/*
 * 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.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.Menu;
import android.view.MenuItem;

import org.spongycastle.bcpg.CompressionAlgorithmTags;
import org.sufficientlysecure.keychain.Constants;
import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.api.OpenKeychainIntents;
import org.sufficientlysecure.keychain.operations.results.SignEncryptResult;
import org.sufficientlysecure.keychain.pgp.KeyRing;
import org.sufficientlysecure.keychain.pgp.PgpConstants;
import org.sufficientlysecure.keychain.pgp.SignEncryptParcel;
import org.sufficientlysecure.keychain.ui.dialog.DeleteFileDialogFragment;
import org.sufficientlysecure.keychain.ui.util.Notify;
import org.sufficientlysecure.keychain.util.Log;
import org.sufficientlysecure.keychain.util.ShareHelper;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;

public class EncryptFilesActivity extends EncryptActivity implements EncryptActivityInterface {

    /* Intents */
    public static final String ACTION_ENCRYPT_DATA = OpenKeychainIntents.ENCRYPT_DATA;

    // enables ASCII Armor for file encryption when uri is given
    public static final String EXTRA_ASCII_ARMOR = OpenKeychainIntents.ENCRYPT_EXTRA_ASCII_ARMOR;

    // preselect ids, for internal use
    public static final String EXTRA_SIGNATURE_KEY_ID = Constants.EXTRA_PREFIX + "EXTRA_SIGNATURE_KEY_ID";
    public static final String EXTRA_ENCRYPTION_KEY_IDS = Constants.EXTRA_PREFIX + "EXTRA_ENCRYPTION_IDS";

    // view
    private int mCurrentMode = MODE_ASYMMETRIC;

    // tabs
    private static final int MODE_ASYMMETRIC = 0;
    private static final int MODE_SYMMETRIC = 1;

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

    public boolean isModeSymmetric() {
        return MODE_SYMMETRIC == mCurrentMode;
    }

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

    @Override
    public boolean isUseCompression() {
        return mUseCompression;
    }

    @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<>();
        return mInputUris;
    }

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

    @Override
    public void onEncryptSuccess(final SignEncryptResult result) {
        if (mDeleteAfterEncrypt) {
            final Uri[] inputUris = mInputUris.toArray(new Uri[mInputUris.size()]);
            DeleteFileDialogFragment deleteFileDialog = DeleteFileDialogFragment.newInstance(inputUris);
            deleteFileDialog.setOnDeletedListener(new DeleteFileDialogFragment.OnDeletedListener() {

                @Override
                public void onDeleted() {
                    if (mShareAfterEncrypt) {
                        // Share encrypted message/file
                        startActivity(sendWithChooserExcludingEncrypt());
                    } else {
                        // Save encrypted file
                        result.createNotify(EncryptFilesActivity.this).show();
                    }
                }

            });
            deleteFileDialog.show(getSupportFragmentManager(), "deleteDialog");

            mInputUris.clear();
            notifyUpdate();
        } else {
            if (mShareAfterEncrypt) {
                // Share encrypted message/file
                startActivity(sendWithChooserExcludingEncrypt());
            } else {
                // Save encrypted file
                result.createNotify(EncryptFilesActivity.this).show();
            }
        }
    }

    @Override
    protected SignEncryptParcel createEncryptBundle() {
        // fill values for this action
        SignEncryptParcel data = new SignEncryptParcel();

        data.addInputUris(mInputUris);
        data.addOutputUris(mOutputUris);

        if (mUseCompression) {
            data.setCompressionId(PgpConstants.sPreferredCompressionAlgorithms.get(0));
        } else {
            data.setCompressionId(CompressionAlgorithmTags.UNCOMPRESSED);
        }
        data.setEnableAsciiArmorOutput(mUseArmor);
        data.setSymmetricEncryptionAlgorithm(PgpConstants.OpenKeychainSymmetricKeyAlgorithmTags.USE_PREFERRED);
        data.setSignatureHashAlgorithm(PgpConstants.OpenKeychainSymmetricKeyAlgorithmTags.USE_PREFERRED);

        if (isModeSymmetric()) {
            Log.d(Constants.TAG, "Symmetric encryption enabled!");
            String passphrase = mPassphrase;
            if (passphrase.length() == 0) {
                passphrase = null;
            }
            data.setSymmetricPassphrase(passphrase);
        } else {
            data.setEncryptionMasterKeyIds(mEncryptionKeyIds);
            data.setSignatureMasterKeyId(mSigningKeyId);
            data.setSignaturePassphrase(mSigningKeyPassphrase);
            data.setNfcState(mNfcHash, mNfcTimestamp);
        }
        return data;
    }

    /**
     * Create Intent Chooser but exclude OK's EncryptActivity.
     */
    private Intent sendWithChooserExcludingEncrypt() {
        Intent prototype = createSendIntent();
        String title = getString(R.string.title_share_file);

        // we don't want to encrypt the encrypted, no inception ;)
        String[] blacklist = new String[]{
                Constants.PACKAGE_NAME + ".ui.EncryptFileActivity",
                "org.thialfihar.android.apg.ui.EncryptActivity"
        };

        return new ShareHelper(this).createChooserExcluding(prototype, title, blacklist);
    }

    private Intent createSendIntent() {
        Intent sendIntent;
        // 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(Constants.ENCRYPTED_FILES_MIME);

        if (!isModeSymmetric() && mEncryptionUserIds != null) {
            Set<String> users = new HashSet<>();
            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;
    }

    protected boolean inputIsValid() {
        // 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) {
                Notify.showNotify(this, R.string.select_encryption_key, Notify.Style.ERROR);
                return false;
            }
        }
        return true;
    }

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

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

    @Override
    protected void initLayout() {
        setContentView(R.layout.encrypt_files_activity);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.encrypt_file_activity, menu);
        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: {
                mCurrentMode = item.isChecked() ? MODE_SYMMETRIC : MODE_ASYMMETRIC;
                updateModeFragment();
                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;
            }
            case R.id.check_enable_compression: {
                mUseCompression = item.isChecked();
                notifyUpdate();
                break;
            }
            default: {
                return super.onOptionsItemSelected(item);
            }
        }
        return true;
    }

    private void updateModeFragment() {
        getSupportFragmentManager().beginTransaction()
                .replace(R.id.encrypt_pager_mode,
                        mCurrentMode == MODE_SYMMETRIC
                                ? new EncryptSymmetricFragment()
                                : new EncryptAsymmetricFragment()
                )
                .commitAllowingStateLoss();
        getSupportFragmentManager().executePendingTransactions();
    }

    /**
     * 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<>();

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

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

        /*
         * Android's Action
         */

        // When sending to OpenKeychain Encrypt via share menu
        if (Intent.ACTION_SEND.equals(action) && type != null) {
            // Files via content provider, override uri and action
            uris.clear();
            uris.add(intent.<Uri>getParcelableExtra(Intent.EXTRA_STREAM));
        }

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

        mUseArmor = extras.getBoolean(EXTRA_ASCII_ARMOR, false);

        // preselect keys given by intent
        mSigningKeyId = extras.getLong(EXTRA_SIGNATURE_KEY_ID);
        mEncryptionKeyIds = extras.getLongArray(EXTRA_ENCRYPTION_KEY_IDS);

        // Save uris
        mInputUris = uris;
    }

}