package dao;

import com.google.gson.Gson;
import model.Event;
import model.Person;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.Reader;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import javax.xml.crypto.Data;

/**
 * Person data access object that performs operations associated with persons
 */
public class PersonDAO
{
    private final Connection conn;

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

    /**
     * Creates a Person
     * @param person
     */
    public void createPerson(Person person) throws DataAccessException
    {
        String sql = "INSERT INTO Persons (personID, associatedUsername, firstName, lastName, gender, " +
                "fatherID, motherID, spouseID) VALUES(?,?,?,?,?,?,?,?)";

        try (PreparedStatement stmt = conn.prepareStatement(sql))
        {
            stmt.setString(1, person.getPersonID());
            stmt.setString(2, person.getAssociatedUsername());
            stmt.setString(3, person.getFirstName());
            stmt.setString(4, person.getLastName());
            stmt.setString(5, person.getGender());
            stmt.setString(6, person.getFatherID());
            stmt.setString(7, person.getMotherID());
            stmt.setString(8, person.getSpouseID());

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

    /**
     * Finds and returns a person associated with a specific personID
     * @param personID
     * @return person associated with the personID
     */
    public Person getPersonByID(String personID) throws DataAccessException
    {
        Person person;
        ResultSet rs = null;
        String sql = "SELECT * FROM Persons WHERE personID = ?;";

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

            if (rs.next())
            {
                person = new Person(rs.getString("personID"), rs.getString("associatedUsername"),
                        rs.getString("firstName"), rs.getString("lastName"), rs.getString("gender"),
                        rs.getString("fatherID"), rs.getString("motherID"), rs.getString("spouseID"));
                return person;
            }
        }
        catch (SQLException e)
        {
            e.printStackTrace();
            throw new DataAccessException("Error encountered while finding person");
        }
        finally
        {
            if (rs != null)
            {
                try
                {
                    rs.close();
                }
                catch (SQLException e)
                {
                    e.printStackTrace();
                }
            }
        }

        return null;
    }

    /**
     * Finds and removes a person associated with a specific personID
     * @param personID
     * @return person associated with the personID
     */
    public void removePersonByID(String personID) throws DataAccessException
    {
        String sql = "DELETE FROM Persons WHERE personID = ?;";

        try (PreparedStatement stmt = conn.prepareStatement(sql))
        {
            stmt.setString(1, personID);
            stmt.executeUpdate();
        }
        catch (SQLException e)
        {
            e.printStackTrace();
            throw new DataAccessException("Error encountered while removing person");
        }
    }

    /**
     *
     * @param username
     * @return a list of Person objects associated with a given User
     */
    public List<Person> findPersonsForUser(String username) throws DataAccessException
    {
        List<Person> personList = new ArrayList<>();
        Person person;
        ResultSet rs = null;
        String sql = "SELECT * FROM Persons WHERE associatedUsername = ?;";

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

            while (rs.next())
            {
                person = new Person(rs.getString("personID"), rs.getString("associatedUsername"),
                        rs.getString("firstName"), rs.getString("lastName"), rs.getString("gender"),
                        rs.getString("fatherID"), rs.getString("motherID"), rs.getString("spouseID"));
                personList.add(person);
            }

            return personList;
        }
        catch (SQLException e)
        {
            e.printStackTrace();
            throw new DataAccessException("Error encountered while finding person");
        }
        finally
        {
            if (rs != null)
            {
                try
                {
                    rs.close();
                }
                catch (SQLException e)
                {
                    e.printStackTrace();
                }
            }
        }
    }

    /**
     * Removes all persons associated with a user
     */
    public void removeUserPersons(String username) throws DataAccessException
    {
        String sql = "DELETE FROM Persons WHERE associatedUsername = ?;";

        try(PreparedStatement stmt = conn.prepareStatement(sql))
        {
            stmt.setString(1, username);
            stmt.executeUpdate();
        }
        catch(SQLException e)
        {
            e.printStackTrace();
            throw new DataAccessException("Error encountered while deleting user's persons from the database");
        }
    }

    /**
     * Removes all the persons from the database
     */
    public void removeAllPersons() throws DataAccessException
    {
        String sql = "DELETE FROM Persons";

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