package com.example.lifegrid;

import android.os.Bundle;
import android.content.Intent;
import android.widget.ImageView;
import android.widget.TextView;
import android.content.Context;
import android.content.SharedPreferences;
import android.net.Uri;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;
import androidx.fragment.app.Fragment;

import com.example.lifegrid.menu.AtivosFragment;
import com.example.lifegrid.menu.GraficosFragment;
import com.example.lifegrid.menu.HomeFragment;
import com.example.lifegrid.menu.MetasFragment;
import com.example.lifegrid.menu.TransacoesFragment;

import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
import com.example.lifegrid.utils.CustomToast;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;

import java.util.Calendar;
import java.util.ArrayList;
import java.util.List;

/**
 * TelaInicialActivity funciona como a janela mestre (Container) de navegação da aplicação.
 * É a responsável por carregar e trocar as visualizações menores (Fragmentos) na área principal do ecrã
 * mediante o clique numa série de botões situados na barra de fundo.
 */
public class TelaInicialActivity extends AppCompatActivity {


    
    private ImageView ivHeaderProfilePicture;
    private TextView tvHeaderUsername;
    
    private Spinner spinnerMes;
    private Spinner spinnerAno;
    
    private String[] meses = {"Janeiro", "Fevereiro", "Março", "Abril", "Maio", "Junho", "Julho", "Agosto", "Setembro", "Outubro", "Novembro", "Dezembro"};

    private androidx.activity.result.ActivityResultLauncher<android.net.Uri> takePictureLauncher;
    private android.net.Uri currentPhotoUri;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_tela_inicial);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });

        takePictureLauncher = registerForActivityResult(
                new androidx.activity.result.contract.ActivityResultContracts.TakePicture(),
                success -> {
                    if (success) {
                        processInvoiceImage(currentPhotoUri);
                    }
                }
        );

        com.google.android.material.floatingactionbutton.FloatingActionButton fabScanInvoice = findViewById(R.id.fabScanInvoice);
        fabScanInvoice.setOnClickListener(v -> startInvoiceScan());

        ivHeaderProfilePicture = findViewById(R.id.ivHeaderProfilePicture);
        tvHeaderUsername = findViewById(R.id.tvHeaderUsername);
        
        spinnerMes = findViewById(R.id.spinnerMes);
        spinnerAno = findViewById(R.id.spinnerAno);

        setupSpinners();

        Fragment homeFragment = new HomeFragment();
        getSupportFragmentManager().beginTransaction()
                .replace(R.id.fragmentContainerView, homeFragment)
                .commit();

        android.view.View.OnClickListener openTransacoesListener = v -> {
            updateNavSelection(findViewById(R.id.carteiraImageView));
            Fragment transacoesFragment = new TransacoesFragment();
            getSupportFragmentManager().beginTransaction()
                    .replace(R.id.fragmentContainerView, transacoesFragment)
                    .commit();
            
        };

        android.view.View.OnClickListener openHomeListener = v -> {
            updateNavSelection(findViewById(R.id.homeImageView));
            Fragment newHomeFragment = new HomeFragment();
            getSupportFragmentManager().beginTransaction()
                    .replace(R.id.fragmentContainerView, newHomeFragment)
                    .commit();
            
        };

        ImageView homeImageView = findViewById(R.id.homeImageView);
        homeImageView.setOnClickListener(openHomeListener);

        ImageView carteiraImageView = findViewById(R.id.carteiraImageView);
        carteiraImageView.setOnClickListener(openTransacoesListener);
        ImageView setaImageView = findViewById(R.id.setaImageView);
        setaImageView.setOnClickListener(v -> {
            updateNavSelection(setaImageView);
            Fragment ativosFragment = new AtivosFragment();
            getSupportFragmentManager().beginTransaction()
                    .replace(R.id.fragmentContainerView, ativosFragment)
                    .commit();
            
        });
        ImageView graficoImageView = findViewById(R.id.graficoImageView);
        graficoImageView.setOnClickListener(v -> {
            updateNavSelection(graficoImageView);
            Fragment graficosFragment = new GraficosFragment();
            getSupportFragmentManager().beginTransaction()
                    .replace(R.id.fragmentContainerView, graficosFragment)
                    .commit();
            
        });
        ImageView alvoImageView = findViewById(R.id.alvoImageView);
        alvoImageView.setOnClickListener(v -> {
            updateNavSelection(alvoImageView);
            Fragment metasFragment = new MetasFragment();
            getSupportFragmentManager().beginTransaction()
                    .replace(R.id.fragmentContainerView, metasFragment)
                    .commit();
            
        });
        ImageView definicoesImageView = findViewById(R.id.definicoesImageView);
        definicoesImageView.setOnClickListener(v -> {
            updateNavSelection(definicoesImageView);
            Intent intent = new Intent(TelaInicialActivity.this, DefinicoesActivity.class);
            startActivity(intent);
        });
    }

    public void startInvoiceScan() {
        java.io.File photoFile = new java.io.File(getFilesDir(), "invoice_" + System.currentTimeMillis() + ".jpg");
        currentPhotoUri = androidx.core.content.FileProvider.getUriForFile(this, getPackageName() + ".fileprovider", photoFile);
        takePictureLauncher.launch(currentPhotoUri);
    }

    private void processInvoiceImage(android.net.Uri imageUri) {
        CustomToast.info(this, "A processar fatura com IA...");
        InvoiceScannerHelper.scanInvoice(this, imageUri, new InvoiceScannerHelper.ScanCallback() {
            @Override
            public void onSuccess(double valor, String descricao, String categoria, String data) {
                runOnUiThread(() -> {
                    Fragment currentFragment = getSupportFragmentManager().findFragmentById(R.id.fragmentContainerView);
                    TransacoesFragment transFragment;
                    if (currentFragment instanceof TransacoesFragment) {
                        transFragment = (TransacoesFragment) currentFragment;
                    } else {
                        updateNavSelection(findViewById(R.id.carteiraImageView));
                        transFragment = new TransacoesFragment();
                        getSupportFragmentManager().beginTransaction()
                                .replace(R.id.fragmentContainerView, transFragment)
                                .commit();
                        getSupportFragmentManager().executePendingTransactions();
                    }
                    transFragment.showNovaTransacaoDialog(valor, descricao, categoria, data);
                    
                    // Save document to Firebase
                    uploadDocumentoToFirebase(imageUri, descricao, data);
                });
            }

            @Override
            public void onError(String error) {
                runOnUiThread(() -> CustomToast.error(TelaInicialActivity.this, error));
            }
        });
    }
    
    private void uploadDocumentoToFirebase(android.net.Uri imageUri, String descricao, String data) {
        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        if (user == null) {
            CustomToast.error(this, "Utilizador não autenticado.");
            return;
        }

        CustomToast.info(this, "A guardar documento na Cloud...");

        String fileName = "invoice_" + System.currentTimeMillis() + ".jpg";
        com.google.firebase.storage.StorageReference storageRef = com.google.firebase.storage.FirebaseStorage.getInstance().getReference()
                .child("users/" + user.getUid() + "/documentos/" + fileName);

        storageRef.putFile(imageUri).addOnSuccessListener(taskSnapshot -> {
            storageRef.getDownloadUrl().addOnSuccessListener(uri -> {
                String downloadUrl = uri.toString();
                DatabaseReference dbRef = FirebaseDatabase.getInstance().getReference("users")
                        .child(user.getUid()).child("documentos").push();

                com.example.lifegrid.models.Documento doc = new com.example.lifegrid.models.Documento(descricao, data, downloadUrl);
                dbRef.setValue(doc).addOnCompleteListener(task -> {
                    if (task.isSuccessful()) {
                        CustomToast.success(TelaInicialActivity.this, "Documento guardado com sucesso!");
                    } else {
                        CustomToast.error(TelaInicialActivity.this, "Erro ao guardar dados na Cloud.");
                    }
                });
            });
        }).addOnFailureListener(e -> {
            CustomToast.error(this, "Erro ao enviar imagem para a Cloud.");
        });
    }
    
    @Override
    protected void onResume() {
        super.onResume();
        SharedPreferences prefs = getSharedPreferences("LifeGridPrefs", Context.MODE_PRIVATE);
        String savedName = prefs.getString("username", "");
        String savedPhotoUri = prefs.getString("profile_photo_uri", "");

        if (ivHeaderProfilePicture != null && !savedPhotoUri.isEmpty()) {
            try {
                ivHeaderProfilePicture.setImageURI(Uri.parse(savedPhotoUri));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        if (tvHeaderUsername != null) {
            if (!savedName.isEmpty()) {
                tvHeaderUsername.setText(savedName);
            } else {
                FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
                if (user != null && user.getDisplayName() != null && !user.getDisplayName().isEmpty()) {
                    tvHeaderUsername.setText(user.getDisplayName());
                } else {
                    tvHeaderUsername.setText("Utilizador");
                }
            }
        }
    }
    
    private void scrollToFragment() {
        android.widget.ScrollView scrollView = findViewById(R.id.mainScrollView);
        android.view.View barraCardView = findViewById(R.id.barraCardView);
        if (scrollView != null && barraCardView != null) {
            scrollView.post(() -> scrollView.smoothScrollTo(0, barraCardView.getTop() - 20));
        }
    }

    private void setupSpinners() {
        ArrayAdapter<String> mesAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, meses);
        mesAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinnerMes.setAdapter(mesAdapter);

        int currentYear = Calendar.getInstance().get(Calendar.YEAR);
        List<String> anos = new ArrayList<>();
        for (int i = currentYear - 5; i <= currentYear + 5; i++) {
            anos.add(String.valueOf(i));
        }
        ArrayAdapter<String> anoAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, anos);
        anoAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinnerAno.setAdapter(anoAdapter);

        // Set current month and year
        spinnerMes.setSelection(Calendar.getInstance().get(Calendar.MONTH));
        spinnerAno.setSelection(anos.indexOf(String.valueOf(currentYear)));

        AdapterView.OnItemSelectedListener listener = new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, android.view.View view, int position, long id) {
                atualizarDadosHome();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {}
        };

        spinnerMes.setOnItemSelectedListener(listener);
        spinnerAno.setOnItemSelectedListener(listener);
    }
    
    public void atualizarDadosHome() {
        Fragment currentFragment = getSupportFragmentManager().findFragmentById(R.id.fragmentContainerView);
        int mesSelecionado = spinnerMes.getSelectedItemPosition() + 1; // 1 to 12
        String anoSelecionado = spinnerAno.getSelectedItem().toString();

        if (currentFragment instanceof HomeFragment) {
            String mesNome = meses[spinnerMes.getSelectedItemPosition()];
            ((HomeFragment) currentFragment).carregarDados(mesSelecionado, anoSelecionado, mesNome);
        } else if (currentFragment instanceof TransacoesFragment) {
            ((TransacoesFragment) currentFragment).setFiltro(mesSelecionado, anoSelecionado);
        } else if (currentFragment instanceof GraficosFragment) {
            String mesNome = meses[spinnerMes.getSelectedItemPosition()];
            ((GraficosFragment) currentFragment).setFiltro(mesSelecionado, anoSelecionado, mesNome);
        }
    }

    private void updateNavSelection(android.widget.ImageView selectedItem) {
        int[] ids = {R.id.homeImageView, R.id.carteiraImageView, R.id.setaImageView, R.id.graficoImageView, R.id.alvoImageView, R.id.definicoesImageView};
        for (int id : ids) {
            android.widget.ImageView iv = findViewById(id);
            if (iv != null) {
                if (iv == selectedItem) {
                    iv.setBackgroundResource(R.drawable.nav_item_selected_bg);
                } else {
                    iv.setBackground(null);
                }
            }
        }
    }

}