/*
 * Copyright (C) 2015 Open Whisper Systems
 *
 * 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 org.thoughtcrime.securesms;

import android.annotation.SuppressLint;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.content.res.TypedArray;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.design.widget.Snackbar;
import android.support.v4.app.Fragment;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.Loader;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.view.ActionMode;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.helper.ItemTouchHelper;
import android.text.TextUtils;
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.TextView;

import org.greenrobot.eventbus.EventBus;
import org.greenrobot.eventbus.Subscribe;
import org.greenrobot.eventbus.ThreadMode;
import org.thoughtcrime.securesms.ConversationListAdapter.ItemClickListener;
import org.thoughtcrime.securesms.components.recyclerview.DeleteItemAnimator;
import org.thoughtcrime.securesms.components.registration.PulsingFloatingActionButton;
import org.thoughtcrime.securesms.components.reminder.DefaultSmsReminder;
import org.thoughtcrime.securesms.components.reminder.DozeReminder;
import org.thoughtcrime.securesms.components.reminder.ExpiredBuildReminder;
import org.thoughtcrime.securesms.components.reminder.OutdatedBuildReminder;
import org.thoughtcrime.securesms.components.reminder.PushRegistrationReminder;
import org.thoughtcrime.securesms.components.reminder.Reminder;
import org.thoughtcrime.securesms.components.reminder.ReminderView;
import org.thoughtcrime.securesms.components.reminder.ShareReminder;
import org.thoughtcrime.securesms.components.reminder.SystemSmsImportReminder;
import org.thoughtcrime.securesms.components.reminder.UnauthorizedReminder;
import org.thoughtcrime.securesms.crypto.MasterSecret;
import org.thoughtcrime.securesms.database.DatabaseFactory;
import org.thoughtcrime.securesms.database.MessagingDatabase.MarkedMessageInfo;
import org.thoughtcrime.securesms.database.loaders.ConversationListLoader;
import org.thoughtcrime.securesms.events.ReminderUpdateEvent;
import org.thoughtcrime.securesms.mms.GlideApp;
import org.thoughtcrime.securesms.notifications.MarkReadReceiver;
import org.thoughtcrime.securesms.notifications.MessageNotifier;
import org.thoughtcrime.securesms.recipients.Recipient;
import org.thoughtcrime.securesms.util.Util;
import org.thoughtcrime.securesms.util.ViewUtil;
import org.thoughtcrime.securesms.util.task.SnackbarAsyncTask;
import org.whispersystems.libsignal.util.guava.Optional;

import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Set;


public class ConversationListFragment extends Fragment
  implements LoaderManager.LoaderCallbacks<Cursor>, ActionMode.Callback, ItemClickListener
{
  public static final String ARCHIVE = "archive";

  @SuppressWarnings("unused")
  private static final String TAG = ConversationListFragment.class.getSimpleName();

  private ActionMode                  actionMode;
  private RecyclerView                list;
  private ReminderView                reminderView;
  private View                        emptyState;
  private TextView                    emptySearch;
  private PulsingFloatingActionButton fab;
  private Locale                      locale;
  private String                      queryFilter  = "";
  private boolean                     archive;

  @Override
  public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    locale  = (Locale) getArguments().getSerializable(PassphraseRequiredActionBarActivity.LOCALE_EXTRA);
    archive = getArguments().getBoolean(ARCHIVE, false);
  }

  @Override
  public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle bundle) {
    final View view = inflater.inflate(R.layout.conversation_list_fragment, container, false);

    reminderView = ViewUtil.findById(view, R.id.reminder);
    list         = ViewUtil.findById(view, R.id.list);
    fab          = ViewUtil.findById(view, R.id.fab);
    emptyState   = ViewUtil.findById(view, R.id.empty_state);
    emptySearch  = ViewUtil.findById(view, R.id.empty_search);

    if (archive) fab.setVisibility(View.GONE);
    else         fab.setVisibility(View.VISIBLE);

    reminderView.setOnDismissListener(() -> updateReminders(true));

    list.setHasFixedSize(true);
    list.setLayoutManager(new LinearLayoutManager(getActivity()));
    list.setItemAnimator(new DeleteItemAnimator());
    list.addItemDecoration(new InsetDividerItemDecoration(getActivity()));

    new ItemTouchHelper(new ArchiveListenerCallback()).attachToRecyclerView(list);

    return view;
  }

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

    setHasOptionsMenu(true);
    fab.setOnClickListener(v -> startActivity(new Intent(getActivity(), NewConversationActivity.class)));
    initializeListAdapter();
  }

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

    updateReminders(true);
    list.getAdapter().notifyDataSetChanged();
    EventBus.getDefault().register(this);
  }

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

    fab.stopPulse();
    EventBus.getDefault().unregister(this);
  }

  public ConversationListAdapter getListAdapter() {
    return (ConversationListAdapter) list.getAdapter();
  }

  public void setQueryFilter(String query) {
    this.queryFilter = query;
    getLoaderManager().restartLoader(0, null, this);
  }

  public void resetQueryFilter() {
    if (!TextUtils.isEmpty(this.queryFilter)) {
      setQueryFilter("");
    }
  }

  @SuppressLint("StaticFieldLeak")
  private void updateReminders(boolean hide) {
    new AsyncTask<Context, Void, Optional<? extends Reminder>>() {
      @Override
      protected Optional<? extends Reminder> doInBackground(Context... params) {
        final Context context = params[0];
        if (UnauthorizedReminder.isEligible(context)) {
          return Optional.of(new UnauthorizedReminder(context));
        } else if (ExpiredBuildReminder.isEligible()) {
          return Optional.of(new ExpiredBuildReminder(context));
        } else if (OutdatedBuildReminder.isEligible()) {
          return Optional.of(new OutdatedBuildReminder(context));
        } else if (DefaultSmsReminder.isEligible(context)) {
          return Optional.of(new DefaultSmsReminder(context));
        } else if (Util.isDefaultSmsProvider(context) && SystemSmsImportReminder.isEligible(context)) {
          return Optional.of((new SystemSmsImportReminder(context)));
        } else if (PushRegistrationReminder.isEligible(context)) {
          return Optional.of((new PushRegistrationReminder(context)));
        } else if (ShareReminder.isEligible(context)) {
          return Optional.of(new ShareReminder(context));
        } else if (DozeReminder.isEligible(context)) {
          return Optional.of(new DozeReminder(context));
        } else {
          return Optional.absent();
        }
      }

      @Override
      protected void onPostExecute(Optional<? extends Reminder> reminder) {
        if (reminder.isPresent() && getActivity() != null && !isRemoving()) {
          reminderView.showReminder(reminder.get());
        } else if (!reminder.isPresent()) {
          reminderView.hide();
        }
      }
    }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, getActivity());
  }

  private void initializeListAdapter() {
    list.setAdapter(new ConversationListAdapter(getActivity(), GlideApp.with(this), locale, null, this));
    getLoaderManager().restartLoader(0, null, this);
  }

  @SuppressLint("StaticFieldLeak")
  private void handleArchiveAllSelected() {
    final Set<Long> selectedConversations = new HashSet<>(getListAdapter().getBatchSelections());
    final boolean   archive               = this.archive;

    int snackBarTitleId;

    if (archive) snackBarTitleId = R.plurals.ConversationListFragment_moved_conversations_to_inbox;
    else         snackBarTitleId = R.plurals.ConversationListFragment_conversations_archived;

    int count            = selectedConversations.size();
    String snackBarTitle = getResources().getQuantityString(snackBarTitleId, count, count);

    new SnackbarAsyncTask<Void>(getView(), snackBarTitle,
                                getString(R.string.ConversationListFragment_undo),
                                getResources().getColor(R.color.amber_500),
                                Snackbar.LENGTH_LONG, true)
    {

      @Override
      protected void onPostExecute(Void result) {
        super.onPostExecute(result);

        if (actionMode != null) {
          actionMode.finish();
          actionMode = null;
        }
      }

      @Override
      protected void executeAction(@Nullable Void parameter) {
        for (long threadId : selectedConversations) {
          if (!archive) DatabaseFactory.getThreadDatabase(getActivity()).archiveConversation(threadId);
          else          DatabaseFactory.getThreadDatabase(getActivity()).unarchiveConversation(threadId);
        }
      }

      @Override
      protected void reverseAction(@Nullable Void parameter) {
        for (long threadId : selectedConversations) {
          if (!archive) DatabaseFactory.getThreadDatabase(getActivity()).unarchiveConversation(threadId);
          else          DatabaseFactory.getThreadDatabase(getActivity()).archiveConversation(threadId);
        }
      }
    }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
  }

  @SuppressLint("StaticFieldLeak")
  private void handleDeleteAllSelected() {
    int                 conversationsCount = getListAdapter().getBatchSelections().size();
    AlertDialog.Builder alert              = new AlertDialog.Builder(getActivity());
    alert.setIconAttribute(R.attr.dialog_alert_icon);
    alert.setTitle(getActivity().getResources().getQuantityString(R.plurals.ConversationListFragment_delete_selected_conversations,
                                                                  conversationsCount, conversationsCount));
    alert.setMessage(getActivity().getResources().getQuantityString(R.plurals.ConversationListFragment_this_will_permanently_delete_all_n_selected_conversations,
                                                                    conversationsCount, conversationsCount));
    alert.setCancelable(true);

    alert.setPositiveButton(R.string.delete, (dialog, which) -> {
      final Set<Long> selectedConversations = (getListAdapter())
          .getBatchSelections();

      if (!selectedConversations.isEmpty()) {
        new AsyncTask<Void, Void, Void>() {
          private ProgressDialog dialog;

          @Override
          protected void onPreExecute() {
            dialog = ProgressDialog.show(getActivity(),
                                         getActivity().getString(R.string.ConversationListFragment_deleting),
                                         getActivity().getString(R.string.ConversationListFragment_deleting_selected_conversations),
                                         true, false);
          }

          @Override
          protected Void doInBackground(Void... params) {
            DatabaseFactory.getThreadDatabase(getActivity()).deleteConversations(selectedConversations);
            MessageNotifier.updateNotification(getActivity());
            return null;
          }

          @Override
          protected void onPostExecute(Void result) {
            dialog.dismiss();
            if (actionMode != null) {
              actionMode.finish();
              actionMode = null;
            }
          }
        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
      }
    });

    alert.setNegativeButton(android.R.string.cancel, null);
    alert.show();
  }

  private void handleSelectAllThreads() {
    getListAdapter().selectAllThreads();
    actionMode.setSubtitle(getString(R.string.conversation_fragment_cab__batch_selection_amount,
                                     String.valueOf(getListAdapter().getBatchSelections().size())));
  }

  private void handleCreateConversation(long threadId, Recipient recipient, int distributionType, long lastSeen) {
    ((ConversationSelectedListener)getActivity()).onCreateConversation(threadId, recipient, distributionType, lastSeen);
  }

  @Override
  public Loader<Cursor> onCreateLoader(int arg0, Bundle arg1) {
    return new ConversationListLoader(getActivity(), queryFilter, archive);
  }

  @Override
  public void onLoadFinished(Loader<Cursor> arg0, Cursor cursor) {
    if ((cursor == null || cursor.getCount() <= 0) && TextUtils.isEmpty(queryFilter) && !archive) {
      list.setVisibility(View.INVISIBLE);
      emptyState.setVisibility(View.VISIBLE);
      emptySearch.setVisibility(View.INVISIBLE);
      fab.startPulse(3 * 1000);
    } else if ((cursor == null || cursor.getCount() <= 0) && !TextUtils.isEmpty(queryFilter)) {
      list.setVisibility(View.INVISIBLE);
      emptyState.setVisibility(View.GONE);
      emptySearch.setVisibility(View.VISIBLE);
      emptySearch.setText(getString(R.string.ConversationListFragment_no_results_found_for_s_, queryFilter));
    } else {
      list.setVisibility(View.VISIBLE);
      emptyState.setVisibility(View.GONE);
      emptySearch.setVisibility(View.INVISIBLE);
      fab.stopPulse();
    }

    getListAdapter().changeCursor(cursor);
  }

  @Override
  public void onLoaderReset(Loader<Cursor> arg0) {
    getListAdapter().changeCursor(null);
  }

  @Override
  public void onItemClick(ConversationListItem item) {
    if (actionMode == null) {
      handleCreateConversation(item.getThreadId(), item.getRecipient(),
                               item.getDistributionType(), item.getLastSeen());
    } else {
      ConversationListAdapter adapter = (ConversationListAdapter)list.getAdapter();
      adapter.toggleThreadInBatchSet(item.getThreadId());

      if (adapter.getBatchSelections().size() == 0) {
        actionMode.finish();
      } else {
        actionMode.setSubtitle(getString(R.string.conversation_fragment_cab__batch_selection_amount,
                                         String.valueOf(adapter.getBatchSelections().size())));
      }

      adapter.notifyDataSetChanged();
    }
  }

  @Override
  public void onItemLongClick(ConversationListItem item) {
    actionMode = ((AppCompatActivity)getActivity()).startSupportActionMode(ConversationListFragment.this);

    getListAdapter().initializeBatchMode(true);
    getListAdapter().toggleThreadInBatchSet(item.getThreadId());
    getListAdapter().notifyDataSetChanged();
  }

  @Override
  public void onSwitchToArchive() {
    ((ConversationSelectedListener)getActivity()).onSwitchToArchive();
  }

  public interface ConversationSelectedListener {
    void onCreateConversation(long threadId, Recipient recipient, int distributionType, long lastSeen);
    void onSwitchToArchive();
}

  @Override
  public boolean onCreateActionMode(ActionMode mode, Menu menu) {
    MenuInflater inflater = getActivity().getMenuInflater();

    if (archive) inflater.inflate(R.menu.conversation_list_batch_unarchive, menu);
    else         inflater.inflate(R.menu.conversation_list_batch_archive, menu);

    inflater.inflate(R.menu.conversation_list_batch, menu);

    mode.setTitle(R.string.conversation_fragment_cab__batch_selection_mode);
    mode.setSubtitle(getString(R.string.conversation_fragment_cab__batch_selection_amount, "1"));

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
      getActivity().getWindow().setStatusBarColor(getResources().getColor(R.color.action_mode_status_bar));
    }

    return true;
  }

  @Override
  public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
    return false;
  }

  @Override
  public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
    switch (item.getItemId()) {
    case R.id.menu_select_all:       handleSelectAllThreads();   return true;
    case R.id.menu_delete_selected:  handleDeleteAllSelected();  return true;
    case R.id.menu_archive_selected: handleArchiveAllSelected(); return true;
    }

    return false;
  }

  @Override
  public void onDestroyActionMode(ActionMode mode) {
    getListAdapter().initializeBatchMode(false);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
      TypedArray color = getActivity().getTheme().obtainStyledAttributes(new int[] {android.R.attr.statusBarColor});
      getActivity().getWindow().setStatusBarColor(color.getColor(0, Color.BLACK));
      color.recycle();
    }

    actionMode = null;
  }

  @Subscribe(threadMode = ThreadMode.MAIN)
  public void onEvent(ReminderUpdateEvent event) {
    updateReminders(false);
  }

  private class ArchiveListenerCallback extends ItemTouchHelper.SimpleCallback {

    ArchiveListenerCallback() {
      super(0, ItemTouchHelper.RIGHT);
    }

    @Override
    public boolean onMove(RecyclerView recyclerView,
                          RecyclerView.ViewHolder viewHolder,
                          RecyclerView.ViewHolder target)
    {
      return false;
    }

    @Override
    public int getSwipeDirs(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
      if (viewHolder.itemView instanceof ConversationListItemAction) {
        return 0;
      }

      if (actionMode != null) {
        return 0;
      }

      return super.getSwipeDirs(recyclerView, viewHolder);
    }

    @SuppressLint("StaticFieldLeak")
    @Override
    public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
      final long threadId    = ((ConversationListItem)viewHolder.itemView).getThreadId();
      final int  unreadCount = ((ConversationListItem)viewHolder.itemView).getUnreadCount();

      if (archive) {
        new SnackbarAsyncTask<Long>(getView(),
                                    getResources().getQuantityString(R.plurals.ConversationListFragment_moved_conversations_to_inbox, 1, 1),
                                    getString(R.string.ConversationListFragment_undo),
                                    getResources().getColor(R.color.amber_500),
                                    Snackbar.LENGTH_LONG, false)
        {
          @Override
          protected void executeAction(@Nullable Long parameter) {
            DatabaseFactory.getThreadDatabase(getActivity()).unarchiveConversation(threadId);
          }

          @Override
          protected void reverseAction(@Nullable Long parameter) {
            DatabaseFactory.getThreadDatabase(getActivity()).archiveConversation(threadId);
          }
        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, threadId);
      } else {
        new SnackbarAsyncTask<Long>(getView(),
                                    getResources().getQuantityString(R.plurals.ConversationListFragment_conversations_archived, 1, 1),
                                    getString(R.string.ConversationListFragment_undo),
                                    getResources().getColor(R.color.amber_500),
                                    Snackbar.LENGTH_LONG, false)
        {
          @Override
          protected void executeAction(@Nullable Long parameter) {
            DatabaseFactory.getThreadDatabase(getActivity()).archiveConversation(threadId);

            if (unreadCount > 0) {
              List<MarkedMessageInfo> messageIds = DatabaseFactory.getThreadDatabase(getActivity()).setRead(threadId, false);
              MessageNotifier.updateNotification(getActivity());
              MarkReadReceiver.process(getActivity(), messageIds);
            }
          }

          @Override
          protected void reverseAction(@Nullable Long parameter) {
            DatabaseFactory.getThreadDatabase(getActivity()).unarchiveConversation(threadId);

            if (unreadCount > 0) {
              DatabaseFactory.getThreadDatabase(getActivity()).incrementUnread(threadId, unreadCount);
              MessageNotifier.updateNotification(getActivity());
            }
          }
        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, threadId);
      }
    }

    @Override
    public void onChildDraw(Canvas c, RecyclerView recyclerView,
                            RecyclerView.ViewHolder viewHolder,
                            float dX, float dY, int actionState,
                            boolean isCurrentlyActive)
    {
      if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) {
        View  itemView = viewHolder.itemView;
        Paint p        = new Paint();
        float alpha    = 1.0f - Math.abs(dX) / (float) viewHolder.itemView.getWidth();

        if (dX > 0) {
          Bitmap icon;

          if (archive) icon = BitmapFactory.decodeResource(getResources(), R.drawable.ic_unarchive_white_36dp);
          else         icon = BitmapFactory.decodeResource(getResources(), R.drawable.ic_archive_white_36dp);

          if (alpha > 0) p.setColor(getResources().getColor(R.color.green_500));
          else           p.setColor(Color.WHITE);

          c.drawRect((float) itemView.getLeft(), (float) itemView.getTop(), dX,
                     (float) itemView.getBottom(), p);

          c.drawBitmap(icon,
                       (float) itemView.getLeft() + getResources().getDimension(R.dimen.conversation_list_fragment_archive_padding),
                       (float) itemView.getTop() + ((float) itemView.getBottom() - (float) itemView.getTop() - icon.getHeight())/2,
                       p);
        }

        viewHolder.itemView.setAlpha(alpha);
        viewHolder.itemView.setTranslationX(dX);
      } else {
        super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
      }
    }
  }

  private static class InsetDividerItemDecoration extends RecyclerView.ItemDecoration {

    private Drawable divider;
    private final Rect bounds = new Rect();
    
    InsetDividerItemDecoration(Context context) {
      TypedArray typedArray = context.obtainStyledAttributes(new int[]{R.attr.conversation_list_item_divider});
      this.divider = typedArray.getDrawable(0);
      typedArray.recycle();
    }

    @Override
    public void onDraw(Canvas canvas, RecyclerView parent, RecyclerView.State state) {
      if (parent.getLayoutManager() == null) {
        return;
      }

      canvas.save();

      final int left;
      final int right;

      if (parent.getClipToPadding()) {
        left  = parent.getPaddingLeft();
        right = parent.getWidth() - parent.getPaddingRight();
        canvas.clipRect(left, parent.getPaddingTop(), right, parent.getHeight() - parent.getPaddingBottom());
      } else {
        left = 0;
        right = parent.getWidth();
      }

      final int childCount = parent.getChildCount();

      for (int i = 0; i < childCount-1; i++) {
        final View child = parent.getChildAt(i);
        parent.getDecoratedBoundsWithMargins(child, bounds);
        final int bottom = bounds.bottom + Math.round(child.getTranslationY());
        final int top = bottom - divider.getIntrinsicHeight();
        divider.setBounds(left, top, right, bottom);
        divider.draw(canvas);
      }

      canvas.restore();
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
      if (divider == null) {
        outRect.set(0, 0, 0, 0);
        return;
      }

      outRect.set(0, 0, 0, divider.getIntrinsicHeight());
    }
  }

}