/*
 * Copyright (C) 2014 Dominik Schürmann <dominik@dominikschuermann.de>
 *
 * 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.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;

import org.openintents.openpgp.OpenPgpSignatureResult;
import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.pgp.KeyRing;
import org.sufficientlysecure.keychain.service.results.DecryptVerifyResult;
import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils;

public abstract class DecryptFragment extends Fragment {
    private static final int RESULT_CODE_LOOKUP_KEY = 0x00007006;

    public static final int REQUEST_CODE_PASSPHRASE = 0x00008001;
    public static final int REQUEST_CODE_NFC_DECRYPT = 0x00008002;

    protected long mSignatureKeyId = 0;

    protected LinearLayout mResultLayout;
    protected RelativeLayout mSignatureLayout;
    protected TextView mResultText;

    protected ImageView mSignatureStatusImage;
    protected TextView mUserId;
    protected TextView mUserIdRest;

    protected Button mLookupKey;

    // State
    protected String mPassphrase;
    protected byte[] mNfcDecryptedSessionKey;

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

        mResultLayout = (LinearLayout) getView().findViewById(R.id.result);
        mResultText = (TextView) getView().findViewById(R.id.result_text);
        mSignatureLayout = (RelativeLayout) getView().findViewById(R.id.result_signature);
        mSignatureStatusImage = (ImageView) getView().findViewById(R.id.ic_signature_status);
        mUserId = (TextView) getView().findViewById(R.id.mainUserId);
        mUserIdRest = (TextView) getView().findViewById(R.id.mainUserIdRest);
        mLookupKey = (Button) getView().findViewById(R.id.lookup_key);
        mLookupKey.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                lookupUnknownKey(mSignatureKeyId);
            }
        });
        mResultLayout.setVisibility(View.GONE);
    }

    private void lookupUnknownKey(long unknownKeyId) {
        Intent intent = new Intent(getActivity(), ImportKeysActivity.class);
        intent.setAction(ImportKeysActivity.ACTION_IMPORT_KEY_FROM_KEYSERVER);
        intent.putExtra(ImportKeysActivity.EXTRA_KEY_ID, unknownKeyId);
        startActivityForResult(intent, RESULT_CODE_LOOKUP_KEY);
    }

    protected void startPassphraseDialog(long subkeyId) {
        Intent intent = new Intent(getActivity(), PassphraseDialogActivity.class);
        intent.putExtra(PassphraseDialogActivity.EXTRA_SUBKEY_ID, subkeyId);
        startActivityForResult(intent, REQUEST_CODE_PASSPHRASE);
    }

    protected void startNfcDecrypt(String pin, byte[] encryptedSessionKey) {
        // build PendingIntent for Yubikey NFC operations
        Intent intent = new Intent(getActivity(), NfcActivity.class);
        intent.setAction(NfcActivity.ACTION_DECRYPT_SESSION_KEY);
        intent.putExtra(NfcActivity.EXTRA_DATA, new Intent()); // not used, only relevant to OpenPgpService
        intent.putExtra(NfcActivity.EXTRA_PIN, pin);

        intent.putExtra(NfcActivity.EXTRA_NFC_ENC_SESSION_KEY, encryptedSessionKey);
        intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP);

        startActivityForResult(intent, REQUEST_CODE_NFC_DECRYPT);
    }

    protected void onResult(DecryptVerifyResult decryptVerifyResult) {
        OpenPgpSignatureResult signatureResult = decryptVerifyResult.getSignatureResult();

        mSignatureKeyId = 0;
        mResultLayout.setVisibility(View.VISIBLE);
        if (signatureResult != null) {
            mSignatureStatusImage.setVisibility(View.VISIBLE);

            mSignatureKeyId = signatureResult.getKeyId();

            String userId = signatureResult.getPrimaryUserId();
            String[] userIdSplit = KeyRing.splitUserId(userId);
            if (userIdSplit[0] != null) {
                mUserId.setText(userIdSplit[0]);
            } else {
                mUserId.setText(R.string.user_id_no_name);
            }
            if (userIdSplit[1] != null) {
                mUserIdRest.setText(userIdSplit[1]);
            } else {
                mUserIdRest.setText(getString(R.string.label_key_id) + ": "
                        + KeyFormattingUtils.convertKeyIdToHex(mSignatureKeyId));
            }

            switch (signatureResult.getStatus()) {
                case OpenPgpSignatureResult.SIGNATURE_SUCCESS_CERTIFIED: {
                    if (signatureResult.isSignatureOnly()) {
                        mResultText.setText(R.string.decrypt_result_signature_certified);
                    } else {
                        mResultText.setText(R.string.decrypt_result_decrypted_and_signature_certified);
                    }

                    mResultLayout.setBackgroundColor(getResources().getColor(R.color.android_green_light));
                    mSignatureStatusImage.setImageResource(R.drawable.overlay_ok);
                    mSignatureLayout.setVisibility(View.VISIBLE);
                    mLookupKey.setVisibility(View.GONE);
                    break;
                }

                case OpenPgpSignatureResult.SIGNATURE_SUCCESS_UNCERTIFIED: {
                    if (signatureResult.isSignatureOnly()) {
                        mResultText.setText(R.string.decrypt_result_signature_uncertified);
                    } else {
                        mResultText.setText(R.string.decrypt_result_decrypted_and_signature_uncertified);
                    }

                    mResultLayout.setBackgroundColor(getResources().getColor(R.color.android_orange_light));
                    mSignatureStatusImage.setImageResource(R.drawable.overlay_ok);
                    mSignatureLayout.setVisibility(View.VISIBLE);
                    mLookupKey.setVisibility(View.GONE);
                    break;
                }

                case OpenPgpSignatureResult.SIGNATURE_KEY_MISSING: {
                    if (signatureResult.isSignatureOnly()) {
                        mResultText.setText(R.string.decrypt_result_signature_unknown_pub_key);
                    } else {
                        mResultText.setText(R.string.decrypt_result_decrypted_unknown_pub_key);
                    }

                    mResultLayout.setBackgroundColor(getResources().getColor(R.color.android_orange_light));
                    mSignatureStatusImage.setImageResource(R.drawable.overlay_error);
                    mSignatureLayout.setVisibility(View.VISIBLE);
                    mLookupKey.setVisibility(View.VISIBLE);
                    break;
                }

                case OpenPgpSignatureResult.SIGNATURE_ERROR: {
                    mResultText.setText(R.string.decrypt_result_invalid_signature);

                    mResultLayout.setBackgroundColor(getResources().getColor(R.color.android_red_light));
                    mSignatureStatusImage.setImageResource(R.drawable.overlay_error);
                    mSignatureLayout.setVisibility(View.GONE);
                    mLookupKey.setVisibility(View.GONE);
                    break;
                }

                default: {
                    mResultText.setText(R.string.error);

                    mResultLayout.setBackgroundColor(getResources().getColor(R.color.android_red_light));
                    mSignatureStatusImage.setImageResource(R.drawable.overlay_error);
                    mSignatureLayout.setVisibility(View.GONE);
                    mLookupKey.setVisibility(View.GONE);
                    break;
                }
            }
        } else {
            mSignatureLayout.setVisibility(View.GONE);
            mLookupKey.setVisibility(View.GONE);

            // successful decryption-only
            mResultLayout.setBackgroundColor(getResources().getColor(R.color.android_purple_light));
            mResultText.setText(R.string.decrypt_result_decrypted);
        }
    }

    /**
     * Should be overridden by MessageFragment and FileFragment to start actual decryption
     */
    protected abstract void decryptStart();

}