Add Wildberries product fetching and rate limiting functionality

internal/wb/common.go

@@ -0,0 +1,59 @@
+package wb
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/golang-jwt/jwt/v5"
+	"net/http"
+	"sipro-mps/internal/marketplace"
+	wbclient "sipro-mps/pkg/api/wb/client"
+	"time"
+)
+
+type WbAuthData struct {
+	Token string `json:"token"`
+}
+
+func NewWbAuthData(token string) WbAuthData {
+	return WbAuthData{
+		Token: token,
+	}
+}
+
+func DecodeWildberriesJwt(token []byte) (WbAuthData, jwt.MapClaims, error) {
+	var authData WbAuthData
+	err := json.Unmarshal(token, &authData)
+	if err != nil {
+		return authData, nil, fmt.Errorf("failed to unmarshal JWT: %w", err)
+	}
+	claims := jwt.MapClaims{}
+	_, _, err = jwt.NewParser().ParseUnverified(authData.Token, claims)
+	if err != nil {
+		return authData, nil, fmt.Errorf("invalid JWT: %w", err)
+	}
+
+	return authData, claims, nil
+}
+
+func GetClientFromMarketplace(mp *marketplace.Marketplace) (*wbclient.Client, error) {
+
+	authData, claims, err := DecodeWildberriesJwt(mp.AuthDataJson)
+	if err != nil {
+		return nil, fmt.Errorf("failed to decode Wildberries JWT")
+	}
+	exp := claims["exp"].(float64)
+	// chec if token is expired, for now unix date
+	now := float64(time.Now().Unix())
+	if exp < now {
+		return nil, fmt.Errorf("token is expired")
+	}
+	securityHandler := NewWildberriesSecurityHandler(authData.Token)
+	httpClient := &http.Client{
+		Transport: NewRateLimitTransport(),
+	}
+	client, err := wbclient.NewClient("https://content-api.wildberries.ru", securityHandler, wbclient.WithClient(httpClient))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create Wildberries client: %w", err)
+	}
+	return client, nil
+}