package com.example.bem;

import android.app.AlertDialog;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatDelegate;
import androidx.appcompat.app.AppCompatActivity;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.firestore.FirebaseFirestore;

import java.util.HashMap;
import java.util.Map;

public class LoginActivity extends AppCompatActivity {

    private FirebaseAuth mAuth;
    private FirebaseFirestore db;
    private SharedPreferences prefs;
    private static final String PREF_DARK_MODE = "dark_mode";

    private EditText inputEmail;
    private EditText inputPassword;
    private EditText inputName;
    private EditText inputPhone;
    private Button btnLogin;
    private TextView textLoginType;
    private TextView textSwitchMode;
    private TextView textForgotPassword;
    private TextView textSwitchToGuardian;
    private ProgressBar progressBar;

    private boolean isRegisterMode = false;
    private boolean isGuardianMode = false;

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

        prefs = getSharedPreferences("app_prefs", MODE_PRIVATE);
        applyThemeFromPrefs();

        mAuth = FirebaseAuth.getInstance();
        db = FirebaseFirestore.getInstance();

        if (mAuth.getCurrentUser() != null) {
            mAuth.signOut();
        }

        setContentView(R.layout.activity_login);

        inputEmail = findViewById(R.id.inputEmail);
        inputPassword = findViewById(R.id.inputPassword);
        inputName = findViewById(R.id.inputName);
        inputPhone = findViewById(R.id.inputPhone);
        btnLogin = findViewById(R.id.btnLogin);
        textLoginType = findViewById(R.id.textLoginType);
        textSwitchMode = findViewById(R.id.textSwitchMode);
        textForgotPassword = findViewById(R.id.textForgotPassword);
        textSwitchToGuardian = findViewById(R.id.textSwitchToGuardian);

        btnLogin.setOnClickListener(v -> handleLogin());
        textSwitchMode.setOnClickListener(v -> toggleMode());
        textForgotPassword.setOnClickListener(v -> showForgotPasswordDialog());
        textSwitchToGuardian.setOnClickListener(v -> switchToGuardianMode());
    }

    private void switchToGuardianMode() {
        isGuardianMode = !isGuardianMode;

        if (isGuardianMode) {
            textLoginType.setText("Login de Responsável");
            textSwitchToGuardian.setText("👤 Sou Utilizador");
            inputPhone.setVisibility(View.VISIBLE);
            inputPhone.setHint("Número de telemóvel");
        } else {
            textLoginType.setText("Login de Utilizador");
            textSwitchToGuardian.setText("🔒 Sou Responsável");
            inputPhone.setVisibility(View.GONE);
        }

        isRegisterMode = false;
        updateUI();
    }

    private void toggleMode() {
        isRegisterMode = !isRegisterMode;
        updateUI();
    }

    private void updateUI() {
        if (isRegisterMode) {
            btnLogin.setText("Criar Conta");
            textSwitchMode.setText("Já tem conta? Entrar");
            inputName.setVisibility(View.VISIBLE);

            if (isGuardianMode) {
                inputPhone.setVisibility(View.VISIBLE);
            }
        } else {
            btnLogin.setText("Entrar");
            textSwitchMode.setText("Não tem conta? Registar");
            inputName.setVisibility(View.GONE);

            if (!isGuardianMode) {
                inputPhone.setVisibility(View.GONE);
            }
        }
    }

    private void handleLogin() {
        String email = inputEmail.getText().toString().trim();
        String password = inputPassword.getText().toString().trim();
        String name = inputName.getText().toString().trim();
        String phone = inputPhone.getText().toString().trim();

        if (TextUtils.isEmpty(email)) {
            inputEmail.setError("Insira o email");
            return;
        }

        if (!android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
            inputEmail.setError("Email inválido");
            return;
        }

        if (TextUtils.isEmpty(password)) {
            inputPassword.setError("Insira a palavra-passe");
            return;
        }

        if (password.length() < 6) {
            inputPassword.setError("Mínimo 6 caracteres");
            return;
        }

        if (isRegisterMode && TextUtils.isEmpty(name)) {
            inputName.setError("Insira o nome");
            return;
        }

        btnLogin.setEnabled(false);

        if (isRegisterMode) {
            registerUser(email, password, name, phone);
        } else {
            loginUser(email, password);
        }
    }

    private void registerUser(String email, String password, String name, String phone) {
        mAuth.createUserWithEmailAndPassword(email, password)
                .addOnCompleteListener(task -> {
                    if (task.isSuccessful()) {
                        FirebaseUser user = mAuth.getCurrentUser();
                        if (user != null) {
                            saveUserData(user.getUid(), email, name, phone, true);
                        } else {
                            btnLogin.setEnabled(true);
                            Toast.makeText(this, "Erro ao obter utilizador. Tente entrar com o email/senha.",
                                    Toast.LENGTH_LONG).show();
                            mAuth.signOut();
                        }
                    } else {
                        btnLogin.setEnabled(true);
                        String error = task.getException() != null ? task.getException().getMessage()
                                : "Erro desconhecido";
                        Toast.makeText(this, "Erro: " + error, Toast.LENGTH_LONG).show();
                    }
                });
    }

    private void saveUserData(String uid, String email, String name, String phone, boolean fromRegister) {
        Map<String, Object> userData = new HashMap<>();
        userData.put("email", email);
        userData.put("name", name);
        userData.put("phone", phone != null ? phone : "");
        userData.put("type", isGuardianMode ? "guardian" : "user");
        userData.put("createdAt", System.currentTimeMillis());

        db.collection("users").document(uid)
                .set(userData)
                .addOnSuccessListener(aVoid -> {
                    if (fromRegister) {
                        Toast.makeText(this, "✓ Conta criada! Faça login para continuar.", Toast.LENGTH_LONG).show();
                        mAuth.signOut();
                        btnLogin.setEnabled(true);
                        // Recarrega a tela limpa
                        Intent intent = getIntent();
                        finish();
                        startActivity(intent);
                    } else {
                        redirectToApp();
                    }
                })
                .addOnFailureListener(e -> {
                    btnLogin.setEnabled(true);
                    Toast.makeText(this, "Erro ao salvar dados: " + e.getMessage(), Toast.LENGTH_LONG).show();
                });
    }

    private void loginUser(String email, String password) {
        mAuth.signInWithEmailAndPassword(email, password)
                .addOnCompleteListener(task -> {
                    if (task.isSuccessful()) {
                        FirebaseUser user = mAuth.getCurrentUser();
                        if (user != null) {
                            checkUserTypeAndRedirect(user.getUid());
                        } else {
                            btnLogin.setEnabled(true);
                            Toast.makeText(this, "Erro ao iniciar sessão. Tente novamente.", Toast.LENGTH_LONG).show();
                        }
                    } else {
                        btnLogin.setEnabled(true);
                        String error = task.getException() != null ? task.getException().getMessage()
                                : "Credenciais inválidas";
                        Toast.makeText(this, "Erro: " + error, Toast.LENGTH_LONG).show();
                    }
                });
    }

    private void checkUserTypeAndRedirect(String uid) {
        db.collection("users").document(uid)
                .get()
                .addOnSuccessListener(document -> {
                    if (document.exists()) {
                        String type = document.getString("type");
                        prefs.edit()
                                .putString("user_type", type != null ? type : "user")
                                .putString("user_name", document.getString("name"))
                                .apply();

                        if ("guardian".equals(type)) {
                            java.util.List<String> managedUsers = (java.util.List<String>) document.get("managedUsers");

                            if (managedUsers != null && !managedUsers.isEmpty()) {
                                redirectToApp();
                            } else {
                                Intent intent = new Intent(LoginActivity.this, InviteCodeActivity.class);
                                intent.putExtra("is_guardian", true);
                                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                                startActivity(intent);
                                finish();
                            }
                        } else {
                            redirectToApp();
                        }
                    } else {
                        // Se o perfil não existe, cria um com base no modo de login atual.
                        FirebaseUser user = mAuth.getCurrentUser();
                        String email = user != null ? user.getEmail() : "";
                        String name = (email != null && email.contains("@")) ? email.substring(0, email.indexOf("@")) : "Utilizador";
                        String userType = isGuardianMode ? "guardian" : "user";

                        Map<String, Object> userData = new HashMap<>();
                        userData.put("email", email);
                        userData.put("name", name);
                        userData.put("phone", "");
                        userData.put("type", userType);
                        userData.put("createdAt", System.currentTimeMillis());

                        db.collection("users").document(uid)
                                .set(userData)
                                .addOnSuccessListener(aVoid -> {
                                    prefs.edit()
                                            .putString("user_type", userType)
                                            .putString("user_name", name)
                                            .apply();

                                    if ("guardian".equals(userType)) {
                                        Intent intent = new Intent(LoginActivity.this, InviteCodeActivity.class);
                                        intent.putExtra("is_guardian", true);
                                        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                                        startActivity(intent);
                                        finish();
                                    } else {
                                        redirectToApp();
                                    }
                                })
                                .addOnFailureListener(e -> {
                                    Toast.makeText(this, "Erro ao criar perfil: " + e.getMessage(), Toast.LENGTH_SHORT).show();
                                    btnLogin.setEnabled(true);
                                });
                    }
                })
                .addOnFailureListener(e -> {
                    Toast.makeText(this, "Erro ao carregar dados do utilizador: " + e.getMessage(), Toast.LENGTH_SHORT).show();
                    btnLogin.setEnabled(true);
                });
    }

    private void redirectToApp() {
        Intent intent = new Intent(this, MainActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        startActivity(intent);
        finish();
    }

    private void showForgotPasswordDialog() {
        View dialogView = getLayoutInflater().inflate(android.R.layout.simple_list_item_1, null);
        EditText emailInput = new EditText(this);
        emailInput.setHint("Email de recuperação");
        emailInput.setInputType(android.text.InputType.TYPE_TEXT_VARIATION_EMAIL_ADDRESS);
        emailInput.setPadding(50, 40, 50, 40);

        new AlertDialog.Builder(this)
                .setTitle("Recuperar Palavra-passe")
                .setMessage("Insira o email para receber o link de recuperação:")
                .setView(emailInput)
                .setPositiveButton("Enviar", (dialog, which) -> {
                    String email = emailInput.getText().toString().trim();
                    if (TextUtils.isEmpty(email)) {
                        Toast.makeText(this, "Insira um email", Toast.LENGTH_SHORT).show();
                        return;
                    }

                    mAuth.sendPasswordResetEmail(email)
                            .addOnSuccessListener(aVoid -> {
                                Toast.makeText(this, "✓ Email enviado! Verifique a caixa de entrada.",
                                        Toast.LENGTH_LONG).show();
                            })
                            .addOnFailureListener(e -> {
                                Toast.makeText(this, "Erro: " + e.getMessage(), Toast.LENGTH_LONG).show();
                            });
                })
                .setNegativeButton("Cancelar", null)
                .show();
    }

    private void applyThemeFromPrefs() {
        boolean dark = getSharedPreferences("app_prefs", MODE_PRIVATE).getBoolean(PREF_DARK_MODE, false);
        AppCompatDelegate
                .setDefaultNightMode(dark ? AppCompatDelegate.MODE_NIGHT_YES : AppCompatDelegate.MODE_NIGHT_NO);
    }
}