feat: refactor product attributes caching logic and add HashArray utility function

pkg/utils/utils.go

@@ -1,8 +1,11 @@
 package utils
 
 import (
+	"encoding/binary"
 	"encoding/json"
 	"fmt"
+	"hash/fnv"
+	"math"
 
 	"github.com/golang-jwt/jwt/v5"
 )
@@ -49,3 +52,74 @@ func DerefSlice[T any](s []*T) []T {
 	}
 	return res
 }
+
+type Hashable interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 |
+		~string | ~bool | ~float32 | ~float64
+}
+
+func HashArray[T Hashable](arr []T) (string, error) {
+	h := fnv.New64a()
+	buf := make([]byte, 8)
+
+	for _, v := range arr {
+		var b []byte
+
+		switch val := any(v).(type) {
+		case int:
+			binary.LittleEndian.PutUint64(buf, uint64(val))
+			b = buf
+		case int8:
+			buf[0] = byte(val)
+			b = buf[:1]
+		case int16:
+			binary.LittleEndian.PutUint16(buf, uint16(val))
+			b = buf[:2]
+		case int32:
+			binary.LittleEndian.PutUint32(buf, uint32(val))
+			b = buf[:4]
+		case int64:
+			binary.LittleEndian.PutUint64(buf, uint64(val))
+			b = buf
+		case uint:
+			binary.LittleEndian.PutUint64(buf, uint64(val))
+			b = buf
+		case uint8:
+			buf[0] = val
+			b = buf[:1]
+		case uint16:
+			binary.LittleEndian.PutUint16(buf, val)
+			b = buf[:2]
+		case uint32:
+			binary.LittleEndian.PutUint32(buf, val)
+			b = buf[:4]
+		case uint64:
+			binary.LittleEndian.PutUint64(buf, val)
+			b = buf
+		case float32:
+			binary.LittleEndian.PutUint32(buf[:4], math.Float32bits(val))
+			b = buf[:4]
+		case float64:
+			binary.LittleEndian.PutUint64(buf, math.Float64bits(val))
+			b = buf
+		case bool:
+			if val {
+				buf[0] = 1
+			} else {
+				buf[0] = 0
+			}
+			b = buf[:1]
+		case string:
+			b = []byte(val)
+		default:
+			return "", fmt.Errorf("unsupported type: %T", val)
+		}
+
+		if _, err := h.Write(b); err != nil {
+			return "", fmt.Errorf("failed to write to hash: %w", err)
+		}
+	}
+
+	return fmt.Sprintf("%x", h.Sum64()), nil
+}