/*
 * Nextcloud Talk application
 *
 * @author Mario Danic
 * Copyright (C) 2017-2018 Mario Danic <mario@lovelyhq.com>
 *
 * 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 com.nextcloud.talk.controllers;


import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import com.bumptech.glide.load.engine.DiskCacheStrategy;
import com.bumptech.glide.load.resource.bitmap.CircleCrop;
import com.bumptech.glide.request.RequestOptions;
import com.nextcloud.talk.R;
import com.nextcloud.talk.api.NcApi;
import com.nextcloud.talk.application.NextcloudTalkApplication;
import com.nextcloud.talk.controllers.base.BaseController;
import com.nextcloud.talk.models.database.UserEntity;
import com.nextcloud.talk.models.json.call.CallOverall;
import com.nextcloud.talk.models.json.chat.ChatMessage;
import com.nextcloud.talk.models.json.chat.ChatOverall;
import com.nextcloud.talk.models.json.generic.GenericOverall;
import com.nextcloud.talk.utils.ApiUtils;
import com.nextcloud.talk.utils.bundle.BundleKeys;
import com.nextcloud.talk.utils.database.user.UserUtils;
import com.nextcloud.talk.utils.glide.GlideApp;
import com.stfalcon.chatkit.commons.ImageLoader;
import com.stfalcon.chatkit.messages.MessageInput;
import com.stfalcon.chatkit.messages.MessagesList;
import com.stfalcon.chatkit.messages.MessagesListAdapter;
import com.stfalcon.chatkit.utils.DateFormatter;

import org.parceler.Parcels;

import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.inject.Inject;

import autodagger.AutoInjector;
import butterknife.BindView;
import io.reactivex.Observer;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.Disposable;
import io.reactivex.schedulers.Schedulers;
import retrofit2.Response;

@AutoInjector(NextcloudTalkApplication.class)
public class ChatController extends BaseController implements MessagesListAdapter.OnLoadMoreListener,
        MessagesListAdapter.Formatter<Date> {
    @Inject
    NcApi ncApi;
    @Inject
    UserUtils userUtils;
    @BindView(R.id.input)
    MessageInput messageInput;
    @BindView(R.id.messagesList)
    MessagesList messagesList;

    private String conversationName;
    private String roomToken;
    private UserEntity currentUser;

    private boolean inChat = false;
    private boolean historyRead = false;
    private int globalLastKnownFutureMessageId = -1;
    private int globalLastKnownPastMessageId = -1;

    private MessagesListAdapter<ChatMessage> adapter;
    private RecyclerView.LayoutManager layoutManager;

    public ChatController(Bundle args) {
        super(args);
        setHasOptionsMenu(true);
        this.conversationName = args.getString(BundleKeys.KEY_CONVERSATION_NAME);
        this.currentUser = Parcels.unwrap(args.getParcelable(BundleKeys.KEY_USER_ENTITY));
        this.roomToken = args.getString(BundleKeys.KEY_ROOM_TOKEN);
    }

    @Override
    protected View inflateView(@NonNull LayoutInflater inflater, @NonNull ViewGroup container) {
        return inflater.inflate(R.layout.controller_chat, container, false);
    }

    @Override
    protected void onViewBound(@NonNull View view) {
        super.onViewBound(view);
        NextcloudTalkApplication.getSharedApplication().getComponentApplication().inject(this);

        boolean adapterWasNull = false;

        if (adapter == null) {
            adapterWasNull = true;
            adapter = new MessagesListAdapter<>(currentUser.getUserId(), new ImageLoader() {
                @Override
                public void loadImage(ImageView imageView, String url) {
                    GlideApp.with(NextcloudTalkApplication.getSharedApplication().getApplicationContext())
                            .asBitmap()
                            .diskCacheStrategy(DiskCacheStrategy.NONE)
                            .load(url)
                            .centerInside()
                            .override(imageView.getMeasuredWidth(), imageView.getMeasuredHeight())
                            .apply(RequestOptions.bitmapTransform(new CircleCrop()))
                            .into(imageView);
                }
            });
        }

        messagesList.setAdapter(adapter);
        adapter.setLoadMoreListener(this);
        adapter.setDateHeadersFormatter(this::format);

        messageInput.setInputListener(input -> {
            sendMessage(input.toString());
            return true;
        });

        if (adapterWasNull) {
            joinRoomWithPassword(null);
        }
    }

    @Override
    protected void onAttach(@NonNull View view) {
        super.onAttach(view);
        if (getActionBar() != null) {
            getActionBar().setDisplayHomeAsUpEnabled(true);
        }
    }

    @Override
    protected String getTitle() {
        return conversationName;
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                inChat = false;
                getRouter().popCurrentController();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    @Override
    public void onDestroy() {
        inChat = false;
        super.onDestroy();
    }

    private void joinRoomWithPassword(@Nullable String password) {
        ncApi.joinRoom(ApiUtils.getCredentials(currentUser.getUserId(), currentUser.getToken()), ApiUtils
                .getUrlForRoomParticipants(currentUser.getBaseUrl(), roomToken), password)
                .subscribeOn(Schedulers.newThread())
                .observeOn(AndroidSchedulers.mainThread())
                .retry(3)
                .subscribe(new Observer<CallOverall>() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onNext(CallOverall callOverall) {
                        inChat = true;
                        pullChatMessages(0);
                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onComplete() {

                    }
                });
    }

    private void sendMessage(String message) {
        Map<String, String> fieldMap = new HashMap<>();
        fieldMap.put("message", message);
        fieldMap.put("actorDisplayName", currentUser.getDisplayName());


        ncApi.sendChatMessage(ApiUtils.getCredentials(currentUser.getUserId(), currentUser.getToken()),
                ApiUtils.getUrlForChat(currentUser.getBaseUrl(), roomToken), fieldMap)
                .subscribeOn(Schedulers.newThread())
                .observeOn(AndroidSchedulers.mainThread())
                .retry(3, observable -> inChat)
                .subscribe(new Observer<GenericOverall>() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onNext(GenericOverall genericOverall) {

                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onComplete() {

                    }
                });
    }
    private void pullChatMessages(int lookIntoFuture) {
        Map<String, Integer> fieldMap = new HashMap<>();
        fieldMap.put("lookIntoFuture", lookIntoFuture);
        fieldMap.put("limit", 25);

        int lastKnown;
        if (lookIntoFuture == 1) {
            lastKnown = globalLastKnownFutureMessageId;
        } else {
            lastKnown = globalLastKnownPastMessageId;
        }

        fieldMap.put("lastKnownMessageId", lastKnown);

        if (lookIntoFuture == 1) {
            ncApi.pullChatMessages(ApiUtils.getCredentials(currentUser.getUserId(), currentUser.getToken()),
                    ApiUtils.getUrlForChat(currentUser.getBaseUrl(), roomToken), fieldMap)
                    .subscribeOn(Schedulers.newThread())
                    .observeOn(AndroidSchedulers.mainThread())
                    .takeWhile(observable -> inChat)
                    .retry(3, observable -> inChat)
                    .subscribe(new Observer<Response>() {
                        @Override
                        public void onSubscribe(Disposable d) {

                        }

                        @Override
                        public void onNext(Response response) {
                            processMessages(response, true);
                            pullChatMessages(1);
                        }

                        @Override
                        public void onError(Throwable e) {

                        }

                        @Override
                        public void onComplete() {

                        }
                    });

        } else {
            ncApi.pullChatMessages(ApiUtils.getCredentials(currentUser.getUserId(), currentUser.getToken()),
                    ApiUtils.getUrlForChat(currentUser.getBaseUrl(), roomToken), fieldMap)
                    .subscribeOn(Schedulers.newThread())
                    .observeOn(AndroidSchedulers.mainThread())
                    .retry(3, observable -> inChat)
                    .subscribe(new Observer<Response>() {
                        @Override
                        public void onSubscribe(Disposable d) {

                        }

                        @Override
                        public void onNext(Response response) {
                            processMessages(response, false);
                        }

                        @Override
                        public void onError(Throwable e) {

                        }

                        @Override
                        public void onComplete() {

                        }
                    });
        }
    }

    private void processMessages(Response response, boolean isFromTheFuture) {
        if (response.code() == 200) {
            boolean shouldForceFuture = false;
            if (globalLastKnownFutureMessageId == -1) {
                shouldForceFuture = true;
            }

            ChatOverall chatOverall = (ChatOverall) response.body();
            List<ChatMessage> chatMessageList = chatOverall.getOcs().getData();

            if (!isFromTheFuture) {
                for (int i = 0; i < chatMessageList.size(); i++) {
                    chatMessageList.get(i).setBaseUrl(currentUser.getBaseUrl());
                    if (globalLastKnownPastMessageId == -1 || chatMessageList.get(i).getJsonMessageId() <
                            globalLastKnownPastMessageId) {
                        globalLastKnownPastMessageId = chatMessageList.get(i).getJsonMessageId();
                    }

                    if (shouldForceFuture) {
                        if (chatMessageList.get(i).getJsonMessageId() > globalLastKnownFutureMessageId) {
                            globalLastKnownFutureMessageId = chatMessageList.get(i).getJsonMessageId();
                        }
                    }
                }

                adapter.addToEnd(chatMessageList, false);

            } else {
                LinearLayoutManager layoutManager = (LinearLayoutManager) messagesList.getLayoutManager();
                for (int i = 0; i < chatMessageList.size(); i++) {
                    chatMessageList.get(i).setBaseUrl(currentUser.getBaseUrl());
                    adapter.addToStart(chatMessageList.get(i),
                            layoutManager.findLastVisibleItemPosition() <= adapter.getItemCount() - 3);
                }

                globalLastKnownFutureMessageId = Integer.parseInt(response.headers().get("X-Chat-Last-Given"));
            }

            if (shouldForceFuture) {
                pullChatMessages(1);
            }
        } else if (response.code() == 304 && !isFromTheFuture) {
            historyRead = true;
        }
    }

    @Override
    public void onLoadMore(int page, int totalItemsCount) {
        if (!historyRead) {
            pullChatMessages(0);
        }
    }


    @Override
    public String format(Date date) {
        if (DateFormatter.isToday(date)) {
            return getResources().getString(R.string.nc_date_header_today);
        } else if (DateFormatter.isYesterday(date)) {
            return getResources().getString(R.string.nc_date_header_yesterday);
        } else {
            return DateFormatter.format(date, DateFormatter.Template.STRING_DAY_MONTH_YEAR);
        }
    }}