/*
 * Copyright (C) 2012-2014 Dominik Schürmann <dominik@dominikschuermann.de>
 * Copyright (C) 2010-2014 Thialfihar <thi@thialfihar.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.sufficientlysecure.keychain.ui;

import android.app.ProgressDialog;
import android.content.Intent;
import android.content.pm.LabeledIntent;
import android.content.pm.ResolveInfo;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.Messenger;
import android.os.Parcelable;
import android.support.v4.app.Fragment;
import android.support.v4.view.PagerTabStrip;
import android.support.v4.view.ViewPager;
import android.view.Menu;
import android.view.MenuItem;

import org.sufficientlysecure.keychain.Constants;
import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.compatibility.ClipboardReflection;
import org.sufficientlysecure.keychain.helper.Preferences;
import org.sufficientlysecure.keychain.pgp.KeyRing;
import org.sufficientlysecure.keychain.service.KeychainIntentService;
import org.sufficientlysecure.keychain.service.KeychainIntentServiceHandler;
import org.sufficientlysecure.keychain.service.PassphraseCacheService;
import org.sufficientlysecure.keychain.ui.adapter.PagerTabStripAdapter;
import org.sufficientlysecure.keychain.ui.dialog.DeleteFileDialogFragment;
import org.sufficientlysecure.keychain.ui.dialog.PassphraseDialogFragment;
import org.sufficientlysecure.keychain.util.Log;
import org.sufficientlysecure.keychain.util.Notify;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class EncryptActivity extends DrawerActivity implements EncryptActivityInterface {

    /* Intents */
    public static final String ACTION_ENCRYPT = Constants.INTENT_PREFIX + "ENCRYPT";

    /* EXTRA keys for input */
    public static final String EXTRA_TEXT = "text";

    // enables ASCII Armor for file encryption when uri is given
    public static final String EXTRA_ASCII_ARMOR = "ascii_armor";

    // preselect ids, for internal use
    public static final String EXTRA_SIGNATURE_KEY_ID = "signature_key_id";
    public static final String EXTRA_ENCRYPTION_KEY_IDS = "encryption_key_ids";

    // view
    ViewPager mViewPagerMode;
    //PagerTabStrip mPagerTabStripMode;
    PagerTabStripAdapter mTabsAdapterMode;
    ViewPager mViewPagerContent;
    PagerTabStrip mPagerTabStripContent;
    PagerTabStripAdapter mTabsAdapterContent;

    // tabs
    Bundle mAsymmetricFragmentBundle = new Bundle();
    Bundle mSymmetricFragmentBundle = new Bundle();
    Bundle mMessageFragmentBundle = new Bundle();
    Bundle mFileFragmentBundle = new Bundle();
    int mSwitchToMode = PAGER_MODE_ASYMMETRIC;
    int mSwitchToContent = PAGER_CONTENT_MESSAGE;

    private static final int PAGER_MODE_ASYMMETRIC = 0;
    private static final int PAGER_MODE_SYMMETRIC = 1;
    private static final int PAGER_CONTENT_MESSAGE = 0;
    private static final int PAGER_CONTENT_FILE = 1;

    // model used by message and file fragments
    private long mEncryptionKeyIds[] = null;
    private String mEncryptionUserIds[] = null;
    private long mSigningKeyId = Constants.key.none;
    private String mPassphrase = "";
    private boolean mUseArmor;
    private boolean mDeleteAfterEncrypt = false;
    private boolean mShareAfterEncrypt = false;
    private ArrayList<Uri> mInputUris;
    private ArrayList<Uri> mOutputUris;
    private String mMessage = "";

    public boolean isModeSymmetric() {
        return PAGER_MODE_SYMMETRIC == mViewPagerMode.getCurrentItem();
    }

    public boolean isContentMessage() {
        return PAGER_CONTENT_MESSAGE == mViewPagerContent.getCurrentItem();
    }

    @Override
    public boolean isUseArmor() {
        return mUseArmor;
    }

    @Override
    public long getSignatureKey() {
        return mSigningKeyId;
    }

    @Override
    public long[] getEncryptionKeys() {
        return mEncryptionKeyIds;
    }

    @Override
    public String[] getEncryptionUsers() {
        return mEncryptionUserIds;
    }

    @Override
    public void setSignatureKey(long signatureKey) {
        mSigningKeyId = signatureKey;
        notifyUpdate();
    }

    @Override
    public void setEncryptionKeys(long[] encryptionKeys) {
        mEncryptionKeyIds = encryptionKeys;
        notifyUpdate();
    }

    @Override
    public void setEncryptionUsers(String[] encryptionUsers) {
        mEncryptionUserIds = encryptionUsers;
        notifyUpdate();
    }

    @Override
    public void setPassphrase(String passphrase) {
        mPassphrase = passphrase;
    }

    @Override
    public ArrayList<Uri> getInputUris() {
        if (mInputUris == null) mInputUris = new ArrayList<Uri>();
        return mInputUris;
    }

    @Override
    public ArrayList<Uri> getOutputUris() {
        if (mOutputUris == null) mOutputUris = new ArrayList<Uri>();
        return mOutputUris;
    }

    @Override
    public void setInputUris(ArrayList<Uri> uris) {
        mInputUris = uris;
        notifyUpdate();
    }

    @Override
    public void setOutputUris(ArrayList<Uri> uris) {
        mOutputUris = uris;
        notifyUpdate();
    }

    @Override
    public String getMessage() {
        return mMessage;
    }

    @Override
    public void setMessage(String message) {
        mMessage = message;
    }

    @Override
    public void notifyUpdate() {
        for (Fragment fragment : getSupportFragmentManager().getFragments()) {
            if (fragment instanceof EncryptActivityInterface.UpdateListener) {
                ((UpdateListener) fragment).onNotifyUpdate();
            }
        }
    }

    @Override
    public void startEncrypt(boolean share) {
        mShareAfterEncrypt = share;
        startEncrypt();
    }

    public void startEncrypt() {
        if (!inputIsValid()) {
            // Notify was created by inputIsValid.
            return;
        }

        // Send all information needed to service to edit key in other thread
        Intent intent = new Intent(this, KeychainIntentService.class);
        intent.setAction(KeychainIntentService.ACTION_ENCRYPT_SIGN);
        intent.putExtra(KeychainIntentService.EXTRA_DATA, createEncryptBundle());

        // Message is received after encrypting is done in KeychainIntentService
        KeychainIntentServiceHandler serviceHandler = new KeychainIntentServiceHandler(this,
                getString(R.string.progress_encrypting), ProgressDialog.STYLE_HORIZONTAL) {
            public void handleMessage(Message message) {
                // handle messages by standard KeychainIntentServiceHandler first
                super.handleMessage(message);

                if (message.arg1 == KeychainIntentServiceHandler.MESSAGE_OKAY) {
                    if (!isContentMessage()) {
                        Notify.showNotify(EncryptActivity.this, R.string.encrypt_sign_successful, Notify.Style.INFO);

                        if (mDeleteAfterEncrypt) {
                            for (Uri inputUri : mInputUris) {
                                DeleteFileDialogFragment deleteFileDialog = DeleteFileDialogFragment.newInstance(inputUri);
                                deleteFileDialog.show(getSupportFragmentManager(), "deleteDialog");
                            }
                            mInputUris.clear();
                            notifyUpdate();
                        }
                    }

                    if (mShareAfterEncrypt) {
                        // Share encrypted message/file
                        startActivity(sendWithChooserExcludingEncrypt(message));
                    } else if (isContentMessage()) {
                        // Copy to clipboard
                        copyToClipboard(message);
                        Notify.showNotify(EncryptActivity.this,
                                R.string.encrypt_sign_clipboard_successful, Notify.Style.INFO);
                    }
                }
            }
        };
        // Create a new Messenger for the communication back
        Messenger messenger = new Messenger(serviceHandler);
        intent.putExtra(KeychainIntentService.EXTRA_MESSENGER, messenger);

        // show progress dialog
        serviceHandler.showProgressDialog(this);

        // start service with intent
        startService(intent);
    }

    private Bundle createEncryptBundle() {
        // fill values for this action
        Bundle data = new Bundle();

        if (isContentMessage()) {
            data.putInt(KeychainIntentService.TARGET, KeychainIntentService.IO_BYTES);
            data.putByteArray(KeychainIntentService.ENCRYPT_MESSAGE_BYTES, mMessage.getBytes());
        } else {
            data.putInt(KeychainIntentService.SOURCE, KeychainIntentService.IO_URIS);
            data.putParcelableArrayList(KeychainIntentService.ENCRYPT_INPUT_URIS, mInputUris);

            data.putInt(KeychainIntentService.TARGET, KeychainIntentService.IO_URIS);
            data.putParcelableArrayList(KeychainIntentService.ENCRYPT_OUTPUT_URIS, mOutputUris);
        }

        // Always use armor for messages
        data.putBoolean(KeychainIntentService.ENCRYPT_USE_ASCII_ARMOR, mUseArmor || isContentMessage());

        // TODO: Only default compression right now...
        int compressionId = Preferences.getPreferences(this).getDefaultMessageCompression();
        data.putInt(KeychainIntentService.ENCRYPT_COMPRESSION_ID, compressionId);

        if (isModeSymmetric()) {
            Log.d(Constants.TAG, "Symmetric encryption enabled!");
            String passphrase = mPassphrase;
            if (passphrase.length() == 0) {
                passphrase = null;
            }
            data.putString(KeychainIntentService.ENCRYPT_SYMMETRIC_PASSPHRASE, passphrase);
        } else {
            data.putLong(KeychainIntentService.ENCRYPT_SIGNATURE_KEY_ID, mSigningKeyId);
            data.putLongArray(KeychainIntentService.ENCRYPT_ENCRYPTION_KEYS_IDS, mEncryptionKeyIds);
        }
        return data;
    }

    private void copyToClipboard(Message message) {
        ClipboardReflection.copyToClipboard(this, new String(message.getData().getByteArray(KeychainIntentService.RESULT_BYTES)));
    }

    /**
     * Create Intent Chooser but exclude OK's EncryptActivity.
     * <p/>
     * Put together from some stackoverflow posts...
     *
     * @param message
     * @return
     */
    private Intent sendWithChooserExcludingEncrypt(Message message) {
        Intent prototype = createSendIntent(message);

        String title = isContentMessage() ? getString(R.string.title_share_message)
                : getString(R.string.title_share_file);

        // fallback on Android 2.3, otherwise we would get weird results
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
            return Intent.createChooser(prototype, title);
        }

        // prevent recursion aka Inception :P
        String[] blacklist = new String[]{Constants.PACKAGE_NAME + ".ui.EncryptActivity"};

        List<LabeledIntent> targetedShareIntents = new ArrayList<LabeledIntent>();

        List<ResolveInfo> resInfoList = getPackageManager().queryIntentActivities(prototype, 0);
        List<ResolveInfo> resInfoListFiltered = new ArrayList<ResolveInfo>();
        if (!resInfoList.isEmpty()) {
            for (ResolveInfo resolveInfo : resInfoList) {
                // do not add blacklisted ones
                if (resolveInfo.activityInfo == null || Arrays.asList(blacklist).contains(resolveInfo.activityInfo.name))
                    continue;

                resInfoListFiltered.add(resolveInfo);
            }

            if (!resInfoListFiltered.isEmpty()) {
                // sorting for nice readability
                Collections.sort(resInfoListFiltered, new Comparator<ResolveInfo>() {
                    @Override
                    public int compare(ResolveInfo first, ResolveInfo second) {
                        String firstName = first.loadLabel(getPackageManager()).toString();
                        String secondName = second.loadLabel(getPackageManager()).toString();
                        return firstName.compareToIgnoreCase(secondName);
                    }
                });

                // create the custom intent list
                for (ResolveInfo resolveInfo : resInfoListFiltered) {
                    Intent targetedShareIntent = (Intent) prototype.clone();
                    targetedShareIntent.setPackage(resolveInfo.activityInfo.packageName);
                    targetedShareIntent.setClassName(resolveInfo.activityInfo.packageName, resolveInfo.activityInfo.name);

                    LabeledIntent lIntent = new LabeledIntent(targetedShareIntent,
                            resolveInfo.activityInfo.packageName,
                            resolveInfo.loadLabel(getPackageManager()),
                            resolveInfo.activityInfo.icon);
                    targetedShareIntents.add(lIntent);
                }

                // Create chooser with only one Intent in it
                Intent chooserIntent = Intent.createChooser(targetedShareIntents.remove(targetedShareIntents.size() - 1), title);
                // append all other Intents
                chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, targetedShareIntents.toArray(new Parcelable[]{}));
                return chooserIntent;
            }

        }

        // fallback to Android's default chooser
        return Intent.createChooser(prototype, title);
    }

    private Intent createSendIntent(Message message) {
        Intent sendIntent;
        if (isContentMessage()) {
            sendIntent = new Intent(Intent.ACTION_SEND);
            sendIntent.setType("text/plain");
            sendIntent.putExtra(Intent.EXTRA_TEXT, new String(message.getData().getByteArray(KeychainIntentService.RESULT_BYTES)));
        } else {
            // file
            if (mOutputUris.size() == 1) {
                sendIntent = new Intent(Intent.ACTION_SEND);
                sendIntent.putExtra(Intent.EXTRA_STREAM, mOutputUris.get(0));
            } else {
                sendIntent = new Intent(Intent.ACTION_SEND_MULTIPLE);
                sendIntent.putExtra(Intent.EXTRA_STREAM, mOutputUris);
            }
            sendIntent.setType("application/pgp-encrypted");
        }
        if (!isModeSymmetric() && mEncryptionUserIds != null) {
            Set<String> users = new HashSet<String>();
            for (String user : mEncryptionUserIds) {
                String[] userId = KeyRing.splitUserId(user);
                if (userId[1] != null) {
                    users.add(userId[1]);
                }
            }
            sendIntent.putExtra(Intent.EXTRA_EMAIL, users.toArray(new String[users.size()]));
        }
        return sendIntent;
    }

    private boolean inputIsValid() {
        if (isContentMessage()) {
            if (mMessage == null) {
                Notify.showNotify(this, R.string.error_message, Notify.Style.ERROR);
                return false;
            }
        } else {
            // file checks

            if (mInputUris.isEmpty()) {
                Notify.showNotify(this, R.string.no_file_selected, Notify.Style.ERROR);
                return false;
            } else if (mInputUris.size() > 1 && !mShareAfterEncrypt) {
                // This should be impossible...
                return false;
            } else if (mInputUris.size() != mOutputUris.size()) {
                // This as well
                return false;
            }
        }

        if (isModeSymmetric()) {
            // symmetric encryption checks


            if (mPassphrase == null) {
                Notify.showNotify(this, R.string.passphrases_do_not_match, Notify.Style.ERROR);
                return false;
            }
            if (mPassphrase.isEmpty()) {
                Notify.showNotify(this, R.string.passphrase_must_not_be_empty, Notify.Style.ERROR);
                return false;
            }

        } else {
            // asymmetric encryption checks

            boolean gotEncryptionKeys = (mEncryptionKeyIds != null
                    && mEncryptionKeyIds.length > 0);

            // Files must be encrypted, only text can be signed-only right now
            if (!gotEncryptionKeys && !isContentMessage()) {
                Notify.showNotify(this, R.string.select_encryption_key, Notify.Style.ERROR);
                return false;
            }

            if (!gotEncryptionKeys && mSigningKeyId == 0) {
                Notify.showNotify(this, R.string.select_encryption_or_signature_key, Notify.Style.ERROR);
                return false;
            }

            if (mSigningKeyId != 0 && PassphraseCacheService.getCachedPassphrase(this, mSigningKeyId) == null) {
                PassphraseDialogFragment.show(this, mSigningKeyId,
                        new Handler() {
                            @Override
                            public void handleMessage(Message message) {
                                if (message.what == PassphraseDialogFragment.MESSAGE_OKAY) {
                                    // restart
                                    startEncrypt();
                                }
                            }
                        }
                );

                return false;
            }
        }
        return true;
    }

    private void initView() {
        mViewPagerMode = (ViewPager) findViewById(R.id.encrypt_pager_mode);
        //mPagerTabStripMode = (PagerTabStrip) findViewById(R.id.encrypt_pager_tab_strip_mode);
        mViewPagerContent = (ViewPager) findViewById(R.id.encrypt_pager_content);
        mPagerTabStripContent = (PagerTabStrip) findViewById(R.id.encrypt_pager_tab_strip_content);

        mTabsAdapterMode = new PagerTabStripAdapter(this);
        mViewPagerMode.setAdapter(mTabsAdapterMode);
        mTabsAdapterContent = new PagerTabStripAdapter(this);
        mViewPagerContent.setAdapter(mTabsAdapterContent);
    }

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

        setContentView(R.layout.encrypt_activity);

        initView();

        // if called with an intent action, do not init drawer navigation
        if (ACTION_ENCRYPT.equals(getIntent().getAction())) {
            // TODO: back button to key?
        } else {
            setupDrawerNavigation(savedInstanceState);
        }

        // Handle intent actions
        handleActions(getIntent());

        mTabsAdapterMode.addTab(EncryptAsymmetricFragment.class,
                mAsymmetricFragmentBundle, getString(R.string.label_asymmetric));
        mTabsAdapterMode.addTab(EncryptSymmetricFragment.class,
                mSymmetricFragmentBundle, getString(R.string.label_symmetric));
        mViewPagerMode.setCurrentItem(mSwitchToMode);

        mTabsAdapterContent.addTab(EncryptMessageFragment.class,
                mMessageFragmentBundle, getString(R.string.label_message));
        mTabsAdapterContent.addTab(EncryptFileFragment.class,
                mFileFragmentBundle, getString(R.string.label_files));
        mViewPagerContent.setCurrentItem(mSwitchToContent);

        mUseArmor = Preferences.getPreferences(this).getDefaultAsciiArmor();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.encrypt_activity, menu);
        menu.findItem(R.id.check_use_armor).setChecked(mUseArmor);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.isCheckable()) {
            item.setChecked(!item.isChecked());
        }
        switch (item.getItemId()) {
            case R.id.check_use_symmetric:
                mSwitchToMode = item.isChecked() ? PAGER_MODE_SYMMETRIC : PAGER_MODE_ASYMMETRIC;

                mViewPagerMode.setCurrentItem(mSwitchToMode);
                notifyUpdate();
                break;
            case R.id.check_use_armor:
                mUseArmor = item.isChecked();
                notifyUpdate();
                break;
            case R.id.check_delete_after_encrypt:
                mDeleteAfterEncrypt = item.isChecked();
                notifyUpdate();
                break;
            default:
                return super.onOptionsItemSelected(item);
        }
        return true;
    }

    /**
     * Handles all actions with this intent
     *
     * @param intent
     */
    private void handleActions(Intent intent) {
        String action = intent.getAction();
        Bundle extras = intent.getExtras();
        String type = intent.getType();
        ArrayList<Uri> uris = new ArrayList<Uri>();

        if (extras == null) {
            extras = new Bundle();
        }

        if (intent.getData() != null) {
            uris.add(intent.getData());
        }

        /*
         * Android's Action
         */
        if (Intent.ACTION_SEND.equals(action) && type != null) {
            // When sending to OpenKeychain Encrypt via share menu
            if ("text/plain".equals(type)) {
                // Plain text
                String sharedText = intent.getStringExtra(Intent.EXTRA_TEXT);
                if (sharedText != null) {
                    // handle like normal text encryption, override action and extras to later
                    // executeServiceMethod ACTION_ENCRYPT in main actions
                    extras.putString(EXTRA_TEXT, sharedText);
                    extras.putBoolean(EXTRA_ASCII_ARMOR, true);
                    action = ACTION_ENCRYPT;
                }
            } else {
                // Files via content provider, override uri and action
                uris.clear();
                uris.add(intent.<Uri>getParcelableExtra(Intent.EXTRA_STREAM));
                action = ACTION_ENCRYPT;
            }
        }

        if (Intent.ACTION_SEND_MULTIPLE.equals(action) && type != null) {
            uris = intent.getParcelableArrayListExtra(Intent.EXTRA_STREAM);
            action = ACTION_ENCRYPT;
        }

        if (extras.containsKey(EXTRA_ASCII_ARMOR)) {
            mUseArmor = extras.getBoolean(EXTRA_ASCII_ARMOR, true);
        }

        String textData = extras.getString(EXTRA_TEXT);

        long signatureKeyId = extras.getLong(EXTRA_SIGNATURE_KEY_ID);
        long[] encryptionKeyIds = extras.getLongArray(EXTRA_ENCRYPTION_KEY_IDS);

        // preselect keys given by intent
        mAsymmetricFragmentBundle.putLongArray(EncryptAsymmetricFragment.ARG_ENCRYPTION_KEY_IDS,
                encryptionKeyIds);
        mAsymmetricFragmentBundle.putLong(EncryptAsymmetricFragment.ARG_SIGNATURE_KEY_ID,
                signatureKeyId);
        mSwitchToMode = PAGER_MODE_ASYMMETRIC;

        /**
         * Main Actions
         */
        if (ACTION_ENCRYPT.equals(action) && textData != null) {
            // encrypt text based on given extra
            mMessageFragmentBundle.putString(EncryptMessageFragment.ARG_TEXT, textData);
            mSwitchToContent = PAGER_CONTENT_MESSAGE;
        } else if (ACTION_ENCRYPT.equals(action) && uris != null && !uris.isEmpty()) {
            // encrypt file based on Uri
            mFileFragmentBundle.putParcelableArrayList(EncryptFileFragment.ARG_URIS, uris);
            mSwitchToContent = PAGER_CONTENT_FILE;
        } else if (ACTION_ENCRYPT.equals(action)) {
            Log.e(Constants.TAG,
                    "Include the extra 'text' or an Uri with setData() in your Intent!");
        }
    }

}