using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.OleDb;

namespace Project1
{
    public class Validator
    {
        public static bool validate(String uid, String password)
        {
            Console.WriteLine("Validation started");
            string sTemp = "";
            int flag = 0;

            try
            {
                string database = "infybank.mdb";
                string connectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + database;
                OleDbConnection dbConnection = new OleDbConnection(connectionString);
                
                string query = "SELECT Password FROM Employee WHERE UserID = '" + uid + "'";
                
                OleDbCommand command = new OleDbCommand(query, dbConnection);
                dbConnection.Open();
                
                OleDbDataReader reader = command.ExecuteReader();

                if (reader.Read())
                {
                    sTemp = reader.GetString(0).ToString();
                    if (sTemp.Equals(password))
                        flag = 1;
                    else
                        flag = 0;
                }
                else
                    flag = 0;
                reader.Close();
                dbConnection.Close();
            }
            catch(Exception e)
            {
                Console.WriteLine(e.Message);
            }

            Console.WriteLine("Validation finished");
            
            if (flag == 1)
            {
                Console.WriteLine("User is valid");
                return true;
            }
            else
            {
                Console.WriteLine("User is invalid");
                return false;
            }
        }

        public static String generateCustID() {

            int flag = 0;

            List<string> idList = new List<string>();

            try {
                string database = "infybank.mdb";
                string connectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + database;
                OleDbConnection dbConnection = new OleDbConnection(connectionString);

                string query = "SELECT CustomerID FROM Customer";

                OleDbCommand command = new OleDbCommand(query, dbConnection);
                dbConnection.Open();

                OleDbDataReader reader = command.ExecuteReader();
                while (reader.Read())
                {
                    idList.Add(reader.GetString(0).ToString());
                    flag = 1;
                }

                reader.Close();
                dbConnection.Close();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }

            if (flag == 0)
                return "1";
            else {
                string[] sArray = idList.ToArray();
                return (Int32.Parse(sArray[sArray.Length - 1]) + 1).ToString();
            }
            
        }

        public static int generateAcNo() {
            List<int> acList = new List<int>();
            int flag = 0;
            try
            {
                string database = "infybank.mdb";
                string connectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + database;
                OleDbConnection dbConnection = new OleDbConnection(connectionString);

                string query = "SELECT AccountNo FROM Account";

                OleDbCommand command = new OleDbCommand(query, dbConnection);
                dbConnection.Open();

                OleDbDataReader reader = command.ExecuteReader();
                while (reader.Read())
                {
                    acList.Add(reader.GetInt32(0));
                    flag = 1;
                }
                
                reader.Close();
                dbConnection.Close();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            if (flag == 0)
                return 1;
            else {
                int[] iArray = acList.ToArray();
                return iArray[iArray.Length - 1] + 1;
            }
        }
    }
}