package hu.blint.ssldroid;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.UnrecoverableKeyException;
import java.security.cert.CertificateException;
import java.util.Collections;
import java.util.Enumeration;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.DialogInterface.OnClickListener;
import android.database.Cursor;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import hu.blint.ssldroid.db.SSLDroidDbAdapter;

//TODO: cacert + crl should be configurable for the tunnel
//TODO: test connection button

public class SSLDroidTunnelDetails extends Activity {
	private EditText name;
	private EditText localport;
	private EditText remotehost;
	private EditText remoteport;
	private EditText pkcsfile;
	private EditText pkcspass;
	private Long rowId;
	private SSLDroidDbAdapter dbHelper;

	@Override
	protected void onCreate(Bundle bundle) {
		super.onCreate(bundle);
		dbHelper = new SSLDroidDbAdapter(this);
		dbHelper.open();
		setContentView(R.layout.tunnel_details);

		Button confirmButton = (Button) findViewById(R.id.tunnel_apply_button);
		name = (EditText) findViewById(R.id.name);
		localport = (EditText) findViewById(R.id.localport);
		remotehost = (EditText) findViewById(R.id.remotehost);
		remoteport = (EditText) findViewById(R.id.remoteport);
		pkcsfile = (EditText) findViewById(R.id.pkcsfile);
		pkcspass = (EditText) findViewById(R.id.pkcspass);
		Button pickFile = (Button) findViewById(R.id.pickFile);
		
		pickFile.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
            	pickFileSimple();
            }
		});

		
		rowId = null;
		Bundle extras = getIntent().getExtras();
		rowId = (bundle == null) ? null : (Long) bundle
				.getSerializable(SSLDroidDbAdapter.KEY_ROWID);
		if (extras != null) {
			rowId = extras.getLong(SSLDroidDbAdapter.KEY_ROWID);
		}
		populateFields();
		confirmButton.setOnClickListener(new View.OnClickListener() {
			public void onClick(View view) {
				if (name.getText().length() == 0) {
					Toast.makeText(getBaseContext(), "Required tunnel name parameter not setup, skipping save", 5).show();
					return;
				}
				//local port validation
				if (localport.getText().length() == 0) {
					Toast.makeText(getBaseContext(), "Required local port parameter not setup, skipping save", 5).show();
					return;
				}
				else {
					//local port should be between 1025-65535 
					int cPort = 0; 
					try {
						cPort = Integer.parseInt(localport.getText().toString());
					} catch (NumberFormatException e){
						Toast.makeText(getBaseContext(), "Local port parameter has invalid number format", 5).show();
						return;
					}
					if (cPort < 1025 || cPort > 65535) {
						Toast.makeText(getBaseContext(), "Local port parameter not in valid range (1025-65535)", 5).show();
						return;
					}
					//check if the requested port is colliding with a port already configured for another tunnel
					SSLDroidDbAdapter dbHelper = new SSLDroidDbAdapter(getBaseContext());
					dbHelper.open();
					Cursor cursor = dbHelper.fetchAllLocalPorts();
					startManagingCursor(cursor);
					while (cursor.moveToNext()){
						String cDbName = cursor.getString(cursor.getColumnIndexOrThrow(SSLDroidDbAdapter.KEY_NAME));
						int cDbPort = cursor.getInt(cursor.getColumnIndexOrThrow(SSLDroidDbAdapter.KEY_LOCALPORT));
						if (cPort == cDbPort){
							Toast.makeText(getBaseContext(), "Local port already configured in tunnel '"+cDbName+"', please change...", 5).show();
							return;
						}		
					}
				}
				//remote host validation
				if (remotehost.getText().length() == 0){
					Toast.makeText(getBaseContext(), "Required remote host parameter not setup, skipping save", 5).show();
					return;
				}
				else {
					//remote host should exist
					try {
						InetAddress.getByName(remotehost.getText().toString());
					} catch (UnknownHostException e){
						Toast.makeText(getBaseContext(), "Remote host not found, please recheck...", 5).show();
					}
				}
				//remote port validation
				if (remoteport.getText().length() == 0){
					Toast.makeText(getBaseContext(), "Required remote port parameter not setup, skipping save", 5).show();
					return;
				}
				else {
					//remote port should be between 1025-65535
					int cPort = 0; 
					try {
						cPort = Integer.parseInt(remoteport.getText().toString());
					} catch (NumberFormatException e){
						Toast.makeText(getBaseContext(), "Remote port parameter has invalid number format", 5).show();
						return;
					}
					if (cPort < 1 || cPort > 65535) {
						Toast.makeText(getBaseContext(), "Remote port parameter not in valid range (1-65535)", 5).show();
						return;
					}	
				}
				if (pkcsfile.getText().length() == 0){
					Toast.makeText(getBaseContext(), "Required PKCS12 file parameter not setup, skipping save", 5).show();
					return;
				}
				else {
					// try to open pkcs12 file with password
					String cPkcsFile = pkcsfile.getText().toString();
					String cPkcsPass = pkcspass.getText().toString();
					try {
						if (checkKeys(cPkcsFile, cPkcsPass) == false){
							return;
						}
					} catch (Exception e) {
						Toast.makeText(getBaseContext(), "PKCS12 problem: "+e.getMessage(), 5).show();
						return;
					}
				}
				saveState();
				setResult(RESULT_OK);
				finish();
			}

		});
	}

	final List<File> getFileNames(File url, File baseurl)
	{
		List<File> names = new LinkedList<File>();
		File[] files = url.listFiles();
		if (files != null) {
			for(File file : url.listFiles()) {
				if (file.getName().startsWith("."))
					continue;
				names.add(file);
			}
		}
		return names;
	}

	private void showFiles(final List<File> names, final File baseurl){
		final String[] namesList = new String[names.size()]; // = names.toArray(new String[] {});
		ListIterator<File> filelist = names.listIterator();
		int i = 0;
		while (filelist.hasNext()){
			File file = filelist.next();
			if (file.isDirectory())
				namesList[i] = file.getAbsolutePath().replaceFirst(baseurl+"/", "")+" (...)";
			else
				namesList[i] = file.getAbsolutePath().replaceFirst(baseurl+"/", "");
			i++;
		}
		Log.d("SSLDroid", "Gathered file names: "+namesList.toString());
		
		// prompt user to select any file from the sdcard root
		new AlertDialog.Builder(SSLDroidTunnelDetails.this)
			.setTitle(R.string.pkcsfile_pick)
			.setItems(namesList, new OnClickListener() {
				public void onClick(DialogInterface arg0, int arg1) {
					String name = namesList[arg1];
					if (names.get(arg1).isDirectory()){
						List<File> names_ = getFileNames(names.get(arg1), baseurl);
						Collections.sort(names_);
						Log.d("SSLDroid", "Array size: "+String.valueOf(names.size()));
						if (names.size() > 0)
							showFiles(names_, baseurl);
					}
					pkcsfile.setText(baseurl.getAbsolutePath()+"/"+name);
				}
			})
			.setNegativeButton(android.R.string.cancel, null).create().show();
	}
	
	//pick a file from /sdcard, courtesy of ConnectBot
	private void pickFileSimple() {
		// build list of all files in sdcard root
		final File sdcard = Environment.getExternalStorageDirectory();
		Log.d("SSLDroid", "SD Card location: "+sdcard.toString());

		// Don't show a dialog if the SD card is completely absent.
		final String state = Environment.getExternalStorageState();
		if (!Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)
				&& !Environment.MEDIA_MOUNTED.equals(state)) {
			new AlertDialog.Builder(SSLDroidTunnelDetails.this)
				.setMessage(R.string.alert_sdcard_absent)
				.setNegativeButton(android.R.string.cancel, null).create().show();
			return;
		}

		List<File> names = new LinkedList<File>();
		names = getFileNames(sdcard, sdcard);
		Collections.sort(names);
		showFiles(names, sdcard);
	}	

	private void populateFields() {
		if (rowId != null) {
			Cursor Tunnel = dbHelper.fetchTunnel(rowId);
			startManagingCursor(Tunnel);
			
			name.setText(Tunnel.getString(Tunnel
					.getColumnIndexOrThrow(SSLDroidDbAdapter.KEY_NAME)));
			localport.setText(Tunnel.getString(Tunnel
					.getColumnIndexOrThrow(SSLDroidDbAdapter.KEY_LOCALPORT)));
			remotehost.setText(Tunnel.getString(Tunnel
					.getColumnIndexOrThrow(SSLDroidDbAdapter.KEY_REMOTEHOST)));
			remoteport.setText(Tunnel.getString(Tunnel
					.getColumnIndexOrThrow(SSLDroidDbAdapter.KEY_REMOTEPORT)));
			pkcsfile.setText(Tunnel.getString(Tunnel
					.getColumnIndexOrThrow(SSLDroidDbAdapter.KEY_PKCSFILE)));
			pkcspass.setText(Tunnel.getString(Tunnel
					.getColumnIndexOrThrow(SSLDroidDbAdapter.KEY_PKCSPASS)));
		}
	}
	
	public boolean checkKeys(String inCertPath, String passw) throws Exception {
		try {
			FileInputStream in_cert = new FileInputStream(inCertPath);
			KeyStore myStore = KeyStore.getInstance("PKCS12");
			myStore.load(in_cert, passw.toCharArray());
			Enumeration<String> eAliases = myStore.aliases();
			while (eAliases.hasMoreElements()) {
				String strAlias = (String) eAliases.nextElement();
				if (myStore.isKeyEntry(strAlias)) {
					// try to retrieve the private key part from PKCS12 certificate
					myStore.getKey(strAlias, passw.toCharArray());
					// try to retrieve the certificate part from PKCS12 certificate
					myStore.getCertificate(strAlias);
				}
			}

		} catch (KeyStoreException e) {
			Toast.makeText(getBaseContext(), "PKCS12 problem: "+e.getMessage(), 10).show();
			return false;
		} catch (NoSuchAlgorithmException e) {
			Toast.makeText(getBaseContext(), "PKCS12 problem: "+e.getMessage(), 10).show();
			return false;
		} catch (CertificateException e) {
			Toast.makeText(getBaseContext(), "PKCS12 problem: "+e.getMessage(), 10).show();
			return false;
		} catch (IOException e) {
			Toast.makeText(getBaseContext(), "PKCS12 problem: "+e.getMessage(), 10).show();
			return false;
		} catch (UnrecoverableKeyException e) {
			Toast.makeText(getBaseContext(), "PKCS12 problem: "+e.getMessage(), 10).show();
			return false;
		}
		return true;
	}
	

	protected void onSaveInstanceState(Bundle outState) {
		super.onSaveInstanceState(outState);
		saveState();
		outState.putSerializable(SSLDroidDbAdapter.KEY_ROWID, rowId);
	}

	@Override
	protected void onPause() {
		super.onPause();
		//saveState();
	}

	@Override
	protected void onResume() {
		super.onResume();
		populateFields();
	}

	private void saveState() {
		String sName = name.getText().toString();
		int sLocalport = 0;
		try{
			sLocalport = Integer.parseInt(localport.getText().toString());
		} catch (NumberFormatException e){
		}
		String sRemotehost = remotehost.getText().toString();
		int sRemoteport = 0;
		try{
			sRemoteport = Integer.parseInt(remoteport.getText().toString());
		} catch (NumberFormatException e){
		} 
		String sPkcsfile = pkcsfile.getText().toString();
		String sPkcspass = pkcspass.getText().toString();
		
		//make sure that we have all of our values correctly set
		if (sName.length() == 0) {
			return;
		}
		if (sLocalport == 0) {
			return;
		}
		if (sRemotehost.length() == 0) {
			return;
		}
		if (sRemoteport == 0) {
			return;
		}
		if (sPkcsfile.length() == 0) {
			return;
		}
		
		if (rowId == null) {
			long id = dbHelper.createTunnel(sName, sLocalport, sRemotehost, 
											sRemoteport, sPkcsfile, sPkcspass);
			if (id > 0) {
				rowId = id;
			}
		} else {
			dbHelper.updateTunnel(rowId, sName, sLocalport, sRemotehost, sRemoteport, 
								  sPkcsfile, sPkcspass);
		}
		Log.d("SSLDroid", "Saving settings...");
		
		//restart the service
		stopService(new Intent(this, SSLDroid.class));
		startService(new Intent(this, SSLDroid.class));
		Log.d("SSLDroid", "Restarting service after settings save...");
		
	}
}