package de.danoeh.antennapod.fragment;

import android.content.res.TypedArray;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.fragment.app.ListFragment;
import androidx.core.view.MenuItemCompat;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;

import org.greenrobot.eventbus.EventBus;
import org.greenrobot.eventbus.Subscribe;
import org.greenrobot.eventbus.ThreadMode;

import java.util.List;

import de.danoeh.antennapod.R;
import de.danoeh.antennapod.activity.MainActivity;
import de.danoeh.antennapod.adapter.FeedItemlistAdapter;
import de.danoeh.antennapod.core.event.DownloadEvent;
import de.danoeh.antennapod.core.event.DownloaderUpdate;
import de.danoeh.antennapod.core.event.FeedItemEvent;
import de.danoeh.antennapod.core.feed.EventDistributor;
import de.danoeh.antennapod.core.feed.FeedItem;
import de.danoeh.antennapod.core.feed.FeedMedia;
import de.danoeh.antennapod.core.service.download.Downloader;
import de.danoeh.antennapod.core.storage.DBReader;
import de.danoeh.antennapod.core.storage.DBWriter;
import de.danoeh.antennapod.core.util.FeedItemUtil;
import de.danoeh.antennapod.core.util.LongList;
import de.danoeh.antennapod.view.EmptyViewHandler;
import io.reactivex.Observable;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.Disposable;
import io.reactivex.schedulers.Schedulers;

public class PlaybackHistoryFragment extends ListFragment {

    public static final String TAG = "PlaybackHistoryFragment";

    private static final int EVENTS = EventDistributor.PLAYBACK_HISTORY_UPDATE |
            EventDistributor.PLAYER_STATUS_UPDATE;

    private List<FeedItem> playbackHistory;
    private FeedItemlistAdapter adapter;
    private List<Downloader> downloaderList;
    private Disposable disposable;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRetainInstance(true);
        setHasOptionsMenu(true);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        // add padding
        final ListView lv = getListView();
        lv.setClipToPadding(false);
        final int vertPadding = getResources().getDimensionPixelSize(R.dimen.list_vertical_padding);
        lv.setPadding(0, vertPadding, 0, vertPadding);

        EmptyViewHandler emptyView = new EmptyViewHandler(getActivity());
        emptyView.setIcon(R.attr.ic_history);
        emptyView.setTitle(R.string.no_history_head_label);
        emptyView.setMessage(R.string.no_history_label);
        emptyView.attachToListView(getListView());

        // played items shoudln't be transparent for this fragment since, *all* items
        // in this fragment will, by definition, be played. So it serves no purpose and can make
        // it harder to read.
        adapter = new FeedItemlistAdapter(getActivity(), itemAccess, true, false);
        setListAdapter(adapter);
    }

    @Override
    public void onStart() {
        super.onStart();
        EventDistributor.getInstance().register(contentUpdate);
        EventBus.getDefault().register(this);
        loadItems();
    }

    @Override
    public void onStop() {
        super.onStop();
        EventBus.getDefault().unregister(this);
        EventDistributor.getInstance().unregister(contentUpdate);
        if (disposable != null) {
            disposable.dispose();
        }
    }

    @Subscribe(sticky = true)
    public void onEvent(DownloadEvent event) {
        Log.d(TAG, "onEvent() called with: " + "event = [" + event + "]");
        DownloaderUpdate update = event.update;
        downloaderList = update.downloaders;
        adapter.notifyDataSetChanged();
    }

    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
        position -= l.getHeaderViewsCount();
        long[] ids = FeedItemUtil.getIds(playbackHistory);
        ((MainActivity) getActivity()).loadChildFragment(ItemFragment.newInstance(ids, position));
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        if (!isAdded()) {
            return;
        }
        super.onCreateOptionsMenu(menu, inflater);
        MenuItem clearHistory = menu.add(Menu.NONE, R.id.clear_history_item, Menu.CATEGORY_CONTAINER, R.string.clear_history_label);
        MenuItemCompat.setShowAsAction(clearHistory, MenuItemCompat.SHOW_AS_ACTION_IF_ROOM);
        TypedArray drawables = getActivity().obtainStyledAttributes(new int[]{R.attr.content_discard});
        clearHistory.setIcon(drawables.getDrawable(0));
        drawables.recycle();
    }

    @Override
    public void onPrepareOptionsMenu(Menu menu) {
        super.onPrepareOptionsMenu(menu);
        MenuItem menuItem = menu.findItem(R.id.clear_history_item);
        if (menuItem != null) {
            menuItem.setVisible(playbackHistory != null && !playbackHistory.isEmpty());
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (!super.onOptionsItemSelected(item)) {
            switch (item.getItemId()) {
                case R.id.clear_history_item:
                    DBWriter.clearPlaybackHistory();
                    return true;
                default:
                    return false;
            }
        } else {
            return true;
        }
    }

    @Subscribe(threadMode = ThreadMode.MAIN)
    public void onEventMainThread(FeedItemEvent event) {
        Log.d(TAG, "onEventMainThread() called with: " + "event = [" + event + "]");
        if(playbackHistory == null) {
            return;
        }
        for(FeedItem item : event.items) {
            int pos = FeedItemUtil.indexOfItemWithId(playbackHistory, item.getId());
            if(pos >= 0) {
                loadItems();
                return;
            }
        }
    }

    private final EventDistributor.EventListener contentUpdate = new EventDistributor.EventListener() {

        @Override
        public void update(EventDistributor eventDistributor, Integer arg) {
            if ((arg & EVENTS) != 0) {
                loadItems();
                getActivity().supportInvalidateOptionsMenu();
            }
        }
    };

    private void onFragmentLoaded() {
        adapter.notifyDataSetChanged();
        getActivity().supportInvalidateOptionsMenu();
    }

    private final FeedItemlistAdapter.ItemAccess itemAccess = new FeedItemlistAdapter.ItemAccess() {

        @Override
        public int getItemDownloadProgressPercent(FeedItem item) {
            if (downloaderList != null) {
                for (Downloader downloader : downloaderList) {
                    if (downloader.getDownloadRequest().getFeedfileType() == FeedMedia.FEEDFILETYPE_FEEDMEDIA
                            && downloader.getDownloadRequest().getFeedfileId() == item.getMedia().getId()) {
                        return downloader.getDownloadRequest().getProgressPercent();
                    }
                }
            }
            return 0;
        }

        @Override
        public int getCount() {
            return (playbackHistory != null) ? playbackHistory.size() : 0;
        }

        @Override
        public FeedItem getItem(int position) {
            if (playbackHistory != null && 0 <= position && position < playbackHistory.size()) {
                return playbackHistory.get(position);
            } else {
                return null;
            }
        }

        @Override
        public LongList getQueueIds() {
            LongList queueIds = new LongList();
            if(playbackHistory == null) {
                return queueIds;
            }
            for (FeedItem item : playbackHistory) {
                if (item.isTagged(FeedItem.TAG_QUEUE)) {
                    queueIds.add(item.getId());
                }
            }
            return queueIds;
        }
    };

    private void loadItems() {
        if(disposable != null) {
            disposable.dispose();
        }
        disposable = Observable.fromCallable(this::loadData)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(result -> {
                    if (result != null) {
                        playbackHistory = result;
                        onFragmentLoaded();
                    }
                }, error -> Log.e(TAG, Log.getStackTraceString(error)));
    }

    @NonNull
    private List<FeedItem> loadData() {
        List<FeedItem> history = DBReader.getPlaybackHistory();
        DBReader.loadAdditionalFeedItemListData(history);
        return history;
    }
}