import { SORTING_DECORATOR_CUSTOM_FIELDS_METADATA_KEY, SORTING_DECORATOR_INDEX_METADATA_KEY, SORTING_DECORATOR_OPTIONS_METADATA_KEY } from "./constants";
import { GraphqlSortingFieldMetadata } from "./decorators/field.decorator";
import { ISortingDecoratorParams } from "./decorators/resolver.decorator";

export type ISortingMetadata = {
  _name_: string;
}

export type SortArgs<T> = {
  [K in keyof T]: 'ASC' | 'DESC';
};

export const convertSortingParameters = (parameters?: (ISortingMetadata)[], customFields?: Map<string, GraphqlSortingFieldMetadata>, options?: ISortingDecoratorParams) => {
  // For tests purposes. The library always provides an array. If object is provided that means that something overrides decorator value, like mocks.
  if (!Array.isArray(parameters)) return parameters;
  
  return parameters && parameters.reduce((accumulatedParams, x) => {
    
    const convertedParams = Object.entries(x).reduce((acc, [k, v]) => {
      if (customFields.has(k)) {
        const field = customFields.get(k);
        acc[field.sqlExp] = v;
      } else {
        if (options?.sqlAlias) {
          acc[`${options?.sqlAlias}.${k}`] = v
        } else {
          acc[k] = v
        }
      }

      return acc;
    }, {});

    return {
      ...accumulatedParams,
      ...convertedParams
    };
  }, {}) || {};
}