package ve.gob.cenditel.tibisaymovil;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.InputStream;


import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.security.*;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.io.*;
import java.lang.reflect.Field;

import com.lowagie.text.pdf.*;

import ee.sk.digidoc.SignedDoc;
import ee.sk.utils.ConvertUtils;

import java.util.Calendar;
import java.util.ArrayList;
import java.util.Random;

import java.security.cert.X509Certificate;
import java.text.SimpleDateFormat;








public class PDFVerifyResultActivity extends Activity {

	private LinearLayout button_share;
    private LinearLayout button_finish;

    // ruta absoluta al archivo a verificar
    private String pdfToVerify;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		
		
		
		//Estilando la barra de titulo
		final boolean customTitleSupported = requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
		
		super.onCreate(savedInstanceState);
		
		setContentView(R.layout.activity_verify_result_pdf);
		
		//Estilando Barra de titulo
		if(customTitleSupported)
			getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.title_bar);
		
		// obtener el archivo pdf a verificar
		Bundle bundle = getIntent().getExtras();
		pdfToVerify = bundle.getString("pdfToVerify");
		TextView pdfName = (TextView) this.findViewById(R.id.filename_text);
		pdfName.setText(pdfToVerify);
		
		// ejecutar el proceso de verificacion del pdf
		doVerification(pdfToVerify);
		
		// habilitar opciones de botones inferiores
		button_share = (LinearLayout) this.findViewById(R.id.button_remove_certificate_zone);
        button_finish = (LinearLayout) this.findViewById(R.id.button_add_certificate_zone);
		
        // habilita el click sobre la acción de finalizar la verificacion de firma y regresar
        button_finish.setOnClickListener(new OnClickListener() 
        {        
        	public void onClick(View v) 
        	{
        	
        		Intent oIntent = new Intent(PDFVerifyResultActivity.this, TibisayMovilActivity.class);
        		oIntent.setAction(Intent.ACTION_VIEW);
        		oIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        		startActivity(oIntent);
	        
        		finish();
        	}
        });

        // habilita el click sobre la acción de compartir el archivo
        button_share.setOnClickListener(new OnClickListener() 
        {        
        	public void onClick(View v) 
        	{
        		shareIt();
        	}
        });

    
    
	} // fin de onCreate
	
	
	/**
     * Ejecuta la verificacion de la firma del pdf utilizando la biblioteca droidtext
     * 
     * */
    private void doVerification(String pdfToVerify) {
    	
    	
    	try {

    		Random rnd = new Random();
            		
    		PdfReader reader = new PdfReader(pdfToVerify);
    		Log.d("VerificadorPDF", "new PdfReader");
        
    		AcroFields af = reader.getAcroFields();
    		Log.d("VerificadorPDF", "reader.getAcroFields()");
        
    		ArrayList names = af.getSignatureNames();
    		Log.d("VerificadorPDF", "af.getSignatureNames()");
		
    		Toast.makeText(getApplicationContext(), "names.size: "+ Integer.toString(names.size()), Toast.LENGTH_SHORT).show();
    		Log.d("VerificadorPDF", Integer.toString(names.size()));
    		
    		if (names.size() == 0) {
    			// el archivo no posee firmas
    			TextView signatureMessage = (TextView) this.findViewById(R.id.archivo_original_a_descifrar);
    			signatureMessage.setText("El documento PDF no está firmado electrónicamente.");
    			
    			TextView labelSignature = (TextView) this.findViewById(R.id.label_archivo_original);
    			labelSignature.setText("Documento:");
    			
    			TextView labelSigners = (TextView) this.findViewById(R.id.label_destinatario_cifrado);
    			labelSigners.setVisibility(View.GONE);
    			
    			ListView listViewSigners = (ListView) this.findViewById(R.id.signatures_list);
    			listViewSigners.setVisibility(View.GONE);
    			return;
    		}else{
    			// el documento si posee firmas
    			//KeyStore kall = PdfPKCS7.loadCacertsKeyStore();

    			// crear certificate factory
        		CertificateFactory cf = CertificateFactory.getInstance("X.509");
    			
        		// crear un KeyStore
        		String keyStoreType = KeyStore.getDefaultType();
              	KeyStore kall = KeyStore.getInstance(keyStoreType);
                kall.load(null, null);
                
             // obtener vector de campos de /res/raw
        		Field[] fields = R.raw.class.getFields();
        		
        		InputStream caInput = null; 
        		
        		// iterar sobre todos los certificados incluidos en /res/raw y cargarlos
        		// en el KeyStore
        		for (int l=0; l < fields.length; l++) {
        			try {
        				Toast.makeText(getApplicationContext(), "PDFVerifyResultActivity - reading certificate: "+Integer.toString(l)+ " "+ 
        					Integer.toString(fields[l].getInt(null)), Toast.LENGTH_SHORT).show();

        				caInput = new BufferedInputStream(getResources().openRawResource(fields[l].getInt(null))); 

        			} catch (IllegalArgumentException e) {

        				Toast.makeText(getApplicationContext(), "PDFVerifyResultActivity: IllegalArgumentException "+e.getMessage(),
        						Toast.LENGTH_SHORT).show();
        				break;
        			} catch (IllegalAccessException e) {

        				Toast.makeText(getApplicationContext(), "PDFVerifyResultActivity: IllegalAccessException "+e.getMessage(),
        						Toast.LENGTH_SHORT).show();
        				break;
        			}
        			                		 
                    Certificate ca;
                    try {
                    	ca = cf.generateCertificate(caInput);
                        //Log.d("**ca:", ((X509Certificate) ca).getSubjectDN());
                        	    
                        //Log.d("*** try: ca.toString()", ca.toString());
                        } finally {
                            caInput.close();
                        }
        			kall.setCertificateEntry("ca"+Integer.toString(l), ca);
        		}// fin de la iteracion sobre /res/raw
    			
    			
    			// se crea el adaptador para mostrar los firmantes del contenedor
    			ListView signerListView = (ListView) findViewById(R.id.signatures_list);
    			final ArrayList<SignerFromPDF> signers = new ArrayList<SignerFromPDF>();

    			boolean invalidSignature = false;
    			
    			for (int i = 0; i < names.size(); i++){    				
    				
    				String name = (String)names.get(i);
    				PdfPKCS7 pk = af.verifySignature(name);
                    Calendar cal = pk.getSignDate();
                    Certificate pkc[] = pk.getCertificates();
                    
                    X509Certificate cert = (X509Certificate) pk.getSigningCertificate();
                        				
    				String cn = cert.getSubjectDN().toString();
    		    	String signerName = ConvertUtils.getCommonName(cn);
    		    	
    		    	SimpleDateFormat date_format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SS");
    		    	String date = date_format.format(pk.getSignDate().getTime());

    		    	String certificateSerial = cert.getSerialNumber().toString();
    		    	String validFrom = cert.getNotBefore().toString();
    		    	String validUntil = cert.getNotAfter().toString();
    		    	String certificateIssuer = cert.getIssuerDN().toString();
    				
    		    	Object fails[] = PdfPKCS7.verifyCertificates(pkc, kall, null, cal);
                    if (fails == null) {
                        System.out.print(pk.getSignName());
                        Toast.makeText(getApplicationContext(), "Firma Válida", Toast.LENGTH_SHORT).show();
                    }
                    else {
                        System.out.print("Firma no válida");
                        Toast.makeText(getApplicationContext(), "Firma NO Válida", Toast.LENGTH_SHORT).show();
                        
                        invalidSignature = true;             
                    }
    		    	
    		    	// agregar el nombre comun del firmante y la fecha y la hora
		    		signers.add(new SignerFromPDF(signerName, cn, date, certificateSerial, validFrom, validUntil, certificateIssuer));
    				
		    		TextView signatureValidation = (TextView) this.findViewById(R.id.archivo_original_a_descifrar);
		    		
		    		if (invalidSignature){
		    			signatureValidation.setText("Firma Inválida");
		    		}else{
		    			signatureValidation.setText("Firma Válida");
		    		}
		    		
		    		
    			}
    			
    			SignerFromPDFAdapter signerAdapter = new SignerFromPDFAdapter(PDFVerifyResultActivity.this, signers);
    		    signerListView.setAdapter(signerAdapter);
    		    signerListView.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() {

    		    	
    				@Override
    				public void onItemClick(AdapterView<?> parent, View view,
    						int position, long id) {
    					    					
    					Toast.makeText(getApplicationContext(), "SE DEBE MOSTRAR INFORMACIÓN DEL FIRMANTE", Toast.LENGTH_SHORT).show();
    					showSignatureDetails(position, signers); 
    				}
    				
    			});

    			
    			
    		} // fin de else: el documento posee firmas
    		
    		
    	}catch(Exception e){
    		Toast.makeText(getApplicationContext(), "Error al verificar pdf:"+e.getMessage(), Toast.LENGTH_LONG).show();
    	}
    	
	}


	// funcion para compartir el documento
	private void shareIt() {
		
		Intent shareIntent = new Intent();
		shareIntent.setAction(Intent.ACTION_SEND);
		File file = new File(pdfToVerify);
		
		
		Uri uri = Uri.fromFile(file);
		Log.i("DEBUG", file.getPath());
		//Log.d("******", getMimeType(file.getPath()));
		//shareIntent.setDataAndType(uri, getMimeType(file.getPath()));
		shareIntent.putExtra(Intent.EXTRA_STREAM, uri);
		shareIntent.setType("application/*");
		startActivity(Intent.createChooser(shareIntent, getResources().getText(R.string.share_it_using)));
	}

	
	// class que abstrae un firmante incluido en un contenedor BDOC
	private class SignerFromPDF {
		
		// nombre del firmante
		private String mName;
		
		// nombre comun del firmante
		private String mCN;
		
		// fecha y hora de la firma
		private String mDate;
		
		// serial del certificado
		private String mCertificateSerial;
		
		// fecha de validez inicial
		private String mValidFrom;
		
		// fecha de validez final
		private String mValidUntil;
		
		// emisor del certificado
		private String mCertificateIssuer;
		
		public SignerFromPDF(String name, String cn, String date, String serial, String validFrom, String validUntil, String issuer){
			mName = name;
			mCN = cn;
			mDate = date;
			mCertificateSerial = serial;
			mValidFrom = validFrom;
			mValidUntil = validUntil;
			mCertificateIssuer = issuer;			
		}
		
		public void setName(String name) {
			this.mName = name;
		}
		
		public String getName() {
			return mName;
		}	
		
		public void setCN(String cn) {
			this.mCN = cn;
		}
		
		public String getCN() {
			return mCN;
		}		
		
		public void setDate(String date) {
			this.mDate = date;
		}
		
		public String getDate() {
			return mDate;
		}
		
		public void setCertificateSerial(String certSerial) {
			this.mCertificateSerial = certSerial;
		}
		
		public String getCertificateSerial() {
			return mCertificateSerial;
		}
		
		public void setValidFrom(String validFrom) {
			this.mValidFrom = validFrom;
		}
		
		public String getValidFrom() {
			return mValidFrom;
		}
		
		public void setValidUntil(String validUntil) {
			this.mValidUntil = validUntil;
		}
		
		public String getValidUntil() {
			return mValidUntil;
		}
		
		public void setCertificateIssuer(String certIssuer) {
			this.mCertificateIssuer = certIssuer;
		}
		
		public String getCertificateIssuer() {
			return mCertificateIssuer;
		}
		
	} // fin de clase SignerFromPDF
	
	// clase que abstrae el adaptador para llenar el ListView de documentos que
	// se encuentran dentro del contenedor BDOC
	private class SignerFromPDFAdapter extends BaseAdapter {

		private ArrayList<SignerFromPDF> mSignerFromPDFList;
		private LayoutInflater lInflater;
		
		private SignerFromPDFAdapter(Context context, ArrayList<SignerFromPDF> signers) {
			this.lInflater = LayoutInflater.from(context);
			this.mSignerFromPDFList = signers;
			
		}
		
		
		@Override
		public int getCount() {			
			return mSignerFromPDFList.size();
		}

		@Override
		public Object getItem(int position) {			
			return mSignerFromPDFList.get(position);
		}

		@Override
		public long getItemId(int position) {			
			return position;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			ViewHolder container = null;
			
			if (convertView == null){
				container = new ViewHolder();
				convertView = lInflater.inflate(R.layout.signer_inside_bdoc_item, null);
				
				container.signer_text = (TextView) convertView.findViewById(R.id.signer_info);
				container.signer_modified = (TextView) convertView.findViewById(R.id.signature_errors);
				container.type_image = (ImageView) convertView.findViewById(R.id.type_image);
				convertView.setTag(container);
			}else{
				container = (ViewHolder) convertView.getTag();
			}
			
			SignerFromPDF doc = (SignerFromPDF) getItem(position);
			container.signer_text.setText(doc.getName());
			container.signer_modified.setText(doc.getName());
			container.type_image.setImageResource(R.drawable.ic_pluma);
			
			return convertView;
		}
	
		
		class ViewHolder{
		      TextView signer_text;
		      TextView signer_modified;
		      ImageView type_image;
		   }
		
	}
	
	/**
     * Lanza la actividad para mostrar detalles de un firmante 
     * 
     * */
	private void showSignatureDetails(int position, ArrayList<SignerFromPDF> signers) {
		
		Log.d("**showSignatureDetails", Integer.toString(position));
		Log.d("** nombre", signers.get(position).getName());
		Intent intent = new Intent(this, ActivitySignerInfo.class);
		
		intent.putExtra("name", signers.get(position).getName());
		intent.putExtra("cn", signers.get(position).getCN());
		intent.putExtra("date", signers.get(position).getDate());
		intent.putExtra("certificateSerial", signers.get(position).getCertificateSerial());
		intent.putExtra("validFrom", signers.get(position).getValidFrom());
		intent.putExtra("validUntil", signers.get(position).getValidUntil());
		intent.putExtra("certificateIssuer", signers.get(position).getCertificateIssuer());
		startActivity(intent);
	}
	
	
}