DAO

package dao;

import db.DBConnection;
import model.Account;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

/**
 * DAO - Data Access Object
 * SRP - 단일책임의 원칙
 */
public class BankDAO {

    public int deleteByNumber(int number){
        Connection conn = DBConnection.getInstance();
        try {
            String sql ="delete from account_tb where number = ?";
            PreparedStatement pstmt = conn.prepareStatement(sql); // 버퍼
            pstmt.setInt(1,number); // 쿼리 완성
            int num = pstmt.executeUpdate(); // flush
            return num;
        } catch (Exception e) {
//            throw new RuntimeException(e); // 호출자에게 위임
            e.printStackTrace();
        }
        return -1;
    }

    public int insert(String password, int balance){
        Connection conn = DBConnection.getInstance();
        try {
            String sql ="insert into account_tb(password, balance, created_at)" +
                    "values(?,?,now())";
            PreparedStatement pstmt = conn.prepareStatement(sql); // 버퍼
            pstmt.setString(1,password);
            pstmt.setInt(2,balance);
            int num = pstmt.executeUpdate();
            return num;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return -1;
    }

    public int updateByNumber(int balance, int number){
        Connection conn = DBConnection.getInstance();
        try {
            String sql ="update account_tb set balance = ? where number = ?";
            PreparedStatement pstmt = conn.prepareStatement(sql); // 버퍼
            pstmt.setInt(1,balance);
            pstmt.setInt(2,number);
            int num = pstmt.executeUpdate();
            return num;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return -1;
    }

    public Account selectByNumber(int number){
        Connection conn = DBConnection.getInstance();
        try {
            String sql = "select * from account_tb where number =?";
            PreparedStatement pstmt = conn.prepareStatement(sql);
            pstmt.setInt(1,number);

            ResultSet rs = pstmt.executeQuery();

            if(rs.next()){ // 커서 한칸 내리기
                Account account = new Account(
                        rs.getInt("number"),
                        rs.getString("password"),
                        rs.getInt("balance"),
                        rs.getTimestamp("created_at")
                );
                return account;
            }

//            System.out.println(isRow);
//            System.out.println(rs.getInt("number"));
//            System.out.println(rs.getString("password"));
//            System.out.println(rs.getInt("balance"));
//            System.out.println(rs.getTimestamp("created_at"));

        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public List<Account> selectAll(){
        Connection conn = DBConnection.getInstance();
        try {
            String sql = "select * from account_tb order by number desc";
            PreparedStatement pstmt = conn.prepareStatement(sql);

            ResultSet rs = pstmt.executeQuery();

            List<Account> accountList = new ArrayList<>();
            while(rs.next()){
                Account account = new Account(
                        rs.getInt("number"),
                        rs.getString("password"),
                        rs.getInt("balance"),
                        rs.getTimestamp("created_at")
                );
                accountList.add(account);
            }
            return accountList;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}