package com.cbcren.vpn;

import android.app.Activity;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import android.content.Intent;

// Imports de WireGuard
import com.wireguard.android.backend.Backend;
import com.wireguard.android.backend.GoBackend;
import com.wireguard.android.backend.Tunnel;
import com.wireguard.config.Config;
import com.wireguard.config.Interface;
import com.wireguard.config.Peer;
import com.wireguard.config.InetEndpoint;
import com.wireguard.config.InetNetwork;

import java.util.Collections;

public class MainActivity extends Activity {

    private TextView statusText;
    private Button connectBtn;
    private Backend backend;
    private Config config;
    private Tunnel tunnel;
    private CountDownTimer timer;

    // --- CONFIGURACIÓN QUEMADA ---
    private static final String CLIENT_PRIV_KEY = "ULfX2KspqzSv9cgfvYxGjbL/3FkOS27iCVCyL+LWGmE=";
    private static final String SERVER_PUB_KEY = "44dNaTOCc/nY6vkqy3fJ+L1RqWDqFqEaEq1IBL/InRM=";
    private static final String SERVER_ENDPOINT = "194.163.191.200:51820";
    private static final String CLIENT_IP = "10.66.66.2/32";
    // -----------------------------

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

        statusText = findViewById(R.id.statusText);
        connectBtn = findViewById(R.id.connectBtn);

        // Inicializar Backend
        try {
            backend = new GoBackend(getApplicationContext());
            tunnel = new SimpleTunnel("XuperTunnel");
            config = createConfig();
        } catch (Exception e) {
            statusText.setText("Error Init: " + e.getMessage());
        }

        connectBtn.setOnClickListener(v -> startVpnSequence());
    }

    private Config createConfig() throws Exception {
        Interface.Builder interfaceBuilder = new Interface.Builder();
        interfaceBuilder.parsePrivateKey(CLIENT_PRIV_KEY);
        interfaceBuilder.parseAddresses(CLIENT_IP);
        interfaceBuilder.parseDnsServers("8.8.8.8");

        Peer.Builder peerBuilder = new Peer.Builder();
        peerBuilder.parsePublicKey(SERVER_PUB_KEY);
        peerBuilder.parseEndpoint(SERVER_ENDPOINT);
        peerBuilder.parseAllowedIPs("0.0.0.0/0"); // Todo por el tunel

        return new Config.Builder()
                .setInterface(interfaceBuilder.build())
                .addPeer(peerBuilder.build())
                .build();
    }

    private void startVpnSequence() {
        if (backend == null) return;

        connectBtn.setEnabled(false);
        statusText.setText("Conectando...");

        // Lanzar Intent de VPN (El sistema pedirá permiso la primera vez)
        Intent intent = GoBackend.VpnService.prepare(this);
        if (intent != null) {
            startActivityForResult(intent, 0);
            return;
        }

        connectTunnel();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == RESULT_OK) {
            connectTunnel();
        } else {
            statusText.setText("Permiso denegado");
            connectBtn.setEnabled(true);
        }
    }

    private void connectTunnel() {
        try {
            // Si ya está corriendo, apagar primero
            backend.setState(tunnel, Tunnel.State.DOWN, null);
            
            // Encender
            backend.setState(tunnel, Tunnel.State.UP, config);
            
            startTimer();
        } catch (Exception e) {
            statusText.setText("Error Conexión: " + e.getMessage());
            connectBtn.setEnabled(true);
        }
    }

    private void startTimer() {
        timer = new CountDownTimer(60000, 1000) {
            public void onTick(long millisUntilFinished) {
                statusText.setText("VPN ACTIVA\n" + (millisUntilFinished / 1000) + " segundos");
            }

            public void onFinish() {
                disconnectTunnel();
            }
        }.start();
    }

    private void disconnectTunnel() {
        try {
            if (backend != null) {
                backend.setState(tunnel, Tunnel.State.DOWN, null);
            }
            statusText.setText("Desconectado.\nAbre XuperTV.");
            connectBtn.setEnabled(true);
            connectBtn.setText("RECONECTAR");
        } catch (Exception e) {
            // Ignorar
        }
    }

    // Clase auxiliar simple para identificar el tunel
    private static class SimpleTunnel implements Tunnel {
        private final String name;
        SimpleTunnel(String name) { this.name = name; }
        @Override public String getName() { return name; }
        @Override public void onStateChange(State newState) {}
    }
}