public class MainActivity extends AppCompatActivity {

private AppCompatActivity activity = MainActivity.this;
private RecyclerView recyclerViewNews;
private List<Noticia> listNoticias;
private NewsRecyclerAdapter newsRecyclerAdapter;
private DBNoticias databaseHelper;
private Button btnLogout;
private LinearLayoutManager mLayoutManager;
UserSession userSession;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    userSession = new UserSession(getApplicationContext());

    recyclerViewNews = findViewById(R.id.recyclerViewNews);
    btnLogout = findViewById(R.id.btlogout);

    TextView usuario = findViewById(R.id.textView5);


    /**
     * Olá mundo by Alciomar
     */
    SharedPreferences sharedPreferences = getSharedPreferences("Reg", Context.MODE_PRIVATE);
    String  uName = sharedPreferences.getString("Name", "");
    usuario.setText(uName.toUpperCase());


    try {
        btnLogout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                userSession.logoutUser();
            }
        });
    } catch (Exception e) {
        e.printStackTrace();
    }

    initStuff();
    getDataFromPostgres();

    FloatingActionButton fab = findViewById(R.id.fabNews);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(MainActivity.this, PostNews.class);
            startActivity(intent);
        }
    });

}


/**
 * This method is to initialize objects to be used
 */
private void initStuff() {

    try {
        listNoticias = new ArrayList<>();
        newsRecyclerAdapter = new NewsRecyclerAdapter(listNoticias);

        mLayoutManager = new LinearLayoutManager(getApplicationContext());
        mLayoutManager.setReverseLayout(true);
        mLayoutManager.setStackFromEnd(true);
        recyclerViewNews.setLayoutManager(mLayoutManager);
        recyclerViewNews.setItemAnimator(new DefaultItemAnimator());
        recyclerViewNews.setHasFixedSize(true);
        recyclerViewNews.setAdapter(newsRecyclerAdapter);
        databaseHelper = new DBNoticias(activity);

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

/**
 * This method is to fetch all user records from SQLite
 */
private void getDataFromPostgres() {
    // AsyncTask is used that SQLite operation not blocks the UI Thread.
    new AsyncTask<Void, Void, Void>() {
        @Override
        protected Void doInBackground(Void... params) {
            listNoticias.clear();
            for (DBNoticias dbNoticias : databaseHelper.getNewsList()) {
                Noticia noticia = new Noticia();
                noticia.setUser_id(dbNoticias.getId());
                noticia.setNewsTitle(dbNoticias.getNewsTitle());
                noticia.setNewsMessage(dbNoticias.getNewsPost());

                listNoticias.add(noticia);
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            newsRecyclerAdapter.notifyDataSetChanged();
        }
    }.execute();
}

public class UserSession {
// Shared Preferences reference
SharedPreferences pref;

// Editor reference for Shared preferences
Editor editor;

// Context
Context _context;

// Shared preferences mode
int PRIVATE_MODE = 0;

// Shared preferences file name
public static final String PREFER_NAME = "Reg";

// All Shared Preferences Keys
public static final String IS_USER_LOGIN = "IsUserLoggedIn";

// User name (make variable public to access from outside)
public static final String KEY_NAME = "Name";

// Email address (make variable public to access from outside)
public static final String KEY_EMAIL = "Email";

public static final String KEY_ID = "IdUser";

// password
public static final String KEY_PASSWORD = "txtPassword";

// Constructor
public UserSession(Context context){
    this._context = context;
    pref = _context.getSharedPreferences(PREFER_NAME, PRIVATE_MODE);
    editor = pref.edit();
}

//Create login session
public void createUserLoginSession(String uName, String uEmail, int uIdUser){
    // Storing login value as TRUE
    editor.putBoolean(IS_USER_LOGIN, true);

    // Storing name in preferences
    editor.putString(KEY_NAME, uName);

    // Storing email in preferences
    editor.putString(KEY_EMAIL,  uEmail);

    editor.putInt(KEY_ID, uIdUser);


    // commit changes
    editor.commit();
}

/**
 * Check login method will check user login status
 * If false it will redirect user to login page
 * Else do anything
 * */
public boolean checkLogin(){
    // Check login status
    if(!this.isUserLoggedIn()){

        // user is not logged in redirect him to Login Activity
        Intent i = new Intent(_context, Login.class);

        // Closing all the Activities from stack
        i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

        // Add new Flag to start new Activity
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

        // Staring Login Activity
        _context.startActivity(i);

        return true;
    } else {
        Intent f = new Intent(_context, MainActivity.class);
        _context.startActivity(f);
    }
    return false;
}



/**
 * Get stored session data
 * */
public HashMap<String, String> getUserDetails(){

    //Use hashmap to store user credentials
    HashMap<String, String> user = new HashMap<String, String>();

    // user name
    user.put(KEY_NAME, pref.getString(KEY_NAME, null));

    // user email id
    user.put(KEY_EMAIL, pref.getString(KEY_EMAIL, null));

    // return user
    return user;
}

/**
 * Clear session details
 * */
public void logoutUser(){

    // Clearing all user data from Shared Preferences
    editor.clear();
    editor.commit();

    // After logout redirect user to MainActivity
    Intent i = new Intent(_context, Login.class);

    // Closing all the Activities
    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

    // Add new Flag to start new Activity
    i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    // Staring Login Activity
    _context.startActivity(i);
}


// Check for login
public boolean isUserLoggedIn(){
    return pref.getBoolean(IS_USER_LOGIN, false);
}

public class PostNews extends AppCompatActivity {

private DBNoticias dbNoticias;
private Button btnpostar;
private EditText editTextCDNewsTitle;
private EditText editTextCDNewsPost;
private Noticia noticia;
private SharedPreferences sharedPreferences;

public void alert(String titulo, String txt){
    AlertDialog alertDialog = new AlertDialog.Builder(PostNews.this).create();
    alertDialog.setTitle(titulo);
    alertDialog.setMessage(txt);
    alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                }
            });
    alertDialog.show();
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_post_news);

    btnpostar = findViewById(R.id.btn_postar);
    dbNoticias = new DBNoticias();

    editTextCDNewsTitle = findViewById(R.id.EditTextNewsTitle);
    editTextCDNewsPost = findViewById(R.id.EditTextNewsPost);

}

public void salvarNoticia(View view) {
    try {
        {
            String newsTitle = editTextCDNewsTitle.getText().toString();
            String newsPost = editTextCDNewsPost.getText().toString();

            if (!(editTextCDNewsTitle.getText().toString().equals("") || editTextCDNewsTitle.getText() == null ||
                    editTextCDNewsPost.getText().toString().equals("") || editTextCDNewsPost.getText() == null

            )) {

                sharedPreferences = getSharedPreferences("Reg", Context.MODE_PRIVATE);
               String  uName = sharedPreferences.getString("Name", "");
               String uEmail = sharedPreferences.getString("Email", "");
               int  uIdUser = sharedPreferences.getInt("IdUser", 0);

                dbNoticias.setNewsTitle(newsTitle);
                dbNoticias.setNewsPost(newsPost);
                dbNoticias.setIdUser(uIdUser);


                dbNoticias.salvar();

                noticia = new Noticia();


                Toast.makeText(getApplicationContext(), "Notícia postada com sucesso",
                        Toast.LENGTH_LONG).show();

                editTextCDNewsTitle.setText("");
                editTextCDNewsPost.setText("");
            }

        }
    }
    catch (Exception e){
        alert("Erro", e.getMessage());
    }
}

public class DBNoticias {

private int id;
private int idUser;
public String newsTitle;
public String newsPost;
public boolean _status;
public String _message;



public DBNoticias(){
    this.id = -1;
    this.newsTitle = "";
    this.newsPost = "";

}

public DBNoticias(AppCompatActivity activity) {

}

public ArrayList<DBNoticias> getNewsList(){
    ArrayList<DBNoticias> lista = new ArrayList<>();
    try {
        ResultSet resultSet = DB.select("SELECT * FROM news");
        if (resultSet != null){
            while (resultSet.next()){

                DBNoticias obj = new DBNoticias();

                obj.setId(resultSet.getInt("id_news"));
                obj.setNewsTitle(resultSet.getString("news_title"));
                obj.setNewsPost(resultSet.getString("news_message"));
                lista.add(obj);
            }
        }
    }catch (Exception ex){
        this._message = ex.getMessage();
        this._status = false;
        this._status = false;
    }
    return lista;
}

public void salvar() throws SQLException, ClassNotFoundException, InstantiationException, IllegalAccessException{
    String comando = "";
    if (this.getId() == -1){


        comando = String.format("INSERT INTO news (news_title, news_message, fk_user_id) VALUES ('%s','%s',%d);",
                this.getNewsTitle(), this.getNewsPost(), this.idUser);
    }else {
        comando = String.format("UPDATE news SET news_title ='%s', news_post = '%s', id_news = %d WHERE id = %d;",
                this.getNewsTitle(), this.getNewsPost(), this.getId());
    }
    DB db =  new DB();
    db.executeQuery(comando);
}

public void apagar() throws SQLException, ClassNotFoundException, InstantiationException, IllegalAccessException{
    String comando = String.format("DELETE FROM news WHERE id = %d;", this.getId());

    DB db =  new DB();
    db.execute(comando);
}