package app.fedilab.android.mastodon.ui.fragment.timeline;
/* Copyright 2021 Thomas Schneider
 *
 * This file is a part of Fedilab
 *
 * 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.
 *
 * Fedilab 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 Fedilab; if not,
 * see <http://www.gnu.org/licenses>. */

import static app.fedilab.android.mastodon.activities.ContextActivity.displayCW;
import static app.fedilab.android.mastodon.activities.ContextActivity.expand;

import android.content.BroadcastReceiver;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Build;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.annotation.NonNull;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProvider;

import androidx.recyclerview.widget.LinearLayoutManager;

import java.util.ArrayList;
import java.util.List;

import app.fedilab.android.R;
import app.fedilab.android.activities.MainActivity;
import app.fedilab.android.databinding.FragmentPaginationBinding;
import app.fedilab.android.mastodon.activities.ContextActivity;
import app.fedilab.android.mastodon.client.entities.api.Context;
import app.fedilab.android.mastodon.client.entities.api.Status;
import app.fedilab.android.mastodon.client.entities.app.Timeline;
import app.fedilab.android.mastodon.helper.DividerDecoration;
import app.fedilab.android.mastodon.helper.Helper;
import app.fedilab.android.mastodon.ui.drawer.StatusAdapter;
import app.fedilab.android.mastodon.viewmodel.mastodon.StatusesVM;


public class FragmentMastodonContext extends Fragment {


    public FirstMessage firstMessage;
    private FragmentPaginationBinding binding;
    private StatusesVM statusesVM;
    private List<Status> statuses;
    private StatusAdapter statusAdapter;
    private boolean refresh;
    //Handle actions that can be done in other fragments
    private final BroadcastReceiver receive_action = new BroadcastReceiver() {
        @Override
        public void onReceive(android.content.Context context, Intent intent) {
            Bundle b = intent.getExtras();
            if (b != null) {
                Status receivedStatus = (Status) b.getSerializable(Helper.ARG_STATUS_ACTION);
                String delete_statuses_for_user = b.getString(Helper.ARG_STATUS_ACCOUNT_ID_DELETED);
                Status status_to_delete = (Status) b.getSerializable(Helper.ARG_STATUS_DELETED);
                Status statusPosted = (Status) b.getSerializable(Helper.ARG_STATUS_POSTED);
                Status status_to_update = (Status) b.getSerializable(Helper.ARG_STATUS_UPDATED);
                if (receivedStatus != null && statusAdapter != null) {
                    int position = getPosition(receivedStatus);
                    if (position >= 0) {
                        statuses.get(position).reblog = receivedStatus.reblog;
                        statuses.get(position).reblogged = receivedStatus.reblogged;
                        statuses.get(position).favourited = receivedStatus.favourited;
                        statuses.get(position).bookmarked = receivedStatus.bookmarked;
                        statuses.get(position).reblogs_count = receivedStatus.reblogs_count;
                        statuses.get(position).favourites_count = receivedStatus.favourites_count;
                        statusAdapter.notifyItemChanged(position);
                    }
                } else if (delete_statuses_for_user != null && statusAdapter != null) {
                    List<Status> statusesToRemove = new ArrayList<>();
                    for (Status status : statuses) {
                        if (status.account.id.equals(delete_statuses_for_user)) {
                            statusesToRemove.add(status);
                        }
                    }
                    for (Status statusToRemove : statusesToRemove) {
                        int position = getPosition(statusToRemove);
                        if (position >= 0) {
                            statuses.remove(position);
                            statusAdapter.notifyItemRemoved(position);
                        }
                    }
                } else if (status_to_delete != null && statusAdapter != null) {
                    int position = getPosition(status_to_delete);
                    if (position >= 0) {
                        statuses.remove(position);
                        statusAdapter.notifyItemRemoved(position);
                    }
                } else if (status_to_update != null && statusAdapter != null) {
                    int position = getPosition(status_to_update);
                    if (position >= 0) {
                        statuses.set(position, status_to_update);
                        statusAdapter.notifyItemChanged(position);
                    }
                } else if (statusPosted != null && statusAdapter != null) {
                    if (requireActivity() instanceof ContextActivity) {
                        int i = 0;
                        for (Status status : statuses) {
                            if (status.id.equals(statusPosted.in_reply_to_id)) {
                                statuses.add((i + 1), statusPosted);
                                statusAdapter.notifyItemInserted((i + 1));
                                if (requireActivity() instanceof ContextActivity) {
                                    //Redraw decorations
                                    statusAdapter.notifyItemRangeChanged(0, statuses.size());
                                }
                                break;
                            }
                            i++;
                        }
                    }
                }
            }
        }
    };
    private Status focusedStatus;
    private String remote_instance, focusedStatusURI;
    private Status firstStatus;
    private boolean pullToRefresh;
    private String user_token, user_instance;

    /**
     * Return the position of the status in the ArrayList
     *
     * @param status - Status to fetch
     * @return position or -1 if not found
     */
    private int getPosition(Status status) {
        int position = 0;
        boolean found = false;
        for (Status _status : statuses) {
            if (_status.id.compareTo(status.id) == 0) {
                found = true;
                break;
            }
            position++;
        }
        return found ? position : -1;
    }

    public View onCreateView(@NonNull LayoutInflater inflater,
                             ViewGroup container, Bundle savedInstanceState) {

        focusedStatus = null;
        pullToRefresh = false;
        focusedStatusURI = null;
        refresh = true;
        if (getArguments() != null) {
            focusedStatus = (Status) getArguments().getSerializable(Helper.ARG_STATUS);
            remote_instance = getArguments().getString(Helper.ARG_REMOTE_INSTANCE, null);
            focusedStatusURI = getArguments().getString(Helper.ARG_FOCUSED_STATUS_URI, null);
        }
        if (remote_instance != null) {
            user_instance = remote_instance;
            user_token = null;
        } else {
            user_instance = MainActivity.currentInstance;
            user_token = MainActivity.currentToken;
        }
        if (focusedStatus == null) {
            getChildFragmentManager().beginTransaction().remove(this).commit();
        }

        binding = FragmentPaginationBinding.inflate(inflater, container, false);
        statusesVM = new ViewModelProvider(FragmentMastodonContext.this).get(StatusesVM.class);
        binding.recyclerView.setNestedScrollingEnabled(true);
        this.statuses = new ArrayList<>();
        focusedStatus.isFocused = true;
        this.statuses.add(focusedStatus);
        statusAdapter = new StatusAdapter(this.statuses, Timeline.TimeLineEnum.UNKNOWN, false, true, remote_instance != null);
        binding.swipeContainer.setRefreshing(false);
        LinearLayoutManager mLayoutManager = new LinearLayoutManager(requireActivity());
        binding.recyclerView.setLayoutManager(mLayoutManager);
        binding.recyclerView.setAdapter(statusAdapter);
        binding.swipeContainer.setOnRefreshListener(() -> {
            if (this.statuses.size() > 0 && !refresh) {
                binding.swipeContainer.setRefreshing(true);
                pullToRefresh = true;
                statusesVM.getContext(user_instance, user_token, focusedStatus.id)
                        .observe(getViewLifecycleOwner(), this::initializeContextView);
            }
        });
        if (focusedStatus != null) {
            statusesVM.getContext(user_instance, user_token, focusedStatus.id)
                    .observe(getViewLifecycleOwner(), this::initializeContextView);
        }

        ContextCompat.registerReceiver(requireActivity(), receive_action, new IntentFilter(Helper.RECEIVE_STATUS_ACTION), ContextCompat.RECEIVER_NOT_EXPORTED);
        return binding.getRoot();
    }

    public void refresh() {
        if (statuses != null) {
            for (Status status : statuses) {
                status.isExpended = displayCW;
            }
            if (statusAdapter != null) {
                statusAdapter.notifyItemRangeChanged(0, statuses.size());
            }
        }
    }

    public void redraw() {
        if (statusAdapter != null && firstStatus != null) {
            pullToRefresh = true;
            String id;
            if (expand) {
                id = firstStatus.id;
            } else {
                id = focusedStatus.id;
            }
            statusesVM.getContext(user_instance, user_token, id)
                    .observe(FragmentMastodonContext.this, this::initializeContextView);
        }
    }


    /**
     * Intialize the common view for the context
     *
     * @param context {@link Context}
     */
    private void initializeContextView(final Context context) {
        refresh = false;
        if (context == null) {
            Helper.sendToastMessage(requireActivity(), Helper.RECEIVE_TOAST_TYPE_ERROR, getString(R.string.toast_error));
            return;
        }
        if (binding == null || !isAdded() || getActivity() == null) {
            return;
        }
        if (pullToRefresh) {
            pullToRefresh = false;
            int size = this.statuses.size();
            statuses.clear();
            statusAdapter.notifyItemRangeRemoved(0, size);
            statuses.add(focusedStatus);
        }
        if (context.ancestors.size() > 0) {
            firstStatus = context.ancestors.get(0);
        } else {
            firstStatus = statuses.get(0);
        }
        if (firstMessage != null) {
            firstMessage.get(firstStatus);
        }

        int statusPosition = context.ancestors.size();
        //Build the array of statuses
        statuses.addAll(0, context.ancestors);
        statusAdapter.notifyItemRangeInserted(0, statusPosition);
        statuses.addAll(statusPosition + 1, context.descendants);
        statusAdapter.notifyItemRangeInserted(statusPosition + 1, context.descendants.size());
        if (binding.recyclerView.getItemDecorationCount() > 0) {
            for (int i = 0; i < binding.recyclerView.getItemDecorationCount(); i++) {
                binding.recyclerView.removeItemDecorationAt(i);
            }
        }
        binding.recyclerView.addItemDecoration(new DividerDecoration(requireActivity(), statuses));
        binding.swipeContainer.setRefreshing(false);
        if (focusedStatusURI == null) {
            binding.recyclerView.scrollToPosition(statusPosition);
        } else {
            int position = 0;
            boolean found = false;
            for (Status status : statuses) {
                if (status.uri.compareToIgnoreCase(focusedStatusURI) == 0) {
                    found = true;
                    break;
                }
                position++;
            }
            if (found) {
                binding.recyclerView.scrollToPosition(position);
                statuses.get(0).isFocused = false;
                statuses.get(position).isFocused = true;
                statusAdapter.notifyItemChanged(0);
                statusAdapter.notifyItemChanged(position);
            }
        }
    }

    @Override
    public void onDestroyView() {
        requireActivity().unregisterReceiver(receive_action);
        super.onDestroyView();
    }


    public interface FirstMessage {
        void get(Status status);
    }
}