+
+type analyticsRepositoryStub struct {
+	purchasingResult *entities.PurchasingAnalytics
+}
+
+func (analyticsRepositoryStub) GetPaymentMethodAnalytics(context.Context, uuid.UUID, *uuid.UUID, time.Time, time.Time) ([]*entities.PaymentMethodAnalytics, error) {
+	return nil, nil
+}
+
+func (analyticsRepositoryStub) GetSalesAnalytics(context.Context, uuid.UUID, *uuid.UUID, time.Time, time.Time, string) ([]*entities.SalesAnalytics, error) {
+	return nil, nil
+}
+
+func (s analyticsRepositoryStub) GetPurchasingAnalytics(context.Context, uuid.UUID, *uuid.UUID, time.Time, time.Time, string) (*entities.PurchasingAnalytics, error) {
+	return s.purchasingResult, nil
+}
+
+func (analyticsRepositoryStub) GetProductAnalytics(context.Context, uuid.UUID, *uuid.UUID, time.Time, time.Time, int) ([]*entities.ProductAnalytics, error) {
+	return nil, nil
+}
+
+func (analyticsRepositoryStub) GetProductAnalyticsPerCategory(context.Context, uuid.UUID, *uuid.UUID, time.Time, time.Time) ([]*entities.ProductAnalyticsPerCategory, error) {
+	return nil, nil
+}
+
+func (analyticsRepositoryStub) GetDashboardOverview(context.Context, uuid.UUID, *uuid.UUID, time.Time, time.Time) (*entities.DashboardOverview, error) {
+	return nil, nil
+}
+
+func (analyticsRepositoryStub) GetProfitLossAnalytics(context.Context, uuid.UUID, *uuid.UUID, time.Time, time.Time, string) (*entities.ProfitLossAnalytics, error) {
+	return nil, nil
+}
+
+func TestAnalyticsProcessorGetPurchasingAnalyticsPassesOutletName(t *testing.T) {
+	outletID := uuid.New()
+	outletName := "Main Outlet"
+	now := time.Date(2026, 5, 1, 0, 0, 0, 0, time.UTC)
+	processor := NewAnalyticsProcessorImpl(analyticsRepositoryStub{
+		purchasingResult: &entities.PurchasingAnalytics{
+			OutletName: &outletName,
+			Summary: entities.PurchasingSummary{
+				TotalPurchases: 125,
+			},
+		},
+	})
+
+	result, err := processor.GetPurchasingAnalytics(context.Background(), &models.PurchasingAnalyticsRequest{
+		OrganizationID: uuid.New(),
+		OutletID:       &outletID,
+		DateFrom:       now,
+		DateTo:         now,
+	})
+
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.Equal(t, &outletID, result.OutletID)
+	require.NotNil(t, result.OutletName)
+	require.Equal(t, outletName, *result.OutletName)
+	require.Equal(t, float64(125), result.Summary.TotalPurchases)
+}

internal/repository/analytics_repository.go

@@ -13,6 +13,7 @@ import (
 type AnalyticsRepository interface {
 	GetPaymentMethodAnalytics(ctx context.Context, organizationID uuid.UUID, outletID *uuid.UUID, dateFrom, dateTo time.Time) ([]*entities.PaymentMethodAnalytics, error)
 	GetSalesAnalytics(ctx context.Context, organizationID uuid.UUID, outletID *uuid.UUID, dateFrom, dateTo time.Time, groupBy string) ([]*entities.SalesAnalytics, error)
+	GetPurchasingAnalytics(ctx context.Context, organizationID uuid.UUID, outletID *uuid.UUID, dateFrom, dateTo time.Time, groupBy string) (*entities.PurchasingAnalytics, error)
 	GetProductAnalytics(ctx context.Context, organizationID uuid.UUID, outletID *uuid.UUID, dateFrom, dateTo time.Time, limit int) ([]*entities.ProductAnalytics, error)
 	GetProductAnalyticsPerCategory(ctx context.Context, organizationID uuid.UUID, outletID *uuid.UUID, dateFrom, dateTo time.Time) ([]*entities.ProductAnalyticsPerCategory, error)
 	GetDashboardOverview(ctx context.Context, organizationID uuid.UUID, outletID *uuid.UUID, dateFrom, dateTo time.Time) (*entities.DashboardOverview, error)
@@ -122,6 +123,159 @@ func (r *AnalyticsRepositoryImpl) GetSalesAnalytics(ctx context.Context, organiz
 	return results, err
 }
 
+func (r *AnalyticsRepositoryImpl) GetPurchasingAnalytics(ctx context.Context, organizationID uuid.UUID, outletID *uuid.UUID, dateFrom, dateTo time.Time, groupBy string) (*entities.PurchasingAnalytics, error) {
+	var summary entities.PurchasingSummary
+	var outletName *string
+
+	if outletID != nil {
+		var outlet struct {
+			Name string
+		}
+		result := r.db.WithContext(ctx).
+			Table("outlets").
+			Select("name").
+			Where("id = ? AND organization_id = ?", *outletID, organizationID).
+			Limit(1).
+			Scan(&outlet)
+		if result.Error != nil {
+			return nil, result.Error
+		}
+		if result.RowsAffected > 0 {
+			outletName = &outlet.Name
+		}
+	}
+
+	summaryQuery := r.db.WithContext(ctx).
+		Table("inventory_movements im").
+		Select(`
+			COALESCE(SUM(im.total_cost), 0) as total_purchases,
+			COUNT(DISTINCT im.reference_id) as total_purchase_orders,
+			COALESCE(SUM(im.quantity), 0) as total_quantity,
+			CASE
+				WHEN COUNT(DISTINCT im.reference_id) > 0
+				THEN COALESCE(SUM(im.total_cost), 0) / COUNT(DISTINCT im.reference_id)
+				ELSE 0
+			END as average_purchase_order_value,
+			COUNT(DISTINCT im.item_id) as total_ingredients,
+			COUNT(DISTINCT po.vendor_id) as total_vendors
+		`).
+		Joins("LEFT JOIN purchase_orders po ON im.reference_id = po.id").
+		Where("im.organization_id = ?", organizationID).
+		Where("im.movement_type = ?", entities.InventoryMovementTypePurchase).
+		Where("im.item_type = ?", "INGREDIENT").
+		Where("im.reference_type = ?", entities.InventoryMovementReferenceTypePurchaseOrder).
+		Where("im.created_at >= ? AND im.created_at <= ?", dateFrom, dateTo)
+
+	summaryQuery = r.resolveOutletID(summaryQuery, outletID, "im.outlet_id")
+
+	if err := summaryQuery.Scan(&summary).Error; err != nil {
+		return nil, err
+	}
+
+	var dateFormat string
+	switch groupBy {
+	case "hour":
+		dateFormat = "DATE_TRUNC('hour', im.created_at)"
+	case "week":
+		dateFormat = "DATE_TRUNC('week', im.created_at)"
+	case "month":
+		dateFormat = "DATE_TRUNC('month', im.created_at)"
+	default:
+		dateFormat = "DATE_TRUNC('day', im.created_at)"
+	}
+
+	var data []entities.PurchasingAnalyticsData
+	dataQuery := r.db.WithContext(ctx).
+		Table("inventory_movements im").
+		Select(`
+			`+dateFormat+` as date,
+			COALESCE(SUM(im.total_cost), 0) as purchases,
+			COUNT(DISTINCT im.reference_id) as purchase_orders,
+			COALESCE(SUM(im.quantity), 0) as quantity,
+			COUNT(DISTINCT im.item_id) as ingredients,
+			COUNT(DISTINCT po.vendor_id) as vendors
+		`).
+		Joins("LEFT JOIN purchase_orders po ON im.reference_id = po.id").
+		Where("im.organization_id = ?", organizationID).
+		Where("im.movement_type = ?", entities.InventoryMovementTypePurchase).
+		Where("im.item_type = ?", "INGREDIENT").
+		Where("im.reference_type = ?", entities.InventoryMovementReferenceTypePurchaseOrder).
+		Where("im.created_at >= ? AND im.created_at <= ?", dateFrom, dateTo).
+		Group(dateFormat).
+		Order(dateFormat)
+
+	dataQuery = r.resolveOutletID(dataQuery, outletID, "im.outlet_id")
+
+	if err := dataQuery.Scan(&data).Error; err != nil {
+		return nil, err
+	}
+
+	var ingredientData []entities.PurchasingIngredientData
+	ingredientQuery := r.db.WithContext(ctx).
+		Table("inventory_movements im").
+		Select(`
+			i.id as ingredient_id,
+			i.name as ingredient_name,
+			COALESCE(SUM(im.quantity), 0) as quantity,
+			COALESCE(SUM(im.total_cost), 0) as total_cost,
+			CASE
+				WHEN SUM(im.quantity) > 0
+				THEN COALESCE(SUM(im.total_cost), 0) / SUM(im.quantity)
+				ELSE 0
+			END as average_unit_cost,
+			COUNT(DISTINCT im.reference_id) as purchase_order_count
+		`).
+		Joins("JOIN ingredients i ON im.item_id = i.id").
+		Where("im.organization_id = ?", organizationID).
+		Where("im.movement_type = ?", entities.InventoryMovementTypePurchase).
+		Where("im.item_type = ?", "INGREDIENT").
+		Where("im.reference_type = ?", entities.InventoryMovementReferenceTypePurchaseOrder).
+		Where("im.created_at >= ? AND im.created_at <= ?", dateFrom, dateTo).
+		Group("i.id, i.name").
+		Order("total_cost DESC")
+
+	ingredientQuery = r.resolveOutletID(ingredientQuery, outletID, "im.outlet_id")
+
+	if err := ingredientQuery.Scan(&ingredientData).Error; err != nil {
+		return nil, err
+	}
+
+	var vendorData []entities.PurchasingVendorData
+	vendorQuery := r.db.WithContext(ctx).
+		Table("inventory_movements im").
+		Select(`
+			v.id as vendor_id,
+			v.name as vendor_name,
+			COALESCE(SUM(im.total_cost), 0) as total_cost,
+			COUNT(DISTINCT im.reference_id) as purchase_order_count,
+			COUNT(DISTINCT im.item_id) as ingredient_count,
+			COALESCE(SUM(im.quantity), 0) as quantity
+		`).
+		Joins("JOIN purchase_orders po ON im.reference_id = po.id").
+		Joins("JOIN vendors v ON po.vendor_id = v.id").
+		Where("im.organization_id = ?", organizationID).
+		Where("im.movement_type = ?", entities.InventoryMovementTypePurchase).
+		Where("im.item_type = ?", "INGREDIENT").
+		Where("im.reference_type = ?", entities.InventoryMovementReferenceTypePurchaseOrder).
+		Where("im.created_at >= ? AND im.created_at <= ?", dateFrom, dateTo).
+		Group("v.id, v.name").
+		Order("total_cost DESC")
+
+	vendorQuery = r.resolveOutletID(vendorQuery, outletID, "im.outlet_id")
+
+	if err := vendorQuery.Scan(&vendorData).Error; err != nil {
+		return nil, err
+	}
+
+	return &entities.PurchasingAnalytics{
+		OutletName:     outletName,
+		Summary:        summary,
+		Data:           data,
+		IngredientData: ingredientData,
+		VendorData:     vendorData,
+	}, nil
+}
+
 func (r *AnalyticsRepositoryImpl) GetProductAnalytics(ctx context.Context, organizationID uuid.UUID, outletID *uuid.UUID, dateFrom, dateTo time.Time, limit int) ([]*entities.ProductAnalytics, error) {
 	var results []*entities.ProductAnalytics
 

internal/repository/tx_manager.go

@@ -28,6 +28,10 @@ func NewTxManager(db *gorm.DB) *TxManager { return &TxManager{db: db} }
 
 // WithTransaction runs fn inside a DB transaction, injecting the *gorm.DB tx into ctx.
 func (m *TxManager) WithTransaction(ctx context.Context, fn func(ctx context.Context) error) error {
+	if m == nil || m.db == nil {
+		return fn(ctx)
+	}
+
 	return m.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
 		ctxTx := context.WithValue(ctx, txKey, tx)
 		return fn(ctxTx)

internal/router/router.go

@@ -325,6 +325,7 @@ func (r *Router) addAppRoutes(rg *gin.Engine) {
 			{
 				analytics.GET("/payment-methods", r.analyticsHandler.GetPaymentMethodAnalytics)
 				analytics.GET("/sales", r.analyticsHandler.GetSalesAnalytics)
+				analytics.GET("/purchasing", r.analyticsHandler.GetPurchasingAnalytics)
 				analytics.GET("/products", r.analyticsHandler.GetProductAnalytics)
 				analytics.GET("/categories", r.analyticsHandler.GetProductAnalyticsPerCategory)
 				analytics.GET("/dashboard", r.analyticsHandler.GetDashboardAnalytics)

internal/service/analytics_service.go

@@ -13,6 +13,7 @@ import (
 type AnalyticsService interface {
 	GetPaymentMethodAnalytics(ctx context.Context, req *models.PaymentMethodAnalyticsRequest) (*models.PaymentMethodAnalyticsResponse, error)
 	GetSalesAnalytics(ctx context.Context, req *models.SalesAnalyticsRequest) (*models.SalesAnalyticsResponse, error)
+	GetPurchasingAnalytics(ctx context.Context, req *models.PurchasingAnalyticsRequest) (*models.PurchasingAnalyticsResponse, error)
 	GetProductAnalytics(ctx context.Context, req *models.ProductAnalyticsRequest) (*models.ProductAnalyticsResponse, error)
 	GetProductAnalyticsPerCategory(ctx context.Context, req *models.ProductAnalyticsPerCategoryRequest) (*models.ProductAnalyticsPerCategoryResponse, error)
 	GetDashboardAnalytics(ctx context.Context, req *models.DashboardAnalyticsRequest) (*models.DashboardAnalyticsResponse, error)
@@ -57,6 +58,19 @@ func (s *AnalyticsServiceImpl) GetSalesAnalytics(ctx context.Context, req *model
 	return response, nil
 }
 
+func (s *AnalyticsServiceImpl) GetPurchasingAnalytics(ctx context.Context, req *models.PurchasingAnalyticsRequest) (*models.PurchasingAnalyticsResponse, error) {
+	if err := s.validatePurchasingAnalyticsRequest(req); err != nil {
+		return nil, fmt.Errorf("validation error: %w", err)
+	}
+
+	response, err := s.analyticsProcessor.GetPurchasingAnalytics(ctx, req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get purchasing analytics: %w", err)
+	}
+
+	return response, nil
+}
+
 func (s *AnalyticsServiceImpl) GetProductAnalytics(ctx context.Context, req *models.ProductAnalyticsRequest) (*models.ProductAnalyticsResponse, error) {
 	// Validate request
 	if err := s.validateProductAnalyticsRequest(req); err != nil {
@@ -168,6 +182,42 @@ func (s *AnalyticsServiceImpl) validateSalesAnalyticsRequest(req *models.SalesAn
 	return nil
 }
 
+func (s *AnalyticsServiceImpl) validatePurchasingAnalyticsRequest(req *models.PurchasingAnalyticsRequest) error {
+	if req == nil {
+		return fmt.Errorf("request cannot be nil")
+	}
+
+	if req.OrganizationID == uuid.Nil {
+		return fmt.Errorf("organization ID is required")
+	}
+
+	if req.DateFrom.IsZero() {
+		return fmt.Errorf("date_from is required")
+	}
+
+	if req.DateTo.IsZero() {
+		return fmt.Errorf("date_to is required")
+	}
+
+	if req.DateFrom.After(req.DateTo) {
+		return fmt.Errorf("date_from cannot be after date_to")
+	}
+
+	if req.GroupBy != "" {
+		validGroupBy := map[string]bool{
+			"day":   true,
+			"hour":  true,
+			"week":  true,
+			"month": true,
+		}
+		if !validGroupBy[req.GroupBy] {
+			return fmt.Errorf("invalid group_by value: %s", req.GroupBy)
+		}
+	}
+
+	return nil
+}
+
 func (s *AnalyticsServiceImpl) validateProductAnalyticsRequest(req *models.ProductAnalyticsRequest) error {
 	if req.OrganizationID == uuid.Nil {
 		return fmt.Errorf("organization ID is required")

internal/service/analytics_service_test.go

@@ -0,0 +1,121 @@
+package service
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"apskel-pos-be/internal/models"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+)
+
+type analyticsProcessorStub struct{}
+
+func (analyticsProcessorStub) GetPaymentMethodAnalytics(context.Context, *models.PaymentMethodAnalyticsRequest) (*models.PaymentMethodAnalyticsResponse, error) {
+	return nil, nil
+}
+
+func (analyticsProcessorStub) GetSalesAnalytics(context.Context, *models.SalesAnalyticsRequest) (*models.SalesAnalyticsResponse, error) {
+	return nil, nil
+}
+
+func (analyticsProcessorStub) GetPurchasingAnalytics(context.Context, *models.PurchasingAnalyticsRequest) (*models.PurchasingAnalyticsResponse, error) {
+	return &models.PurchasingAnalyticsResponse{}, nil
+}
+
+func (analyticsProcessorStub) GetProductAnalytics(context.Context, *models.ProductAnalyticsRequest) (*models.ProductAnalyticsResponse, error) {
+	return nil, nil
+}
+
+func (analyticsProcessorStub) GetProductAnalyticsPerCategory(context.Context, *models.ProductAnalyticsPerCategoryRequest) (*models.ProductAnalyticsPerCategoryResponse, error) {
+	return nil, nil
+}
+
+func (analyticsProcessorStub) GetDashboardAnalytics(context.Context, *models.DashboardAnalyticsRequest) (*models.DashboardAnalyticsResponse, error) {
+	return nil, nil
+}
+
+func (analyticsProcessorStub) GetProfitLossAnalytics(context.Context, *models.ProfitLossAnalyticsRequest) (*models.ProfitLossAnalyticsResponse, error) {
+	return nil, nil
+}
+
+func TestAnalyticsServiceGetPurchasingAnalyticsValidation(t *testing.T) {
+	service := NewAnalyticsServiceImpl(analyticsProcessorStub{})
+	now := time.Date(2026, 5, 1, 0, 0, 0, 0, time.UTC)
+
+	tests := []struct {
+		name    string
+		req     *models.PurchasingAnalyticsRequest
+		wantErr string
+	}{
+		{
+			name: "missing organization",
+			req: &models.PurchasingAnalyticsRequest{
+				DateFrom: now,
+				DateTo:   now,
+			},
+			wantErr: "organization ID is required",
+		},
+		{
+			name: "missing date_from",
+			req: &models.PurchasingAnalyticsRequest{
+				OrganizationID: uuid.New(),
+				DateTo:         now,
+			},
+			wantErr: "date_from is required",
+		},
+		{
+			name: "missing date_to",
+			req: &models.PurchasingAnalyticsRequest{
+				OrganizationID: uuid.New(),
+				DateFrom:       now,
+			},
+			wantErr: "date_to is required",
+		},
+		{
+			name: "reversed dates",
+			req: &models.PurchasingAnalyticsRequest{
+				OrganizationID: uuid.New(),
+				DateFrom:       now.AddDate(0, 0, 1),
+				DateTo:         now,
+			},
+			wantErr: "date_from cannot be after date_to",
+		},
+		{
+			name: "invalid group_by",
+			req: &models.PurchasingAnalyticsRequest{
+				OrganizationID: uuid.New(),
+				DateFrom:       now,
+				DateTo:         now,
+				GroupBy:        "quarter",
+			},
+			wantErr: "invalid group_by value: quarter",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			resp, err := service.GetPurchasingAnalytics(context.Background(), tt.req)
+
+			require.Nil(t, resp)
+			require.Error(t, err)
+			require.Contains(t, err.Error(), tt.wantErr)
+		})
+	}
+}
+
+func TestAnalyticsServiceGetPurchasingAnalyticsAllowsEmptyGroupBy(t *testing.T) {
+	service := NewAnalyticsServiceImpl(analyticsProcessorStub{})
+	now := time.Date(2026, 5, 1, 0, 0, 0, 0, time.UTC)
+
+	resp, err := service.GetPurchasingAnalytics(context.Background(), &models.PurchasingAnalyticsRequest{
+		OrganizationID: uuid.New(),
+		DateFrom:       now,
+		DateTo:         now,
+	})
+
+	require.NoError(t, err)
+	require.NotNil(t, resp)
+}

internal/service/order_service.go

@@ -199,7 +199,7 @@ func (s *OrderServiceImpl) createIngredientTransactions(ctx context.Context, ord
 		// Calculate waste quantities
 		transactions, err := s.calculateWasteQuantities(productRecipes, float64(orderItem.Quantity))
 		if err != nil {
-			return nil, fmt.Errorf("failed to calculate waste quantities for product %s: %w", err)
+			return nil, fmt.Errorf("failed to calculate waste quantities for product %s: %w", orderItem.ProductID, err)
 		}
 
 		// Set common fields for all transactions

internal/service/order_service_table_test.go

@@ -114,6 +114,14 @@ func (m *MockTableRepository) GetByID(ctx context.Context, id uuid.UUID) (*entit
 	return args.Get(0).(*entities.Table), args.Error(1)
 }
 
+func (m *MockTableRepository) GetByToken(ctx context.Context, token string) (*entities.Table, error) {
+	args := m.Called(ctx, token)
+	if args.Get(0) == nil {
+		return nil, args.Error(1)
+	}
+	return args.Get(0).(*entities.Table), args.Error(1)
+}
+
 func (m *MockTableRepository) GetByOutletID(ctx context.Context, outletID uuid.UUID) ([]entities.Table, error) {
 	args := m.Called(ctx, outletID)
 	if args.Get(0) == nil {
@@ -182,6 +190,11 @@ func (m *MockTableRepository) GetByOrderID(ctx context.Context, orderID uuid.UUI
 	return args.Get(0).(*entities.Table), args.Error(1)
 }
 
+func (m *MockTableRepository) UpdateToken(ctx context.Context, tableID uuid.UUID, token string) error {
+	args := m.Called(ctx, tableID, token)
+	return args.Error(0)
+}
+
 func TestCreateOrderWithTableOccupation(t *testing.T) {
 	// Setup
 	ctx := context.Background()

internal/transformer/analytics_transformer.go

@@ -138,6 +138,91 @@ func SalesAnalyticsModelToContract(resp *models.SalesAnalyticsResponse) *contrac
 	}
 }
 
+// PurchasingAnalyticsContractToModel converts contract request to model
+func PurchasingAnalyticsContractToModel(req *contract.PurchasingAnalyticsRequest) *models.PurchasingAnalyticsRequest {
+	var dateFrom, dateTo time.Time
+
+	if fromTime, toTime, err := util.ParseDateRangeToJakartaTime(req.DateFrom, req.DateTo); err == nil {
+		if fromTime != nil {
+			dateFrom = *fromTime
+		}
+		if toTime != nil {
+			dateTo = *toTime
+		}
+	}
+
+	return &models.PurchasingAnalyticsRequest{
+		OrganizationID: req.OrganizationID,
+		OutletID:       parseOutletID(req.OutletID),
+		DateFrom:       dateFrom,
+		DateTo:         dateTo,
+		GroupBy:        req.GroupBy,
+	}
+}
+
+// PurchasingAnalyticsModelToContract converts model response to contract
+func PurchasingAnalyticsModelToContract(resp *models.PurchasingAnalyticsResponse) *contract.PurchasingAnalyticsResponse {
+	if resp == nil {
+		return nil
+	}
+
+	data := make([]contract.PurchasingAnalyticsData, len(resp.Data))
+	for i, item := range resp.Data {
+		data[i] = contract.PurchasingAnalyticsData{
+			Date:           item.Date,
+			Purchases:      item.Purchases,
+			PurchaseOrders: item.PurchaseOrders,
+			Quantity:       item.Quantity,
+			Ingredients:    item.Ingredients,
+			Vendors:        item.Vendors,
+		}
+	}
+
+	ingredientData := make([]contract.PurchasingIngredientData, len(resp.IngredientData))
+	for i, item := range resp.IngredientData {
+		ingredientData[i] = contract.PurchasingIngredientData{
+			IngredientID:       item.IngredientID,
+			IngredientName:     item.IngredientName,
+			Quantity:           item.Quantity,
+			TotalCost:          item.TotalCost,
+			AverageUnitCost:    item.AverageUnitCost,
+			PurchaseOrderCount: item.PurchaseOrderCount,
+		}
+	}
+
+	vendorData := make([]contract.PurchasingVendorData, len(resp.VendorData))
+	for i, item := range resp.VendorData {
+		vendorData[i] = contract.PurchasingVendorData{
+			VendorID:           item.VendorID,
+			VendorName:         item.VendorName,
+			TotalCost:          item.TotalCost,
+			PurchaseOrderCount: item.PurchaseOrderCount,
+			IngredientCount:    item.IngredientCount,
+			Quantity:           item.Quantity,
+		}
+	}
+
+	return &contract.PurchasingAnalyticsResponse{
+		OrganizationID: resp.OrganizationID,
+		OutletID:       resp.OutletID,
+		OutletName:     resp.OutletName,
+		DateFrom:       resp.DateFrom,
+		DateTo:         resp.DateTo,
+		GroupBy:        resp.GroupBy,
+		Summary: contract.PurchasingSummary{
+			TotalPurchases:            resp.Summary.TotalPurchases,
+			TotalPurchaseOrders:       resp.Summary.TotalPurchaseOrders,
+			TotalQuantity:             resp.Summary.TotalQuantity,
+			AveragePurchaseOrderValue: resp.Summary.AveragePurchaseOrderValue,
+			TotalIngredients:          resp.Summary.TotalIngredients,
+			TotalVendors:              resp.Summary.TotalVendors,
+		},
+		Data:           data,
+		IngredientData: ingredientData,
+		VendorData:     vendorData,
+	}
+}
+
 // ProductAnalyticsContractToModel converts contract request to model
 func ProductAnalyticsContractToModel(req *contract.ProductAnalyticsRequest) *models.ProductAnalyticsRequest {
 	var dateFrom, dateTo time.Time

internal/transformer/analytics_transformer_test.go

@@ -0,0 +1,76 @@
+package transformer
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"apskel-pos-be/internal/contract"
+	"apskel-pos-be/internal/models"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPurchasingAnalyticsContractToModelParsesDateRangeAndOutlet(t *testing.T) {
+	orgID := uuid.New()
+	outletID := uuid.New().String()
+
+	req := &contract.PurchasingAnalyticsRequest{
+		OrganizationID: orgID,
+		OutletID:       &outletID,
+		DateFrom:       "01-05-2026",
+		DateTo:         "02-05-2026",
+		GroupBy:        "week",
+	}
+
+	result := PurchasingAnalyticsContractToModel(req)
+
+	require.Equal(t, orgID, result.OrganizationID)
+	require.NotNil(t, result.OutletID)
+	require.Equal(t, outletID, result.OutletID.String())
+	require.Equal(t, "week", result.GroupBy)
+
+	location, err := time.LoadLocation("Asia/Jakarta")
+	require.NoError(t, err)
+	require.Equal(t, time.Date(2026, 5, 1, 0, 0, 0, 0, location), result.DateFrom)
+	require.Equal(t, time.Date(2026, 5, 2, 23, 59, 59, int(time.Second-time.Nanosecond), location), result.DateTo)
+}
+
+func TestPurchasingAnalyticsContractToModelIgnoresInvalidOutlet(t *testing.T) {
+	outletID := "not-a-uuid"
+
+	result := PurchasingAnalyticsContractToModel(&contract.PurchasingAnalyticsRequest{
+		OutletID: &outletID,
+		DateFrom: "01-05-2026",
+		DateTo:   "02-05-2026",
+	})
+
+	require.Nil(t, result.OutletID)
+}
+
+func TestPurchasingAnalyticsModelToContractCopiesOutletName(t *testing.T) {
+	outletID := uuid.New()
+	outletName := "Main Outlet"
+
+	result := PurchasingAnalyticsModelToContract(&models.PurchasingAnalyticsResponse{
+		OrganizationID: uuid.New(),
+		OutletID:       &outletID,
+		OutletName:     &outletName,
+	})
+
+	require.NotNil(t, result)
+	require.Equal(t, &outletID, result.OutletID)
+	require.NotNil(t, result.OutletName)
+	require.Equal(t, outletName, *result.OutletName)
+}
+
+func TestPurchasingAnalyticsModelToContractOmitsNilOutletName(t *testing.T) {
+	result := PurchasingAnalyticsModelToContract(&models.PurchasingAnalyticsResponse{
+		OrganizationID: uuid.New(),
+	})
+
+	payload, err := json.Marshal(result)
+	require.NoError(t, err)
+	require.NotContains(t, string(payload), "outlet_name")
+}