package de.danoeh.antennapod.fragment;

import android.content.Context;
import android.content.res.TypedArray;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.support.v4.view.MenuItemCompat;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;

import java.util.List;

import de.danoeh.antennapod.R;
import de.danoeh.antennapod.adapter.DownloadLogAdapter;
import de.danoeh.antennapod.core.feed.EventDistributor;
import de.danoeh.antennapod.core.service.download.DownloadStatus;
import de.danoeh.antennapod.core.storage.DBReader;
import de.danoeh.antennapod.core.storage.DBWriter;
import de.danoeh.antennapod.menuhandler.MenuItemUtils;
import de.danoeh.antennapod.menuhandler.NavDrawerActivity;

/**
 * Shows the download log
 */
public class DownloadLogFragment extends ListFragment {

    private static final String TAG = "DownloadLogFragment";

    private List<DownloadStatus> downloadLog;
    private DownloadLogAdapter adapter;

    private boolean viewsCreated = false;
    private boolean itemsLoaded = false;

    @Override
    public void onStart() {
        super.onStart();
        setHasOptionsMenu(true);
        EventDistributor.getInstance().register(contentUpdate);
        startItemLoader();
    }

    @Override
    public void onStop() {
        super.onStop();
        EventDistributor.getInstance().unregister(contentUpdate);
        stopItemLoader();
    }

    @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);

        viewsCreated = true;
        if (itemsLoaded) {
            onFragmentLoaded();
        }
    }

    private void onFragmentLoaded() {
        if (adapter == null) {
            adapter = new DownloadLogAdapter(getActivity(), itemAccess);
            setListAdapter(adapter);
        }
        setListShown(true);
        adapter.notifyDataSetChanged();
        getActivity().supportInvalidateOptionsMenu();
    }

    private DownloadLogAdapter.ItemAccess itemAccess = new DownloadLogAdapter.ItemAccess() {

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

        @Override
        public DownloadStatus getItem(int position) {
            return (downloadLog != null) ? downloadLog.get(position) : null;
        }
    };

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

        @Override
        public void update(EventDistributor eventDistributor, Integer arg) {
            if ((arg & EventDistributor.DOWNLOADLOG_UPDATE) != 0) {
                startItemLoader();
            }
        }
    };

    private ItemLoader itemLoader;

    private void startItemLoader() {
        if (itemLoader != null) {
            itemLoader.cancel(true);
        }
        itemLoader = new ItemLoader();
        itemLoader.execute();
    }

    private void stopItemLoader() {
        if (itemLoader != null) {
            itemLoader.cancel(true);
        }
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        super.onCreateOptionsMenu(menu, inflater);
        if (itemsLoaded && !MenuItemUtils.isActivityDrawerOpen((NavDrawerActivity) getActivity())) {
            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);
        if (itemsLoaded && !MenuItemUtils.isActivityDrawerOpen((NavDrawerActivity) getActivity())) {
            menu.findItem(R.id.clear_history_item).setVisible(downloadLog != null && !downloadLog.isEmpty());
        }
    }

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

    private class ItemLoader extends AsyncTask<Void, Void, List<DownloadStatus>> {

        @Override
        protected void onPostExecute(List<DownloadStatus> downloadStatuses) {
            super.onPostExecute(downloadStatuses);
            if (downloadStatuses != null) {
                downloadLog = downloadStatuses;
                itemsLoaded = true;
                if (viewsCreated) {
                    onFragmentLoaded();
                }
            }
        }

        @Override
        protected List<DownloadStatus> doInBackground(Void... params) {
            Context context = getActivity();
            if (context != null) {
                return DBReader.getDownloadLog(context);
            }
            return null;
        }
    }
}