import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
 
public class DataService {
    DatabaseConnection database;
    public DataService(DatabaseConnection database) {
        this.database = database;
    }
    public List<Employee> getEmployees() {
        List<Employee> employee = new ArrayList<>();
        try {
            employee = tryGetEmployees();
        }catch(SQLException e) {
            System.err.println("Hiba! A lekérdezés sikertelen!");
            System.err.println(e.getMessage());
        }
        return employee;
    }
    public List<Employee> tryGetEmployees() throws SQLException {
        List<Employee> employees = new ArrayList<>();
        String sql = "select id, name, city, salary from employees";
        Connection conn = database.connectDb();
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery(sql);
        while(rs.next()) {
            Employee employee = new Employee();
            employee.id = rs.getInt("id");
            employee.name = rs.getString("name");
            employee.city = rs.getString("city");
            employee.salary = rs.getDouble("salary");
            employees.add(employee);
        }
        database.closeDb(conn);
        return employees;
    }
 
    public void tryInsertEmployee(String name, String city) throws SQLException {
        Connection conn = database.connectDb();
        String sql = "insert into employees " +
                "(name, city) values " +
                "(?, ?)";
        PreparedStatement pstmt = conn.prepareStatement(sql);
        pstmt.setString(1, name);
        pstmt.setString(2, city);
        pstmt.execute();
        database.closeDb(conn);
    }
    public void insertEmployee(String name, String city) {
        try {
            tryInsertEmployee(name, city);
        } catch (SQLException ex) {
            System.err.println("Hiba! A beszúrás sikertelen!");
        }
    }
 
}