package dao;

import model.Person;
import model.User;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * User data access object that performs operations associated with users
 */
public class UserDAO
{
    private final Connection conn;

    public UserDAO(Connection conn)
    {
        this.conn = conn;
    }

    /**
     * Creates a user
     * @param user
     */
    public void createUser(User user) throws DataAccessException
    {
        String sql = "INSERT INTO Users (username, password, email, firstName, " +
                "lastName, gender, personID) VALUES(?,?,?,?,?,?,?)";

        try (PreparedStatement stmt = conn.prepareStatement(sql))
        {
            stmt.setString(1, user.getUsername());
            stmt.setString(2, user.getPassword());
            stmt.setString(3, user.getEmail());
            stmt.setString(4, user.getFirstName());
            stmt.setString(5, user.getLastName());
            stmt.setString(6, user.getGender());
            stmt.setString(7, user.getPersonID());

            stmt.executeUpdate();
        }
        catch(SQLException e)
        {
            e.printStackTrace();
            throw new DataAccessException("Error encountered while inserting into the database");
        }
    }

    /**
     * Attempts to validate a user given a username and password
     * @param username
     * @param password
     * @return true if user is validated, false otherwise
     */
    public boolean validate(String username, String password) throws DataAccessException
    {
        ResultSet rs = null;
        String sql = "SELECT * FROM Users WHERE username = ? AND password = ?;";

        try (PreparedStatement stmt = conn.prepareStatement(sql))
        {
            stmt.setString(1, username);
            stmt.setString(2, password);
            rs = stmt.executeQuery();

            if (rs.next())
            {
                return true;
            }
        }
        catch (SQLException e)
        {
            e.printStackTrace();
            throw new DataAccessException("Error encountered while validating user");
        }
        finally
        {
            if (rs != null)
            {
                try
                {
                    rs.close();
                }
                catch (SQLException e)
                {
                    e.printStackTrace();
                }
            }
        }
        return false;
    }

    /**
     * Finds and returns a user associated with a specific userID
     * @param userID
     * @return User associated with the username
     */
    public User getUserByID(String userID) throws DataAccessException
    {
        User user;
        ResultSet rs = null;
        String sql = "SELECT * FROM Users WHERE username = ?;";

        try (PreparedStatement stmt = conn.prepareStatement(sql))
        {
            stmt.setString(1, userID);
            rs = stmt.executeQuery();

            if (rs.next())
            {
                user = new User(rs.getString("username"), rs.getString("password"),
                        rs.getString("email"), rs.getString("firstName"), rs.getString("lastName"),
                        rs.getString("gender"), rs.getString("personID"));
                return user;
            }
        }
        catch (SQLException e)
        {
            e.printStackTrace();
            throw new DataAccessException("Error encountered while finding user");
        }
        finally
        {
            if (rs != null)
            {
                try
                {
                    rs.close();
                }
                catch (SQLException e)
                {
                    e.printStackTrace();
                }
            }
        }
        return null;
    }

    /**
     * Removes every user from the database
     */
    public void removeAllUsers() throws DataAccessException
    {
        String sql = "DELETE FROM Users";

        try(PreparedStatement stmt = conn.prepareStatement(sql))
        {
            stmt.executeUpdate();
        }
        catch(SQLException e)
        {
            e.printStackTrace();
            throw new DataAccessException("Error encountered while deleting from the database");
        }
    }
}