import { Request, Response } from "express";
import DynamicQueryBuilder from "../../helpers/dynamicQueryBuilder";
import { dataSource } from "../../data-source";

/**
 * @description get all table metas
 * @param req {Request} Express req object
 * @param res {Response} Express res object
 * @returns {Promise<*>}
 */
export async function getAllTableMeta(req: Request, res: Response): Promise<any> {
  let tableMetas = DynamicQueryBuilder.getAllTableMeta();

  res.json(tableMetas);
}

/**
 * @description get meta by tablename
 * @param req {Request} Express req object
 * @param res {Response} Express res object
 * @returns {Promise<*>}
 */
export async function getTableMetaByTablename(req: Request, res: Response): Promise<any> {
  const tablename = req.params.tablename;
  let tableMeta = DynamicQueryBuilder.getTableMeta(tablename);

  res.json(tableMeta);
}

/**
 * @description execute Query
 * @param req {Request} Express req object
 * @param res {Response} Express res object
 * @returns {Promise<*>}
 */
export async function executeQuery(req: Request, res: Response): Promise<any> {
  let offset = parseInt((req.query.offset as string) ?? "0");
  let count = parseInt((req.query.count as string) ?? "25");
  const query = req.body.query;

  if (typeof query == "string") {
    const upperQuery = query.trim().toUpperCase();
    if (!upperQuery.startsWith("SELECT") || /INSERT|UPDATE|DELETE|ALTER|DROP|CREATE|TRUNCATE/.test(upperQuery)) {
      return res.json({
        stats: "error",
        sql: query,
        code: "UNALLOWED",
        msg: "Not allowed to change rows",
      });
    }

    try {
      let data: Array<any> = [];

      const result = await dataSource
        .transaction(async (manager) => {
          data = await manager.query(query);

          throw new Error("AllwaysRollbackQuery");
        })
        .catch((error) => {
          if (error.message === "AllwaysRollbackQuery") {
            return {
              stats: "success",
              rows: data,
              total: data.length,
              offset: offset,
              count: count,
            };
          } else {
            return {
              stats: "error",
              sql: error.sql,
              code: error.code,
              msg: error.sqlMessage,
            };
          }
        });
      res.send(result);
    } catch (error) {
      res.json({
        stats: "error",
        sql: error.sql,
        code: error.code,
        msg: error.sqlMessage,
      });
    }
  } else {
    try {
      let [rows, total] = await DynamicQueryBuilder.buildQuery(query, offset, count).getManyAndCount();

      res.json({
        stats: "success",
        rows: DynamicQueryBuilder.flattenQueryResult(rows),
        total: total,
        offset: offset,
        count: count,
      });
    } catch (error) {
      res.json({
        stats: "error",
        sql: error.sql,
        code: error.code,
        msg: error.sqlMessage,
      });
    }
  }
}