/*
 * Copyright (C) 2017 Schürmann & Breitmoser GbR
 *
 * 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.linked;


import android.arch.lifecycle.ViewModelProviders;
import android.graphics.PorterDuff;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.ViewAnimator;

import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.linked.LinkedAttribute;
import org.sufficientlysecure.keychain.linked.LinkedTokenResource;
import org.sufficientlysecure.keychain.model.SubKey.UnifiedKeyInfo;
import org.sufficientlysecure.keychain.operations.results.LinkedVerifyResult;
import org.sufficientlysecure.keychain.operations.results.OperationResult;
import org.sufficientlysecure.keychain.operations.results.OperationResult.OperationLog;
import org.sufficientlysecure.keychain.pgp.WrappedUserAttribute;
import org.sufficientlysecure.keychain.service.SaveKeyringParcel;
import org.sufficientlysecure.keychain.service.input.CryptoInputParcel;
import org.sufficientlysecure.keychain.ui.base.CryptoOperationFragment;
import org.sufficientlysecure.keychain.ui.keyview.UnifiedKeyInfoViewModel;
import org.sufficientlysecure.keychain.ui.util.Notify;

public abstract class LinkedIdCreateFinalFragment extends CryptoOperationFragment {
    private ImageView mVerifyImage;
    private TextView mVerifyStatus;
    private ViewAnimator mVerifyAnimator;

    private long masterKeyId;
    byte[] fingerprint;

    // This is a resource, set AFTER it has been verified
    LinkedTokenResource mVerifiedResource = null;
    private ViewAnimator mVerifyButtonAnimator;

    protected abstract View newView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState);

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

        UnifiedKeyInfoViewModel viewModel = ViewModelProviders.of(requireActivity()).get(UnifiedKeyInfoViewModel.class);
        viewModel.getUnifiedKeyInfoLiveData(requireContext()).observe(this, this::onLoadUnifiedKeyInfo);
    }

    private void onLoadUnifiedKeyInfo(UnifiedKeyInfo unifiedKeyInfo) {
        this.masterKeyId = unifiedKeyInfo.master_key_id();
        this.fingerprint = unifiedKeyInfo.fingerprint();
    }

    @NonNull
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        final View view = newView(inflater, container, savedInstanceState);

        View nextButton = view.findViewById(R.id.next_button);
        if (nextButton != null) {
            nextButton.setOnClickListener(v -> cryptoOperation());
        }

        view.findViewById(R.id.back_button).setOnClickListener(
                v -> ((LinkedIdWizard) requireActivity()).loadFragment(null, LinkedIdWizard.FRAG_ACTION_TO_LEFT));

        mVerifyAnimator = view.findViewById(R.id.verify_progress);
        mVerifyImage = view.findViewById(R.id.verify_image);
        mVerifyStatus = view.findViewById(R.id.verify_status);
        mVerifyButtonAnimator = view.findViewById(R.id.verify_buttons);

        view.findViewById(R.id.button_verify).setOnClickListener(v -> proofVerify());

        view.findViewById(R.id.button_retry).setOnClickListener(v -> proofVerify());

        setVerifyProgress(false, null);
        mVerifyStatus.setText(R.string.linked_verify_pending);

        return view;
    }

    abstract LinkedTokenResource getResource(OperationLog log);

    private void setVerifyProgress(boolean on, Boolean success) {
        if (success == null) {
            mVerifyStatus.setText(R.string.linked_verifying);
            displayButton(on ? 2 : 0);
        } else if (success) {
            mVerifyStatus.setText(R.string.linked_verify_success);
            mVerifyImage.setImageResource(R.drawable.status_signature_verified_cutout_24dp);
            mVerifyImage.setColorFilter(getResources().getColor(R.color.android_green_dark),
                    PorterDuff.Mode.SRC_IN);
            displayButton(2);
        } else {
            mVerifyStatus.setText(R.string.linked_verify_error);
            mVerifyImage.setImageResource(R.drawable.status_signature_unknown_cutout_24dp);
            mVerifyImage.setColorFilter(getResources().getColor(R.color.android_red_dark),
                    PorterDuff.Mode.SRC_IN);
            displayButton(1);
        }
        mVerifyAnimator.setDisplayedChild(on ? 1 : 0);
    }

    public void displayButton(int button) {
        if (mVerifyButtonAnimator.getDisplayedChild() == button) {
            return;
        }
        mVerifyButtonAnimator.setDisplayedChild(button);
    }

    protected void proofVerify() {
        setVerifyProgress(true, null);

        new AsyncTask<Void,Void,LinkedVerifyResult>() {

            @Override
            protected LinkedVerifyResult doInBackground(Void... params) {
                long timer = System.currentTimeMillis();

                OperationLog log = new OperationLog();
                LinkedTokenResource resource = getResource(log);
                if (resource == null) {
                    return new LinkedVerifyResult(LinkedVerifyResult.RESULT_ERROR, log);
                }

                LinkedVerifyResult result = resource.verify(getActivity(), fingerprint);

                // ux flow: this operation should take at last a second
                timer = System.currentTimeMillis() -timer;
                if (timer < 1000) try {
                    Thread.sleep(1000 -timer);
                } catch (InterruptedException e) {
                    // never mind
                }

                if (result.success()) {
                    mVerifiedResource = resource;
                }
                return result;
            }

            @Override
            protected void onPostExecute(LinkedVerifyResult result) {
                super.onPostExecute(result);
                if (result.success()) {
                    setVerifyProgress(false, true);
                } else {
                    setVerifyProgress(false, false);
                    // on error, show error message
                    result.createNotify(getActivity()).show(LinkedIdCreateFinalFragment.this);
                }
            }
        }.execute();

    }

    @Override
    protected void cryptoOperation() {
        if (mVerifiedResource == null) {
            Notify.create(getActivity(), R.string.linked_need_verify, Notify.Style.ERROR)
                    .show(LinkedIdCreateFinalFragment.this);
            return;
        }

        super.cryptoOperation();
    }

    @Override
    protected void cryptoOperation(CryptoInputParcel cryptoInput) {
        if (mVerifiedResource == null) {
            Notify.create(getActivity(), R.string.linked_need_verify, Notify.Style.ERROR)
                    .show(LinkedIdCreateFinalFragment.this);
            return;
        }

        super.cryptoOperation(cryptoInput);
    }

    @Nullable
    @Override
    public Parcelable createOperationInput() {
        SaveKeyringParcel.Builder builder=
                SaveKeyringParcel.buildChangeKeyringParcel(masterKeyId, fingerprint);
        WrappedUserAttribute ua = LinkedAttribute.fromResource(mVerifiedResource).toUserAttribute();
        builder.addUserAttribute(ua);
        return builder.build();
    }

    @Override
    public void onCryptoOperationSuccess(OperationResult result) {
        requireActivity().finish();
    }

    @Override
    public void onCryptoOperationError(OperationResult result) {
        result.createNotify(getActivity()).show(this);
    }

}