public class KorisniciModel {
    private ObservableList<Korisnik> korisnici = FXCollections.observableArrayList();
    private SimpleObjectProperty<Korisnik> trenutniKorisnik = new SimpleObjectProperty<>();

    private static KorisniciModel instanca = null;

    private Connection conn=null;
    private PreparedStatement stmt;

    private int maksId(){
        try {
            stmt=conn.prepareStatement("Select MAX(id)+1 from korisnik");
            ResultSet rs=stmt.executeQuery();
            return rs.getInt(1);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return 1;
    }

    public KorisniciModel() {
        try{
                if(conn==null) {
                    conn = DriverManager.getConnection("jdbc:sqlite:korisnici.db");
                    regenerisiBazu();
                }
        } catch(SQLException e) {
        System.out.println(e.getMessage());
        }
    }

    private void regenerisiBazu() {
        Scanner ulaz = null;
        try {
            ulaz = new Scanner(new FileInputStream("korisnici.db.sql"));
            String sqlUpit = "";
            while (ulaz.hasNext()) {
                sqlUpit += ulaz.nextLine();
                if ( sqlUpit.length() > 1 && sqlUpit.charAt( sqlUpit.length()-1 ) == ';') {
                    try {
                        Statement stmt = conn.createStatement();
                        stmt.execute(sqlUpit);
                        sqlUpit = "";
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }
            }
            ulaz.close();
        } catch (FileNotFoundException e) {
        System.out.println(e.getMessage());
        }
    }



    private static void initialize() {
        instanca = new KorisniciModel();
    }

    public static KorisniciModel dajInstancu() {
        if (instanca == null) initialize();
        return instanca;
    }




    public void napuni() {
        try {

            stmt = conn.prepareStatement("SELECT id,ime, prezime, email, username, password FROM korisnik");
            ResultSet rs = stmt.executeQuery();
            while (rs.next()) {
                Korisnik k = new Korisnik(rs.getString(2), rs.getString(3), rs.getString(4), rs.getString(5),rs.getString(6));
                k.setId(rs.getInt(1));
                korisnici.add(k);
            }
        } catch(SQLException e) {
            System.out.println("Neuspješno čitanje iz baze: " + e.getMessage());
        }

    }

    public void izmijeniKorisnika(Korisnik k){
        try {
            stmt=conn.prepareStatement("UPDATE korisnik set ime=?,prezime=?,email=?,username=?,password=? where id=?");
            stmt.setString(1,k.getIme());
            stmt.setString(2,k.getPrezime());
            stmt.setString(3,k.getEmail());
            stmt.setString(4,k.getUsername());
            stmt.setString(5,k.getPassword());
            stmt.setInt(6,k.getId());
            stmt.executeUpdate();
            System.out.println(k.getId());
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    public ObservableList<Korisnik> getKorisnici() {
        return korisnici;
    }

    public void setKorisnici(ObservableList<Korisnik> korisnici) {
        this.korisnici = korisnici;
    }

    public Korisnik getTrenutniKorisnik() {
        return trenutniKorisnik.get();
    }

    public SimpleObjectProperty<Korisnik> trenutniKorisnikProperty() {
        return trenutniKorisnik;
    }

    public void setTrenutniKorisnik(Korisnik trenutniKorisnik) {
        if(this.trenutniKorisnik.get()!=null) {
            izmijeniKorisnika(this.trenutniKorisnik.get());
        }
        this.trenutniKorisnik.set(trenutniKorisnik);
    }

    public void setTrenutniKorisnik(int i) {
        this.trenutniKorisnik.set(korisnici.get(i));
    }
    public void diskonektuj(){
        try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        conn=null;
    }
}