helper.js

const db = require('./db');

const Helper = {
    CheckRequestParams: (req, requiredParams) => {
      for (const param of requiredParams) {
        if (!req.body.hasOwnProperty(param)) {
            return { status: 400, result: 'bad_request' };
        }
      }
      return null;
    },

    GetPrivateKeyFromDB: async (user_id) => {
      try {
        const row = await new Promise((resolve, reject) => {
          db.get("SELECT private_key FROM accounts WHERE user_id =?", 
            [user_id], 
            (err, row) => err? reject(err) : resolve(row));
        });
        return row;
      } catch (error) {
        console.error("An error has occurred - " + error);
        return null;
      }
    },
  
    ValidateSession: async (user_id, private_key) => {
      const row = await Helper.GetPrivateKeyFromDB(user_id);
      if (!row) {
        return { status: 1, result: 'Error: user does not exist' };
      }
      if (row.private_key!== private_key) {
        return { status: 1, result: 'wrong private key' };
      }
      return { status: 0, result: 'Success' };
    },

    GetFromDB: async (user_id, columns) => {
        try {
          const columnQuery = columns.join(', ');
          const row = await new Promise((resolve, reject) => {
            db.get(`SELECT ${columnQuery} FROM accounts WHERE user_id =?`, 
              [user_id],
              (err, row) => err? reject(err) : resolve(row)
            );
          });
          return row;
        } catch (error) {
          console.error("An error has occurred - " + error);
          return null;
        }
    },
  
    UpdateDB: async (user_id, updates) => {
        try {
          const updateKeys = Object.keys(updates);
          const updateValues = updateKeys.map(key => updates[key]);
      
          const updateQuery = updateKeys.reduce((query, key, index) => {
            query += `${key} =?`;
            if (index < updateKeys.length - 1) {
              query += ', ';
            }
            return query;
          }, '');
      
          await new Promise((resolve, reject) => {
            db.run(`UPDATE accounts SET ${updateQuery} WHERE user_id =?`, 
              [...updateValues, user_id],
              (err) => err? reject(err) : resolve()
            );
          });
          return { status: 0, result: 'Success' };
        } catch (error) {
          console.error("An error has occurred - " + error);
          return { status: 500, result: 'internal_error' };
        }
    },

    InsertIntoDB: async (table, columns, values) => {
        try {
          const columnQuery = columns.join(', ');
          const valueQuery = values.map(() => '?').join(', ');
          await new Promise((resolve, reject) => {
            db.run(`INSERT INTO ${table}(${columnQuery}) VALUES(${valueQuery})`, 
              values,
              (err) => err? reject(err) : resolve()
            );
          });
          return { status: 0, result: "Success" };
        } catch (error) {
          console.error('Error inserting into database:', error);
          return { status: 1, result: "Error" };
        }
    },

    DeleteFromDB: async (table, column, value) => {
        try {
          await new Promise((resolve, reject) => {
            db.run(`DELETE FROM ${table} WHERE ${column} =?`, 
              [value],
              (err) => err? reject(err) : resolve()
            );
          });
          return true;
        } catch (error) {
          console.error('Error deleting from database:', error);
          return null;
        }
    }
  };
  
module.exports = Helper;