import { z } from "zod";
import { MongoFilter, parse } from "./utils/queryParser";

export const pageMetadata = z.object({
  count: z.number(),
  page: z.number(),
  pageSize: z.number(),
});

export const pageQueryParams = z.object({
  page: z.number().optional(),
  pageSize: z.number().optional(),
  sort: z.string().optional(),
  filter: z.string().optional(),
  searchToken: z.string().optional(),
});

export type PageQueryParams = z.infer<typeof pageQueryParams>;

export function getSortObject(
  params: PageQueryParams,
  validFields: Array<string>
) {
  const sortObj: Record<string, 1 | -1> = {};

  if (params.sort && params.sort != "") {
    const sortOptions = params.sort.split(",");
    sortOptions.forEach((item) => {
      const order = item.startsWith("-") ? -1 : 1;
      const field = item.replace("-", "").trim();

      if (validFields.includes(field)) sortObj[field] = order;
    });
  }

  if (Object.keys(sortObj).length == 0) sortObj["createdAt"] = -1;

  return sortObj;
}

export function getFilterObject(params: PageQueryParams) {
  if (params.filter && params.filter != "") {
    const parsedQuery = parse(params.filter.split("|")).filter(
      (query) => Object.keys(query).length > 0
    );
    return parsedQuery;
  }
}

export function getTaggedUsersFilter(
  filterObj: MongoFilter[],
  sortObj: Record<string, 1 | -1>
) {
  const taggedUserFilterIndex = filterObj.findIndex((item) =>
    Object.keys(item).includes("taggedUsers")
  );

  let taggedFilter = [];
  if (taggedUserFilterIndex != -1) {
    const filterItem = filterObj[taggedUserFilterIndex].taggedUsers;
    let filterValues = null;

    let notFlag = false;
    if (filterItem["$eq"]) {
      filterValues = [filterItem["$eq"]];
    } else if (filterItem["$ne"]) {
      filterValues = [filterItem["$ne"]];
      notFlag = true;
    } else if (filterItem["$in"]) {
      filterValues = filterItem["$in"];
    } else {
      filterValues = filterItem["$nin"];
      notFlag = true;
    }

    const condition = notFlag ? { $exists: false } : { $exists: true };

    taggedFilter = [
      {
        $addFields: {
          taggedUsersFilter: {
            $filter: {
              input: "$taggedUsers",
              as: "user",
              cond: { $in: ["$$user.userId", filterValues] },
            },
          },
        },
      },
      { $match: { "taggedUsersFilter.0": condition } },
      { $sort: { "taggedUsersFilter.taggedAt": sortObj.taggedUsers ?? -1 } },
    ];
  }

  return { taggedFilter, taggedUserFilterIndex };
}