/*
 * Copyright 2015 Synced Synapse. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.xbmc.kore.ui;

import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.provider.BaseColumns;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.widget.SwipeRefreshLayout;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorTreeAdapter;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.PopupMenu;
import android.widget.RelativeLayout;
import android.widget.TextView;

import org.xbmc.kore.R;
import org.xbmc.kore.Settings;
import org.xbmc.kore.host.HostManager;
import org.xbmc.kore.jsonrpc.event.MediaSyncEvent;
import org.xbmc.kore.jsonrpc.type.PlaylistType;
import org.xbmc.kore.provider.MediaContract;
import org.xbmc.kore.service.library.LibrarySyncService;
import org.xbmc.kore.utils.LogUtils;
import org.xbmc.kore.utils.MediaPlayerUtils;
import org.xbmc.kore.utils.UIUtils;

import java.util.HashMap;

import butterknife.ButterKnife;
import butterknife.InjectView;

/**
 * Presents a list of episodes for a TV show
 */
public class TVShowEpisodeListFragment extends AbstractDetailsFragment
        implements LoaderManager.LoaderCallbacks<Cursor> {
    private static final String TAG = LogUtils.makeLogTag(TVShowEpisodeListFragment.class);

    public interface OnEpisodeSelectedListener {
        public void onEpisodeSelected(int tvshowId, int episodeId);
    }

    public static final String TVSHOWID = "tvshow_id";
    public static final String SEASON = "season";

    private final String BUNDLE_SAVEDINSTANCE_LISTPOSITION = "lposition";
    private final String BUNDLE_SAVEDINSTANCE_ITEMPOSITION = "iposition";
    private final String BUNDLE_SAVEDINSTANCE_GROUPSEXPANDED = "groupsexpanded";

    // Loader IDs. Must be -1 to differentiate from group position
    private static final int LOADER_SEASONS = -1;

    private int listPosition = 0;
    private int itemPosition = 0;

    private HashMap<Integer, Boolean> groupsExpanded = new HashMap<>();
    private HashMap<Integer, Boolean> childCursorsLoading;
    private boolean isReturning; // used to determine if we are returning to this fragment and need to restore the state

    // Displayed show id
    private int tvshowId = -1;

    // Activity listener
    private OnEpisodeSelectedListener listenerActivity;

    private SeasonsEpisodesAdapter adapter;

    @InjectView(R.id.list) ExpandableListView seasonsEpisodesListView;
    @InjectView(R.id.swipe_refresh_layout) SwipeRefreshLayout swipeRefreshLayout;
    @InjectView(android.R.id.empty) TextView emptyView;

    @Override
    protected View createView(LayoutInflater inflater, ViewGroup container) {
        tvshowId = getArguments().getInt(TVSHOWID, -1);
        if (tvshowId == -1) {
            // There's nothing to show
            return null;
        }

        ViewGroup root = (ViewGroup) inflater.inflate(R.layout.fragment_tvshow_episodes_list, container, false);
        ButterKnife.inject(this, root);

        // Configure the adapter and start the loader
        adapter = new SeasonsEpisodesAdapter(getActivity());
        seasonsEpisodesListView.setAdapter(adapter);

        return root;
    }

    @Override
    protected String getSyncType() {
        return LibrarySyncService.SYNC_SINGLE_TVSHOW;
    }

    @Override
    protected String getSyncID() {
        return LibrarySyncService.SYNC_TVSHOWID;
    }

    @Override
    protected int getSyncItemID() {
        return tvshowId;
    }

    @Override
    protected SwipeRefreshLayout getSwipeRefreshLayout() {
        return swipeRefreshLayout;
    }

    @Override
    protected void onDownload() {

    }

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

        seasonsEpisodesListView.setEmptyView(emptyView);
        seasonsEpisodesListView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
            @Override
            public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) {
                if (parent.isGroupExpanded(groupPosition)) {
                    parent.collapseGroup(groupPosition);
                    groupsExpanded.remove(groupPosition);
                } else {
                    parent.expandGroup(groupPosition);
                    groupsExpanded.put(groupPosition, true);
                }
                return true;
            }
        });
        seasonsEpisodesListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
                // Get the movie id from the tag
                EpisodeViewHolder tag = (EpisodeViewHolder) v.getTag();
                // Notify the activity
                listenerActivity.onEpisodeSelected(tvshowId, tag.episodeId);
                return true;
            }
        });

        setHasOptionsMenu(true);

        if (savedInstanceState != null) {
            listPosition = savedInstanceState.getInt(BUNDLE_SAVEDINSTANCE_LISTPOSITION, 0);
            itemPosition = savedInstanceState.getInt(BUNDLE_SAVEDINSTANCE_ITEMPOSITION, 0);
            groupsExpanded = (HashMap) savedInstanceState.getSerializable(BUNDLE_SAVEDINSTANCE_GROUPSEXPANDED);
            isReturning = true;
        }

        initLoader();
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            listenerActivity = (OnEpisodeSelectedListener) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString() + " must implement OnEpisodeSelectedListener");
        }
    }

    @Override
    public void onPause() {
        super.onPause();

        //Save scroll position
        listPosition = seasonsEpisodesListView.getFirstVisiblePosition();
        View itemView = seasonsEpisodesListView.getChildAt(0);
        if (itemView != null) {
            itemPosition = itemView.getTop();
        } else {
            itemPosition = 0;
        }

        isReturning = true;
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);

        outState.putInt(BUNDLE_SAVEDINSTANCE_ITEMPOSITION, itemPosition);
        outState.putInt(BUNDLE_SAVEDINSTANCE_LISTPOSITION, listPosition);
        outState.putSerializable(BUNDLE_SAVEDINSTANCE_GROUPSEXPANDED, groupsExpanded);
    }

    @Override
    public void onDetach() {
        super.onDetach();
        listenerActivity = null;
    }


    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        if (!isAdded()) {
            // HACK: Fix crash reported on Play Store. Why does this is necessary is beyond me
            super.onCreateOptionsMenu(menu, inflater);
            return;
        }
        inflater.inflate(R.menu.tvshow_episode_list, menu);

        // Setup filters
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
        menu.findItem(R.id.action_hide_watched)
            .setChecked(preferences.getBoolean(Settings.KEY_PREF_TVSHOW_EPISODES_FILTER_HIDE_WATCHED, Settings.DEFAULT_PREF_TVSHOW_EPISODES_FILTER_HIDE_WATCHED));

        super.onCreateOptionsMenu(menu, inflater);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_hide_watched:
                item.setChecked(!item.isChecked());
                SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
                preferences.edit()
                           .putBoolean(Settings.KEY_PREF_TVSHOW_EPISODES_FILTER_HIDE_WATCHED, item.isChecked())
                           .apply();
                getLoaderManager().restartLoader(LOADER_SEASONS, null, this);
                break;
            default:
                break;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onSyncProcessEnded(MediaSyncEvent event) {
        if (event.status == MediaSyncEvent.STATUS_SUCCESS) {
            getLoaderManager().restartLoader(LOADER_SEASONS, null, this);
        }
    }

    /**
     * Loader callbacks
     */
    /** {@inheritDoc} */
    @Override
    public Loader<Cursor> onCreateLoader(int id, Bundle bundle) {
        if (!isAdded()) {
            LogUtils.LOGD(TAG, "Trying to create a loader, but the fragment isn't added. " +
                               "Loader Id: " + id);
            return null;
        }

        Uri uri;
        StringBuilder selection = new StringBuilder();
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
        boolean tvshowEpisodesFilterHideWatched =
                preferences.getBoolean(Settings.KEY_PREF_TVSHOW_EPISODES_FILTER_HIDE_WATCHED, Settings.DEFAULT_PREF_TVSHOW_EPISODES_FILTER_HIDE_WATCHED);
        switch (id) {
            case LOADER_SEASONS:
                // Load seasons
                uri = MediaContract.Seasons.buildTVShowSeasonsListUri(getHostInfo().getId(), tvshowId);

                // Filters
                if (tvshowEpisodesFilterHideWatched) {
                    selection.append(MediaContract.SeasonsColumns.WATCHEDEPISODES)
                             .append("!=")
                             .append(MediaContract.SeasonsColumns.EPISODE);
                }

                return new CursorLoader(getActivity(), uri,
                                        SeasonsListQuery.PROJECTION, selection.toString(), null, SeasonsListQuery.SORT);
            default:
                // Load episodes for a season. Season is in bundle
                int season = bundle.getInt(SEASON);
                uri = MediaContract.Episodes.buildTVShowSeasonEpisodesListUri(getHostInfo().getId(), tvshowId, season);

                // Filters
                if (tvshowEpisodesFilterHideWatched) {
                    selection.append(MediaContract.EpisodesColumns.PLAYCOUNT)
                             .append("=0");
                }

                return new CursorLoader(getActivity(), uri,
                                        EpisodesListQuery.PROJECTION, selection.toString(), null, EpisodesListQuery.SORT);
        }
    }

    /** {@inheritDoc} */
    @Override
    public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
        switch (cursorLoader.getId()) {
            case LOADER_SEASONS:
                adapter.setGroupCursor(cursor);
                setState(cursor);
                // To prevent the empty text from appearing on the first load, set it now
                emptyView.setText(getString(R.string.no_episodes_found));
                break;
            default:
                // Check if the group cursor is set before setting the children cursor
                // Somehow, when popping the back stack, the children cursor are reloaded first...
                if (adapter.getCursor() != null) {
                    int id = cursorLoader.getId();
                    adapter.setChildrenCursor(id, cursor);
                    childCursorsLoading.remove(id);
                    if (isReturning && childCursorsLoading.isEmpty()) {
                        isReturning = false;
                        //All previous expanded child cursors loaded. Now we can finally restore the list position
                        seasonsEpisodesListView.setSelectionFromTop(listPosition, itemPosition);
                    }
                }
                break;
        }
    }

    /** {@inheritDoc} */
    @Override
    public void onLoaderReset(Loader<Cursor> cursorLoader) {
        switch (cursorLoader.getId()) {
            case LOADER_SEASONS:
                adapter.setGroupCursor(null);
                break;
            default:
                // Check if the group cursor is set before setting the children cursor
                // Somehow, when popping the back stack, the children cursor are reloaded first...
                if (adapter.getCursor() != null) {
                    try {
                        adapter.setChildrenCursor(cursorLoader.getId(), null);
                    } catch (NullPointerException exc) {
                        // Errrr... Adapter expired?
                        LogUtils.LOGW(TAG, "Adapter expired.");
                    }
                }
                break;
        }
    }

    private void setState(Cursor cursor) {
        if (cursor.getCount() == 1) {
            seasonsEpisodesListView.expandGroup(0);
        } else if (cursor.getCount() > 0) {
            cursor.moveToFirst();
            do {
                int position = cursor.getPosition();

                // Expand the first season that has unseen episodes
                int unwatched = cursor.getInt(SeasonsListQuery.EPISODE) - cursor.getInt(SeasonsListQuery.WATCHEDEPISODES);
                if (groupsExpanded.isEmpty() && (unwatched > 0)) {
                    seasonsEpisodesListView.expandGroup(position);
                    groupsExpanded.put(position, true);
                    break;
                }

                if (groupsExpanded.get(position) != null) {
                    seasonsEpisodesListView.expandGroup(position);
                }
            } while (cursor.moveToNext());
        }
    }

    private void initLoader() {
        childCursorsLoading = new HashMap<>();
        for (int id : groupsExpanded.keySet()) {
            childCursorsLoading.put(id, true);
        }
        getLoaderManager().initLoader(LOADER_SEASONS, null, this);
    }

    /**
     * Seasons list query parameters.
     */
    private interface SeasonsListQuery {
        String[] PROJECTION = {
                BaseColumns._ID,
                MediaContract.Seasons.SEASON,
                MediaContract.Seasons.THUMBNAIL,
                MediaContract.Seasons.EPISODE,
                MediaContract.Seasons.WATCHEDEPISODES
        };

        String SORT = MediaContract.Seasons.SEASON + " ASC";

        final int ID = 0;
        final int SEASON = 1;
        final int THUMBNAIL = 2;
        final int EPISODE = 3;
        final int WATCHEDEPISODES = 4;
    }

    /**
     * Episodes list query parameters.
     */
    private interface EpisodesListQuery {
        String[] PROJECTION = {
                BaseColumns._ID,
                MediaContract.Episodes.EPISODEID,
                MediaContract.Episodes.EPISODE,
                MediaContract.Episodes.THUMBNAIL,
                MediaContract.Episodes.PLAYCOUNT,
                MediaContract.Episodes.TITLE,
                MediaContract.Episodes.RUNTIME,
                MediaContract.Episodes.FIRSTAIRED,
        };

        String SORT = MediaContract.Episodes.EPISODE + " ASC";

        final int ID = 0;
        final int EPISODEID = 1;
        final int EPISODE = 2;
        final int THUMBNAIL = 3;
        final int PLAYCOUNT = 4;
        final int TITLE = 5;
        final int RUNTIME = 6;
        final int FIRSTAIRED = 7;
    }

    /**
     * Adapter for the {@link android.widget.ExpandableListView}
     * Manages the seasons and episodes list
     */
    private class SeasonsEpisodesAdapter extends CursorTreeAdapter {

        private int themeAccentColor;
        private int iconCollapseResId,
                iconExpandResId;

        private HostManager hostManager;
        private int artWidth, artHeight;

        public SeasonsEpisodesAdapter(Context context) {
            // Cursor will be set vir CursorLoader
            super(null, context);

            // Get the default accent color
            Resources.Theme theme = context.getTheme();
            TypedArray styledAttributes = theme.obtainStyledAttributes(new int[] {
                    R.attr.colorAccent,
                    R.attr.iconCollapse,
                    R.attr.iconExpand,
            });
            themeAccentColor = styledAttributes.getColor(0, getResources().getColor(R.color.accent_default));
            iconCollapseResId = styledAttributes.getResourceId(1, R.drawable.ic_expand_less_white_24dp);
            iconExpandResId = styledAttributes.getResourceId(2, R.drawable.ic_expand_more_white_24dp);
            styledAttributes.recycle();

            this.hostManager = HostManager.getInstance(context);

            // Get the art dimensions
            Resources resources = context.getResources();
            artWidth = (int)(resources.getDimension(R.dimen.seasonlist_art_width) /
                             UIUtils.IMAGE_RESIZE_FACTOR);
            artHeight = (int)(resources.getDimension(R.dimen.seasonlist_art_heigth) /
                              UIUtils.IMAGE_RESIZE_FACTOR);
        }

        @Override
        public View newGroupView(Context context, Cursor cursor, boolean isExpanded, ViewGroup parent) {
            final View view = LayoutInflater.from(context)
                                            .inflate(R.layout.list_item_season, parent, false);
            return view;
        }

        @Override
        public View newChildView(Context context, Cursor cursor, boolean isLastChild, ViewGroup parent) {
            final View view = LayoutInflater.from(context)
                                            .inflate(R.layout.list_item_episode, parent, false);

            // Setup View holder pattern
            EpisodeViewHolder viewHolder = new EpisodeViewHolder();
            viewHolder.container = (RelativeLayout)view.findViewById(R.id.container);
            viewHolder.titleView = (TextView)view.findViewById(R.id.title);
            viewHolder.detailsView = (TextView)view.findViewById(R.id.details);
            viewHolder.episodenumberView = (TextView)view.findViewById(R.id.episode_number);
            viewHolder.contextMenuView = (ImageView)view.findViewById(R.id.list_context_menu);
            viewHolder.checkmarkView = (ImageView)view.findViewById(R.id.checkmark);

            view.setTag(viewHolder);
            return view;
        }

        @Override
        public void bindGroupView(View view, Context context, Cursor cursor, boolean isExpanded) {
            TextView seasonView = (TextView)view.findViewById(R.id.season);
            TextView episodesView = (TextView)view.findViewById(R.id.episodes);
            ImageView artView = (ImageView)view.findViewById(R.id.art);

            seasonView.setText(String.format(context.getString(R.string.season_number),
                                             cursor.getInt(SeasonsListQuery.SEASON)));
            int numEpisodes = cursor.getInt(SeasonsListQuery.EPISODE),
                    watchedEpisodes = cursor.getInt(SeasonsListQuery.WATCHEDEPISODES);
            episodesView.setText(String.format(context.getString(R.string.num_episodes),
                                               numEpisodes, numEpisodes - watchedEpisodes));

            UIUtils.loadImageWithCharacterAvatar(context, hostManager,
                                                 cursor.getString(SeasonsListQuery.THUMBNAIL),
                                                 String.valueOf(cursor.getInt(SeasonsListQuery.SEASON)),
                                                 artView, artWidth, artHeight);

            ImageView indicator = (ImageView)view.findViewById(R.id.status_indicator);
            if (isExpanded) {
                indicator.setImageResource(iconCollapseResId);
            } else {
                indicator.setImageResource(iconExpandResId);
            }
        }

        @Override
        public void bindChildView(View view, Context context, Cursor cursor, boolean isLastChild) {
            final EpisodeViewHolder viewHolder = (EpisodeViewHolder)view.getTag();

            // Save the episode id
            viewHolder.episodeId = cursor.getInt(EpisodesListQuery.EPISODEID);

            viewHolder.episodenumberView.setText(
                    String.format(context.getString(R.string.episode_number),
                                  cursor.getInt(EpisodesListQuery.EPISODE)));
            int runtime = cursor.getInt(EpisodesListQuery.RUNTIME) / 60;
            String duration =  runtime > 0 ?
                               String.format(context.getString(R.string.minutes_abbrev), String.valueOf(runtime)) +
                               "  |  " + cursor.getString(EpisodesListQuery.FIRSTAIRED) :
                               cursor.getString(EpisodesListQuery.FIRSTAIRED);
            viewHolder.titleView.setText(cursor.getString(EpisodesListQuery.TITLE));
            viewHolder.detailsView.setText(duration);

            if (cursor.getInt(EpisodesListQuery.PLAYCOUNT) > 0) {
                viewHolder.checkmarkView.setVisibility(View.VISIBLE);
                viewHolder.checkmarkView.setColorFilter(themeAccentColor);
            } else {
                viewHolder.checkmarkView.setVisibility(View.INVISIBLE);
            }

            // For the popupmenu
            ImageView contextMenu = (ImageView)view.findViewById(R.id.list_context_menu);
            contextMenu.setTag(viewHolder);
            contextMenu.setOnClickListener(contextlistItemMenuClickListener);
        }

        @Override
        public Cursor getChildrenCursor(Cursor groupCursor) {
            // Check if the fragment is attached to avoid IllegalStateException...
            if (!isAdded()) return null;

            // Start the episodes loader
            final int season = groupCursor.getInt(SeasonsListQuery.SEASON);
            Bundle bundle = new Bundle();
            bundle.putInt(SEASON, season);
            int groupPositon = groupCursor.getPosition();
            // The season id will be passed in a bundle to the loadermanager, and the group id
            // will be used as the loader's id
            LoaderManager loaderManager = getLoaderManager();
            if ((loaderManager.getLoader(groupPositon) == null) ||
                (loaderManager.getLoader(groupPositon).isReset())) {
                loaderManager.initLoader(groupPositon, bundle, TVShowEpisodeListFragment.this);
            } else {
                loaderManager.restartLoader(groupPositon, bundle, TVShowEpisodeListFragment.this);
            }

            return null;
        }
    }

    /**
     * View holder pattern, only for episodes
     */
    private static class EpisodeViewHolder {
        RelativeLayout container;
        TextView titleView;
        TextView detailsView;
        TextView episodenumberView;
        ImageView contextMenuView;
        ImageView checkmarkView;
        //        ImageView artView;

        int episodeId;
    }

    private View.OnClickListener contextlistItemMenuClickListener = new View.OnClickListener() {
        @Override
        public void onClick(final View v) {
            final EpisodeViewHolder viewHolder = (EpisodeViewHolder)v.getTag();

            final PlaylistType.Item playListItem = new PlaylistType.Item();
            playListItem.episodeid = viewHolder.episodeId;

            final PopupMenu popupMenu = new PopupMenu(getActivity(), v);
            popupMenu.getMenuInflater().inflate(R.menu.musiclist_item, popupMenu.getMenu());
            popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                @Override
                public boolean onMenuItemClick(MenuItem item) {
                    switch (item.getItemId()) {
                        case R.id.action_play:
                            MediaPlayerUtils.play(TVShowEpisodeListFragment.this, playListItem);
                            return true;
                        case R.id.action_queue:
                            MediaPlayerUtils.queue(TVShowEpisodeListFragment.this, playListItem, PlaylistType.GetPlaylistsReturnType.VIDEO);
                            return true;
                    }
                    return false;
                }
            });
            popupMenu.show();
        }
    };

}