Catalog DTO and object models

"EPiServer" : {
      "Commerce" : {
        "CatalogOptions" : {
          "Cache" : {
            "UseCache"                      : true,
            "ContentVersionCacheExpiration" : "00:15:00",
            "CollectionCacheExpiration"     : "00:15:00",
            "EntryCacheExpiration"          : "00:15:00",
            "NodeCacheExpiration"           : "00:15:00"
          }
        }
      }
    }

<?xml version="1.0"?>
    <Catalog autoConfigure="true">
    <Connection connectionStringName="EcfSqlConnection" />
    <Cache enabled="true" 
           collectionTimeout="0:1:0" 
           entryTimeout="0:1:0" 
           nodeTimeout="0:1:0" 
           schemaTimeout="0:2:0" />

namespace Mediachase.Commerce.Catalog.Objects
    {
        /// <summary>
        /// The Entry parameter serves as a container element that is a child of the Entries element, and
        /// represents the Catalog Entry element, which can be Product, Variant, Bundle or any other type of product.
        /// </summary>
        [Serializable]
        public class Entry
        {
        }
    }

private void SampleEntryAdd()
    {
      int catalogId = 2;
     
      // Get a CatalogDto object.
      CatalogDto catalogDto = CatalogContext.Current.GetCatalogDto(catalogId, new CatalogResponseGroup(CatalogResponseGroup.ResponseGroup.CatalogInfo));
     
      if (catalogDto.Catalog.Count > 0)
      {
        // Get a CatalogEntryDto object.
        CatalogEntryDto entry = CatalogContext.Current.GetCatalogEntryDto("PRODUCT_CODE",
          new CatalogEntryResponseGroup(CatalogEntryResponseGroup.ResponseGroup.CatalogEntryInfo));
     
        if (entry.CatalogEntry.Count == 0)
        {
          // Get a new entry row for your catalog entry.
          CatalogEntryDto.CatalogEntryRow newEntryRow = entry.CatalogEntry.NewCatalogEntryRow();
     
          // Set entry properties.
          newEntryRow.ApplicationId = AppContext.Current.ApplicationId;
          newEntryRow.CatalogId = catalogDto.Catalog[0].CatalogId;
          newEntryRow.ClassTypeId = "Variation";
          newEntryRow.Code = "PRODUCT_CODE";
          newEntryRow.EndDate = DateTime.Now.AddYears(2).ToUniversalTime();
          newEntryRow.IsActive = true;
          newEntryRow.MetaClassId = 32;
          newEntryRow.Name = "PRODUCT_NAME";
          newEntryRow.StartDate = DateTime.UtcNow;
          newEntryRow.TemplateName = "DigitalCameras"; // system-defined template of type 'entry'
          newEntryRow.SetSerializedDataNull();
          if (newEntryRow.RowState == DataRowState.Detached)
            entry.CatalogEntry.AddCatalogEntryRow(newEntryRow);
     
          // Set variation properties.
          CatalogEntryDto.VariationRow newVariationRow = entry.Variation.NewVariationRow();
          newVariationRow.ListPrice = Convert.ToDecimal(1000.00);
          newVariationRow.MaxQuantity = 50;
          newVariationRow.SetMerchantIdNull();
          newVariationRow.MinQuantity = 5;
          newVariationRow.PackageId = 0;
          newVariationRow.TaxCategoryId = 0;
          newVariationRow.TrackInventory = true;
          newVariationRow.WarehouseId = 0;
          newVariationRow.Weight = Convert.ToDouble(4);
          newVariationRow.CatalogEntryId = entry.CatalogEntry[0].CatalogEntryId;
          if (newVariationRow.RowState == DataRowState.Detached)
            entry.Variation.AddVariationRow(newVariationRow);
     
          // Set inventory properties.
          CatalogEntryDto.InventoryRow newInventoryRow = entry.Inventory.NewInventoryRow();
          newInventoryRow.AllowBackorder = false;
          newInventoryRow.AllowPreorder = false;
          newInventoryRow.ApplicationId = AppContext.Current.ApplicationId;
          newInventoryRow.BackorderAvailabilityDate = DateTime.UtcNow;
          newInventoryRow.BackorderQuantity = 0;
          newInventoryRow.InStockQuantity = Convert.ToDecimal(75);
          newInventoryRow.InventoryStatus = 1;
          newInventoryRow.PreorderAvailabilityDate = DateTime.UtcNow;
          newInventoryRow.PreorderQuantity = 0;
          newInventoryRow.ReorderMinQuantity = 15;
          newInventoryRow.ReservedQuantity = 10;
          newInventoryRow.SkuId = "mark_test7";
          if (newInventoryRow.RowState == DataRowState.Detached)
            entry.Inventory.AddInventoryRow(newInventoryRow);
     
          // Set seo properties.
          CatalogEntryDto.CatalogItemSeoRow newSeoRow = entry.CatalogItemSeo.NewCatalogItemSeoRow();
          newSeoRow.ApplicationId = AppContext.Current.ApplicationId;
          newSeoRow.CatalogEntryId = entry.CatalogEntry[0].CatalogEntryId;
          newSeoRow.CatalogNodeId = 62;
          newSeoRow.Description = "DESCRIPTION";
          newSeoRow.LanguageCode = "en-us";
          newSeoRow.Uri = "SEO-FRIENDLY-URL.aspx";
          if (newSeoRow.RowState == DataRowState.Detached)
            entry.CatalogItemSeo.AddCatalogItemSeoRow(newSeoRow);
     
          // Save the entry.
          CatalogContext.Current.SaveCatalogEntry(entry);
     
          // Save the metadata attributes associated with the catalog entry.
          MetaDataContext metaContext = new MetaDataContext();
          MetaClass metaClass = MetaClass.Load(metaContext, "Publications");
          MetaObject metaObj = MetaObject.NewObject(metaContext, entry.CatalogEntry[0].CatalogEntryId, metaClass.Id, "name");
          MetaHelper.SetMetaFieldValue(metaContext, metaObj, "Title", new object[] { "New Book Title" });
          MetaHelper.SetMetaFieldValue(metaContext, metaObj, "ID", new object[] { "New Id" });
          MetaHelper.SetMetaFieldValue(metaContext, metaObj, "Description", new object[] { "New Description" });
          MetaHelper.SetMetaFieldValue(metaContext, metaObj, "Theme", new object[] { "New Book Title" });
          MetaHelper.SetMetaFieldValue(metaContext, metaObj, "Highlight", new object[] { false });
          metaObj.AcceptChanges(metaContext);
     
          // Set the entry node relation.
          CatalogRelationDto relation = new CatalogRelationDto();
          CatalogRelationDto.NodeEntryRelationRow nodeRelation = relation.NodeEntryRelation.NewNodeEntryRelationRow();
          nodeRelation.CatalogId = 2;
          nodeRelation.CatalogEntryId = entry.CatalogEntry[0].CatalogEntryId;
          nodeRelation.CatalogNodeId = 62;
          nodeRelation.SortOrder = 0;
          if (nodeRelation.RowState == DataRowState.Detached)
            relation.NodeEntryRelation.AddNodeEntryRelationRow(nodeRelation);
     
          // Save the relation.
          CatalogContext.Current.SaveCatalogRelationDto(relation);
        }
      }
    }

MetaDataContext MDContext = CatalogContext.MetaDataContext;
    
      MDContext.UseCurrentUICulture = false;
      //string 
      foreach (string language in Languages)
        {
          MDContext.Language = language;
          MetaHelper.SetMetaFieldValue(metaobj)...
          metaObj.AcceptChanges(MDContext);
        }
      MDContext.UseCurrentUICulture = true;