private void ProcessSchema()

in src/Core/Services/MetadataProviders/CosmosSqlMetadataProvider.cs [211:298]
71 lines of code
11 McCabe index (conditional complexity)

        private void ProcessSchema(
            IReadOnlyList<FieldDefinitionNode> fields,
            Dictionary<string, ObjectTypeDefinitionNode> schemaDocument,
            string currentPath,
            IncrementingInteger tableCounter,
            EntityDbPolicyCosmosModel? parentEntity = null,
            HashSet<string>? visitedEntities = null)
        {
            // Traverse the fields and add them to the path
            foreach (FieldDefinitionNode field in fields)
            {
                // Create a tracker to keep track of visited entities to detect circular references
                HashSet<string> trackerForFields = new();
                if (visitedEntities is not null)
                {
                    trackerForFields = visitedEntities;
                }

                // If the entity is build-in type, do not go further to check circular reference
                if (GraphQLUtils.IsBuiltInType(field.Type))
                {
                    continue;
                }

                string entityType = field.Type.NamedType().Name.Value;

                AssertIfEntityIsAvailableInConfig(entityType);

                // If the entity is already visited, then it is a circular reference
                if (!trackerForFields.Add(entityType))
                {
                    throw new DataApiBuilderException(
                        message: $"Circular reference detected in the provided GraphQL schema for entity '{entityType}'.",
                        statusCode: System.Net.HttpStatusCode.InternalServerError,
                        subStatusCode: DataApiBuilderException.SubStatusCodes.ErrorInInitialization);
                }

                string? alias = null;
                bool isArrayType = field.Type is ListTypeNode;
                if (isArrayType)
                {
                    // Since we don't have query structure here,
                    // we are going to generate alias and use this counter to generate unique alias for each table at later stage.
                    alias = $"table{tableCounter.Next()}";
                }

                EntityDbPolicyCosmosModel currentEntity = new(
                                Path: currentPath,
                                EntityName: entityType,
                                ColumnName: field.Name.Value,
                                Alias: alias);

                // If entity is defined in the runtime config, only then generate Join for this entity
                if (EntityWithJoins.ContainsKey(entityType))
                {
                    EntityWithJoins[entityType].Add(currentEntity);
                }
                else
                {
                    EntityWithJoins.Add(
                        entityType,
                        new List<EntityDbPolicyCosmosModel>() {
                        currentEntity
                        });
                }

                if (parentEntity is not null)
                {
                    if (string.IsNullOrEmpty(currentEntity.JoinStatement))
                    {
                        currentEntity.JoinStatement = parentEntity.JoinStatement;
                    }
                    else
                    {
                        currentEntity.JoinStatement = parentEntity.JoinStatement + " JOIN " + currentEntity.JoinStatement;
                    }
                }

                // If the field is an array type, we need to create a table alias which will be used when creating JOINs to that table.
                ProcessSchema(
                    fields: schemaDocument[entityType].Fields,
                    schemaDocument: schemaDocument,
                    currentPath: isArrayType ? $"{alias}" : $"{currentPath}.{field.Name.Value}",
                    tableCounter: tableCounter,
                    parentEntity: isArrayType ? currentEntity : null,
                    visitedEntities: trackerForFields);
            }
        }