perf: optimize ListProducts using database-level pagination, search, and branch filtering

controllers/product_controller.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net/http"
 	"strconv"
+	"strings"
 
 	"service-warungpos-go/config"
 	"service-warungpos-go/models"
@@ -292,8 +293,10 @@ func ListProducts(c *gin.Context) {
 	categoryFilter := c.Query("category_id")
 	activeOnlyStr := c.DefaultQuery("active_only", "true")
 	activeOnly := activeOnlyStr == "true"
+	searchQuery := c.Query("search")
+	limitStr := c.Query("limit")
+	skipStr := c.Query("skip")
 
-	var products []models.Product
 	query := config.DB.Preload("Category").Where("company_id = ?", *user.CompanyID)
 
 	if activeOnly {
@@ -306,30 +309,30 @@ func ListProducts(c *gin.Context) {
 		}
 	}
 
-	if err := query.Find(&products).Error; err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal mengambil data produk"})
-		return
+	if searchQuery != "" {
+		query = query.Where("LOWER(name) LIKE ? OR LOWER(sku) LIKE ?", "%"+strings.ToLower(searchQuery)+"%", "%"+strings.ToLower(searchQuery)+"%")
 	}
 
-	// Filter ketersediaan cabang (BranchProduct)
+	// Filter ketersediaan cabang (BranchProduct) di level database
 	if branchID != nil {
-		var branchProducts []models.BranchProduct
-		config.DB.Where("branch_id = ?", *branchID).Find(&branchProducts)
+		query = query.Where("id NOT IN (SELECT product_id FROM branch_products WHERE branch_id = ? AND is_available = ?)", *branchID, false)
+	}
 
-		bpMap := make(map[uint]bool)
-		for _, bp := range branchProducts {
-			bpMap[bp.ProductID] = bp.IsAvailable
+	// Terapkan pagination jika limit diisi
+	if limitStr != "" {
+		if limit, err := strconv.Atoi(limitStr); err == nil {
+			query = query.Limit(limit)
 		}
-
-		var filteredProducts []models.Product
-		for _, p := range products {
-			isAvailable, exists := bpMap[p.ID]
-			// Jika belum disetting di cabang (exists=false), default-nya adalah tersedia (isAvailable=true)
-			if !exists || isAvailable {
-				filteredProducts = append(filteredProducts, p)
-			}
+	}
+	if skipStr != "" {
+		if skip, err := strconv.Atoi(skipStr); err == nil {
+			query = query.Offset(skip)
 		}
-		c.JSON(http.StatusOK, filteredProducts)
+	}
+
+	var products []models.Product
+	if err := query.Find(&products).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal mengambil data produk"})
 		return
 	}