DCAv2GUI/app/src/main/java/com/example/dcav2gui/MainActivity.java

package com.example.dcav2gui;

import android.view.MenuItem;

import androidx.lifecycle.ViewModelProvider;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;//
import android.os.Bundle;
import android.view.Menu;
import android.widget.Toast;

import com.example.dcav2gui.ui.home.HomeFragment;
import com.example.dcav2gui.ui.settings.SettingsData;
import com.example.dcav2gui.ui.settings.SettingsViewModel;
import com.google.android.material.navigation.NavigationView;

import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.AppCompatActivity;

import com.example.dcav2gui.databinding.ActivityMainBinding;

import java.io.File;
import java.util.Objects;

public class MainActivity extends AppCompatActivity {

    private AppBarConfiguration mAppBarConfiguration;
    private ActivityMainBinding binding;
    public static SettingsData globalSettings;
    public HomeFragment.HomeCache homeViewCache;
    public static InstanceInterface.ExchangeStatsData binanceCache;
    public static InstanceInterface.ExchangeStatsData gateioCache;
    public static InstanceInterface.ExchangeStatsData kucoinCache;
    public static InstanceInterface.ExchangeStatsData okxCache;



    public HomeFragment.HomeCache getHomeViewCache() {
        return homeViewCache;
    }

    public void setHomeViewCache(HomeFragment.HomeCache newCache) {
        this.homeViewCache = newCache;
    }

    public void setInstanceCache(InstanceInterface.ExchangeStatsData binance,
                                 InstanceInterface.ExchangeStatsData gateio,
                                 InstanceInterface.ExchangeStatsData kucoin,
                                 InstanceInterface.ExchangeStatsData okx) {
        binanceCache = binance;
        gateioCache = gateio;
        kucoinCache = kucoin;
        okxCache = okx;
    }

    public static InstanceInterface.ExchangeStatsData getInstanceCache(String exchange) {
        if (Objects.equals(exchange, "binance")) {
            return binanceCache;
        } else if (Objects.equals(exchange, "gateio")) {
            return gateioCache;
        } else if (Objects.equals(exchange, "kucoin")) {
            return kucoinCache;
        } else  {
            return okxCache;
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        setSupportActionBar(binding.appBarMain.toolbar);
        DrawerLayout drawer = binding.drawerLayout;
        NavigationView navigationView = binding.navView;
        mAppBarConfiguration = new AppBarConfiguration.Builder(
                R.id.nav_home,
                R.id.nav_binance,
                R.id.nav_gateio,
                R.id.nav_kucoin,
                R.id.nav_okx
                )
                .setOpenableLayout(drawer)
                .build();
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
        NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
        NavigationUI.setupWithNavController(navigationView, navController);

        // Load settings
        SettingsViewModel settingsViewModel = new ViewModelProvider(this).get(SettingsViewModel.class);
        globalSettings = settingsViewModel.loadSettings(this);

        if (globalSettings==null) {
            Toast.makeText(this, "Please enter your credentials in the settings menu", Toast.LENGTH_LONG).show();
        }
    }

    public static SettingsData getGlobalSettings() {
        return globalSettings;
    }

    public void updateGlobalSettings() {
        SettingsViewModel settingsViewModel = new ViewModelProvider(this).get(SettingsViewModel.class);
        globalSettings = settingsViewModel.loadSettings(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;

    }

    private boolean isSettingsFileExists() {
        File file = new File(getFilesDir(), "settings.json");
        return file.exists();
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        if (id == R.id.action_settings) {
            // Navigate to the SettingsFragment
            NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
            navController.navigate(R.id.nav_settings);
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public boolean onSupportNavigateUp() {
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
        return NavigationUI.navigateUp(navController, mAppBarConfiguration)
                || super.onSupportNavigateUp();
    }
}